TI1 LM96511CCSM/NOPB Ultrasound receive analog front end Datasheet

LM96511
LM96511 Ultrasound Receive Analog Front End (AFE)
Data Manual
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Literature Number: SNAS476H
May 2010 – Revised May 2013
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Contents
1
INTRODUCTION
1.1
1.2
1.3
2
3
4
5
6
2
.................................................................................................................. 6
FEATURES .................................................................................................................. 6
APPLICATIONS ............................................................................................................. 6
DESCRIPTION .............................................................................................................. 6
........................................................................................................ 7
2.1
KEY SPECIFICATIONS .................................................................................................... 7
2.2
Simplified LM96511 Block Diagram ...................................................................................... 8
2.3
Typical Application .......................................................................................................... 8
2.4
Connection Diagrams ...................................................................................................... 9
ELECTRICAL SPECIFICATIONS .......................................................................................... 15
3.1
Absolute Maximum Ratings .............................................................................................. 15
3.2
Operating Ratings ......................................................................................................... 15
3.3
AFE Electrical Characteristics (B-Mode) ............................................................................... 16
3.4
CW Doppler Electrical Characteristics .................................................................................. 18
3.5
LNA Electrical Characteristics ........................................................................................... 19
3.6
DVGA Electrical Characteristics ......................................................................................... 20
3.7
ADC Electrical Characteristics ........................................................................................... 21
3.8
Digital Input and Output Characteristics ................................................................................ 22
GENERAL DIAGRAMS ........................................................................................................ 24
4.1
TIMING DIAGRAMS ...................................................................................................... 24
TYPICAL PERFORMANCE CHARACTERISTICS ..................................................................... 27
5.1
General Typical Performance Characteristics ......................................................................... 27
5.2
CW Doppler Plots ......................................................................................................... 30
OVERVIEW ....................................................................................................................... 32
6.1
LNA INPUT AMPLITUDE RANGE ...................................................................................... 32
6.2
TYPICAL INPUT CONFIGURATION ................................................................................... 33
6.3
PROGRAMMABLE INPUT IMPEDANCE & LNA GAIN SELECTION .............................................. 34
6.4
OFFSET SOFT-TRIM ..................................................................................................... 35
6.5
DYNAMIC RANGE ........................................................................................................ 36
6.6
DVGA OPERATION ....................................................................................................... 36
6.6.1
DVGA Half Step Mode ......................................................................................... 40
6.6.2
DVGA CLK Pin .................................................................................................. 40
6.6.3
CW/DVGA RST Pin ............................................................................................ 41
6.6.4
DVGA UP Pin: .................................................................................................. 41
6.6.5
DVGA Accelerated Gain Adjustment: ........................................................................ 41
6.7
THE LM96511 ADC ....................................................................................................... 42
6.8
ADC OUTPUT INTERFACE ............................................................................................. 43
6.9
12–BIT SIGMA DELTA (ΣΔ) ADC CORE .............................................................................. 43
6.10 INSTANT OVERLOAD RECOVERY .................................................................................... 44
6.11 USING IOR ON MODE ................................................................................................... 44
6.11.1 Standard Use of IOR On Mode ............................................................................... 44
6.11.2 Advanced Use of IOR On Mode .............................................................................. 44
6.12 INTEGRATED PRECISION LC PLL ADVANTAGES ................................................................. 45
6.13 DIGITAL DECIMATION FILTER AND EQUALIZER .................................................................. 45
6.14 OUTPUT CLOCK SYNCHRONIZATION ACROSS MULTIPLE CHIPS ............................................ 46
6.15 CAPACITOR SELECTION ............................................................................................... 46
6.16 ADC OUTPUT CONSIDERATIONS .................................................................................... 47
6.16.1 Output Driving Voltage, ADC IO DVDD ...................................................................... 47
6.16.1.1 Output Modes and Output Common Mode ..................................................... 47
6.16.1.2 Termination ......................................................................................... 47
6.16.1.3 LVDS Output Training Sequences ............................................................... 48
DEVICE INFORMATION
Contents
Copyright © 2010–2013, Texas Instruments Incorporated
LM96511
www.ti.com
6.17
6.18
6.19
6.20
6.21
6.22
SNAS476H – MAY 2010 – REVISED MAY 2013
The Voltage Reference ...................................................................................................
CW Doppler Section Theory of Operation .............................................................................
6.18.1 CW DOPPLER NOISE ANALYSIS ...........................................................................
6.18.2 CW DOPPLER 16x LO SOURCE IMPLEMENTATION ...................................................
LM96511 Power Management ...........................................................................................
6.19.1 POWER-UP SEQUENCING ..................................................................................
SPI™ Interface .............................................................................................................
6.20.1 THE SERIAL PERIPHERAL INTERFACE ..................................................................
6.20.2 ACCESS TO THE SERIAL PERIPHERAL INTERFACE ..................................................
6.20.3 CONNECTING MULTIPLE LM96511 DEVICES TOGETHER ...........................................
6.20.4 SERIAL PERIPHERAL INTERFACE READ AND WRITE SPEED ......................................
SPI™ Register Map .......................................................................................................
SPI™ Register Map Notes ...............................................................................................
Revision History
48
49
52
53
54
55
56
56
56
57
58
58
61
......................................................................................................................... 70
Copyright © 2010–2013, Texas Instruments Incorporated
Contents
3
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
List of Figures
2-1
Simplified LM96511 Block Diagram ............................................................................................. 8
2-2
8-Channel Transmit/Receive Chipset ........................................................................................... 9
2-3
376–Pin NFBGA Package (18 Rows by 32 Columns)
See Package Number NZJ0376A .............................................................................................. 10
2-4
376–Pin NFBGA Package (18 Rows by 32 Columns)
See Package Number NZJ0376A .............................................................................................. 10
4-1
B-Mode ADC Data Output Timing.............................................................................................. 24
4-2
B-Mode ADC Data Output Level Definitions .................................................................................. 25
4-3
CW CLK Level Definitions....................................................................................................... 25
4-4
SPI™ Write Timing ............................................................................................................... 25
4-5
SPI™ Read Timing............................................................................................................... 26
4-6
CW/DVGA RST Timing (CW Doppler Mode) ................................................................................. 26
6-1
Ultra-Sound System Block Diagram ........................................................................................... 32
6-2
Signal Path (B-Mode) Single Channel
Including Input Clamp and Diode Bridge ...................................................................................... 33
6-3
Standard Input Termination ..................................................................................................... 34
6-4
Active Termination Schematic .................................................................................................. 35
6-5
Offset Distribution Histogram including Soft-Trim Improvement ........................................................... 35
6-6
LM96511 in Typical TGC Operation at 5MHz ................................................................................ 36
6-7
Periodic TGC Ramp: Example 1 (Half-Step Disable bit = 1) ............................................................... 37
6-8
DVGA UP bit Change (Half-Step Disable bit = 1) ............................................................................ 38
6-9
Periodic TGC Ramp: Example 2 (Half Step Disable bit = 1) ............................................................... 38
6-10
Basic Gain Adjustment (Half Step Disable Bit = 1) .......................................................................... 39
6-11
Accelerated Gain Adjustment (Half Step Disable bit = 1) ................................................................... 39
6-12
Gain Reset with DVGA UP bit = 0 ............................................................................................. 40
6-13
DVGA Gain control “Micro Illustration” of the Gain Stair Case ............................................................. 40
6-14
LM96511 ADC Block Diagram .................................................................................................. 42
6-15
ADC WCLK
6-16
6-17
6-18
6-19
6-20
6-21
6-22
6-23
6-24
6-25
6-26
6-27
6-28
6-29
6-30
4
.......................................................................................................................
PLL Phase Noise Transfer Function: ADC CLK = 40 MHz .................................................................
Digital Filter Transfer Function .................................................................................................
DAC LPF Capacitor ..............................................................................................................
LVDS Training Sequence .......................................................................................................
Reference Sharing ...............................................................................................................
Signal Path (CW Doppler) Single Channel ...................................................................................
I-V with Integrated 2–Pole LFP .................................................................................................
CW Doppler LPF Gain/Phase Characteristics ................................................................................
CW Doppler Output (I or Q) Implementation (64 Receive Channels) .....................................................
CW Doppler Low-Phase Noise Clock Source Design .......................................................................
LM3881 Power Sequencer Can be Used for Proper LM96511 Power-Up ...............................................
SPI™ Bus Master Slave Connection ..........................................................................................
SPI™ Compatible Read/Write Timing Diagram ..............................................................................
SPI™ Compatible Interconnect for Multiple LM96511's (Open Drain Mode) .............................................
CW Doppler Shadow Register Representation...............................................................................
List of Figures
43
45
46
47
48
49
50
50
51
53
54
56
56
57
58
67
Copyright © 2010–2013, Texas Instruments Incorporated
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
List of Tables
.................................................................................................................
2-1
Pin Descriptions
6-1
ADC Output Mode Summary ................................................................................................... 47
6-2
LM96511 Power Consumption for Various Conditions ...................................................................... 54
6-3
Recommended Operating Conditions ......................................................................................... 56
6-4
DVGA Initial Attenuation Truth Table .......................................................................................... 68
6-5
DVGA Notation ................................................................................................................... 68
6-6
Offset Trim “Write” Truth Table ................................................................................................. 69
6-7
Offset Trim “Write” and “Read” Example ...................................................................................... 69
Copyright © 2010–2013, Texas Instruments Incorporated
List of Tables
11
5
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
LM96511 Ultrasound Receive Analog Front End (AFE)
Check for Samples: LM96511
1
INTRODUCTION
1.1
FEATURES
12
• 8-Channel LNA, DVGA, and 12-bit Continuous
Time ΣΔ ADC
• Programmable Active Termination LNA
• 8-channel, Integrated CW Doppler Beamforer
• Low-Power Consumption
1.2
•
•
•
•
•
•
•
•
Embedded ADC Digital Filter
ADC Instant Overload Recovery
Embedded ADC “Clock-Cleaning” PLL
11 mm x 17 mm RoHS NFBGA Package
APPLICATIONS
Ultrasound Imaging
Communications
Portable Instrumentation
Sonar
1.3
DESCRIPTION
The LM96511 is an 8-channel integrated analog front end (AFE) module for multi-channel applications,
particularly medical ultrasound. Each of the 8 signal paths consists of a low noise amplifier (LNA), a
digitally programmable variable gain amplifier (DVGA) and a 12-bit, 40 Mega Samples Per Second
(MSPS) analog-to-digital converter (ADC) with Instant Overload Recovery (IOR). The architecture of the
DVGA is a digitally-controlled linear-in-dB step attenuator driving a fixed-gain post-amplifier (PA). The
ADC uses a Continuous-Time-Sigma-Delta (CTΣΔ) architecture with digital decimation filtering to
maximize dynamic performance and provide an alias free input bandwidth to ADC CLK / 2. The ADC
digital outputs are serialized and provided on differential LVDS outputs. The ADC includes an on-chip
clock cleaner PLL.
In addition, for baseband CW Doppler Beamformer applications, an 8-channel demodulator with 16
discrete phase rotation angles is included.
Selective power reduction is included to minimize consumption of idle sections during interleaved imaging
modes.
An SPI™ compatible serial interface allows dynamic digital programming and control. Texas Instruments
offers a full development package for sale which includes acquisition analysis hardware and software with
user friendly GUI for device programming and control.
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
Copyright © 2010–2013, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date. Products conform to
specifications per the terms of the Texas Instruments standard warranty. Production
processing does not necessarily include testing of all parameters.
LM96511
www.ti.com
2
DEVICE INFORMATION
2.1
KEY SPECIFICATIONS
SNAS476H – MAY 2010 – REVISED MAY 2013
VALUE
UNIT
(Full path unless noted)
B-Mode:
Total Input Voltage Noise (RTI)
0.9 nV/vHz
Max AFE Gain
58
Single-Ended Input Swing
500mVpp
Programmable Maximum DVGA Attenuation
38, 36, 34, 32
dB
Programmable Post Amp Gain
31 or 38
dB
Attenuator Step Resolution
0.05 or 0.1
dB
ADC Resolution
12
bits
Conversion Rate (ADC CLK)
40
MSPS
ADC Digital Filter stop band attenuation
72
dB
ADC Digital Filter Passband Ripple
± 0.01
dB
ADC Instant Overload Recovery
1 ADC Clock Period
Power Consumption (per channel)
110 mW
dB
CW Doppler Mode:
Phase Rotation Resolution
22.5 degrees
Phase Noise (Per Channel, Offset = 5KHz)
-144 dBc/Hz
Dynamic Range
-161 dB/Hz
Amplitude Quadrature Error (I to Q)
± 0.04
Phase Quadrature Error (I to Q)
± 0.10°
Power Consumption (Per Channel)
208 mW
dB
Common Specifications:
LNA Input Voltage Noise
0.82 nV/vHz
Operating temp. Range
0 to +70°C
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
7
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
2.2
www.ti.com
Simplified LM96511 Block Diagram
DVGA
LNA IN
CH0+
Attenuator
Attenuator
LNA
LNA
ADC DOUT
CH0+
6'
CT6'
CT
ADC
ADC
Post
Post
AmpAmp
-
LNA IN
CH0-
12b
12
Serializer
Serializer
1b
1b
LVDS
LVDS
SLVS
SLVS
ADC DOUT
CH0-
B - Mode
Mode
CW Doppler (D - Mode)
XX
CW I CH0
XX
CW Q CH0
Channel 0
Channel
Channel
Channel 7
22
22
00°°
90 °
90°
Divide by 16 &
Phase Shift
To
ToRegisters
Registers
Reference
Reference
& Bias
SPI
SPI
ADC WCLK+
PLL && CMU
PLL
CMU
ADC WCLKADC BCLK+
ADC CLK-
ADC CLK+
ADC SPI CS*
SPI DIO
AMS SPI CS*
SPI CLK
CW/DVGA RST
DVGA CLK
DVGA UP
CW CLK-
CW CLK+
ADC BCLK-
Figure 2-1. Simplified LM96511 Block Diagram
2.3
Typical Application
Figure 2-2. 8-Channel Transmit/Receive Chipset
8
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
2.4
SNAS476H – MAY 2010 – REVISED MAY 2013
Connection Diagrams
Top View
Figure 2-3. 376–Pin NFBGA Package (18 Rows by 32 Columns)
See Package Number NZJ0376A
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
9
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Top View
Figure 2-4. 376–Pin NFBGA Package (18 Rows by 32 Columns)
See Package Number NZJ0376A
10
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Table 2-1. Pin Descriptions
Ball Id.
(Row_Column)
Pin Name
Function
Description
Amplifier Signals
U1
LNA IN CH0+
R1
LNA IN CH1+
N1
LNA IN CH2+
L1
LNA IN CH3+
J1
LNA IN CH4+
G1
LNA IN CH5+
E1
LNA IN CH6+
D2
LNA IN CH7+
V1
LNA IN CH0-
T2
LNA IN CH1-
P2
LNA IN CH2-
M2
LNA IN CH3-
K2
LNA IN CH4-
H2
LNA IN CH5-
F2
LNA IN CH6-
D1
LNA IN CH7-
V2
LNA OUT CH0-
T1
LNA OUT CH1-
P1
LNA OUT CH2-
M1
LNA OUT CH3-
K1
LNA OUT CH4-
H1
LNA OUT CH5 -
F1
LNA OUT CH6-
D4
LNA OUT CH7-
V8
DVGA BYP CH0
T17
DVGA BYP CH1
R16
DVGA BYP CH2
L15
DVGA BYP CH3
J17
DVGA BYP CH4
D16
DVGA BYP CH5
C15
DVGA BYP CH6
B9
DVGA BYP CH7
J14
J15
CW CLK+
CW CLK-
V10
CW I CH0
V14
CW I CH1
P15
CW I CH2
M16
CW I CH3
G16
CW I CH4
E15
CW I CH5
B16
CW I CH6
A11
CW I CH7
LNA Non-Inverting Input
Input
LNA Inverting Input
Output
LNA Inverting Output
Bypass
Decoupling Capacitor to Analog Ground
Input
CW DOPPLER Differential Input Clock +
CW DOPPLER Differential Input Clock -
Output
CW DOPPLER In-Phase output current
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
11
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Table 2-1. Pin Descriptions (continued)
Ball Id.
(Row_Column)
Pin Name
Function
Description
U10
CW Q CH0
V17
CW Q CH1
P17
CW Q CH2
N14
CW Q CH3
G14
CW Q CH4
F14
CW Q CH5
A17
CW Q CH6
B11
CW Q CH7
K14
DVGA CLK
DVGA GAIN Clock
L17
DVGA UP
1 = Increment DVGA gain
0 = Decrement DVGA gain
A6
DVGA INIT MSB
B5
DVGA INIT LSB
Output
CW DOPPLER Quadrature-Phase output current
Amplifier Controls
K15
CW/DVGA RST
K16
AMP CW/DVGA
DVGA Initial Gain Control. Sets the initial DVGA gain. See Section 6.
Input
1 = CW DOPPLER Phase and DVGA Gain Reset
0 = B-mode
1 = CW DOPPLER mode
A1
LNA PD
A2
DVGA PD
1 = LNA Power-down
1 = DVGA Power-down
A3
AMP RST
1 = Reset all Amplifier SPI™ Registers
B1
DVGA PA HI
Post Amplifier Gain:
1= 38 dB
0= 31 dB
ADC Signals
B22
A22
ADC CLK+
ADC CLK-
V31
ADC DOUT CH0+
U32
ADC DOUT CH1+
P32
ADC DOUT CH2+
L32
ADC DOUT CH3+
J32
ADC DOUT CH4+
G32
ADC DOUT CH5+
E32
ADC DOUT CH6+
C32
ADC DOUT CH7+
V32
ADC DOUT CH0-
T32
ADC DOUT CH1-
N32
ADC DOUT CH2-
K32
ADC DOUT CH3-
H32
ADC DOUT CH4-
F32
ADC DOUT CH5-
D32
ADC DOUT CH6-
B32
ADC DOUT CH7-
12
Input
Differential Input Clock. The input clock must lie in the range of 40 to
40.5 MHz. It is used by the PLL to generate the internal sampling
clocks.
Output
Differential Serial Outputs for channels 0 to 7. Each pair of outputs
provides the serial output for the specific channel. The default output
is LVDS format, but programming the appropriate control registers,
the output format can be changed to SLVS .
By programming TX_term (bit 4) in the LVDS Control register, it is
possible to internally terminate these outputs with 100Ω resistors.
