AD AD9653-125EBZ Quad, 16-bit, 125 msps, serial lvds 1.8 v Datasheet

FUNCTIONAL BLOCK DIAGRAM
AVDD
VIN+A
VIN–A
VIN+B
GENERAL DESCRIPTION
The AD9653 is a quad, 16-bit, 125 MSPS analog-to-digital converter (ADC) with an on-chip sample-and-hold circuit
designed for low cost, low power, small size, and ease of use.
The product operates at a conversion rate of up to 125 MSPS
and is optimized for outstanding dynamic performance and low
power in applications where a small package size is critical.
The ADC requires a single 1.8 V power supply and LVPECL-/
CMOS-/LVDS-compatible sample rate clock for full performance
operation. No external reference or driver components are
required for many applications.
The ADC automatically multiplies the sample rate clock for the
appropriate LVDS serial data rate. A data clock output (DCO) for
capturing data on the output and a frame clock output (FCO)
for signaling a new output byte are provided. Individual-channel
power-down is supported and typically consumes less than 2 mW
when all channels are disabled. The ADC contains several features
designed to maximize flexibility and minimize system cost, such
PIPELINE
ADC
VIN–B
RBIAS
VREF
16
16
DRVDD
SERIAL
LVDS
D0+A
D0–A
D1+A
D1–A
SERIAL
LVDS
D0+B
D0–B
SERIAL
LVDS
SERIAL
LVDS
D1+B
D1–B
FCO+
FCO–
D0+C
D0–C
D1+C
D1–C
SERIAL
LVDS
D0+D
D0–D
SERIAL
LVDS
D1+D
D1–D
DCO+
DCO–
SERIAL
LVDS
DIGITAL
SERIALIZER
DIGITAL
SERIALIZER
SENSE
AD9653
1V
REF
SELECT
SERIAL
LVDS
AGND
PIPELINE
ADC
SCLK/DTP
SERIAL PORT
INTERFACE
16
DIGITAL
SERIALIZER
DIGITAL
SERIALIZER
CLOCK
MANAGEMENT
CLK–
VIN+D
VIN–D
16
CLK+
PIPELINE
ADC
SYNC
VIN+C
VIN–C
VCM
APPLICATIONS
Medical ultrasound and MRI
High speed imaging
Quadrature radio receivers
Diversity radio receivers
Test equipment
PDWN
PIPELINE
ADC
CSB
1.8 V supply operation
Low power: 164 mW per channel at 125 MSPS
SNR = 76.5 dBFS at 70 MHz (2.0 V p-p input span)
SNR = 77.5 dBFS at 70 MHz (2.6 V p-p input span)
SFDR = 90 dBc (to Nyquist, 2.0 V p-p input span)
DNL = ±0.7 LSB; INL = ±3.5 LSB (2.0 V p-p input span)
Serial LVDS (ANSI-644, default) and low power, reduced
range option (similar to IEEE 1596.3)
650 MHz full power analog bandwidth
2 V p-p input voltage range (supports up to 2.6 V p-p)
Serial port control
Full chip and individual channel power-down modes
Flexible bit orientation
Built-in and custom digital test pattern generation
Multichip sync and clock divider
Programmable output clock and data alignment
Standby mode
10538-001
FEATURES
SDIO/OLM
Data Sheet
Quad, 16-Bit, 125 MSPS, Serial LVDS 1.8 V
Analog-to-Digital Converter
AD9653
Figure 1.
as programmable output clock and data alignment and digital
test pattern generation. The available digital test patterns
include built-in deterministic and pseudorandom patterns, along
with custom user-defined test patterns entered via the serial port
interface (SPI).
The AD9653 is available in a RoHS-compliant, 48-lead LFCSP.
It is specified over the industrial temperature range of −40°C to
+85°C. This product is protected by a U.S. patent.
PRODUCT HIGHLIGHTS
1.
2.
3.
4.
5.
Small Footprint.
Four ADCs are contained in a small, space-saving package.
Low power of 164 mW/channel at 125 MSPS with scalable
power options.
Pin compatible to the AD9253 14-bit quad and the AD9633
12-bit quad ADC.
Ease of Use.
A data clock output (DCO) operates at frequencies of up to
500 MHz and supports double data rate (DDR) operation.
User Flexibility.
The SPI control offers a wide range of flexible features to
meet specific system requirements.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2012 Analog Devices, Inc. All rights reserved.