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Table 2-1. Pin Descriptions (continued)
Ball Id.
(Row_Column)
A30
A29
Pin Name
Function
ADC WCLK+
ADC WCLK-
Output
A32
A31
ADC BCLK+
ADC BCLK-
Description
Word Clock. Differential output frame clock used to indicate the bit
boundary of each data sample. Information on timing can be seen in
Electrical Characteristics. By programming TX_term (bit 4) in the
LVDS Control register, it is possible to internally terminate these
outputs with 100Ω resistors.
Bit clock. Differential output clock used for sampling the serial
outputs. Information on timing can be seen in Electrical
Characteristics. By programming TX_term (bit 4) in the LVDS
Control register, it is possible to internally terminate these outputs
with 100Ω resistors.
ADC Controls
This pin is an active low reset for the entire ADC, both analog and
digital components. The pin must be held low for 500 ns then
returned to high in order to ensure that the chip is reset correctly.
U25
_______
ADC RST
V26
ADC CW/DVGA
V22
ADC VREF
V21
ADC VREF GND
U23
ADC RREF
Output
External 10k ±1% resistor to ADC Analog GND. Used to set internal
bias currents. Required regardless of the type of reference used.
V23
ADC LPF BYP
Bypass
Capacitor required by the Modulator DAC's LP Filter. Must be at
least 100 nF to ADC Analog GND. Can be increased to 10 µF to
minimize close-in phase noise.
Input
0 = B-mode
1 = CW DOPPLER mode, PLL and References are still active to
minimize recovery time.
Input
ADC Optional External Reference Voltage; Improves channel-tochannel and converter-to-converter matching.
If Internal Reference is used, connect to AGND.
SPI™ Compatible Interface
B3
SPI™ CLK
Input
B4
SPI™ DIO
Input/Output
A5
__________
ADC SPI™ CS
A4
__________
AMP SPI™ CS
SPI™ clock
SPI™ Data Input/Output
0 = ADC SPI™ Chip Select
Input
0 = Amplifier SPI™ Chip Select.
Power and Ground
A10, B8, C16, C17,
D14, D15, D17, E4,
E14, G3, J3, J16,
K17, L3, L16, M4, N4,
R3, R14, R15, T4,
T14, T15, U4, U7, U8,
U13, V4, V6, V13
AMP AVCC A
B10, B14, B15, C14,
E16, E17, H15, G15,
M14, M15, P16, R17,
T16, U9, U16, V9, B2,
C2, E2, F4, G4, H4,
J4, K4, L4, N2, P4, T3
CW AVCC
V5, A7, B7, H16, H17,
U14, U15
AMP DVDD
B6, L14
Amplifier Analog Power
Nominally +3.3V.
CW DOPPLER Analog Power
Nominally +5.0V.
Power
DVGA Digital Power. Nominally +3.3V.
AMP IO DVDD
Amplifier IO Digital Power. Connect to ADC IO DVDD. Nominally
+1.2V.
B30, G31, H31, U31
ADC IO DVDD
ADC IO Digital Power. Nominally +1.2V.
A19, C18, F18, J18,
M19, R19, U19, U24,
U26, U28, V27, V29
ADC AVDD
ADC Analog Power. Nominally +1.2V.
A26, B25, B26, U27,
V28
ADC DVDD
ADC Digital Power. Nominally +1.2V .
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
13
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Table 2-1. Pin Descriptions (continued)
Ball Id.
(Row_Column)
Pin Name
A9, A12, A13, A16,
A23, A24, A25, B17,
B19, B20, B21, B23,
B24, B29, B31, C3,
C19, C31, D3, D18,
D19, F3, F17, F19,
F31, G17, G18, G19,
H3, J19, J31, K3,
K19, K31, L18, L31,
M3, M17, M18, M32,
N17, N18, P3, P14,
P18, P31, R4, R18,
R31, T18, T19, U3,
U6, U12, U21, U22,
U30, V3, V11, V12,
V15, V19, V24, V25
AGND
F7, F8, F9, F10, F11,
G7, G8, G9, G10,
G11, H7, H8, H9,
H10, H11, J7, J8, J9,
J10, J11, K7, K8, K9,
K10, K11, L7, L8, L9,
L10, L11, M7, M8,
M9, M10, M11, N7,
N8, N9, N10, N11
AMP THRM GND
F23, F24, F25, F26,
F27, G23, G24, G25,
G26, G27, H23, H24,
H25, H26, H27, J23,
J24, J25, J26, J27,
K23, K24, K25, K26,
K27, L23, L24, L25,
L26, L27. M23, M24,
M25, M26, M27, N23,
N24, N25, N26, N27
Description
Analog Ground
Ground
Thermal Ground (Connect to AGND)
ADC THRM GND
A14, A15, B12, B13,
F15, F16, N15, N16,
U11, V16
CW DGND
A8, H14, U5, U17
AMP DGND
A27, A28, B27, B28,
D31, E31, M31, N31,
U29, V30
Function
Digital Ground
ADC IO DGND
No Connect
Important: “NC” pins should be left unconnected. Any connection to these pins could affect performance and functionality.
A18, A20, A21, B18,
C1, E3, E18, E19,
G2, H18, H19, J2,
K18, L2, L19, N3,
N19, P19, R2, U2,
U18, U20, V18, V20,
R32, T31, V7, C4
14
NC
Do Not Connect
DEVICE INFORMATION
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
3
ELECTRICAL SPECIFICATIONS
3.1
Absolute Maximum Ratings
(1) (2)
Supply Voltage (CW AVCC)
-0.3V and +6V
Supply Voltage (AMP AVCC A, AMP DVDD)
-0.3V and +3.63V
Supply Voltage (ADC AVDD, ADC DVDD)
-0.3V and +1.44V
IO Supply Voltage (AMP IO DVDD, ADC IO DVDD)
-0.3V and +2.0V
Voltage at Analog Inputs
-0.3V and +2.0V
Voltage at SPI™ Compatible inputs (SPI™ CLK, SPI™ DIO, AMP SPI™ CS, ADC
SPI™ CS)
-0.3V and +2.0V
Input Current at any pin other than a Supply Voltage and LNA Inputs
LNA Inputs
(1)
(2)
3.2
25 mA
2.6 Vpp & ±10 mA
Absolute maximum ratings are those values beyond which the safety of the device cannot be ensured. They are not meant to imply that
the device should be operated at these limits. Operating Ratings indicate conditions for which the device is specified to be functional, but
do not specify specific performance limits. Specifications and test conditions are specified in the Electrical Characteristics sections
below. Operations of the device beyond the Operating Ratings is not recommended as it may degrade the lifetime of the device. All
voltages are measured with respect to GND = AGND = DNGD = 0V, unless otherwise specified.
If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
Operating Ratings
(1)
Operation Temperature Range
0°C to + 70°C
Supply Voltage (CW AVCC)
+4.75V to +5.25V
Supply Voltage (AMP AVCC A, AMP DVDD)
+3.13V to 3.47V
Supply Voltage (ADC AVDD, ADC DVDD)
+1.14V to +1.26V
IO Supply Voltage (AMP IO DVDD, ADC io DVD)
+1.14V to +1.89V
SPI™ Compatible Inputs (SPI™ CLK, SPI™ DIO, AMP SPI™ CS, ADC SPI™ CS)
+1.14V to +1.89V
ADC CLK Input Frequency
40 MHz
ADC CLK Duty Cycle
30 to 70%
DVGA CLK Frequency
< 100 MHz
Ground Difference |AGND - DGND|
ESD Tolerance (2):
(1)
(2)
50 mV
Human Body Model
1500V
Machine Model
100V
Charge Device Model
750V
Absolute maximum ratings are those values beyond which the safety of the device cannot be ensured. They are not meant to imply that
the device should be operated at these limits. Operating Ratings indicate conditions for which the device is specified to be functional, but
do not specify specific performance limits. Specifications and test conditions are specified in the Electrical Characteristics sections
below. Operations of the device beyond the Operating Ratings is not recommended as it may degrade the lifetime of the device. All
voltages are measured with respect to GND = AGND = DNGD = 0V, unless otherwise specified.
Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of
JEDEC). Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
15
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
3.3
www.ti.com
AFE Electrical Characteristics (B-Mode)
Unless otherwise noted, specified limits apply for AMP AVCC A = 3.3V, CW AVCC = 5V, AMP IO DVDD = ADC IO DVDD =
1.2V, ADC AVDD = ADC DVDD = 1.2V, Full Scale ADC Output with RF Input at 5 MHz, DVGA PA HI = LO; AMP CW/DVGA
pin = ADC CW/DVGA pin = LO, FCLK = 40 MSPS; Clock duty cycle stabilization enabled; IOR On Mode. All 8 channels
powered. Boldface limits apply for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Conditions
Min
Typ
Max
Units
Total Input (RTI) Voltage Noise
See , No Active Feedback, Input AC
shorted to ground
0.9
nV/√Hz
Noise Figure
Equivalent 50Ω termination using Active
Feedback (RFB = 301Ω)
3.7
dB
Single-Ended LNA Input Swing
1 dB SNR Loss (TGC in Operation).
(1) (2)
Externally Programmable Input Resistance
Range (overall)
Offset Related Full Scale Amplitude Loss
380
50
Max DVGA Gain. 1δ
(3)
Max DVGA Gain, IOR Off Mode. 1δ,
mVPP
Ω
2k
-0.23
(3)
dB
-0.15
Offset Tempco
-0.22
LSB/ ºC
Max DVGA Gain, Error < ±1%
1/fCLK
seconds
Max DVGA Gain, Error < ±1%
1/fCLK
Ch-Ch Gain Match
Worst case across DVGA Gain Range
± 0.06
±0.2
dB
Ch-Ch Phase Match
Worst case across DVGA Gain Range
±0.35
±0.75
ºC
±0.20
±0.80
ns
Overload Recovery
Ch-Ch Group Delay Match
Ch-Ch Crosstalk
Bandwidth
Min DVGA Gain.
(4)
-61
Min DVGA Gain.
(4)
-62
Min DVGA Gain.
(4)
dBc
-62
-3 dB, Small Signal
Mid DVGA gain, -6dB FS, DVGA PA HI
pin= LO
seconds
fCLK/2
60
MHz
63
Mid DVGA gain, -1dB FS, DVGA PA HI
pin= LO
62
Mid DVGA gain, -6dB FS, DVGA PA HI
pin= HI
57
Mid DVGA gain, -1dB FS, DVGA PA HI
pin= HI
56
fin = 5 MHz, -6dBFS, Mid DVGA Gain
-72
fin = 5 MHz, -1dBFS, Mid DVGA Gain
-68
fin = 5 MHz, -6dBFS, Mid DVGA Gain
-52
fin = 5 MHz, -1dBFS, Mid DVGA Gain
-43
DVGA Clock Feedthrough
DVGA CLK frequency = 7.5MHz
-95
dBFS
Spurious Noise near fin, fin ± (3/8 x fin)
fin = 2 to 20 MHz
-84
dBFS
-83
dBFS
fin = 5 MHz, -6 dBFS, Mid DVGA Gain
88
dBFS
fin = 5 MHz, -1 dBFS, Mid DVGA Gain
82
Active Mode, IO DVDD = 1.2V
880
Active Mode, IO DVDD = 1.8V
905
Power Down
50
SNR
HD2
HD3
Spurious Noise near 2fin, 2 x fin ± (3/4 x fin)
SFDR
Power Consumption
(1)
(2)
(3)
16
-60
dBFS
dBFS
910
mW
The LNA non-inverting input is always driven single-ended. The inverting input is always AC grounded. See Section 6 for typical
connection diagrams in Figure 6-2.
Please take note of the LNA Input Amplitude Range information described in the Section 6.1
Maximum expected full scale amplitude loss due to DC offset (minimum DVGA attenuation):
= 20 x log
(4)
dBFS
§212 - |Offset (LSB)| ·
¸
¨
12
2
¹
©
For Further information, refer to Section 6.4.
One channel with active input and the worst of the other 7 channels measured.
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
AFE Electrical Characteristics (B-Mode) (continued)
Unless otherwise noted, specified limits apply for AMP AVCC A = 3.3V, CW AVCC = 5V, AMP IO DVDD = ADC IO DVDD =
1.2V, ADC AVDD = ADC DVDD = 1.2V, Full Scale ADC Output with RF Input at 5 MHz, DVGA PA HI = LO; AMP CW/DVGA
pin = ADC CW/DVGA pin = LO, FCLK = 40 MSPS; Clock duty cycle stabilization enabled; IOR On Mode. All 8 channels
powered. Boldface limits apply for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Power Supply Current
Wake-up Time
(5)
Conditions
Min
Typ
AMP AVCC = 3.3V
155
AMP DVDD = 3.3V
1.6
CW AVCC = 5.0V
3.2
ADC AVDD = 1.2V
147
ADC DVDD = 1.2V
104
IO DVDD = 1.2V
35
From Stand-By (From CW DOPPLER to B
Mode when AMP CW/DVGA pin is
switched from HI to LO). See (5)
15
Max
Units
mA
mA
20
µs
“Wake up” time defined as the time it takes the output (or its digital representation) to reach within 10% of expected.
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
17
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
3.4
www.ti.com
CW Doppler Electrical Characteristics
Unless otherwise noted, specified limits apply for AMP AVCC A = 3.3V, CW AVCC = 5V, AMP IO DVDD = ADC IO DVDD =
1.2V, ADC AVDD = ADC DVDD = 1.2V; Full Scale ADC Output with RF Input at 5 MHz; CW CLK = 80 MHz (LVPECL levels),
AMP CW/DVGA pin = ADC CW/DVGA = HI. Boldface limits apply for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Conditions
Min
Typ
Max
Units
Phase Noise
fOFFSET = 5kHz with LNA Input = 240 mVPP
@ 5 MHz. See (1)
-144
Dynamic Range (DNR)
IP1dB referred to RTI Noise
-161
dB/Hz
1.2
nV/√Hz
RTI Noise
dBc/Hz
Single-Ended LNA Input Swing
1dB Compression (CW Doppler Mode).
(IP1dB). (2) & (3)
500
mVPP
Phase Rotation Resolution
16 dynamically selectable angles
22.5
degrees
Phase Temperature Coefficient
I or Q. See
±20
milli°C
Phase Quadrature Accuracy
I to Q. ±6δ. See
± 0.10
ºC
(4)
(4) (5)
Phase Match
I to I or Q to Q. See
Amplitude Match
I to Q. See
(6)
Amplitude Temperature Coefficient
I or Q. See
(4)
(6) (5)
(5)
&
(7)
CW CLK Input Freq Range
See
RF Input Freq Range
CW CLK = 16 x RF Input frequency. See
(7)
±0.35
ºC
±0.04
dB
±11
mdB/°C
12
240
MHz
0.7
15
MHz
Equal tones (f1 = 10 KHz offset, f2 = 15
KHz offset). See (8)
-72
Unequal tones. (f1 = 10 KHz offset, f2 = 15
KHz offset). See (8)
-50
Channel-to-Channel Crosstalk
“I” or “Q” output of undriven channel
relative to driven channel
-95
Output Signal Current
I or Q, Per Channel, LNA Input = 380mVPP
Output Noise Current Density
fOFFSET = 5KHz with no LNA Input
Third order IMD (IMD3)
±3.9
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
dBc
±4.2
±4.5
53
Output Compliance Range
Output Impedance
dBc
DC to 50 kHz
mA
pA/√Hz
2.1 to 3.6
V
100k
Ω
Per 1 Hz BW, offset 1 kHz from a 5 MHz, FS input. Output Phase noise, expressed in - dBc/Hz, follows both RF input and CW CLK
phase noise. To meet the demodulated Output specification, integrated phase noise of both the RF Input signal and CW CLK must be
better than -160 dBc/Hz at 1 kHz offset.
The LNA non-inverting input is always driven single-ended. The inverting input is always AC grounded. See Section 6 for typical
connection diagrams in Figure 6-2.
Please take note of the LNA Input Amplitude Range information described in the Section 6.1
Within one channel
Ensured by characterization for all phases.
Channel-to-Channel
This parameter is specified by design and/or characterization and is not tested in production.
Intermodulation Distortion with unequal tones performed using (ΔP = 25 dB).
80.00 MHz
Wenzel Attenuator
+3.3V
Minicircuits 2.1k
ADT1-1
1.2k
0.1 PF
0.1 PF
?P
50
2.1k
+3.3V
TeK
AFG3252
Attenuator1
(dB)
0
25
Attenuator2Attenuator1
(dB)
0
25
fIN1
TeK
AFG3252
Attenuator2 fIN2
IMD3
CW
CLK-
CW
CLK+
CW I Chx
or
CW Q Chx
CI_V
RI_V
LM96511
?f
f1 - ?f
f1
f2
f2 + ?f
330
Splitter/
Combiner
5.015 MHz
18
100
2.2 nF 310
CFB RFB
5.010 MHz
'P
1.2k
+
-
100 nF
LNA
+
Audio
Precision
AP2700
100 nF
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
CW Doppler Electrical Characteristics (continued)
Unless otherwise noted, specified limits apply for AMP AVCC A = 3.3V, CW AVCC = 5V, AMP IO DVDD = ADC IO DVDD =
1.2V, ADC AVDD = ADC DVDD = 1.2V; Full Scale ADC Output with RF Input at 5 MHz; CW CLK = 80 MHz (LVPECL levels),
AMP CW/DVGA pin = ADC CW/DVGA = HI. Boldface limits apply for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Power Consumption
3.5
Typ
Max
Active Mode (ADC CW/DVGA pin = HI)
Conditions
Min
1.66
1.70
Power Down
0.05
Units
W
LNA Electrical Characteristics
Parameter
Conditions
Min
Typ
(1)
Max
Input Voltage Noise
See
Input Current Noise
RS=50Ω, f=1Mhz, No Active Termination,
See (1)
5
Input Capacitance
Each Input to ground
17
pF
500
mV p-p
3
Vp-p
Single-Ended Input Swing
0.82
Units
1 dB Compression. See
pA/√Hz
(1) (2)
Max Differential Output Swing
HD2
HD3
fin = 5MHz, -6dBFS out, Minimum DVGA
Gain
-55
1.65
LNA Gain
Single-ended In to Differential Out
Power Consumption
Total, 8 channels Active
Power Up Time
From Power-Down mode
(2)
dBc
-52
Output VCM
(1)
nV/√Hz
19
20
V
21
280
10
dB
mW
µs
The LNA non-inverting input is always driven single-ended. The inverting input is always AC grounded. See Section 6 for typical
connection diagrams in Figure 6-2.
Please take note of the LNA Input Amplitude Range information described in the Section 6.1
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
19
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
3.6
www.ti.com
DVGA Electrical Characteristics
Unless otherwise noted, specified limits apply for AMP AVCC A = AMP DVDD = 3.3V; “half-step” enabled (SPI™ Register
1Ah[3] = 1), fin = 5MHz. Boldface limits apply for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Post Amp Gain
Selectable DVGA Initial Attenuation (See
Table 6-4)
Attenuation Steps
Attenuation error from nominal
Min
Typ
Max
DVGA PA HI = HI
Conditions
36.0
38.0
40.0
DVGA PA HI = LO
28.4
31
32.4
DVGA UP pin = HI
CW/DVGA RST pin = HI
DVGA INIT MSB pin = LO
DVGA INIT LSB pin= LO
36.0
38.0
40.0
DVGA UP pin = HI
CW/DVGA RST pin = HI
DVGA INIT MSB pin = LO
DVGA INIT LSB pin= HI
34.0
36.0
38.0
DVGA UP pin = HI
CW/DVGA RST pin = HI
DVGA INIT MSB pin = HI
DVGA INIT LSB pin= LO
32.0
34.0
36.0
DVGA UP pin = HI
CW/DVGA RST pin = HI
DVGA INIT MSB pin = HI
DVGA INIT LSB pin= HI
30.0
32.0
34.0
DVGA UP pin = LO
CW/DVGA RST pin = HI
DVGA INIT MSB pin = X
DVGA INIT LSB pin= X
-1.6
0
2.4
SPI™ Register 1Ah[3] = 0
0.05
SPI™ Register 1Ah[3] = 1
0.1
See
(1)
Attenuator step error from 0.05dB
PA Input Noise
Power-Up Time
(1)
20
From Power-Down mode
Units
dB
dB
dB
±0.15
dB
±20
mdB
3.6
nV/√Hz
0.1
µs
“Nominal” attenuation defined as straight line connecting minimum attenuation (0dB) to maximum attenuation (38dB).
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
3.7
SNAS476H – MAY 2010 – REVISED MAY 2013
ADC Electrical Characteristics
Unless otherwise noted, specified limits apply for ADC AVDD = ADC DVDD = 1.2V, ADC IO DVDD = 1.2V; FCLK = 40 MSPS;
Clock duty cycle stabilization enabled; IOR On Mode. AMP CW/DVGA pin = ADC CW/DVGA pin = LO. Boldface limits apply
for TA = TMIN to TMAX; All other limits apply for TA = +25°C.
Parameter
Conditions
Min
Typ
(1)
Resolution
No missing codes. See
Sampling Rate
ADC CLK
40
Conversion Latency
Equalizer On
19
Input Range (Differential)
IOR On Mode
3.12
IOR Off Mode
4.6
ADC CLK Duty Cycle
20
19
50
RMS Clock Jitter
Generated by PLL. Integrated from 0MHz
to BWLoop
300
PLL Loop Filter Bandwidth (BWLoop)
Low Bandwidth (ADC CLK = 40MHz)
415
High Bandwidth (ADC CLK = 40MHz)
Over-sampling Frequency
Signal-to-Noise Ratio (SNR)
Single-Tone SFDR
67.6
4.4MHz Input, IOR Off Mode
69.1
4.4MHz Input
Digital Filter Passband
Ripple < ± 0.01dB
ADC CLK = 40MHz, Ripple < ± 0.01dB
Digital Filter -3 dB Frequency
Digital Filter Stop Band Attenuation
bits
40.5
MSPS
19
Samples
VPP
80
KHz
MHz
dBFS
76
dBFS
67
dBFS
22
MHz
17.6
25
MHz
20
fin ≥ 34.5 MHz
72
dB
19
samples
Digital Filter Group Delay Ripple (peak to
peak)
fin< 22 Mhz with Equalizer On. See
Instant Overload Recovery (IOR)
≤ 5dB above Full Scale (dBFS)
(1)
0.05
1
All 8 channels Active (PD = 0) at 40 MSPS
(Group Delay Equalizer OFF)
350
All 8 channels Active (PD = 0) at 40MSPS
(Group Delay Equalizer ON)
383
(2)
Power Consumption (Sleep)
Sleep mode, all 8 channels. See
Power Consumption (Power Down)
Power-Down mode, all 8 channels
Recovery Time from CW Doppler Mode
Power-up Time
(1)
(2)
MHz
ADC CLK = 40MHz
Digital filter Group Delay
Power Consumption (Active)
%
fsecond
800
4.4MHz Input, IOR On Mode
Units
12
1.5
640
Signal-To-Noise-and-Distortion (SINAD)
Max
samples
Sample
Clock
cycle
mW
40
mW
5
mW
ADC CW/DVGA pin switch from Hi to LO
170
µs
From single channel Power Down (SPI™
register 01h)
6
From Power Down mode (SPI™ register
00h[0] = HI)
20
µs
ms
This parameter is specified by design and/or characterization and is not tested in production.
Sleep mode keeps the PLL, Reference and Bias networks active to allow fast recovery and interleaved imaging modes.
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
21
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
3.8
www.ti.com
Digital Input and Output Characteristics
Unless otherwise noted, specified limits apply ADC AVDD = ADC DVDD = 1.2V; ADC CLK = 40 MHz, ADC IO DVDD = AMP
IO DVDD = 1.2V, ADC data out RL=100Ω, SPI™ DIO capacitance = 5pF; Boldface limits apply for TA = TMIN to TMAX; All
other limits apply for TA = +25°C.
Parameter
Conditions
Min
Typ
Max
Units
Single Ended I/O: SPI™ CLK, SPI™ DIO, ADC SPI™ CS, AMP SPI™ CS, DVGA CLK, DVGA UP, DVGA INIT MSB, DVGA INIT LSB,
CW/DVGA RST, AMP CW/DVGA, ADC CW/DVGA, LNA PD, DVGA PD, AMP RST, DVGA PA HI:
Levels & Generic Specifications:
Logical Input “HI” Voltage
900
mV
Logical Input “LO” Voltage
300
mV
Logical Input Current
±1
µA
SPI™ DIO Logical Output “HI” Voltage
Test run at 1MHz
SPI™ DIO Logical Output “LO” Voltage
Test run at 1MHz
950
IO DVDD
0
mV
250
mV
Timing:
CW/DVGA RST Setup Time
Falling edge must precede CW CLK+ rising
transition by (tCWS). See Figure 4-6
CW/DVGA RST Hold Time
Falling edge must follow CW CLK+ rising
transition by (tCWH). See Figure 4-6
CW/DVGA RST Pulse Width
CW/DVGA RST Removal time
CW Doppler Mode. See Figure 4-6
(1)
See
(2)
ns
0
ns
200
20
ns
DVGA CLK pin Freq
DVGA CLK pin Rise and Fall Time
ns
2
B-Mode
See
2
DVGA CLK pin Pulse Width
100
MHz
7
ns
4
ns
AMP SPI™ CS or ADC SPI™ CS Setup
Time (tSSELS)
See Figure 4-4
15
ns
AMP SPI™ CS or ADC SPI™ CSHold
Time (tSSELH)
See Figure 4-4
3
ns
AMP SPI™ CS or ADC SPI™ CSHI Time
(TSSELH)
Read / Write Transactions. See Figure 4-5
SPI™ DIO Setup Time (tWS)
Write Transaction. See Figure 4-4
SPI™ DIO Hold Time (tWH)
SPI™ CLK Write Period (tSCLK)
SPI™ Read Propagation Delay (tOD)
Read Transaction Propagation Delay. See
Figure 4-5
SPI™ Master Hi-Z End (tHiZ-E)
Read Transaction End of SPI™ Master
HiZ. See Figure 4-5
SPI™ Read Valid Time (tVALD)
Read Transaction. See Figure 4-5
SPI™ CLK Read Period (tSCLKRD)
Read Clock Period. See Figure 4-5
250
ns
110
40
Write Transaction. See Figure 4-4
24
40
ns
Write Clock Period. See Figure 4-4
0.2
1
µs
SPI™ CLK Duty Cycle (tSCKL / tSCLKH)
See Figure 4-4
SPI™ CLK Rise / Fall Time (tSCLKR /
tSCLKF)
See Figure 4-4
ns
120
ns
100
ns
tSCLKRD tOD
ns
0.2
µs
45
% of
SPI™ CLK
Period
55
50
ns
Differential Input:
Levels & Generic Specifications:
LVDS, Common Voltage. See
CW CLK Level (See Figure 4-3)
(2)
LVPECL, Common Voltage. See
LVDS, Differential Voltage. See
1.2
(2)
(2)
LVPECL, Differential Voltage. See
CW CLK Input Impedance
(1)
(2)
22
(2)
2.0
240
400
600
800
Differential
10
V
mV
kΩ
“Removal time” refers to the time CW/DVGA RST must be low prior to the rising edge of DVGA CLK.
This parameter is specified by design and/or characterization and is not tested in production.
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Digital Input and Output Characteristics (continued)
Unless otherwise noted, specified limits apply ADC AVDD = ADC DVDD = 1.2V; ADC CLK = 40 MHz, ADC IO DVDD = AMP
IO DVDD = 1.2V, ADC data out RL=100Ω, SPI™ DIO capacitance = 5pF; Boldface limits apply for TA = TMIN to TMAX; All
other limits apply for TA = +25°C.
Parameter
ADC CLK Level
Conditions
Min
Typ
Max
Units
0.4 to
ADC
AVDD
Common Mode (AC Coupled within
LM96511). See (3)
V
Differential Mode Drive (peak-to-peak) or
Single Ended. See (3)
200
400
ADC
AVDD
ADC IO DVDD = 1.2V
Reduced CM LVDS, RL = 100Ω, OCM = 0.
See (2)
318
370
428
ADC IO DVDD = 1.8V
LVDS, RL = 100Ω, OCM= 1. See
280
350
417
262
330
393
ADC IO DVDD = 1.2V
Reduced CM LVDS, RL = 100Ω, OCM = 0.
See (2)
895
945
1000
ADC IO DVDD = 1.8V
LVDS, RL = 100Ω, OCM= 1. See
1200
1265
1340
185
225
270
4
4.5
mA
-10
±1
10
µA
mV
Differential Output:
Levels & Generic Specifications:
Output Differential Voltage (VOD)
ADC IO DVDD = 1.2V
SLVS, RL = 100Ω. See
Output Common Mode Voltage (VOCM)
ADC IO DVDD = 1.2V
SLVS, RL = 100Ω. See
Output Short Circuit Current (IOS)
Shorted to GND.
High Impedance Output Current (IOZ)
Tri-stated (opened)
(2)
(2)
(2)
(2)
mV
mV
Timing:
ADC BCLK (Bit Clock) Period (tBCLK)
ADC CLK= 40 MHz. See Figure 4-1
Bit Clock (ADC BCLK) Jitter (RMS)
See
ADC WCLK (Word Clock) Period (tWCLK)
ADC CLK= 40 MHz. See Figure 4-1
Output Data Edge to Output Clock
Edge Setup Time (tS)
ADC CLK= 40 MHz. See Figure 4-1
Output Data Edge to Output Clock
Edge Hold Time (tH)
ADC CLK= 40 MHz. See Figure 4-1
Output Data Valid Window (tDV)
ADC CLK= 40 MHz. See
4.16
(4)
ns
2
(4)
Figure 4-1
ps
25
ns
480
900
ps
770
1150
ps
1410
1820
ps
Rise/ Fall Time
320
See Figure 4-1
ADC Input Clock to Word Clock Delay
(tprop)
ADC CLK = 40 MHz. Upon applying RST
signal or a proper power reset.
5.4
ns
Upon applying RST signal or a proper
power reset.
5.1
ns
(3)
(4)
-720
-295
ps
Data Edge to Word Edge Skew (tDWS)
220
ps
ADC CLK input(s) minimum swing should never extend more negative than ground because of ESD protection diode(s) to ground.
This parameter is specified by design and/or characterization and is not tested in production.
ELECTRICAL SPECIFICATIONS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
23
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
4
GENERAL DIAGRAMS
4.1
TIMING DIAGRAMS
tprop
ADC CLK-
ADC CLK
ADC CLK+
tBCLK
ADC BCLK+
ADC Bit Clock
ADC BCLKtR
tDWS
tF
tDWS
tWCLK
ADC WCLKADC Word Clock
ADC WCLK+
tDV
tH
ADC DOn+
ADC Output data
D10 D11
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10 D11
D0
D1
D2
D3
D4
D5
ADC DOntS
Sample n+1
Sample n
Figure 4-1. B-Mode ADC Data Output Timing
ADC IO
DVDD
VOCM + VOD/2
Differential
output signal
VOCM
VOCM - VOD/2
0
Figure 4-2. B-Mode ADC Data Output Level Definitions
24
GENERAL DIAGRAMS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
AMP
DVDD
VOCM + VOD/2
CW CLK
Levels
VOCM
VOCM - VOD/2
0
Figure 4-3. CW CLK Level Definitions
tSCLK
tSSELS
tSCLKL
tSSELH
tSCLKF
tSCLKR
tWH
tWS
tSCLKH
SPI CLK
SPI DIO
90%
10%
10%
D7
R/W
A7
90%
D0
ADC SPI CS or
AMP SPI CS
Figure 4-4. SPI™ Write Timing
tOD
tSCLKRD
tVALD
tHIzE
SPI CLK
SPI DIO
A7
R/W
D7
D0
tSSELHI
ADC SPI CS or
AMP SPI CS
Figure 4-5. SPI™ Read Timing
GENERAL DIAGRAMS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
25
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Phase Reset
Initiated
CW CLKCW CLK
CW CLK+
tCW
tCWS
CW/DVGA RST
tCWH
Figure 4-6. CW/DVGA RST Timing (CW Doppler Mode)
26
GENERAL DIAGRAMS
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
5
TYPICAL PERFORMANCE CHARACTERISTICS
5.1
General Typical Performance Characteristics
Unless otherwise noted, AMP AVCC A = AMP DVDD= 3.3V, CW AVCC = 5V; ADC AVDD = ADC DVDD = 1.2V, ADC IO
DVDD = AMP IO DVDD = 1.2V, Full Scale RF Input at 5 MHz; CW CLK = 80 MHz; FCLK = 40 MSPS, TA =+25°C.
AFE Gain
vs.
Steps (DVGA PA HI = HI)
Attenuation Error from Nominal
Attenuation Error from Nominal (dB)
0.02
Nominal Gain = Straight Line
from Min to Max Attenuation
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
0
10
20
30
DVGA Attenuation (dB)
40
Figure 5-2.
Attenuation Step Error from 0.1 dB
Attenuation Step Error from 0.05 dB
ATTENUATION STEP ERROR FROM 0.05 dB (dB)
Figure 5-1.
Attenuation Step Error from 0.1dB (dB)
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
0
10
20
30
DVGA Attenuation (dB)
40
0.020
0.015
0.020
0.010
0.015
0.010
0.005
0.005
0 0
-0.005
-0.010
-0.005
-0.015
-0.010
-0.020
-0.015
-0.020
0
10
20
30
DVGA ATTENUATION (dB)
Figure 5-3.
Figure 5-4.
Gain Variation from Nominal
vs
Supply Voltage
Gain Variation from Nominal
vs
Temperature
0.250
40
0.4
70°C
0.3
SUPPLY -5%
DELTA GAIN (dB)
DELTA GAIN (dB)
0.125
0.000
0.1
0.0
0°C
SUPPLY +5%
-0.125
-0.2
-0.250
-40
Delta Gain Referenced to
AMP AVCC A pin = 3.3V Condition
-30
-20
-10
DVGA GAIN (dB)
Figure 5-5.
Copyright © 2010–2013, Texas Instruments Incorporated
0
Delta Gain Referenced to 25°C Condition
-0.3
-40
-30
-20
-10
0
DVGA GAIN (dB)
Figure 5-6.
TYPICAL PERFORMANCE CHARACTERISTICS
Submit Documentation Feedback
Product Folder Links: LM96511
27
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Unless otherwise noted, AMP AVCC A = AMP DVDD= 3.3V, CW AVCC = 5V; ADC AVDD = ADC DVDD = 1.2V, ADC IO
DVDD = AMP IO DVDD = 1.2V, Full Scale RF Input at 5 MHz; CW CLK = 80 MHz; FCLK = 40 MSPS, TA =+25°C.
LNA S11
vs.
Frequency
0
0.9
-50
0.8
Phase
1.0
0.9
0.7
0.8 RFB = 310Ö (RIN = 50Ö)
0.7
0.6
0.6 CFB = 2.2 nF
0.5
0.5
0.4
0.3
0.4
0.2
Magnitude
0.1
0.3
0.0
0.2
-100
0
-50
-150
-100
-150
-200
-200
-250
-250
-300
-350
-300
-400
-450
-350
-500
-400
0.1
-450
0.0
0.1
1
10
100
1000
PHASE (o)
MAGNITUDE (dB)
1.0
AFE Offset Distribution IOR On Mode,
Minimum DVGA attenuation, DVGA PA HI pin = LO)
-500
10,000
F (MHz)
Figure 5-7.
Figure 5-8.
HD
vs.
LNA Input Swing (PA HI pin = LO)
HD
vs.
LNA Input Swing (PA HI pin = HI)
0.02
0.02
DVGA Attenuation = 38 dB
0.01 (Gain Parked)
ADC Swing
DVGA PA HI pin = LO
0
IOR Off Mode
DVGA Attenuation = 38 dB
0.01 (Gain Parked)
DVGA PA HI pin = HI
ADC Swing
0
IOR Off Mode
-0.01
HD (dBc)
HD (dBc)
-0.01
-0.02
-0.03
HD3
-0.04
-0.05
-0.03
HD3
-0.04
-0.05
HD2
-0.06
-0.07
0
-0.02
HD2
-0.06
10
20
30
-0.07
0
40
10
LNA Input Swing (mVpp)
30
40
Figure 5-9.
Figure 5-10.
RTI Noise
vs.
Frequency (DVGA Attenuation = 0dB)
RTI Noise
vs.