AD9653
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Clock Input Considerations ...................................................... 25
Applications ....................................................................................... 1
Power Dissipation and Power-Down Mode ........................... 27
General Description ......................................................................... 1
Digital Outputs and Timing ..................................................... 27
Functional Block Diagram .............................................................. 1
Output Test Modes ..................................................................... 30
Product Highlights ........................................................................... 1
Serial Port Interface (SPI) .............................................................. 31
Revision History ............................................................................... 2
Configuration Using the SPI ..................................................... 31
Specifications..................................................................................... 3
Hardware Interface ..................................................................... 32
DC Specifications ......................................................................... 3
Configuration Without the SPI ................................................ 32
AC Specifications.......................................................................... 5
SPI Accessible Features .............................................................. 32
Digital Specifications ................................................................... 7
Memory Map .................................................................................. 33
Switching Specifications .............................................................. 8
Reading the Memory Map Register Table............................... 33
Timing Specifications .................................................................. 9
Memory Map Register Table ..................................................... 34
Absolute Maximum Ratings .......................................................... 11
Memory Map Register Descriptions ........................................ 37
Thermal Resistance .................................................................... 11
Applications Information .............................................................. 39
ESD Caution ................................................................................ 11
Design Guidelines ...................................................................... 39
Pin Configuration and Function Descriptions ........................... 12
Power and Ground Recommendations ................................... 39
Typical Performance Characteristics ........................................... 14
Exposed Pad Thermal Heat Slug Recommendations ............ 39
VREF = 1.0 V ................................................................................. 14
VCM ............................................................................................. 39
VREF = 1.3 V ................................................................................. 17
Reference Decoupling ................................................................ 39
Equivalent Circuits ......................................................................... 21
SPI Port ........................................................................................ 39
Theory of Operation ...................................................................... 22
Crosstalk Performance .............................................................. 39
Analog Input Considerations.................................................... 22
Outline Dimensions ....................................................................... 40
Voltage Reference ....................................................................... 23
Ordering Guide .......................................................................... 40
REVISION HISTORY
5/12—Revision 0: Initial Version
Rev. 0 | Page 2 of 40
Data Sheet
AD9653
SPECIFICATIONS
DC SPECIFICATIONS
AVDD = 1.8 V, DRVDD = 1.8 V, 2.0 V p-p full-scale differential input at −1.0 dBFS; VREF = 1.0 V, DCS off, unless otherwise noted.
Table 1.
Parameter 1
RESOLUTION
ACCURACY
No Missing Codes
Offset Error
Offset Matching
Gain Error
Gain Matching
Differential Nonlinearity (DNL)
Temperature
Full
Full
Full
Full
Full
Full
25°C
Full
25°C
Integral Nonlinearity (INL)
TEMPERATURE DRIFT
Offset Error
INTERNAL VOLTAGE REFERENCE
Output Voltage (1.0 V Mode)
Load Regulation at 1.0 mA (VREF = 1.0 V)
Input Resistance
INPUT-REFERRED NOISE
VREF = 1.0 V
ANALOG INPUTS
Differential Input Voltage (VREF = 1.0 V)
Common-Mode Voltage
Common-Mode Range
Differential Input Resistance
Differential Input Capacitance
POWER SUPPLY
AVDD
DRVDD
IAVDD 2
IDRVDD (ANSI-644 Mode)2
IDRVDD (Reduced Range Mode)2
TOTAL POWER CONSUMPTION
DC Input
Sine Wave Input (Four Channels Including Output Drivers, ANSI-644 Mode)
Sine Wave Input (Four Channels Including Output Drivers, Reduced Range Mode)
Power-Down
Standby 3
1
Min
16
−0.49
−0.14
−12.3
1.0
−0.77
Max
Unit
Bits
0.17
0.39
2.37
5.8
0.95
±3.5
% FSR
% FSR
% FSR
% FSR
LSB
LSB
LSB
LSB
3.5
ppm/°C
Guaranteed
−0.3
+0.2
−5
1.1
±0.7
−7.26
Full
Full
Full
25°C
Typ
0.98
8.18
1.0
2
7.5
1.01
25°C
2.7
LSB rms
Full
Full
25°C
25°C
25°C
2
0.9
V p-p
V
V
kΩ
pF
Full
Full
Full
Full
25°C
Full
Full
25°C
25°C
Full
0.5
1.3
2.6
7
1.7
1.7
1.8
1.8
305
60
45
1.9
1.9
330
64
V
V
mA
mA
mA
607
657
630
2
356
649
708
mW
mW
mW
mW
mW
392
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
Measured with a low input frequency, full-scale sine wave on all four channels.
3
Can be controlled via the SPI.
2
Rev. 0 | Page 3 of 40
V
mV
kΩ
AD9653
Data Sheet
AVDD = 1.8 V, DRVDD = 1.8 V, 2.6 V p-p full-scale differential input at −1.0 dBFS; VREF = 1.3 V; 0°C to 85°C, DCS off, unless otherwise noted.