Frequency (DVGA Attenuation = 32dB)
1.4
1.2
20
DVGA Attenuation = 0 dB
RFB = Open
RS = 0:
DVGA PA HI pin = Lo
15
RTI Noise (nV Hz)
1.6
RTI Noise (nV/ Hz)
20
LNA Input Swing (mVpp)
1.0
0.8
0.6
DVGA PA HI pin= Hi
DVGA attenuation = 32 dB
RFB = Open
DVGA PA HI pin = LO
RS =0:
10
0.4
DVGA PA HI pin = HI
5
0.2
0.0
0
5M
10M
15M
20M
f (Hz)
Figure 5-11.
28
TYPICAL PERFORMANCE CHARACTERISTICS
Submit Documentation Feedback
Product Folder Links: LM96511
0
0
5M
10M
15M
20M
f (Hz)
Figure 5-12.
Copyright © 2010–2013, Texas Instruments Incorporated
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Unless otherwise noted, AMP AVCC A = AMP DVDD= 3.3V, CW AVCC = 5V; ADC AVDD = ADC DVDD = 1.2V, ADC IO
DVDD = AMP IO DVDD = 1.2V, Full Scale RF Input at 5 MHz; CW CLK = 80 MHz; FCLK = 40 MSPS, TA =+25°C.
Far-Field Overload Recovery
@ Post Amp Output (No User Access)
AFE (B-Mode) Overload Recovery
1V/Div
100 ns/Div
Figure 5-13.
Figure 5-14.
Spectral Response @ fIN=10 MHz,
ADC CLK = 400 mHz, IOR On
Close-In Spectral Response @ fIN=1.9 MHz,
TGC Running, Cosine 6 Term Window
Figure 5-15.
Figure 5-16.
ADC INL
ADC DNL
Figure 5-17.
Figure 5-18.
Copyright © 2010–2013, Texas Instruments Incorporated
TYPICAL PERFORMANCE CHARACTERISTICS
Submit Documentation Feedback
Product Folder Links: LM96511
29
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Unless otherwise noted, AMP AVCC A = AMP DVDD= 3.3V, CW AVCC = 5V; ADC AVDD = ADC DVDD = 1.2V, ADC IO
DVDD = AMP IO DVDD = 1.2V, Full Scale RF Input at 5 MHz; CW CLK = 80 MHz; FCLK = 40 MSPS, TA =+25°C.
5.2
CW Doppler Plots
CW Doppler IMD3, Unequal Tones
See Electrical Characteristics (5),
10kHz & 15kHz Offset,
25 dB Separation
Figure 5-19.
CW Doppler Output Noise (CWDIFF CLK = 80.0MHz)
-120
80
CW Doppler Phase Noise,
See Electrical Characteristics
LNA Input = 240 mVpp @ 5.00 MHz
Single Channel (I or Q Output)
70
Phase Noise (dBc/Hz)
Output Noise Density (pA/RtHz)
Singe Channel (I or Q Output)
60
50
-130
-140
40
30
100
1,000
f (Hz)
10,000
-150
100
Figure 5-20.
(5)
(6)
30
(6)
1k
10k
f (Hz)
Figure 5-21.
“Removal time” refers to the time CW/DVGA RST must be low prior to the rising edge of DVGA CLK.
Per 1 Hz BW, offset 1 kHz from a 5 MHz, FS input. Output Phase noise, expressed in - dBc/Hz, follows both RF input and CW CLK
phase noise. To meet the demodulated Output specification, integrated phase noise of both the RF Input signal and CW CLK must be
better than -160 dBc/Hz at 1 kHz offset.
TYPICAL PERFORMANCE CHARACTERISTICS
Submit Documentation Feedback
Product Folder Links: LM96511
Copyright © 2010–2013, Texas Instruments Incorporated
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
I-Q Quadrature Phase Error (Within Channel)
0.02
I-Q Output Amplitude Match (Within Channel)
0.01 Ch6
0.01
0.02
|Amplitude Mismatch (%)|
Phase Error (degrees)
Unless otherwise noted, AMP AVCC A = AMP DVDD= 3.3V, CW AVCC = 5V; ADC AVDD = ADC DVDD = 1.2V, ADC IO
DVDD = AMP IO DVDD = 1.2V, Full Scale RF Input at 5 MHz; CW CLK = 80 MHz; FCLK = 40 MSPS, TA =+25°C.
0 Ch1
-0.01
Ch5
Ch0
-0.02
-0.03
Ch4
Ch2
-0.04
-0.05 Ch3
Ch7
0
-0.02
Ch4
-0.04
-0.07
0
Figure 5-22.
Copyright © 2010–2013, Texas Instruments Incorporated
Ch5
-0.05
-0.07
0
40
Ch3
Ch1
-0.03
-0.06
20
30
SPI Phase Data (#)
Ch0
-0.01
-0.06
10
Ch2
Ch6
Ch7
10
20
30
SPI Phase Data (#)
40
Figure 5-23.
TYPICAL PERFORMANCE CHARACTERISTICS
Submit Documentation Feedback
Product Folder Links: LM96511
31
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
6
www.ti.com
OVERVIEW
The LM96511 is an eight-channel, fully integrated entire subsystem intended for ultrasound receive
applications. LM96511 consolidates many receiver functions currently residing in multiple IC’s, thereby
achieving lower cost, higher board density, higher performance, lower system integration cost, and lower
power consumption. The LM96511 has two distinct signal paths: one for B-mode (Brightness) and the
other for CW-mode (CW Doppler). The LM96511 consists of the following blocks / functions for each of its
8 channels:
1. Low-Noise Amplifier (LNA) with programmable input impedance for improved ultrasound probe
matching characteristics
2. Digital Variable Gain Amplifier (DVGA) with capability to increase or decrease gain (linear in dB) using
digital input for rate of change control
3. 12-Bit ADC with on board PLL for superior jitter reduction
4. CW Doppler output (I and Q) with 16 user selectable phase rotation
5. SPI™ compatible interface for user programming and control
FPGA / DSP Block
TXBeamformer
HV Pulser
Beamformer
Control
Timing
HV
Mux/
Demux
HV Protection
T/ R switch
DVGA Control
LM96511
8 - Channel Analog
Front End
RX Beamformer
LNA +DVGA+ADC
+ CW Doppler I/Q Demod
Cable
Transducer
Summing
Amps
Power
ADC
ADC
CW- Doppler
Processing
B-Mode and
Color Doppler
Processing
Temp Sensor
.
Display and Post Processor
Figure 6-1. Ultra-Sound System Block Diagram
6.1
LNA INPUT AMPLITUDE RANGE
The input amplitude range of the LM96511’s Low Noise Amplifier is well suited for ultrasound applications
in both CW and B-Mode operation. However, T/R switch leakage and strong echoes from near-field or
acoustically dense material is unavoidable. Because of such large transient signal amplitudes and
increasing DVGA gain during TGC, overload at the LNA input impairs signal integrity in ultrasound
applications. Thus, it is very important to prevent the LM96511 inputs from being overloaded by:
1. Limiting the input signal amplitude (see further explanation in Section 6.2)
2. Gating the transmit signal path before it reaches the T/R switch
3. Clamping the input signal with a pair of back-to-back signal diodes as additional protection against
overload at the LNA input
32
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Furthermore, in B-Mode TGC operation, when the LNA functions in series with the DVGA and PostAmplifier, the maximum input signal swing is subject to the LNA’s output slew rate limitation. Because the
LNA has a maximum differential output slew rate of 100V/μs, or 50V/μs at its inverting output, the input
signal should be adjusted such that the inverting output of the LNA does not exceed this 50V/μs limit. In
addition to limiting the input signal slew rate, to avoid further overload effects induced by surges in input
bias current associated with the maximum slew rate limitation, the signal swing at the LNA input should be
limited to 200mVPP for optimal performance across typical signal frequencies above 5MHz. Ultimately, it is
most important to ensure that the input signal is within the LNA’s slew rate limitation. Thus, as shown and
explained further in the next section, the input circuit to the LM96511 should have the current source for
the T/R switch diode bridge carefully selected to limit the input current to the LNA (~1mA) and include a
capacitor (~100pF) and resistor (~100Ω) to ground.
6.2
TYPICAL INPUT CONFIGURATION
The schematic in Figure 6-2 shows a typical B-Mode input configuration circuit for the LM96511. The input
is typically AC coupled through a T/R switch diode bridge configuration which blocks the transmit (Tx) high
voltage pulses from the receive (Rx) low voltage inputs.
+5V
5 k:
I_source
Tx
S1
Diode
Bridge
C1
100 pF
Signal
Source
R1
100:
I_source
5 k:
Max gain = 51 dB or 58 dB
Schottky CIN
Clamp
1 nF
RS
LNA
20 dB
Attenuator
0 dB to -38 dB
Post Amp
31 dB
or 38 dB
CT6'
ADC
12 b
Serial
LVDS/
SLVS
output
1 nF
To
CW_Doppler Path
-5V
Digital gain
control
PA GAIN
Figure 6-2. Signal Path (B-Mode) Single Channel
Including Input Clamp and Diode Bridge
It is recommended to use Texas Instrument's LM96530 T/R switch with the LM96511 AFE for optimal
operation and performance. Alternatively, the discrete 4-diode bridge T/R switch shown in Figure 6-2 may
be used. In such designs, diode characteristics are not ideal, and thus the LM96511 inputs should be
protected from the resulting leakage transients, as well as strong reflections. Thus, the transmit signal
path should be gated off with switch S1.
During Ultrasound Rx, switch S1 is open and, with no input signal, “I_source” flowing from the top current
source, through the 4 diodes, to the bottom current source. The Input signal crosses the diode bridge to
the LM96511 input as long as the current through CIN is less than “I_source” (~1mA). Larger input signal
amplitudes which require excess CIN current beyond I_source's value will thus be limited by the diode
bridge action. During the Tx cycle, switch S1 is shorted so that the Diode Bridge is current starved and
any leakage from the T/R switch (not shown) will be strongly attenuated. This ensures effective isolation
for maximum protection in the presence of any Tx leakage.
In addition to gating the transmit path with switch S1, capacitor C1 and termination resistor R1 must be
included to improve overload recovery time and reduce reflection. C1 acts as a filter to suppress high
voltage transient spikes, while R1 acts to divide the signal amplitude down to a favorable level for the
LM96511 input, e.g., 200mVPP. This provides adequate protection for the LNA input. C1 (~100pF) also
acts to band-limit the input signal to ensure that it is within the LNA's slew rate limitation. Although R1 may
increase the noise figure and the input impedance seen by the ultrasound transducer, it still provides good
harmonic distortion and low offset.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
33
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Finally, the Schottky clamp diodes provide an additional level of overload protection where the LM96511
input swing is limited to ~ ± 0.35V regardless of the LM96511’s input impedance.
6.3
PROGRAMMABLE INPUT IMPEDANCE & LNA GAIN SELECTION
The LM96511 input termination can be configured in either of two ways:
1. Standard Termination is illustrated in Figure 6-3, where the receive (Rx) probe (through the T/R
switch) is terminated with RT for proper cable termination, and AC coupled to the LNA's non-inverting
input. The inverting input is returned to ground through a capacitor.
+5V
1 nF
+
VOUTLNA
VOUT+
-
RT
1 nF
Figure 6-3. Standard Input Termination
2. Active feedback termination is illustrated in Figure 6-4, where no termination resistor is used and
feedback (RFB + CFB) sets the effective input impedance to provide proper cable termination. This
termination scheme is employed for improved harmonic distortion and noise performance. With no
physical termination resistor, there is no resistor thermal noise degradation of the LNA noise, and thus
increased SNR compared to standard termination.
However, as with any amplifier with active feedback termination, abrupt increases in input amplitude may
diminish the active termination and may even result in total loss of termination, which will then further
overload the LM96511 inputs. It is important to be mindful that with active feedback termination, the LNA
is:
1. Even more susceptible to overload effects associated with the maximum slew rate limitation mentioned
above
2. Subject to gain reduction at higher output amplitudes
Thus, in achieving better harmonic distortion and noise performance, active feedback termination may be
employed, but as long as the input signal is limited to an amplitude of 200mVPP and slew-rate limited such
that the LNA inverting output slew rate is less than 50V/μs.
RFB
CFB
+5V
C1
+
VOUTLNA
-
VOUT+
Figure 6-4. Active Termination Schematic
34
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Active impedance termination is achieved through an external shunt feedback resistor from LNA IN+ to
LNA OUT-. The input resistance RIN is given by the equation below, where A is the LNA single-ended
gain (=10V/V ÷ 2 = 5V/V) and 5kΩ is the un-terminated input impedance of the LM96511 LNA. CFB is
required in series with RFB, since the DC levels at LNA IN+ and LNA OUT- are unequal.
RFB
RIN =
6.4
1+ A
|| 5 k:
RIN (Ω)
RFB (Ω)
50
301
7
453
100
619
200
1.24k
1k
7.5k
3k
45.3k
OFFSET SOFT-TRIM
To minimize offset, the LM96511 is laser trimmed during manufacturing. To improve accuracy and to allow
periodic calibration, if needed, the LM96511’s LNA and Post-Amplifier (PA) include provisions for offset
trim using the SPI™ compatible interface after chip power-up (volatile).
In B-mode, LNA offset trim improves gain-dependant offset shift, while PA offset trim reduces fixed offset
to maximize the LM96511 ADC’s Full-Scale swing for maximum dynamic range. SPI™ offset trim should
be performed with a software algorithm (Soft-Trim) that looks at the ADC code, at various DVGA
attenuation settings, and then invokes a binary search for the best value that centers the ADC code. A
couple of iterations are usually adequate to “zero-in” on the best Soft-Trim setting for each channel. Texas
Instruments provides such software algorithms to its customers for use “as-is” or for modification to meet
individual requirements.
Figure 6-5 shows the LM96511 B-mode offset, measured through the ADC. As can be seen, Soft-trim
allows extremely accurate offset adjustment (typically within 1LSB) and allows significant tightening of the
distribution.
Figure 6-5. Offset Distribution Histogram including Soft-Trim Improvement
Maximum expected full scale amplitude loss due to DC offset is:
= 20 x log
§212 - |Offset (LSB)| ·
¸
¨
12
2
¹
©
(1)
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
35
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
6.5
www.ti.com
DYNAMIC RANGE
Figure 6-5 shows the LM96511 B-mode TGC in action. In this diagram, a 5MHz ultrasound signal enters
the LNA with 350mVPP single ended Near Field (NF) amplitude and the signal path headroom runs into
clipping. 3.5VPP differential NF amplitude appears at the LNA output (Differential gain = 20dB) where the
DVGA TGC will equalize the signal so that the ADC FS range of 3.12VPP (with IOR On or 4.4VPP with IOR
off) can be transversed to maximize the data acquisition resolution. Note that the LM96511’s B-mode ADC
operates off a 1.2V supply and yet can accommodate 3.12VPP_FS with IOR on or 4.4VPP_FS with IOR off.
This is because of the coupling resistor ladder built into the ADC in spite of ADC input noise level
performance which does not impact ENOB.
IOR-Level
350 mV
Differential
3.5V
Differential
3.12V
TGC
Differential
3.5V
ADC
Dynamic
Range
IOR-Level
31 dB
&
38 dB
DVGA
-32 dB
-
20 dB
6'
ADC
Figure 6-6. LM96511 in Typical TGC Operation at 5MHz
6.6
DVGA OPERATION
The LM96511 features a linear-in-dB, digital variable gain amplifier which consists of a digitally variable
attenuator and post amplifier. The attenuator has a variable range of 0 to -38dB (or -36, -34, or -32dB
depending on settings) in increments of either 0.05dB or 0.1dB per LSB step (depending on the “Half
Step” mode setting). The variable gain operation is essentially achieved with a “Clock and Reset” scheme.
There are three digital control signals for the attenuator: DVGA CLK, CW/DVGA RST, and DVGA UP.
The heart of the variable gain control lies in the DVGA CLK and CW/DVGA RST logic input signals, as
illustrated in Figure 6-7. The positive edge of every CLK pulse will increment or decrement each gain step
for as long as the CW/DVGA RST logic pulse is LOW. For a periodic gain ramp-up sequence, the
negative edge of every CW/DVGA RST pulse begins a ramp upwards, and the positive edge of every
RESET pulse ends the ramp, resetting the gain back to its DVGA Initial Attenuation. The number of DVGA
CLK pulses during each LOW interval of the CW/DVGA RST pulse, determines the duration of the gain
ramp, while the frequency of the DVGA CLK pulses determines the slope of the gain ramp.
36
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
The DVGA UP input determines whether gain is incremented or decremented. Depending on the logic
level of this input, the DVGA can begin at the bottom of the gain ramp (maximum attenuation setting) and
proceed to ramp up, or at the top of the gain ramp (minimum attenuation setting) and proceed to ramp
down. Figure 6-8 illustrates how this logic level can also be dynamically changed midway through a ramp
up or ramp down operation, which can allow the sonographer to flatten the image’s grey background or to
reduce the level of a bright reflector.
DVGA UP
|
CW/DVGA
RST
|
DVGA
CLK
Max Gain
|
|
GAIN (dB)
Initial Gain
Figure 6-7. Periodic TGC Ramp: Example 1 (Half-Step Disable bit = 1)
Must be 8 1 DVGA CLK Period
|
|
Must be 8 1 DVGA CLK Period
|
DVGA UP
|
CW/DVGA RST
DVGACLK
|
Ramp polarity
change occurs
on the 2nd
rising DVGA
CLK edge
|
GAIN (dB)
MIN GAIN
Figure 6-8. DVGA UP bit Change (Half-Step Disable bit = 1)
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
37
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
DVGA UP
|
CW/DVGA
RST
|
DVGA
CLK
Max Gain
|
|
GAIN (dB)
Initial Gain
Figure 6-9. Periodic TGC Ramp: Example 2 (Half Step Disable bit = 1)
DVGA UP
|
CW\DVGA
RST
DVGA CLK
|
|
Min Removal
Time (20 ns)
GAIN (dB)
Initial Gain
Figure 6-10. Basic Gain Adjustment (Half Step Disable Bit = 1)
38
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
DVGA UP
|
CW/DVGA
RST
|
DVGA
CLK
100 MHz
10 MHz
10 MHz
|
GAIN (dB)
Initial Gain
Figure 6-11. Accelerated Gain Adjustment (Half Step Disable bit = 1)
DVGA UP
|
CW/DVGA
RST
|
DVGA
CLK
100 MHz
10 MHz
|
Max Gain
Ramp polarity
change occurs on
the 1st rising
DVGA CLK edge
GAIN (dB)
Initial Gain
Figure 6-12. Gain Reset with DVGA UP bit = 0
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
39
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Half step disabled, 0.1 dB
DVGA UP pin
DVGA Gain
DVGA CLK pin
Half step enabled, 0.05 dB
DVGA UP pin
DVGA Gain
DVGA CLK pin
Figure 6-13. DVGA Gain control “Micro Illustration” of the Gain Stair Case
6.6.1
DVGA Half Step Mode
Another feature of the DVGA which makes it ideal for TGC (Time Gain Control) Applications is its ultra-fine
gain step resolution. In its default startup state, the step attenuator is controlled with the clock and reset
scheme described above, where each DVGA CLK rising edge changes attenuation by 1/2 step (0.05 dB
typical), and the following DVGA CLK falling edge changes attenuation by another 1/2 step (0.05 dB
typical). In other words one complete DVGA CLK cycle changes attenuation by 0.1dB. Alternatively, the
Half Step mode may be disabled so that a gain step of 0.1dB will occur on the positive edge of the DVGA
CLK and no gain change will occur on the negative edge of the DVGA CLK. The Half Step mode is
controlled via SPI™ compatible interface register 0x1Ah, bit 3 (0x1A[3] = “1”, Half Step Disabled, 0.1dB
step).