Table 2.
Parameter 1
RESOLUTION
ACCURACY
No Missing Codes
Offset Error
Offset Matching
Gain Error
Gain Matching
Differential Nonlinearity (DNL)
Integral Nonlinearity (INL)
TEMPERATURE DRIFT
Offset Error
INTERNAL VOLTAGE REFERENCE
Output Voltage (1.3 V Programmable Mode)
Load Regulation at 1.0 mA (VREF = 1.3 V)
Input Resistance
INPUT-REFERRED NOISE
VREF = 1.3 V
ANALOG INPUTS
Differential Input Voltage (VREF = 1.3 V)
Common-Mode Voltage
Common-Mode Range
Differential Input Resistance
Differential Input Capacitance
POWER SUPPLY
AVDD
DRVDD
IAVDD 2
IDRVDD (ANSI-644 Mode)2
IDRVDD (Reduced Range Mode)2
TOTAL POWER CONSUMPTION
DC Input
Sine Wave Input (Four Channels Including Output Drivers, ANSI-644 Mode)
Sine Wave Input (Four Channels Including Output Drivers, Reduced Range Mode)
Power-Down
Standby 3
1
2
3
Temperature
Min
16
Typ
Max
25°C
25°C
25°C
25°C
25°C
25°C
25°C
Guaranteed
−0.3
+0.2
−5
1.1
±0.8
±5.0
% FSR
% FSR
% FSR
% FSR
LSB
LSB
25°C
3.5
ppm/°C
25°C
25°C
25°C
1.3
6.5
7.5
V
mV
kΩ
25°C
2.1
LSB rms
25°C
25°C
25°C
25°C
25°C
2.6
0.9
2.6
7
V p-p
V
V
kΩ
pF
25°C
25°C
25°C
25°C
25°C
1.8
1.8
314
60
45
V
V
mA
mA
mA
25°C
25°C
25°C
25°C
25°C
614
673
646
2
371
mW
mW
mW
mW
mW
0.6
1.3
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
Measured with a low input frequency, full-scale sine wave on all four channels.
Can be controlled via the SPI.
Rev. 0 | Page 4 of 40
Unit
Bits
Data Sheet
AD9653
AC SPECIFICATIONS
AVDD = 1.8 V, DRVDD = 1.8 V, 2.0 V p-p full-scale differential input at −1.0 dBFS; VREF = 1.0 V, DCS off, unless otherwise noted.
Table 3.
Parameter 1
SIGNAL-TO-NOISE RATIO (SNR)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
SIGNAL-TO-NOISE-AND-DISTORTION RATIO (SINAD)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
EFFECTIVE NUMBER OF BITS (ENOB)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
WORST HARMONIC (SECOND OR THIRD)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
Temperature
Min
Typ
75.5
78
77.8
76.5
73.9
71.5
dBFS
dBFS
dBFS
dBFS
dBFS
74.6
78
77.7
76.1
73.6
70.3
dBFS
dBFS
dBFS
dBFS
dBFS
12.1
12.7
12.6
12.4
11.9
11.4
Bits
Bits
Bits
Bits
Bits
78
96
93
89
87
77
dBc
dBc
dBc
dBc
dBc
−78
−98
−93
−89
−87
−77
dBc
dBc
dBc
dBc
dBc
−85
−96
−98
−94
−89
−83
dBc
dBc
dBc
dBc
dBc
25°C
25°C
25°C
−90
91
87
dBc
dB
dB
25°C
25°C
25°C
31
79
650
dB
dB
MHz
25°C
25°C
Full
25°C
25°C
25°C
25°C
Full
25°C
25°C
25°C
25°C
Full
25°C
25°C
25°C
25°C
Full
25°C
25°C
25°C
25°C
Full
25°C
25°C
Max
Unit
WORST OTHER HARMONIC OR SPUR
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
TWO-TONE INTERMODULATION DISTORTION (IMD)—AIN1 AND AIN2 = −7.0 dBFS
fIN1 = 70.5 MHz, fIN2 = 72.5 MHz
CROSSTALK 2
CROSSTALK (OVERRANGE CONDITION) 3
POWER SUPPLY REJECTION RATIO (PSRR) 4
AVDD
DRVDD
ANALOG INPUT BANDWIDTH, FULL POWER
1
25°C
25°C
Full
25°C
25°C
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
Crosstalk is measured at 70 MHz with −1.0 dBFS analog input on one channel and no input on the adjacent channel.
Overrange condition is defined as the input being 3 dB above full scale.