6.6.2
DVGA CLK Pin
The DVGA clock frequency determines the rate of change of attenuation (i.e. DVGA gain). The DVGA will
increment or decrement gain by one step (0.05dB or 0.1dB) with each DVGA CLK cycle when CW/DVGA
RST pin is low. The Maximum DVGA clock frequency is 100MHz which sets the maximum gain change
rate at 10dB/μs. The minimum DVGA CLK pulse duration (either high or low state) is 4ns. To take
advantage of Half Step DVGA clocking, it is recommended to keep DVGA CLK duty cycle close to 50%.
40
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
6.6.3
SNAS476H – MAY 2010 – REVISED MAY 2013
CW/DVGA RST Pin
When CW/DVGA RST is LOW, the step attenuator will increment or decrement attenuation with each
DVGA CLK pulse. In the absence of DVGA CLK, the step attenuator will remain at its current attenuation
until either CW/DVGA RST is pulled HIGH or a DVGA CLK pulse is applied. For example, assume DVGA
UP is held HIGH while CW/DVGA RST is LOW and 74 clock cycles are applied. The attenuation is
reduced by 74 steps or 7.4 dB. If CW/DVGA RST is still held LOW and 10 additional clock pulses are
applied, the attenuation is further reduced by 1dB. If CW/DVGA RST is pulled HIGH, the attenuation will
return to the DVGA Initial Attenuation (as shown in Table 6-4). The first positive CLK edge following a
HIGH to LOW DVGA RST transition is valid and will increment or decrement gain depending on whether
DVGA UP is HIGH or LOW respectively.
6.6.4
DVGA UP Pin:
DVGA UP pin determines the DVGA Initial Attenuation point and whether attenuation is decremented or
incremented (i.e. DVGA gain increment or decrement respectively). If DVGA UP is HIGH, the DVGA gain
will increment upwards, towards the Minimum Attenuation (Maximum Gain) limit of 0dB. If DVGA UP is
LOW, the DVGA gain will decrement downwards, towards the minimum gain limit (38 dB of full attenuation
assuming the “attenuation range setting” is at 38dB). DVGA UP can be dynamically switched during an
increment or decrement operation.
After DVGA UP is switched from LOW to HIGH (or HIGH to LOW), the first positive edge of DVGA CLK
synchronizes the new state with the DVGA CLK. The second positive edge of DVGA CLK will decrement
(or increment) the DVGA Gain.
6.6.5
DVGA Accelerated Gain Adjustment:
With the LM96511’s clock and reset scheme and the ability for a high frequency DVGA clock (max =
100MHz), it is possible to get to the desired TGC starting point quickly. Assuming a DVGA “attenuation
range setting” of 32dB selected, the fastest way to achieve DVGA attenuations of 16-32 dB is to apply a
CW/DVGA RST pulse with DVGA UP HIGH (to get to 32dB attenuation) followed by a succession of
DVGA CLK pulses sufficient to get to the attenuation level desired. For attenuations from 0-15.9 dB, it is
faster to apply a CW/DVGA RST pulse with DVGA UP LOW (to get to 0dB attenuation) and followed by a
succession of fast DVGA CLK pulses. Figure 6-11 and Figure 6-12 illustrate examples of this feature in
order to explain the accelerated gain adjustment sequence more clearly.
In certain instances, an important parameter may be the time required for this operation (i.e.,
“T_attenuation”). Starting from the rising edge of the CW/DVGA RST pulse, the total time is the sum of the
CW/DVGA RST minimum pulse width (“T_RST_width” = 200ns), the minimum time required to start the
DVGA CLK from the CW/DVGA RST’s LOW state (i.e.,“ DVGA RST removal time” which is listed in
Electrical Characteristics as, “T_RST_rem” = 20 ns), and the time required to clock the DVGA to achieve
the desired attenuation (“Attenuation” in dB):
• T_attenuation = T_RST_wdith + T_RST_mem + 10ns/ step x (Attenuation / 0.1dB/ step)
– For 0 ≤ Attenuation ≤ 15.9 dB (DVGA UP = 0 during clocking)
• T_attenuation = T_RST_wdith + T_RST_mem + 10ns/ step x ((32 – Attenuation) / 0.1dB/ step)
– For 16 ≤ Attenuation ≤ 32 dB (DVGA UP = 1 during clocking)
For example, with a 32 dB DVGA attenuation range, to achieve 20 dB DVGA attenuation, the time
required is:
• T_attenuation = T_RST_wdith + T_RST_mem + 10n s/ step x ((32 – Attenuation) / 0.1 B/ step)
• T_attenuation = 200 ns + 20 ns + 10 ns/ step x ((32 – 20) / 0.1 dB/ step) = 1.42 μs
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
41
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
6.7
www.ti.com
THE LM96511 ADC
The LM96511 ADC employs a number of unique strategies to provide a high performance multi-channel
AFE that offers a significant power consumption reduction when compared to competing architectures, as
well as easing system level design. The ultra-low power performance of the LM96511 ADC is derived from
the implementation of a fast continuous time sigma delta (CTΣΔ) modulator. Other features of this
technology are:
• Intrinsic anti-alias filter: The digital decimating filter provides an intrinsic anti-alias filter, eliminating
external analog filter components, and simplifying multi-channel designs.
• Instant overload recovery (IOR) system ensures extremely fast recovery from overload (< one clock
cycle), and no settling errors on return from overload.
• Ultra-low inter-channel crosstalk.
• Digital Equalizer provides low group delay and hence minimizes signal path delay variation.
CMOS IN
ADC CLK+ (SE)
PLL
LVDS
Input
ADC
CLK-
Output
LVDS
SLVS
ADC
BCLK+
Output
LVDS
SLVS
ADC
WCLK+
LC
VCO
ADC
CONTROL
ADC SLEEP
ADC RST
ADC AVDD
Register
1.2V
Register
AGND
1.2V to 1.8V
ADC DVDD
1.2V
ADC
BCLK-
ADC
WCLKADC IO
DVDD
ADC IO
DGND
Input+
(from PA)
Clipping Control
12 bit
3 bit
1.3 kÖ
Serializer
1 bit
CTÐ'
Digital Decimation Filter
Modulator
Input(from PA)
Output
LVDS
SLVS
1.3 kÖ
Register
Register
Register
Register
ADC
DOUT
CHn+
ADC
DOUT
CHn-
Register
ADC LPF BYP
8 times
Reference and Bias
ADC RREF
IRef
SPI Control
To Registers
0.5V
DC
Register
SPI DIO SPI CLK ADC SPI CS
Figure 6-14. LM96511 ADC Block Diagram
The major components of the LM96511 ADC, shown in Figure 6-14, are: clipping control; CTΣΔ
modulator; digital decimation filter; 12-bit serializer; and finally the LVDS/SLVS outputs. The PLL is critical
to the operation of the LM96511 ADC, and the PLL also provides the bit and word clock outputs. The
SPI™ Compatible Control Interface gives uncomplicated user access to the ADC registers.
42
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
6.8
SNAS476H – MAY 2010 – REVISED MAY 2013
ADC OUTPUT INTERFACE
The ADC outputs provide a sampling clock and data information. The output sampling or bit clock is a
differential high speed bit clock that is 6 times the input clock and 90° out of phase with respect to the
output data information. This clock is automatically synchronized to the input ADC clock within the
LM96511. However, this bit clock is not phase aligned with the input ADC clock.
The output data information consists of two components: the serialized ADC output data and the output
word or frame clock. Each serialized data word or frame is 12-bits wide. The word clock output provides
framing information necessary for deserialization of the data by identifying the bit boundary of each data
word sample. The word clock is a lower frequency clock that is phase aligned (within a very small skew,
tDWS) with the data and is primarily used as a strobe to capture and align data words in a parallel register
within the deserializer. The rising edge of the word clock is aligned (within a very small skew) with the LSB
of a data word output from the ADC. The word clock signal is sampled on the positive and negative edges
of the bit clock output. Thus, a rising edge of the word clock indicates that a full data word is available to
load into a deserializer’s parallel register and that a new data word begins. This word clock is not phase
aligned with the input ADC clock.
tBCLK
ADC BCLK+
ADC Bit Clock
ADC BCLKtDWS
tDWS
tWCLK
ADC WCLKADC Word Clock
ADC WCLK+
ADC DOn+
ADC Output data
D10 D11
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10 D11
D0
D1
D2
D3
D4
D5
ADC DOn-
Sample n
Sample n+1
Figure 6-15. ADC WCLK
6.9
12–BIT SIGMA DELTA (ΣΔ) ADC CORE
The LM96511 ADC comprises eight analog ADC channels using a CTΣΔ architecture, which provides very
high dynamic performance with ultra-low power, while operating from a minimal 1.2V supply.
The CTΣΔ ADC architecture uses a third order sigma delta modulator operating at a nominal 16 times
over-sampling rate in combination with a 3-bit quantizer. The modulator output is coupled to a power
efficient digital decimation filter that decimates the high rate modulator output (640 MHz) to provide output
data at a sample rate of 40 MSPS. A benefit of the CTΣΔ design is that the ADC requires no external antialias filters for most applications. This benefit is derived from a combination of the design of the analog
sigma delta modulator and digital decimation filter. The digital filter achieves a steep transition band, and
provides 72 dB of attenuation in the stop band. Using the digital equalizer, the signal transfer
characteristics including phase performance can be optimized so as to minimize group delay variation. In
applications where it is not required, the digital equalizer can be disabled to further save power.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
43
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
6.10 INSTANT OVERLOAD RECOVERY
The LM96511 features an overload handling system which provides instantaneous recovery from signals
driving the ADC inputs beyond the full-scale input range. The ADC can operate in two different modes. In
the default ADC mode (IOR Off mode) a full-scale input range of 4.2 VPP is supported, here the ADC
operates with some inherent overload recovery time, similar to a conventional ADC.
In the IOR On mode, the ADC has a reduced 3.2 VPP full scale input range, but provides a significant
benefit in that the ADC can now be driven by input voltages as high as 5 dB beyond the nominal full-scale
(fIN < 12 MHz), that is 5.7 VPP, and will recover instantaneously. In a number of applications this feature
can help simplify input stage design and manufacturing set-up and calibration. The LM96511 recovers
immediately from overload with no missing codes and no settling time.
The proprietary strategy used within the LM96511 ADC uses high speed patented clamp techniques to
limit the input signal and keep it within the stable input range of the ADC. This process happens at a
speed equivalent to the on-chip over-sampling rate of 640 MHz. The advantage of this system is that it
responds immediately to out of range signals. While the inputs are over-range the ADC outputs a full scale
result. As the over-range input is removed the ADC adjusts to the input signal level and is able to provide
sampled data instantaneously. The LM96511’s behavior on emerging from overload is repeatable and
independent of whether the input signal was positive or negative going at the point of overload.
6.11 USING IOR ON MODE
As discussed earlier, IOR On mode provides instantaneous recovery from overload conditions, with no
ringing and correct data output as soon as the input returns in range.
6.11.1 Standard Use of IOR On Mode
The recommended way to enable IOR On mode is by setting bit 4 (IOR) of the Modulator Overload
Control register (02h). Setting this bit will enable IOR mode with the default settings for Digital Gain Factor
(DGF) in the Decimator Clipping Control register (0Ah) and OL in the Modulator Overload Control register
(02h). Setting the IOR mode bit to 0 will restore DGF and OL to their default values, hence putting the
LM96511 back into IOR Off mode.
As can be seen in Electrical Characteristics, using IOR On mode gives a slight reduction in SNR
performance, and also a reduction of the full scale input range to 3.2VPP differential.
6.11.2 Advanced Use of IOR On Mode
The registers described above allow the user to customize IOR On mode. In order to correctly set the
DGF and OL values, it is necessary to understand how the IOR On mode functions. The implementation
of IOR On mode in the LM96511’s ADC consists of analog and digital parts working in tandem.
The analog clipping circuitry, controlled by OL, is designed to protect the sigma delta modulator from large
signal inputs. Using an analog clamp, signals are soft-limited to the less than the 4.2VPP full scale range of
the modulator. OL gives the value at which the circuit will begin to clamp.
The digital filter of the ADC12EU050 is where the full scale input range is selected and the hard limiting of
the signal takes place. DGF selects the gain of the digital filter, and hence the new full scale input range of
the ADC.
In order to set a custom value for DGF, Custom Gain Setting (CGS), bit 7 of the Decimator Clipping
Control register (0Ah), must be set. The DGF can then be set, based on the application requirements. OL
should then be set to a value approximately half-way between the new full scale input range (which was
just selected by DGF) and the default full scale input range of 4.2VPP. OL must be set to a value higher
than DGF, otherwise the signal will be limited by the analog clipping circuitry, rather than the digital
circuitry, and overload recovery will be impacted.
44
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
6.12 INTEGRATED PRECISION LC PLL ADVANTAGES
The LM96511 ADC includes an integrated high performance “clean up” phase locked loop (PLL),
simplifying the need for a low jitter external clock for ADC CLK pin(s). The PLL serves three important
functions; it generates a highly accurate internal sampling clock source of up to 640 MHz; a clock for the
LVDS serializers at 600 MHz; and it provides a low jitter clock for other internal components. With its jitter
clean-up capability this PLL allows lower performance system clocks to be used.
The ADC CLK pin(s) are AC coupled within the LM96511 so that the common mode voltage is not critical.
The clock can be single ended or differential (unused ADC CLK input can be grounded). A single ended
clock input should be connected to ADC CLK+ (B22) pin, and ADC CLK- (A22) pin should be grounded.
Furthermore, the ADC CLK source can be a sine or square wave for maximum flexibility. Datasheet
parameter testing is done with a “clean”, differential square wave clock source routed as 100Ω differential
pairs, and terminated with a 100Ω resistor close to LM96511 clock inputs.
The benefit of having an on chip PLL is that in most applications a high precision clock source is not
required. The impact of aperture jitter on the ADC’s performance is reduced dramatically by the jitter
clean-up properties of the PLL, which ensures that any RMS jitter outside of the PLL bandwidth is
attenuated. The PLL also significantly relaxes the input clock duty cycle requirements, accepting input
clock duty cycles of 20% to 80%.
The PLL offers two choices of bandwidth, selectable by SPI™ register 03h[1] (SHBW). For the majority of
systems, the default bandwidth of 415 KHz is suitable. If the system already contains a high performance
clock, with excellent RMS jitter performance up to a 1.5 MHz bandwidth, then the PLL’s high bandwidth
mode may be used.
40
20
GAIN (dB)
0
-20
-40
-60
Loop Bandwidth at 0.415 MHz
Loop Bandwidth at 1.50 MHz
-80
1
10
10
2
10
3
10
4
10
5
10
6
10
7
8
10
OFFSET (Hz)
Figure 6-16. PLL Phase Noise Transfer Function: ADC CLK = 40 MHz
On the input clock, excessive RMS jitter within the PLL bandwidth will be seen in the output spectrum as
sidebands, or close in phase noise, around the fundamental signal.
6.13 DIGITAL DECIMATION FILTER AND EQUALIZER
The digital decimation filter is an integral part of the sigma delta architecture. It decimates the oversampled data from the modulator down to the sample rate, and its extremely sharp low pass characteristic
combined with the modulator’s broad band response provides the intrinsic anti-alias filter. The digital low
pass filter exhibits 72 dB of attenuation in the stop band. Figure 6-17 shows the digital filter transfer
function at 40 MSPS, compared to a third order Butterworth transfer function.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
45
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Figure 6-17. Digital Filter Transfer Function
Due to the digital implementation of the filter, the filter parameters automatically scale with the ADC
sampling frequency.
Such steep digital filters introduce group delay problems, but the LM96511 ADC includes a digital
equalizer, which reduces group delay ripple variation to less than 0.05 samples. In applications where
group delay is not of concern, the equalizer can be turned off through the SPI™ interface (register address
0Bh) in order to save power.
6.14 OUTPUT CLOCK SYNCHRONIZATION ACROSS MULTIPLE CHIPS
In systems containing more than one LM96511, it is often required that the timing of output samples is
synchronized across the multiple chips. The PLL in the LM96511 ADC takes care of this automatically by
frequency-locking the output clocks with the input clock for each LM96511 device. However, the user must
still ensure, using correct board layout and clock buffering techniques, that the input clock to each
LM96511 ADC (ADC CLK) is synchronized to each other. If this is the case, then the output bit clocks
from each LM96511 ADC will also be synchronized. This means that output samples are aligned with
each other.
6.15 CAPACITOR SELECTION
The ADC LPF BYP pin provides the capacitance for the low pass filter between the DAC bias block and
the DAC in the sigma-delta modulator. The filter blocks noise from the DAC Bias block from entering the
DAC. Any noise which passes through this filter will be seen in the spectrum as side skirts around the
carrier. The filter circuit, which is a first order RC filter, is shown in Figure 6-18
LM96511 ADC 6' Modulator
RDCAP
DAC
Bias
DAC
1.5 k5
ADC LPF BYP
CDCAP
AGND
Figure 6-18. DAC LPF Capacitor
46
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
The ADC LPF BYP pin must be connected to AGND through a low leakage, minimum 100 nF capacitor. If
the application is especially sensitive to close to the carrier phase noise, then it is recommended to
increase CDCAP, up to a maximum of 10 μF. For other applications where close to the carrier phase noise
is not important, the capacitor can be kept small in order to reduce costs and minimize board space. The
corner frequency of this filter is determined by the equation:
´
¶
=
1
2SRDCAPCDCAP
(2)
6.16 ADC OUTPUT CONSIDERATIONS
The LM96511 offers a variety of output settings in order to cater for different system design and
integration needs
6.16.1 Output Driving Voltage, ADC IO DVDD
The ADC output driver voltage, ADC IO DVDD, can be set between 1.2V and 1.8V. An ADC IO DVDD of
1.2V will offer the lowest power consumption. Because ADC IO DVDD can be varied, the LM96511
provides, via the SPI™ registers, the ability to adjust the output common mode voltage.