4
PSRR is measured by injecting a sinusoidal signal at 10 MHz to the power supply pin and measuring the output spur on the FFT. PSRR is calculated as the ratio of the
amplitudes of the spur voltage over the pin voltage, expressed in decibels.
2
3
Rev. 0 | Page 5 of 40
AD9653
Data Sheet
AVDD = 1.8 V, DRVDD = 1.8 V, 2.6 V p-p full-scale differential input at −1.0 dBFS; VREF = 1.3 V; 0°C to 85°C, DCS off, unless otherwise
noted.
Table 4.
Parameter 1
SIGNAL-TO-NOISE RATIO (SNR)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
SIGNAL-TO-NOISE-AND-DISTORTION RATIO (SINAD)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
EFFECTIVE NUMBER OF BITS (ENOB)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
WORST HARMONIC (SECOND OR THIRD)
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
WORST OTHER HARMONIC OR SPUR
fIN = 9.7 MHz
fIN = 15 MHz
fIN = 70 MHz
fIN = 128 MHz
fIN = 200 MHz
TWO-TONE INTERMODULATION DISTORTION (IMD)—AIN1 AND AIN2 = −7.0 dBFS
fIN1 = 70.5 MHz, fIN2 = 72.5 MHz
CROSSTALK 2
CROSSTALK (OVERRANGE CONDITION) 3
POWER SUPPLY REJECTION RATIO (PSRR) 4
AVDD
DRVDD
ANALOG INPUT BANDWIDTH, FULL POWER
1
Temperature
Min
Typ
Max
Unit
25°C
25°C
25°C
25°C
25°C
80
79.4
77.5
74.4
71.7
dBFS
dBFS
dBFS
dBFS
dBFS
25°C
25°C
25°C
25°C
25°C
79.8
79.2
76.1
74
69.9
dBFS
dBFS
dBFS
dBFS
dBFS
25°C
25°C
25°C
25°C
25°C
13
12.9
12.3
12
11.3
Bits
Bits
Bits
Bits
Bits
25°C
25°C
25°C
25°C
25°C
94
94
82
86
75
dBc
dBc
dBc
dBc
dBc
25°C
25°C
25°C
25°C
25°C
−94
−94
−82
−87
−75
dBc
dBc
dBc
dBc
dBc
25°C
25°C
25°C
25°C
25°C
−100
−99
−96
−86
−84
dBc
dBc
dBc
dBc
dBc
25°C
25°C
25°C
−90
91
87
dBc
dB
dB
25°C
25°C
25°C
31
79
650
dB
dB
MHz
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
Crosstalk is measured at 70 MHz with −1.0 dBFS analog input on one channel and no input on the adjacent channel.
Overrange condition is defined as the input being 3 dB above full scale.
4
PSRR is measured by injecting a sinusoidal signal at 10 MHz to the power supply pin and measuring the output spur on the FFT. PSRR is calculated as the ratio of the
amplitudes of the spur voltage over the pin voltage, expressed in decibels.
2
3
Rev. 0 | Page 6 of 40
Data Sheet
AD9653
DIGITAL SPECIFICATIONS
AVDD = 1.8 V, DRVDD = 1.8 V, unless otherwise noted.
Table 5.
Parameter 1
CLOCK INPUTS (CLK+, CLK−)
Logic Compliance
Differential Input Voltage 2
Input Voltage Range
Input Common-Mode Voltage
Input Resistance (Differential)
Input Capacitance
LOGIC INPUTS (PDWN, SYNC, SCLK)
Logic 1 Voltage
Logic 0 Voltage
Input Resistance
Input Capacitance
LOGIC INPUT (CSB)
Logic 1 Voltage
Logic 0 Voltage
Input Resistance
Input Capacitance
LOGIC INPUT (SDIO)
Logic 1 Voltage
Logic 0 Voltage
Input Resistance
Input Capacitance
LOGIC OUTPUT (SDIO) 3
Logic 1 Voltage (IOH = 800 μA)
Logic 0 Voltage (IOL = 50 μA)
DIGITAL OUTPUTS (D0±x, D1±x), ANSI-644
Logic Compliance
Differential Output Voltage (VOD)
Output Offset Voltage (VOS)
Output Coding (Default)
DIGITAL OUTPUTS (D0±x, D1±x), LOW POWER,
REDUCED SIGNAL OPTION
Logic Compliance
Differential Output Voltage (VOD)
Output Offset Voltage (VOS)
Output Coding (Default)
Temp
Min
Full
Full
Full
25°C
25°C
0.2
AGND − 0.2
Full
Full
25°C
25°C
1.2
0
Full
Full
25°C
25°C
1.2
0
Full
Full
25°C
25°C
1.2
0
Typ
Max
Unit
3.6
AVDD + 0.2
V p-p
V
V
kΩ
pF
AVDD + 0.2
0.8
V
V
kΩ
pF
AVDD + 0.2
0.8
V
V
kΩ
pF
AVDD + 0.2
0.8
V
V
kΩ
pF
CMOS/LVDS/LVPECL
0.9
15
4
30
2
26
2
26
5
Full
Full
1.79
0.05
V
V
Full
Full
290
1.15
LVDS
345
400
1.25
1.35
Twos complement
mV
V
Full
Full
160
1.15
LVDS
200
230
1.25
1.35
Twos complement
mV
V
1
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
This is specified for LVDS and LVPECL only.