6.16.1.1 Output Modes and Output Common Mode
Three different output modes are also supported: SLVS, LVDS and reduced common mode LVDS. SLVS
and LVDS modes output data according to their respective specifications. Reduced common mode LVDS
must be used when the output driver voltage, ADC IO DVDD, is 1.2V. The standard LVDS common mode
voltage is 1.2V, which is obviously not feasible if ADC IO DVDD is 1.2V. Therefore, the output common
mode voltage must be set to 1.0V by setting the bit OCM in the LVDS Control Register to 0.
When ADC IO DVDD is 1.8V, the standard LVDS common mode voltage of 1.25V must be used, by
setting OCM (SPI™ Register 0Ch) equal to 1. Table 6-1 summarizes these different output modes:
Table 6-1. ADC Output Mode Summary
Output Mode
ADC IO DVDD (V)
SPI™ Register 0Ch[1] (OCM)
SPI™ Register 0Ch[0] (SLVS)
Reduced CM LVDS
1.2
0
0
Output Common Mode (V)
1.0
LVDS
1.8
1
0
1.25
SLVS
1.2
X
1
0.175
SLVS mode offers the lowest power consumption followed by reduced common mode LVDS and then the
standard LVDS.
As well as the different output modes, the output drive current can also be controlled via the LVDS Control
Register. The default output drive current is 2.5 mA, but this can be increased to 3.5 mA or 5 mA,
depending on output trace routing and receiver requirements. Power consumption of the LM96511 will
increase slightly as the output driver current is increased.
6.16.1.2 Termination
The final control feature available in the LVDS Control Register is the choice between internal and
external 100Ω termination. Although the termination is recommended to be as close to the receiver as
possible, in some cases it may be necessary or desirable to perform this termination at the transmitter.
Internal 100Ω termination at the transmitter (the LM96511) is enabled by setting the SPI™ register bit
TX_term to 1.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
47
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
6.16.1.3 LVDS Output Training Sequences
Often it is necessary to calibrate the LVDS receiver, for example an FPGA or DSP, so that skew between
the eight ADC output channels is minimized. In order to simplify this process, the LM96511 provides three
LVDS training modes, where a pre-defined or custom pattern is output on all eight channels
simultaneously. While a training mode is active, the word and bit clocks are output as usual. In order to
select a training mode, the TSEL bits of the Decimator Control Register (0Bh) must be programmed via
the SPI™ compatible interface.
There are two pre-defined training patterns, or a custom pattern can be loaded via the SPI™ compatible
interface into the Serializer Custom Pattern 0 and 1 Registers (08h and 09h). In order to return to normal
ADC operation after skew calibration, the TSEL bits should be returned to their default value of 00.
ADC
Outputs
CH0 Decimator Output
Training Sequence 1:
000000111111
CH0 Serializer
DO0+
DO0-
CH7 Serializer
DO7+
DO7-
Training Sequence 2:
101010101010
Training Sequence 3:
Custom Pattern
Serializer Custom
Pattern Registers
10h and 11h
TSEL[0]
TSEL[1]
CH7 Decimator Output
From Decimator
Control Register 16h
Figure 6-19. LVDS Training Sequence
6.17 The Voltage Reference
The LM96511 ADC provides an on chip, ±5% tolerance voltage reference (ADC RREF), together with all
necessary biasing circuits and current sources. A 10kΩ (±1%) resistor (RREF) must be connected
between ADC RREF and AGND in order to establish the biasing current of the ADC.
If a tighter tolerance reference is required for improved thermal stability, an external voltage reference can
be connected between the ADC VREF and AGND pins. This external reference must be able to support a
20kΩ internal load tied to the internal voltage reference (500 mV nominal). The RREF resistor must be
connected even when using an external reference.
When using the internal reference, ADC VREF should be connected to AGND through a 100 nF capacitor.
Chip-to-chip gain matching between several LM96511 ADCs can be improved by connecting the ADC
VREF pins of the ADCs. This is shown in Figure 6-20:
48
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
10 k5
(±1%)
RREF
10 k5
(±1%)
RREF
AGND
ADC VREF
ADC RREF
LM96511
n
AGND
ADC VREF
ADC RREF
LM96511
2
AGND
ADC VREF
ADC RREF
LM96511
1
10 k5
(±1%)
RREF
AGND
plane
Figure 6-20. Reference Sharing
6.18 CW Doppler Section Theory of Operation
As illustrated in Figure 6-21 below, the LM96511 includes a CW Doppler demodulator for analog
beamforming in ultrasound applications. Eight single-ended in-phase (CW I Chx) and quadrature (CW Q
Chx) output pin currents (16 total pins for 8 channels) are summed together using an external summing
amplifier (one each for I and Q outputs) as shown. Each channel’s phase can be controlled in 22.5°
increments using a 4 bit phase code with an SPI™ compatible interface register. With a common RF input
applied to all channels and the same phase code programmed, all 8 channels’ outputs will be nominally in
phase (I to I and Q to Q). If, for example, Channel 5’s phase code is changed from the default value of
0000 to 0101, the Channel 5 output will lead any Channel with phase code 0000 by 112.5° (= 5 x 22.5°).
With N-phase-aligned channels summed together, the SNR increases by √N or 3 dB every time N
doubles, since the CW Doppler signal increases by N but uncorrelated noise increases by √N. Similarly,
the LNAs and demodulators do not share any references or internal functions in order to keep their noise
contributions uncorrelated.
The CW Doppler section requires a differential 16x Local Oscillator (LO) input. The clock source used
must have high fidelity and low phase noise to maintain low Doppler phase noise. The typical LO common
mode (CM) level is 1.2V with a 0.4Vpp differential swing (100Ω differential source). Internally, the LO input
is divided by 16 and fed to doubly-balanced demodulators. The LO duty cycle should be close to 50%. A
Doppler Reset pin is provided (CW/DVGA RST) which resets all the LO dividers to allow synchronization
by placing the divider's individual counters in a known state. This allows several LM96511’s to be used
with additional channels.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
49
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
LNA IN CH 0+
B - mode path
Sleep Mode
LNA
LNA IN CH 0 -
I OUT
Other I Channels
Summing
Amplifier
X
CW I CH 0
CW Q CH 0
X
Q OUT
Other Q Channels
0°
CW CLK +
Summing
Amplifier
90 °
Divide by 16
CW CLK -
Phase Control
(individual phase adjust
for each channel)
)
LM96511
Figure 6-21. Signal Path (CW Doppler) Single Channel
Individual I and individual Q outputs are summed together using a single-supply summing amplifier which
observes the LM96511 Doppler output compliance range (2.1V to 3.6V). Figure 6-22 shows one such
implementation employed on the LM96511 Reference Board (available for purchase from Texas
Instruments):
R3
82
C2
47 nF
R2
200
R1
82
C1
330 nF
++
+2.5V
I1
5V
-U1
½ LMP7732
I-V Converter
Figure 6-22. I-V with Integrated 2–Pole LFP
It is important to be mindful of noise, especially 1/f noise in the power supplies, particularly the “+2.5V”
supply tied to the non-inverting input of the summing Op Amp.
50
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
A low noise Op Amp (LMP7732) is selected for this application to minimize the noise impact. The “I1”
current source represents a single output current from the CW Doppler section of the LM96511. Other
outputs can be paralleled together. The I-V converter output is then AC coupled to a 24-bit ADC (AsahiKasei (AKM) Part # AK5386VT) input for acquisition and processing. The use of a high bit count (or proaudio grade) ADC is essential in keeping the noise floor low to maximize SNR.
The I-V converter of Figure 6-22 is biased for single supply (VCC=5V) operation with its non-inverting input
tied to a low noise +2.5V reference. The Feedback action ensures low CW DOPPLER output compliance.
The 2nd order Butterworth LPF in Figure 6-22 has a passband gain of ~38 dB.Ω (=R3=82 V/Amp).
Figure 6-23 shows the I-V converter’s transfer function:
20
35
Gain
0
30
-20
25
-40
20
15
-60
Phase
-80
10
-100
5
-120
0
-140
-5
-160
-10
1.0e2
1.0e3
1.0e4
TRANSIMPEDANCE PHASE (°)
TRANSIMPEDANCE GAIN (dB. )
40
-180
1.0e5
f (Hz)
Figure 6-23. CW Doppler LPF Gain/Phase Characteristics
With a typical ±4.2 mA from each CW DOPPLER output and 4 channels summed together, the Op Amp
output voltage is ±1.38V (= ±4.2 mA x 4 x 82 ohm) from VCC/2, which can be supported with a single 5V
supply and the op amp’s Rail-to-Rail output. The LMP7732 has approximately 17 mA (± 4.2 mA x 4)
output current capability required when its output is at least 0.4V away from either rail, which is the
present case.
The LPF in Figure 6-22 has a -3dB bandwidth of 10 KHz, suitable for CW Doppler blood flow applications.
The Doppler shift expression below shows the shift in frequency as a function of target speed:
'´
¶D = ±
where
•
•
•
•
2'Q
cos T
O
ΔfD = Change in frequency (CW Doppler output tone frequency) (Hz)
Δν = Speed difference between target and ultra source (m/s)
λ = Wavelength of ultra-sound signal (m/cycle)
θ = Angle between incident wave and the velocity vector of the moving target
(3)
With a typical ultrasound propagation speed of 1540 m/s and 5MHz repetition rate, the wavelength, λ, is
308 μm/cycle. Assuming a 0° incidence angle, blood flowing at around 15 cm/s will produce a frequency
shift of 974 Hz:
2 x 0.15(m/s)
x cos(0)
308(Pm/s)
(4)
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
51
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
6.18.1 CW DOPPLER NOISE ANALYSIS
The combination I-V converter & LPF of Figure 6-22, slightly degrades the LM96511 Doppler output noise.
From the Section 3.4, with 53 pA/√Hz typical RMS noise from each of the four LM96511 outputs summed,
one can expect 8.7 nV/√Hz (= 53 pA/√Hz x 82Ω x √4) of typical RMS noise voltage density at the I-V
converter output, assuming a noiseless I-V converter.
The I-V converter noise contribution is dominated by the LMP7732's voltage noise (= 2.9nV/√Hz) and its
noise gain (≊ (1+R3/R1)= 2V/V passband approximation) resulting in 5.8nV/√Hz typical rms noise at the
output. Resistor (R1-R3) thermal noise accounts for another 3.9nV/√Hz for a total RSS noise of 7nV/√Hz
at the I-V converter output. The impact on the LM96511 related noise is 2.3 dB :
20 x log
(7.0 nV/RtHz)
2
+ (8.7 nV/RtHz )
2
8.7 nV/RtHz
(5)
With a 10 kHz LPF and the LM96511's typical ±3mA current from each output, and assuming a sinusoidal
peak-to-RMS ratio of √2, one can expect a SNR of 119 dB:
20 x log
3 mA x 8 x 82: x 1/ 2
(7 nV) 2 + (8.7 nV) 2 x 10 kHz
(6)
Note that the LMP7732's low 1/f noise corner frequency (= 3Hz) helps in keeping the 1/f noise
inconsequential thus maintaining high SNR.
Figure 6-24 shows an implementation of 64 CW Doppler receive channels for either “I” or “Q” outputs.
Each LM96511 CW Doppler output is represented by a current source symbol. In this implementation,
each primary I-V converter (U1) handles 4 channels while U2 sums the outputs of all I-V converters. R4,
R5, C3, and C4 form a combination high-pass and low-pass filter that strips the DC component and
attenuates the signals beyond ~50 KHz. Analog switch S1 is used to selectively shutdown channels;
Often, a 128 channel ultrasound system operates with 64 receive channels. Switches S2 and S3 are used
to set the overall gain. This is commonly done to optimize dynamic range depending on the target Doppler
echo. The U2 gain is set for FS output (3VPP in this case) with offset frequency signal amplitudes typically
20 dB down from the FS CW Doppler output, or about ±0.42 mA from each LM96511 output.
52
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
R3
82
R2
200
-
R4
1k
U1
½ LMP7732
C1
330 nF
+
C3
0.68 PF
S1
R5
1k
R7
C4
3.9 nF
I-V_Converter
+2.5V
R1
82
C6
5V
C5
S3
LM96511 (4 Outputs)
C2
47 nF
-
R4
1k
U1
½ LMP7732
C1
330 nF
+
C3
0.68 PF
S1
5V
-
R5
1k
U2
½ LMP7732
+
C4
3.9 nF
I-V_Converter
+2.5V
R1
82
C2
47 nF
5V
+2.5V
LM96511 (4 Outputs)
S2
R6
R3
82
R2
200
To ADC
Input
3Vpp Out
Full Scale
Repeated as
needed
(64 Receive
Channels Total)
R3
82
R2
200
LM96511 (4 Outputs)
-
R4
1k
5V
U1
½ LMP7732
C1
330 nF
+
+2.5V
R1
82
C2
47 nF
I-V_Converter
C3
0.68 PF
S1
R5
1k
C4
3.9 nF
Figure 6-24. CW Doppler Output (I or Q) Implementation (64 Receive Channels)
6.18.2 CW DOPPLER 16x LO SOURCE IMPLEMENTATION
In order to achieve the phase noise performance specified in Electrical Characteristics, the CW_Doppler
16x LO source (CW CLK input pins) should have low jitter (low phase noise). The performance
specifications reflected in this datasheet were obtained with highly accurate 80 MHz (for 5MHz
CW_Doppler signal) sources made by Wenzel Associates, Inc. Their oscillators exhibit ~ -165 dBc/ Hz @
10 KHz phase noise. The 16xLO implemented in the LM96511 Reference design, uses a lower cost
oscillator from Vectron International, which exhibits acceptable phase noise performance (-145 dBc/Hz @
10 KHz) in conjunction with Texas Instrument's LMK01000 low phase-noise clock buffer-divider chip. By
dividing down from a higher frequency source, one can achieve 6dB of improvement in phase noise for
every divide-by-two. The block diagram below shows this in more detail:
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
53
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
5V
Vectron
320 MHz
150
LMK01000
240
1 nF
CLKout3
LVPECL
CLKout3*
CLKIn0
C1310A10103-320MHz
150
100
CLKout0
CLKIn0*
CLKout0* LVDS
1 nF
240
100
LEuWire
CW
CLK+
CW
CLK-
DATAuWire
CLKuWire
LMK01000 MICROWIRE
Programming
Pins
ADC CLK+
100
40 MHz
LM96511
ADC CLK-
Figure 6-25. CW Doppler Low-Phase Noise Clock Source Design
In Figure 6-25, a low phase noise 320 MHz source is divided by 4 (MICROWIRE programmable) in an
LMK01000 to provide an 80.0 MHz CW CLK for a 5.0 MHz ultrasound signal. Other LMK01000 outputs
are available for auxiliary functions like the 40 MHz B-mode ADC clock. Keep in mind however that the
low-phase noise of this approach is not required by the B-mode ADC CLK because of its integrated PLL.
The faster edges and lower signal swing of the LMK01000's LVPECL outputs (CLKout3-7) provide better
phase noise performance (lower jitter) than the LVDS outputs (CLKout0-2).
6.19 LM96511 Power Management
Table 6-2. LM96511 Power Consumption for Various Conditions
AMP CW/DVGA &
ADC CW/DVGA
Pins
Operating
Condition
LNA
DVGA
B-Mode
ON
(LNA
PD=LO)
280 mW
ON (DVGA
PD=LO)
230 mW
—
POWER
DOWN
(LNA
PD=HI)
12 mW
POWER
DOWN
(DVGA
PD=HI)
14 mW
CW Doppler Mode
ON (LNA
PD=LO)
280 mW
—
POWER
DOWN
(LNA
PD=HI)
12 mW
0
1
(1)
54
Doppler
Demod.
ADC
Total Power
Consumption
ON
350 mW
884 mW
SLEEP MODE (1)
40 mW
N/A
OFF
24 mW
1.63W
POWER
DOWN
14mW
ON
1.3W
40 mW
N/A
ADC in Sleep Mode using SPI™ compatible register 00h[1]. See Section 6.21.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
The ADC within the LM96511 operates normally at ultra-low power levels. In addition, several power
management modes are provided:
• Power Down (Accessible through PD bit of Top Control Register, 00h[0], or through individual channel
power down, 01h[0-7]. See Section 6.21)
• Sleep (Accessible through SLEEP bit of Top Control Register 00h[1]. See Section 6.21)
Power Down is the lowest power consumption mode, but with a longer wake-up time than Sleep mode. In
power down mode, all circuits in the ADC chip are turned off, including the PLL, reference and bias
circuits.
The LM96511 ADC Power consumption in Sleep mode is higher than in Power Down mode, but pin
access (ADC CW/DVGA pin) and fast wake-up enables duty cycle powering of the ADC.
The LM96511 ADC also allows channel by channel Power Down through the ADC/ LVDS Channel Power
Down register (SPI™ register 01h[0-7]). When a single channel is in Power Down, the ΣΔ modulator,
digital decimating filter and LVDS outputs for that channel will be shut off, with the corresponding single
channel reduction in power consumption.
6.19.1 POWER-UP SEQUENCING
The ADC within the LM96511 should be powered-up prior to the amplifier section. The ADC contains a
power-on reset circuit, connected to ADC AVDD. To ensure correct reset operation, the power supplies
should be provided in the following order (10 ms minimum delay between each supply):
1. ADC IO DVDD (connected to AMP IO DVDD) (1.2V)
2. ADC DVDD (1.2V)
3. ADC AVDD (1.2V)
4. The remaining supplies simultaneously or in any order: AMP AVCC A (3.3V), CW AVCC (5V), AMP
DVDD (3.3V)
Additionally, it is required that the rise time for ADC DVDD and ADC AVDD each is longer than 40 μs.
If the ADC power-up sequence order above (steps 1-3) is not followed, then , prior to amplifier power-up
(step 4), the user should apply a 10ms duration reset via the reset pin (ADC RST), and wait another 10ms
before applying the amplifier power (step 4).
One method of power sequencing is to use the LM3881, or equivalent, Power Sequencer IC. When used
with on-board regulators with shutdown capability (e.g. LP3878), the LM3881 can provide a simple, costeffective way of controlling the sequence of 3 supplies.
Input Supply
(2.7V ± 5.5V)
LM3881
VCC
EN
INV
FLAG1
Flag1 Æ
ADC DVDD Regulator
FLAG2
Flag2 Æ
ADC AVDD Regulator
FLAG3
Flag3 Æ
AMP AVCC, CW AVCC,
& AMP DVDD Regulators
TADJ
CADJ
GND
Figure 6-26. LM3881 Power Sequencer Can be Used for Proper LM96511 Power-Up
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
55
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
LM3881’s “Flag1” output is the first to come-up and “Flag3” is the last. For the LM96511, the ADC IO
DVDD regulator will be the first to come-up and thus need not be controlled by the LM3881. ADC DVDD
will be controlled by the LM3881 “Flag1” output, ADC AVDD by “Flag2” output, and “Flag3” powers-up the
rest of the supplies simultaneously.
To power down, turn off the voltages in the exact reverse order.
Table 6-3. Recommended Operating Conditions
IOR
On (SPI™ Register 02h[4]= 1)
ADC Sampling Rate
40/40.5 MSPS (SPI™ Register 00h[4]=1)
DVGA Initial Attenuation (See Table 6-5)
32dB (DVGA INIT MSB = HI, DVGA INIT LSB = HI)
DVGA PA HI
LO
ADC Data Out
LVDS
Equalizer
Off (SPI™ Register 0Bh[4]=0) (Default)
CGS
Auto Gain (SPI™ Register 0Ah[7]= 0) (Default)
SHBW (PLL Bandwdith)
Low Bandwidth (SPI™ Register 03h[1]= 0) (Default)
DVGA Half-Step Disable
0 (SPI™ Register 1Ah[3]= 0) (Default)
All Other Conditions
Default
6.20 SPI™ Interface
6.20.1 THE SERIAL PERIPHERAL INTERFACE
The LM96511 provides several user controlled functions which are accessed through a standard SPI™
compatible, Serial Interface. Figure 6-27 illustrates a method to convert a “four wire” SPI™ compatible
controller (Data Out, Data In, Clock, and Chip Select) to the “three-wire” (bi-directional Data In / Out)
SPI™ compatible interface required by LM96511. The Serial Interface offers users with a range of supply
voltages from 1.2V to 1.8V. The Level Translator shown allows the SPI™ Controller to Write to or Read
from the LM96511 even if it uses a different supply voltage than LM96511.
TRI-STATE®
or Hi-Z Buffer
output_enable
SPI
Controller
(Master)
e.g. DSP,
Microcontroller,
FPGA
serial_out
Note: ADC SPI CS* and
AMP SPI CS* should
never be enabled (low) at
the same time
serial_in
SPI DIO
clock
SPI CLK
LM96511
ADC SPI CS
chip_select_b
chip_select_a
AMP SPI CS
Figure 6-27. SPI™ Bus Master Slave Connection
6.20.2 ACCESS TO THE SERIAL PERIPHERAL INTERFACE
The SPI™ compatible interface is accessed through the use of four pins: ADC SPI™ CS, AMP SPI™ CS,
SPI™ DIO, and SPI™ CLK. The SPI™ DIO is the data input/ output bidirectional port. The SPI™ DIO
voltage levels are between the SPI™ supply voltage and ground. The SPI™ CLK acts as the SPI™
compatible clock input. Two chip selects are used to access the two functional parts of the device, ADC
SPI™ CS for the ADC segment and AMP SPI™ CS for the amplifier segment. The generic timing diagram
in Figure 6-28 shows the relative timing of the signals used to access the Serial Interface. Figure 4-4 and
Figure 4-5 are included to give timing specifics for write mode and read mode respectively. Values for
these specific parameters can be found in Section 3.8.
56
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
The initial conditions for the SPI™ compatible signals are the beginning of an access sequence as follows:
SPI™ CLK will start low, both AMP SPI™ CS and ADC SPI™ CS will start high, and SPI™ DIO will be
undriven. To start an SPI™ access, either AMP SPI™ CS or ADC SPI™ CS (never both at the same time)
will be brought low. At the same time, SPI™ DIO should be driven to the MSB of the address to be
accessed. The SPI™ CLK will then start and rise in the center of the address bits from MSB to LSB. Each
address is represented with 7 bits, A[7:1], the first 7 bits of the sequence on SPI™ DIO . The eighth bit in
the SPI™ DIO sequence, A[0] denotes a read or write access command, R/W. If the access is a read
access, R/W = 1, then the user must disable the master line driven on the next falling edge of SPI™ CLK.
At this point, the line will be driven by the SPI™ compatible interface of the LM96511 (slave). As the SPI™
CLK continues to toggle, the SPI™ slave will drive out the bits associated with the address input to the
part D[7:0]. After the eight bits have been shifted out, the chip select can be returned high. If the access is
a write access, R/W = 0, the user must drive the 8 bits associated with the address given, D[7:0], on the
next eight SPI™ compatible clock cycles. After these 8 bits are shifted in, the chip select can return to the
high state ending the transaction. If multiple transactions are done on a single SPI™, the associated chip
select must be returned high between successive commands. During a write command, if the chip select
signal is pulled high prior to the appropriate time, the write access will not be completed and the internal
SPI™ compatible interface may not properly clear. At this point, a hard reset may be necessary to
overcome a bad state, and writing may need to recommence. Two reset pins are also available on the
LM96511, AMP RST (active HI) and ADC RST (active LO). These reset pins will asynchronously clear the
AMP SPI™ and ADC SPI™ respectively.
SPI CLK
AMP/ADC SPI CS
SPI DIO
A7
A6
A5
A4
A3
A2
A1
SPI DIO is driven from externally
R/W
D7
D6
D5
D4
D3
D2
D1
D0
If R/W = 1 (read), the SPI drives SPI DIO.
If R/W = 0 (write), SPI DIO is driven externally.
Figure 6-28. SPI™ Compatible Read/Write Timing Diagram
6.20.3 CONNECTING MULTIPLE LM96511 DEVICES TOGETHER
In certain applications, more than one LM96511 may need to be accessed by the same SPI™ compatible
master controller. In this case, separate chip selects will be required for each AMP SPI™ CS pin in the
system. This is due to the fact that each amplifier path will have path specific information which will need
to be relayed to the paths individually. The ADC SPI™ CS can typically be shared as the ADC channels
have very few channel specific programming requirements. An exception may be made in the case of a
user who would choose to power down certain ADC’s in the system (done through ADC SPI™ register), in
which case separate lines would be needed for each . A shared ADC SPI™ CS system is shown in
Figure 6-29. The user must realize that connecting the chip selects of numerous chips in any system will
negate the use of read mode for the affected SPI™ slaves. This is due to bus contention issues as each
slave will attempt to drive its value at that address.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
57
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Tri-state or
Hi-Z Buffer
output_enable
SPI
Master
SDATA_OUT
SDATA
SPI DIO
SDATA_IN
LM96511
SCLK
e.g. DSP,
Microcontroller,
FPGA
SPI CLK
SCLK
chip_select_b_1
ADC Chip Select to multiple ADCs
ADC SPI CS
chip_select_a_1
AMP SPI CS
1-N
chip_select_a_N
SPI DIO
LM96511
SPI CLK
ADC SPI CS
AMP SPI CS
Figure 6-29. SPI™ Compatible Interconnect for Multiple LM96511's (Open Drain Mode)
6.20.4 SERIAL PERIPHERAL INTERFACE READ AND WRITE SPEED
SPI™ CLK controls the speed of interaction with the LM96511. See Section 3.8 for the timing information.
The following table shows the complete set of user accessible SPI™ compatible registers, with
descriptions of the functionality of each bit in the following section.
6.21 SPI™ Register Map
•
•
•
The “Address” column corresponds to A7-A1 (MSB –LSB).
A0, which is the R/W bit, is not considered as part of the address.
“RSV” = Reserved (See notes if applicable.)
Register Index — ADC Section (Enabled with ADC SPI™ CS):
Addr
b[7]
b[6]
b[5]
b[4]
b[3]
b[2]
b[1]
b[0]
Default
CBR
40/40.5
SRES
0
SLEEP
PD
00h
PD5
PD4
PD3
PD2
PD1
PD0
00h
0
0
IOR
0
0
0
0
00h
0
0
0
0
0
SHBW
STCAL
00h
0
INVCLK
100HYS
50HYS
20HYS
10HYSOFF
HYSOFF
00h
ADC Top Control Register (Note 1)
00h
0
0
ADC / LVDS Channel Power Down Register (
01h
PD7
PD6
(1)
)
Modulator Overload Control Register ( (2))
02h
0
PLL Control Register (
03h
(3)
)
0
LVDS Input Clock Hysteresis ( (4))
05h
(1)
(2)
(3)
(4)
58
0
The LNA non-inverting input is always driven single-ended. The inverting input is always AC grounded. See Section 6 for typical
connection diagrams in Figure 6-2.
Min and Max limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlation
using Statistical Quality Control (SQC) methods. Limits are used to calculate Texas Instrument’s Average Outgoing Quality Level
(AOQL).
Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary
over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped
production material.
Sleep mode keeps the PLL, Reference and Bias networks active to allow fast recovery and interleaved imaging modes.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Register Index — ADC Section (Enabled with ADC SPI™ CS):
Addr
b[7]
b[6]
Serializer Custom Pattern 0 Register (
08h
Custom
Pattern[7]
b[5]
b[4]
b[3]
b[2]
b[1]
b[0]
Default
Custom
Pattern[5]
Custom
Pattern[4]
Custom
Pattern[
3]
Custom
Pattern[2]
Custom
Pattern[1]
Custom
Pattern[0]
00h
0
0
Custom
Custom
Pattern[ Pattern[10
11]
]
Custom
Pattern[9]
Custom
Pattern[8]
00h
(5)
)
Custom
Pattern[6]
Serializer Custom Pattern 1 Register ( (5))
09h
0
0
Decimator Clipping Control Register ( (6))
DGFa
0Ah
CGS
Decimator Control Register (
0Bh
0
DGFb
0
a[2]
a[1]
a[0]
b[2]
b[1]
b[0]
00h
0
0
EQON
DFS
MSB
TSEL[1]
TSEL[0]
00h
0
0
TX_term
I_drive[
1]
I_drive[0]
OCM
SLVS
00h
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
(7)
)
LVDS Control Register ( (8))
0Ch
ADC Die ID (Read Only)
0Fh
(5)
(6)
(7)
(8)
Per 1 Hz BW, offset 1 kHz from a 5 MHz, FS input. Output Phase noise, expressed in - dBc/Hz, follows both RF input and CW CLK
phase noise. To meet the demodulated Output specification, integrated phase noise of both the RF Input signal and CW CLK must be
better than -160 dBc/Hz at 1 kHz offset.
Within one channel
Channel-to-Channel
One channel with active input and the worst of the other 7 channels measured.
Register Index— Amplifier Section (Enabled with AMP SPI™ CS):
Doppler Controls ( (1))
11h
0
0
0
0
CH0
PH[3]
CH0
PH[2]
CH0
PH[1]
CH0
PH[0]
00h
12h
0
0
0
0
CH1
PH[3]
CH1
PH[2]
CH1
PH[1]
CH1
PH[0]
00h
13h
0
0
0
0
CH2
PH[3]
CH2
PH[2]
CH2
PH[1]
CH2
PH[0]
00h
14h
0
0
0
0
CH3
PH[3]
CH3
PH[2]
CH3
PH[1]
CH3
PH[0]
00h
15h
0
0
0
0
CH4
PH[3]
CH4
PH[2]
CH4
PH[1]
CH4
PH[0]
00h
16h
0
0
0
0
CH5
PH[3]
CH5
PH[2]
CH5
PH[1]
CH5
PH[0]
00h
17h
0
0
0
0
CH6
PH[3]
CH6
PH[2]
CH6
PH[1]
CH6
PH[0]
00h
18h
0
0
0
0
CH7
PH[3]
CH7
PH[2]
CH7
PH[1]
CH7
PH[0]
00h
CS5
CS4
CS3
CS2
CS1
CS0
00h
0
0
Half
Step
Disable
(0=0.05
db;
1=0.1d
b
R_EN
R1
R0
00h
Individual CW Doppler Channel Phase Update Register ( (2))
19h
CS7
CS6
DVGA Attenuation Control Register ( (3))
1Ah
(1)
(2)
(3)
0
0
“Nominal” attenuation defined as straight line connecting minimum attenuation (0dB) to maximum attenuation (38dB).
This parameter is specified by design and/or characterization and is not tested in production.
Ensured by characterization for all phases.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
59
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Register Index— Amplifier Section (Enabled with AMP SPI™ CS):
LNA Offset Trim ( (4))
1Bh
LNA Ch0
Polarity
LNA Ch0 D6
(MSB)
LNA Ch0 D5
LNA Ch0
D4
LNA
Ch0 D3
LNA Ch0
D2
LNA Ch0 D1
LNA Ch0 D0
(LSB)
Factory
Set
1Ch
LNA Ch1
Polarity
LNA Ch1 D6
(MSB)
LNA Ch1 D5
LNA Ch1
D4
LNA
Ch1 D3
LNA Ch1
D2
LNA Ch1 D1
LNA Ch1 D0
(LSB)
Factory
Set
1Dh
LNA Ch2
Polarity
LNA Ch2 D6
(MSB)
LNA Ch2 D5
LNA Ch2
D4
LNA
Ch2 D3
LNA Ch2
D2
LNA Ch2 D1
LNA Ch2 D0
(LSB)
Factory
Set
1Eh
LNA Ch3
Polarity
LNA Ch3 D6
(MSB)
LNA Ch3 D5
LNA Ch3
D4
LNA
Ch3 D3
LNA Ch3
D2
LNA Ch3 D1
LNA Ch3 D0
(LSB)
Factory
Set
1Fh
LNA Ch4
Polarity
LNA Ch4 D6
(MSB)
LNA Ch4 D5
LNA Ch4
D4
LNA
Ch4 D3
LNA Ch4
D2
LNA Ch4 D1
LNA Ch4 D0
(LSB)
Factory
Set
20h
LNA Ch5
Polarity
LNA Ch5 D6
(MSB)
LNA Ch5 D5
LNA Ch5
D4
LNA
Ch5 D3
LNA Ch5
D2
LNA Ch5 D1
LNA Ch5 D0
(LSB)
Factory
Set
21h
LNA Ch6
Polarity
LNA Ch6 D6
(MSB)
LNA Ch6 D5
LNA Ch6
D4
LNA
Ch6 D3
LNA Ch6
D2
LNA Ch6 D1
LNA Ch6 D0
(LSB)
Factory
Set
22h
LNA Ch7
Polarity
LNA Ch7 D6
(MSB)
LNA Ch7 D5
LNA Ch7
D4
LNA
Ch7 D3
LNA Ch7
D2
LNA Ch7 D1
LNA Ch7 D0
(LSB)
Factory
Set
Post Amp (PA) Offset Trim ( (5))
23h
0
0
0
PA Ch0
Polarity
PA Ch0
D3
(MSB)
PA Ch0
D2
PA Ch0 D1
PA Ch0 D3
(LSB)
Factory
Set
24h
0
0
0
PA Ch1
Polarity
PA Ch1
D3
(MSB)
PA Ch1
D2
PA Ch1 D1
PA Ch1 D3
(LSB)
Factory
Set
25h
0
0
0
PA Ch2
Polarity
PA
Ch20
D3
(MSB)
PA Ch2
D2
PA Ch2 D1
PA Ch2 D3
(LSB)
Factory
Set
26h
0
0
0
PA Ch3
Polarity
PA Ch3
D3
(MSB)
PA Ch3
D2
PA Ch3 D1
PA Ch3 D3
(LSB)
Factory
Set
27h
0
0
0
PA Ch4
Polarity
PA Ch4
D3
(MSB)
PA Ch4
D2
PA Ch4 D1
PA Ch4 D3
(LSB)
Factory
Set
28h
0
0
0
PA Ch5
Polarity
PA Ch5
D3
(MSB)
PA Ch5
D2
PA Ch5 D1
PA Ch5 D3
(LSB)
Factory
Set
29h
0
0
0
PA Ch6
Polarity
PA Ch6
D3
(MSB)
PA Ch6
D2
PA Ch6 D1
PA Ch6 D3
(LSB)
Factory
Set
2Ah
0
0
0
PA Ch70
Polarity
PA Ch7
D3
(MSB)
PA Ch7
D2
PA Ch7 D1
PA Ch7 D3
(LSB)
Factory
Set
Reserved Registers (RSV)
2Bh
RSV
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
2Ch
RSV
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
2Dh
RSV
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
2Eh
RSV
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
2Fh
RSV
RSV
RSV
RSV
RSV
RSV
RSV
RSV
N/A
Id[6]
Id[5]
Id[4]
Id[3]
Id[2]
Id[1]
Id[0]
N/A
Chip ID (Read Only)
30h
(4)
(5)
60
Id[7]
“Removal time” refers to the time CW/DVGA RST must be low prior to the rising edge of DVGA CLK.
“Removal time” refers to the time CW/DVGA RST must be low prior to the rising edge of DVGA CLK.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
6.22 SPI™ Register Map Notes
1. ADC Top Control Register The Top Control Register is the basic initialization and control register for
the LM96511 ADC.
Bit
Description
7:6
Write 0
5
CBR: Control Bus Read. When asserted register 00h (this register) can be
read, but no other registers. When de-asserted all other registers can be read,
but not register 00h.
0: Register 00h cannot be read using SPI™ Read. All other registers can be
read back.
1: Register 00h can be read using SPI™ Read. All other registers cannot be
read back.
4
40/40.5 Selects the ADC sample rate. This bit should be set according to the
applied input clock to obtain optimal performance.
1: 40-40.5 MSPS
3
SRES: Software Reset. When asserted the software reset will reset the
LM96511 ADC device. SRES performs the same function as the hardware
reset (ADC RST pin). The SRES is self clearing in approximately 2 µs.