3
This is specified for 13 SDIO/OLM pins sharing the same connection.
2
Rev. 0 | Page 7 of 40
AD9653
Data Sheet
SWITCHING SPECIFICATIONS
AVDD = 1.8 V, DRVDD = 1.8 V, unless otherwise noted.
Table 6.
Parameter 1, 2
CLOCK 3
Input Clock Rate
Conversion Rate
Clock Pulse Width High (tEH)
Clock Pulse Width Low (tEL)
OUTPUT PARAMETERS3
Propagation Delay (tPD)
Rise Time (tR) (20% to 80%)
Fall Time (tF) (20% to 80%)
FCO Propagation Delay (tFCO)
DCO Propagation Delay (tCPD) 4
DCO to Data Delay (tDATA)4
DCO to FCO Delay (tFRAME) 4
Lane Delay (tLD)
Data to Data Skew (tDATA-MAX − tDATA-MIN)
Wake-Up Time (Standby)
Wake-Up Time (Power-Down) 5
Pipeline Latency
APERTURE
Aperture Delay (tA)
Aperture Uncertainty (Jitter, tJ)
Out-of-Range Recovery Time
Temp
Min
Full
Full
Full
Full
20
20
Full
Full
Full
Full
Full
Full
Full
Typ
Max
Unit
1000
125
MHz
MSPS
ns
ns
4.00
4.00
Full
25°C
25°C
Full
2.3
300
300
2.3
tFCO + (tSAMPLE/16)
(tSAMPLE/16)
(tSAMPLE/16)
90
±50
250
375
16
25°C
25°C
25°C
1
135
1
1.5
(tSAMPLE/16) − 300
(tSAMPLE/16) − 300
1
3.1
(tSAMPLE/16) + 300
(tSAMPLE/16) + 300
±200
ns
ps
ps
ns
ns
ps
ps
ps
ps
ns
μs
Clock cycles
ns
fs rms
Clock cycles
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.
Measured on standard FR-4 material.
Can be adjusted via the SPI. The conversion rate is the clock rate after the divider.
4
tSAMPLE/16 is based on the number of bits in two LVDS data lanes. tSAMPLE = 1/fS.
5
Wake-up time is defined as the time required to return to normal operation from power-down mode.
2
3
Rev. 0 | Page 8 of 40
Data Sheet
AD9653
TIMING SPECIFICATIONS
Table 7.
Parameter
SYNC TIMING REQUIREMENTS
tSSYNC
tHSYNC
SPI TIMING REQUIREMENTS
tDS
tDH
tCLK
tS
tH
tHIGH
tLOW
tEN_SDIO
tDIS_SDIO
Description
Limit
Unit
SYNC to rising edge of CLK+ setup time
SYNC to rising edge of CLK+ hold time
See Figure 75
Setup time between the data and the rising edge of SCLK
Hold time between the data and the rising edge of SCLK
Period of the SCLK
Setup time between CSB and SCLK
Hold time between CSB and SCLK
SCLK pulse width high
SCLK pulse width low
Time required for the SDIO pin to switch from an input to an output relative to the
SCLK falling edge (not shown in Figure 75)
Time required for the SDIO pin to switch from an output to an input relative to the
SCLK rising edge (not shown in Figure 75)
0.24
0.40
ns typ
ns typ
2
2
40
2
2
10
10
10
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
10
ns min
Timing Diagrams
Refer to the Memory Map Register Descriptions section and Table 23 for SPI register settings.