0: Software Reset Inactive
1: Software Reset Active
2
0
1
SLEEP: Sleep Mode. Powers down the device with the exception of the PLL
and the reference blocks. The time to wake-up from sleep mode is < 10 µs.
0: Sleep Mode Inactive
1:Sleep Mode Active
0
PD: Power Down Mode. Completely powers down the device. The power up
time is approximately 20 ms.
0: PD Mode Inactive, device operates normally
1: PD Mode Active, device powered down
2. ADC/LVDS Channel Power Down Register The ADC/ LVDS Channel Power Down Mode Register
provides the capability to independently put each ADC channel in Power Down mode.
Bit
Description
7
PD7: Channel 7 Power Down
0: Channel Active
1: Channel Power Down
6
PD6: Channel 6 Power Down
0: Channel Active
1: Channel Power Down
5
PD5: Channel 5 Power Down
0: Channel Active
1: Channel Power Down
4
PD4: Channel 4 Power Down
0: Channel Active
1: Channel Power Down
3
PD3: Channel 3 Power Down
0: Channel Active
1: Channel Power Down
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
61
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Bit
Description
2
PD2: Channel 2 Power Down
0: Channel Active
1: Channel Power Down
1
PD1: Channel 1Power Down
0: Channel Active
1: Channel Power Down
0
PD0: Channel 0 Power Down
0: Channel Active
1: Channel Power Down
3. Modulator Overload Control Register
Bit
7:5
4
3:0
Description
Write 0
IOR: Enable IOR On Mode (Instand Overload Recovery)
This bit can be used to quickly enable IOR mode with the default IOR
settings for DGF (see register 0Ah).
0: IOR Mode Disabled
1: IOF Mode Enabled
Write 0
4. PLL Control Register
Bit
7:2
Description
Write 0
4
SHBW: Set PLL to High Bandwidth. The selection of the PLL
bandwidth permits to set the sensitivity of the PLL to input clock jitter.
Less bandwidth decreases the sensitivity to input clock jitter.
The PLL Bandwidth is related to the sampling frequency, the exact
values of which can be found in Section 3.3. The PLL will pass any
input clock jitter up to the PLL bandwidth, while jitter above the PLL
bandwidth will be attenuated. Low bandwidth mode should be used for
high jitter input clocks, while high bandwidth mode can be used for
high-quality, low jitter input clocks.
0: PLL bandwidth is set to Low Bandwidth (400 kHz).
1: PLL bandwidth is set to High Bandwidth (1.4 MHz).
0
STCAL: Start VCO calibration. The calibration can be manually
started in order to assure that the frequency tuning margin is
maximum, for example, in case of large temperature change during
operation it can be useful to restart the calibration.
0: The VCO calibration starts automatically if a Loss of Lock is
detected.
1: The VCO calibration is restarted.
5. LVDS Input Clock - Hysteresis Affects ADC CLK input hysteresis level.
Bit
7:6
5
62
Description
Write 0
INVCLK: Invert Input Reference Clock. This bit is used to invert the
input clock.
0: Reference input clock not inverted.
1: Reference input clock inverted.
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Bit
Description
4
100HYS: Enable 100 mV hysteresis. This bit enables 100 mV
hysteresis. It should be used for a CMOS input clock only.
0: Normal operation (10 mV hysteresis).
1: 100 mV hysteresis (CMOS input clock only)
3
50HYS: Enable 50 mV hysteresis. This bit enables 50 mV hysteresis.
It should be used for a CMOS input clock only.
0: Normal operation (10 mV hysteresis).
1: 50 mV hysteresis (CMOS input clock only)
2
20HYS: Enable 50 mV hysteresis. This bit enables 20 mV hysteresis.
It should be used for a CMOS input clock only.
0: Normal operation (10 mV hysteresis).
1: 20 mV hysteresis (CMOS input clock only)
1
10HYSOFF: Disable 10 mV hysteresis. 10 mV hysteresis is the
default setting. This bit is used to disable 10 mV hysteresis, in the
case where another hysteresis setting is desired, for example when
using a CMOS input clock.
0: 10 mV hysteresis. (LVDS Input clock only).
1: 10 mV hysteresis disabled.
0
HYSOFF: Disable all hysteresis settings This bit is used to disable
all hysteresis settings.
0: Normal operation (10 mV hysteresis).
1: All hysteresis settings disabled.
6. Serializer Custom Pattern 0 and 1 Registers Address: 08h (pattern 0): This register in conjunction
with register 09h provides storage for the custom de-skew pattern. See register 0Bh for a description of
how this training sequence is used.
Bit
7:0
Description
Custom Pattern [7:0]. This pattern forms the lower byte of Custom
Pattern [11:0] which is output by the serializer when the Training
Sequence Select bits (bits 1:0) of the Decimator Control Register are
set to select Training sequence 3.
7. Address: 09h (pattern 1): This register in conjunction with User Register 08h provides storage for the
custom de-skew pattern. See register 0Bh for a description of how this training sequence is used.
Bit
Description
7:4
Write 0
3:0
Custom Pattern [11:8]. This pattern forms the upper 4 bits of Custom
Pattern [11:0] which is output by the serializer when the Training
Sequence Select bits (bits 1:0) of the Decimator Control Register are
set to select Training sequence 3.
8. Decimator Clipping Control Register
Bit
Description
7
CGS: Custom Gain Setting. This bit is used to override the automatic
gain settings for ADC and IOR modes. If the user wishes to write a
custom digital gain coefficient using a[2:0] and b[2:0] of this register,
then the CGS bit must be set.
0: Normal operation Automatic gain settings used
1: Custom Gain Setting Gain setting from a[2:0] and b[2:0] used
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
63
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Bit
Description
6
Write 0
5:3
a[2:0]: Digital Gain Coefficient. In IOR on mode, the input range of an
ADC channel is limited to 3.12 Vpp. In IOR off mode the input range is
4.20 Vpp. The output of the digital filter has to be scaled according to
the selected mode (the filter data has to be mapped in to the 12bit
output data), the difference between 3.12 Vpp and 4.20 Vpp is -2.6 dB,
hence the digital filter gain has to be set to 2.6 dB when in IOR on
mode and to 0dB when in IOR off mode (default mode). This is
performed by setting a Digital Gain Factor (DGF) which is calculated
DGF =
32 + 4 x DGFa + DGFb
26
using the following formula:
The mapping of the coefficient values for a[2:0] is as follows:
011 = Not used. Defaults to 2
010 = 2
001 = 1
000 = 0
111 = −1
110 = −2
101 = Not used. Defaults to −2
100 = Not used. Defaults to −2
The mapping of the coefficient values for b[2:0] is shown below. shows
the available Digital Gain Coefficient settings.
2:0
The mapping of the coefficient values for b[2:0] is as follows:
011 = Not used. Defaults to 2
010 = 2
001 = 1
000 = 0
111 = −1
110 = −2
101 = Not used. Defaults to −2
100 = Not used. Defaults to −2
9. DGF To Digital Gain Look-Up Table
64
Coefficient a[2:0]
Coefficient b[2:0]
Digital Gain (dB)
Equivalent ADC
Full Scale Input
Range (Vpp)
010
010
4.16
2.60
010
001
3.95
2.66
010
000
3.74
2.74
010
111
3.52
2.80
010
110
3.29
2.88
001
001
3.06
2.96
001
000
2.82
3.04
001
111
2.58
3.12
OVERVIEW
IOR ON Mode Default
Setting
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Coefficient a[2:0]
Coefficient b[2:0]
Digital Gain (dB)
Equivalent ADC
Full Scale Input
Range (Vpp)
001
110
2.33
3.22
000
001
2.07
3.3
000
000
1.80
3.42
000
111
1.53
3.52
000
110
1.24
3.64
111
001
0.95
3.96
111
000
0.64
3.90
111
111
0.33
4.04
111
110
0
4.20
110
001
-0.34
4.32
110
000
-0.70
4.56
110
111
-1.07
4.76
110
110
-1.45
4.96
IOR Off Mode Default
Setting
10. Decimator Control Register
Bit
7:5
Description
Write 0
4
EQON: Equalizer Enable. This bit is used to enable or disable the
digital equalizer. The equalizer can be switched on in order to reduce
the group delay of the output data, at the cost of increased power.
0: Equalizer Disabled
1: Equalizer Enabled
3
DFS: Data Format Select. Selects the format, either Offset Binary or
Twos Complement of the output data.
0: 2s Complement
1: Offset Binary
2
MSB: Select the bit order of the LVDS output data stream.
0: LSB first
1: MSB first
1:0
TSEL[1:0]: Training Sequence Select. These bits select the LVDS
output data. The default mode of operation is where the filter output
data is serialized.
In the remaining modes the selected training sequence is repeatedly
output from the serializer this allows the receiving data capture circuitry
to perform the de-skewing process.
One of three known words can be selected, the first two words are
hard-coded in the block, the third one, the custom pattern, is written
into Registers 08h and 09h Serializer Custom Pattern Registers.
Note: The outputs bit-clock and word-clock are not affected by the
value of the Training Sequence Select bits.
00 ADC data[11:0]
01 Training Sequence 1: 000000111111
10 Training Sequence 2: 101010101010
11 Training Sequence 3: Custom Pattern
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
65
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
11. LVDS Control Register
Bit
7:5
4
3:2
Description
Write 0
TX_term: Enable Internal 100Ω termination for data outputs.
0: Internal 100Ω termination disabled.
1: Internal 100Ω termination enabled.
I_drive[1:0]: Controls the current drive of the data outputs.
00: 2.5 mA
01: 3.5 mA
10: Reserved
11: 5mA
1
OCM: Output Common mode. Allows the output common mode to be
shifted depending on the setting of ADC IO DVDD.
If bit 0 of this register, SLVS, is set to 1 then changing OCM will have
no impact on the output common mode. The output common mode in
SLVS mode is fixed, as described in Electrical Characteristics.
For ADC IO DVDD = 1.2V, OCM must be set to 0.
For ADC IO DVDD = 1.8V, OCM must be set to 1.
0: Output Common Mode, VOCM = 1.0V
1: Output Common Mode, VOCM = 1.25V
0
SLVS: Select the format for output data, either LVDS or SLVS. The
differences in timing and electrical specifications between the two
modes can be seen in Electrical Characteristics. If this bit is set to 1
(SLVS mode), OCM has no effect and the output common mode will
be set for SLVS as described in Electrical Characteristics. When LVDS
mode is selected, the output common mode must be selected using
the OCM bit of this register.
0: LVDS Mode
1: SLVS Mode
12. Doppler Controls:
Bit
Description
7:4
Write 0
3:0
Chx[3:0]: CW Doppler Channel “x” (0-7) phase angle in binary format
from 0° (0000) to 360° (1111) in 22.5° increments.
13. Individual CW Doppler Channel Phase Update The SPI™ compatible registers for the Doppler
function (i.e. 11h-18h) are shadow registers that will only be loaded into an active working register on
CW CLK+ rising edge after a CW/DVGA RST (pin K15) pulse (see Figure 4-6). This load action will
also reset all counters in the CW Doppler mixer. Upon initial chip power-up, CW Doppler register load
and mixer counter reset occurs (see Section 6.21 for default values). SPI™ Read operation reads the
value of the Shadow register (not the Active register). However, Shadow and Active register values
should be the same assuming no Write operation after the pervious CW/DVGA RST high state.
66
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Figure 6-30. CW Doppler Shadow Register Representation
In addition to being able to load all CW Doppler channels 0-7 phase angles simultaneously, it is also
possible to load each channel’s phase angle individually using SPI™ address 19h. For example, to
update phase angle for channel 5 and channel 6 only, the following data is written to 19h: 01100000.
This way, Channel 5 and 6 Active register is updated with data in 16h and 17h but Active registers for
the other 6 channels are left intact.
Bit
Description
7
CS7: This bit allows CW Doppler channel 7 phase angle to be updated
to the value in shadow register 18h.
0: Active register for channel 7 left intact
1: Load active register for channel 7 with 18h data when CW/DVGA
RST is pulled HI
6
CS6: This bit allows CW Doppler channel 6 phase angle to be updated
to the value in shadow register 17h.
0: Active register for channel 6 left intact
1: Load active register for channel 6 with 17h data when CW/DVGA
RST is pulled HI
5
CS5: This bit allows CW Doppler channel 5 phase angle to be updated
to the value in shadow register 16h.
0: Active register for channel 5 left intact
1: Load active register for channel 5 with 16h data when CW/DVGA
RST is pulled HI
4
CS4: This bit allows CW Doppler channel 4 phase angle to be updated
to the value in shadow register 15h.
0: Active register for channel 4 left intact
1: Load active register for channel 4 with 15h data when CW/DVGA
RST is pulled HI
3
CS3: This bit allows CW Doppler channel 3 phase angle to be updated
to the value in shadow register 14h.
0: Active register for channel 3 left intact
1: Load active register for channel 3 with 14h data when CW/DVGA
RST is pulled HI
2
CS2: This bit allows CW Doppler channel 2 phase angle to be updated
to the value in shadow register 13h.
0: Active register for channel 2 left intact
1: Load active register for channel 2 with 13h data when CW/DVGA
RST is pulled HI
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
67
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Bit
Description
1
CS1: This bit allows CW Doppler channel 1 phase angle to be updated
to the value in shadow register 12h.
0: Active register for channel 1 left intact
1: Load active register for channel 1 with 12h data when CW/DVGA
RST is pulled HI
0
CS0: This bit allows CW Doppler channel 0 phase angle to be updated
to the value in shadow register 11h.
0: Active register for channel 0 left intact
1: Load active register for channel 0 with 11h data when CW/DVGA
RST is pulled HI
14. DVGA Attentuation Control: When the CW/DVGA RST pin is HIGH, the step attenuator block in the
DVGA can be reset to one of five discrete selectable DVGA Initial Attenuations: 38, 36, 34, 32, or 0 dB.
This DVGA Initial Attenuation can be set by either the SPI™ compatible register or by physically
applying logic level voltages to ball pin A6 (DVGA INIT MSB), B5 (DVGA INIT LSB), and L17 (DVGA
UP). See Table 6-4. SPI™ address 1Ah[2:0] are the register bits used. Normal attenuator gain clocking
can be resumed only after CW/DVGA RST pin is returned to 0.
Table 6-4. DVGA Initial Attenuation Truth Table
DVGA UP
E_EN
R1
R0
DVGA INIT
MSB
DVGA INIT
LSB
Attenuation with
CW/DVGA RST pin
High (dB)
L17 pin
1Ah[2]
1Ah[1]
1Ah[0]
A6 pin
B5 pin
1
1
0
0
X
X
38
1
1
0
1
X
X
36
1
1
1
0
X
X
34
1
1
1
1
X
X
32
1
0
X
X
0
0
38
1
0
X
X
0
1
36
1
0
X
X
1
0
34
1
0
X
X
1
1
32
0
X
X
X
X
X
0
15. The following short-hand notation for the DVGA gain has been used:
Table 6-5. DVGA Notation
DVGA Gain (dB)
DVGA Attenuation (dB)
Short-hand Name
0
0
Max DVGA Gain
-19
19
Mid DVGA Gain
-38
38
Min DVGA Gain
16. LNA and PA Offset Trim Control Register: There are 7 bits dedicated to LNA offset trim, plus the
polarity bit. The maximum positive offset is 1111,1111 and the maximum negative offset is 0111,1111
with X000,0000 for minimum trim. There are 4 bits dedicated to PA offset trim, plus the polarity bit. The
maximum positive offset is 1,1111 and the maximum negative offset is 0,1111 with X,0000 for
minimum trim. The SPI™ compatible trim data operates through the same die fuses that are used for
factory laser trim. The data written into a particular bit is influenced by whether the fuse related to that
bit is blown at the factory or not. Here is what should be written to the SPI™ compatible bits for a
particular “intended data”:
68
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
LM96511
www.ti.com
SNAS476H – MAY 2010 – REVISED MAY 2013
Table 6-6. Offset Trim “Write” Truth Table
Write Data
Intended Data
Factory Blown Fuse
Factory Un-Blown Fuse
0
1
0
1
0
1
To know whether a fuse is blown at the factory or not, the register should be read-back at power up (or
after AMP RST pulse); a “1” indicates a blown fuse. Here is an example, related to LNA offset trim, for
easier understanding:
Table 6-7. Offset Trim “Write” and “Read” Example
SPI™ Read Back at Power-up or after AMP RST
0000 1100
Intended Data
0000 1010
SPI™ Write Data
0000 0110
SPI™ Read Data (after Write)
0000 1010
OVERVIEW
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
69
LM96511
SNAS476H – MAY 2010 – REVISED MAY 2013
www.ti.com
Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision G (May 2013) to Revision H
•
70
Changed layout of National Data Sheet to TI format
Page
..........................................................................
OVERVIEW
69
Copyright © 2010–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM96511
PACKAGE OPTION ADDENDUM
www.ti.com
8-May-2015
PACKAGING INFORMATION
Orderable Device
Status
(1)
LM96511CCSM/NOPB
ACTIVE
Package Type Package Pins Package
Drawing
Qty
NFBGA
NZJ
376
132
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Green (RoHS
& no Sb/Br)
SNPB
Level-4-260C-72 HR
Op Temp (°C)
Device Marking
(4/5)
0 to 70
LM96511
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
8-May-2015
Addendum-Page 2
MECHANICAL DATA
NZJ0376A
SLM376A (Rev A)
www.ti.com
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest
issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of
non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products
Applications
Audio
www.ti.com/audio
Automotive and Transportation
www.ti.com/automotive
Amplifiers
amplifier.ti.com
Communications and Telecom
www.ti.com/communications
Data Converters
dataconverter.ti.com
Computers and Peripherals
www.ti.com/computers
DLP® Products
www.dlp.com
Consumer Electronics
www.ti.com/consumer-apps
DSP
dsp.ti.com
Energy and Lighting
www.ti.com/energy
Clocks and Timers
www.ti.com/clocks
Industrial
www.ti.com/industrial
Interface
interface.ti.com
Medical
www.ti.com/medical
Logic
logic.ti.com
Security
www.ti.com/security
Power Mgmt
power.ti.com
Space, Avionics and Defense
www.ti.com/space-avionics-defense
Microcontrollers
microcontroller.ti.com
Video and Imaging
www.ti.com/video
RFID
www.ti-rfid.com
OMAP Applications Processors
www.ti.com/omap
TI E2E Community
e2e.ti.com
Wireless Connectivity
www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2015, Texas Instruments Incorporated
Similar pages