N–1
VIN±x
N
tA
CLK–
tEH
N+1
tEL
CLK+
DCO–
tCPD
DDR
DCO+
SDR
DCO
FCO–
tFCO
tFRAME
FCO+
D0–A
BITWISE
MODE
D0+A
tPD
tDATA
D14
N – 17
D12
N – 17
D10
N – 17
D08
N – 17
D06
N – 17
D04
N – 17
D02
N – 17
LSB
N – 17
MSB
N – 17
D13
N – 17
D11
N – 17
D09
N – 17
D07
N – 17
D05
N – 17
D03
N – 17
D01
N – 17
D07
N – 17
D06
N – 17
D05
N – 17
D04
N – 17
D03
N – 17
D02
N – 17
D01
N – 17
MSB
N – 17
D14
N – 17
D13
N – 17
D12
N – 17
D11
N – 17
D10
N – 17
D09
N – 17
D12
N – 16
D10
N – 16
D08
N – 16
D06
N – 16
D04
N – 16
D02
N – 16
LSB
N – 16
MSB
N – 16
D13
N – 16
D11
N – 16
D09
N – 16
D07
N – 16
D05
N – 16
D03
N – 16
D01
N – 16
LSB
N – 17
D07
N – 16
D06
N – 16
D05
N – 16
D04
N – 16
D03
N – 16
D02
N – 16
D01
N – 16
LSB
N – 16
D08
N – 17
MSB
N – 16
D14
N – 16
D13
N – 16
D12
N – 16
D11
N – 16
D10
N – 16
D09
N – 16
D08
N – 16
tLD
D1–A
D1+A
D14
N – 16
FCO–
FCO+
D0–A
D0+A
D1–A
D1+A
Figure 2. 16-Bit DDR/SDR, Two-Lane, 1× Frame Mode (Default)
Rev. 0 | Page 9 of 40
10538-002
BYTEWISE
MODE
AD9653
Data Sheet
N–1
VIN±x
N
tA
tEH
CLK–
N+1
tEL
CLK+
tCPD
DCO–
DDR
DCO+
SDR
DCO
tFCO
FCO–
tFRAME
FCO+
tPD
D0–A
BITWISE
MODE
tDATA
D0+A
D14
N – 17
D12
N – 17
D10
N – 17
D08
N – 17
D06
N – 17
D04
N – 17
D02
N – 17
LSB
N – 17
MSB
N – 17
D13
N – 17
D11
N – 17
D09
N – 17
D07
N – 17
D05
N – 17
D03
N – 17
D01
N – 17
D07
N – 17
D06
N – 17
D05
N – 17
D04
N – 17
D03
N – 17
D02
N – 17
D01
N – 17
MSB
N – 17
D14
N – 17
D13
N – 17
D12
N – 17
D11
N – 17
D10
N – 17
D09
N – 17
D14
N – 16
D12
N – 16
D10
N – 16
D08
N – 16
D06
N – 16
D04
N – 16
D02
N – 16
LSB
N – 16
MSB
N – 16
D13
N – 16
D11
N – 16
D09
N – 16
D07
N – 16
D05
N – 16
D03
N – 16
D01
N – 16
LSB
N – 17
D07
N – 16
D06
N – 16
D05
N – 16
D04
N – 16
D03
N – 16
D02
N – 16
D01
N – 16
LSB
N – 16
D08
N – 17
MSB
N – 16
D14
N – 16
D13
N – 16
D12
N – 16
D11
N – 16
D10
N – 16
D09
N – 16
D08
N – 16
tLD
D1–A
D1+A
FCO–
FCO+
D0–A
D0+A
D1–A
D1+A
10538-003
BYTEWISE
MODE
Figure 3. 16-Bit DDR/SDR, Two-Lane, 2× Frame Mode
N–1
VIN±x
tA
N
tEL
tEH
CLK–
CLK+
DCO–
tCPD
DCO+
FCO–
tFCO
tFRAME
FCO+
MSB
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
LSB
MSB
D14
D13
N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 17 N – 16 N – 16 N – 16
Figure 4. Wordwise DDR, One-Lane, 1× Frame, 16-Bit Output Mode
CLK+
tSSYNC
tHSYNC
SYNC
Figure 5. SYNC Input Timing Requirements
Rev. 0 | Page 10 of 40
10538-004
D0+x
tDATA
tPD
10538-005
D0–x
Data Sheet
AD9653
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 8.
Parameter
Electrical
AVDD to AGND
DRVDD to AGND
Digital Outputs
(D0±x, D1±x, DCO+, DCO−, FCO+,
FCO−) to AGND
CLK+, CLK− to AGND
VIN+x, VIN−x to AGND
SCLK/DTP, SDIO/OLM, CSB to AGND
SYNC, PDWN to AGND
RBIAS to AGND
VREF, SENSE to AGND
Environmental
Operating Temperature
Range (Ambient, VREF = 1.0 V)
Operating Temperature
Range (Ambient, VREF = 1.3 V)
Maximum Junction
Temperature
Lead Temperature
(Soldering, 10 sec)
Storage Temperature
Range (Ambient)
Rating
Table 9. Thermal Resistance
−0.3 V to +2.0 V
−0.3 V to +2.0 V
−0.3 V to +2.0 V
Package Type
48-Lead LFCSP
7 mm × 7 mm
(CP-48-13)
−0.3 V to +2.0 V
−0.3 V to +2.0 V
−0.3 V to +2.0 V
−0.3 V to +2.0 V
−0.3 V to +2.0 V
−0.3 V to +2.0 V
1
Air Flow
Velocity
(m/sec)
0.0
1.0
2.5
θJA1
23.7
20.0
18.7
θJB
7.8
N/A
N/A
θJC
7.1
N/A
N/A
Unit
°C/W
°C/W
°C/W
θJA for a 4-layer PCB with solid ground plane (simulated). Exposed pad
soldered to PCB.
ESD CAUTION
−40°C to +85°C
0°C to 85°C
150°C
300°C
−65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Rev. 0 | Page 11 of 40
AD9653
Data Sheet
48
47
46
45
44
43
42
41
40
39
38
37
VIN+C
VIN–C
AVDD
AVDD
SYNC
VCM
VREF
SENSE
RBIAS
AVDD
VIN–B
VIN+B
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
AD9653
TOP VIEW
(Not to Scale)
36
35
34
33
32
31
30
29
28
27
26
25
VIN+A
VIN–A
AVDD
PDWN
CSB
SDIO/OLM
SCLK/DTP
DRVDD
D0+A
D0–A
D1+A
D1–A
NOTES
1. THE EXPOSED THERMAL PAD ON THE BOTTOM OF THE
PACKAGE PROVIDES THE ANALOG GROUND FOR THE PART.
THIS EXPOSED PAD MUST BE CONNECTED TO GROUND FOR
PROPER OPERATION.
10538-006
D1–C
D1+C
D0–C
D0+C
DCO–
DCO+
FCO–
FCO+
D1–B
D1+B
D0–B
D0+B
13
14
15
16
17
18
19
20
21
22
23
24
VIN+D 1
VIN–D 2
AVDD 3
AVDD 4
CLK– 5
CLK+ 6
AVDD 7
DRVDD 8
D1–D 9
D1+D 10
D0–D 11
D0+D 12
Figure 6. 48-Lead LFCSP Pin Configuration, Top View
Table 10. Pin Function Descriptions
Pin No.
0
1
2
3, 4, 7, 34, 39, 45, 46
5, 6
8, 29
9, 10
11, 12
13, 14
15, 16
17, 18
19, 20
21, 22
23, 24
25, 26
27, 28
30
31
32
33
Mnemonic
AGND,
Exposed Pad
VIN+D
VIN−D
AVDD
CLK−, CLK+
DRVDD
D1−D, D1+D
D0−D, D0+D
D1−C, D1+C
D0−C, D0+C
DCO−, DCO+
FCO−, FCO+
D1−B, D1+B
D0−B, D0+B
D1−A, D1+A
D0−A, D0+A
SCLK/DTP
SDIO/OLM
CSB
PDWN
35
36
37
38
40
41
42
43
VIN−A
VIN+A
VIN+B
VIN−B
RBIAS
SENSE
VREF
VCM
Description
Analog Ground, Exposed Pad. The exposed thermal pad on the bottom of the package provides the
analog ground for the part. This exposed pad must be connected to ground for proper operation.
ADC D Analog Input True.
ADC D Analog Input Complement.
1.8 V Analog Supply Pins.
Differential Encode Clock. PECL, LVDS, or 1.8 V CMOS inputs.
Digital Output Driver Supply.
Channel D Digital Outputs.
Channel D Digital Outputs.
Channel C Digital Outputs.
Channel C Digital Outputs.
Data Clock Outputs.
Frame Clock Outputs.
Channel B Digital Outputs.
Channel B Digital Outputs.
Channel A Digital Outputs.
Channel A Digital Outputs.
SPI Clock Input/Digital Test Pattern.
SPI Data Input and Output Bidirectional SPI Data/Output Lane Mode.
SPI Chip Select Bar. Active low enable; 30 kΩ internal pull-up.
Digital Input, 30 kΩ Internal Pull-Down.
PDWN high = power-down device.
PDWN low = run device, normal operation.
ADC A Analog Input Complement.
ADC A Analog Input True.
ADC B Analog Input True.
ADC B Analog Input Complement.
Sets Analog Current Bias. Connect to 10 kΩ (1% tolerance) resistor to ground.
Reference Mode Selection.
Voltage Reference Input and Output.
Analog Input Common-Mode Voltage.
Rev. 0 | Page 12 of 40
Data Sheet
Pin No.
44
47
48
AD9653
Mnemonic
SYNC
VIN−C
VIN+C
Description
Digital Input. SYNC input to clock divider.
ADC C Analog Input Complement.
ADC C Analog Input True.
Rev. 0 | Page 13 of 40
AD9653
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
VREF = 1.0 V
0
0
125MSPS
9.7MHz AT –1dBFS
SNR = 77.1dB (78.1dBFS)
SFDR = 96.8dBc
–15
–30
AMPLITUDE (dBFS)
–45
–60
–75
–90
+
2
–105
4
3
6
5
–45
–60
–75
2
3
–90
5
–105
0
6
12
18
24
30
36
42
48
54
–135
10538-007
–135
60
FREQUENCY (MHz)
0
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
Figure 7. Single-Tone 16k FFT with fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
Figure 10. Single-Tone 16k FFT with fIN = 70 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
0
0
125MSPS
15MHZ AT –1dBFS
SNR = 76.8dB (77.8dBFS)
SFDR = 95.2dBc
–30
–30
–45
–60
–75
–90
2
+
4
3
6
–105
125MSPS
128MHz AT –1dBFS
SNR = 73.2dB (74.2dBFS)
SFDR = 86.6dBc
–15
AMPLITUDE (dBFS)
–15
–45
–60
–75
4
3
–105
5
+
2
–90
5
6
–120
–120
0
6
12
18
24
30
36
42
48
54
–135
10538-008
–135
60
FREQUENCY (MHz)
0
6
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
10538-011
AMPLITUDE (dBFS)
12
6
10538-010
–120
–120
Figure 11. Single-Tone 16k FFT with fIN = 128 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
Figure 8. Single-Tone 16k FFT with fIN = 15 MHZ,
fSAMPLE = 125 MSPS, VREF = 1.0 V
0
0
125MSPS
64MHz AT –1dBFS
SNR = 75.7dB (76.7dBFS)
SFDR = 87.2dBc
–30
–30
–45
–60
–75
3
2
–90
4
+ 5
6
–45
–60
2 +
–90
–105
–120
–120
6
12
18
24
30
36
FREQUENCY (MHz)
42
48
54
60
Figure 9. Single-Tone 16k FFT with fIN = 64 MHz, fSAMPLE = 125 MSPS,
VREF = 1.0 V
5
6
4
48
54
–135
10538-009
–135
3
–75
–105
0
125MSPS
200.5MHz AT –1dBFS
SNR = 70.7dB (71.7dBFS)
SFDR = 76.6dBc
–15
AMPLITUDE (dBFS)
–15
AMPLITUDE (dBFS)
+
6
4
0
6
12
18
24
30
36
FREQUENCY (MHz)
42
60
10538-012
AMPLITUDE (dBFS)
–30
125MSPS
70MHz AT –1dBFS
SNR = 75.6dB (76.6dBFS)
SFDR = 85.5dBc
–15
Figure 12. Single-Tone 16k FFT with fIN = 200.5 MHz at fSAMPLE = 125 MSPS,
VREF = 1.0 V
Rev. 0 | Page 14 of 40
Data Sheet
AD9653
120
120
SFDRFS
100
SFDR (dBc)
SNRFS
80
SNR/SFDR (dBFS/dBc)
SNR/SFDR (dBFS/dBc)
100
60
SFDR
40
20
80
SNR (dBFS)
60
40
SNR
–90
–80
–70
–60
–50
–40
–30
–20
–10
0
INPUT AMPLITUDE (dBFS)
0
10538-013
–20
–100
0
20
40
60
80
100
120
140
160
180
200
INPUT FREQUENCY (MHz)
Figure 13. SNR/SFDR vs. Input Amplitude (AIN), fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
10538-016
20
0
Figure 16. SNR/SFDR vs. fIN, fSAMPLE = 125 MSPS, Clock Divider = 8, VREF = 1.0 V
0
100
–15
95
SNR/SFDR(dBFS/dBc)
AMPLITUDE (dBFS)
–30
–45
–60
–75
2F1 + F2
2F2 + F1
–90
F2 – F1
2F1 – F2
F2 – F1
F1 + F2
SFDR (dBc)
90
85
80
+
–105
SNR (dBFS)
75
0
6
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
70
–40
10538-014
–135
–20
0
20
40
60
80
TEMPERATURE (C)
Figure 14. Two-Tone 16k FFT with fIN1 = 70.5 MHz and fIN2 = 72.5 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
10538-017
–120
Figure 17. SNR/SFDR vs. Temperature, fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.0 V
0
4.5
–20
1.5
SFDR (dBc)
INL (LSB)
SFDR/IMD3(dBc/dBFS)
3.0
–40
IMD3 (dBc)
–60
0
–1.5
–80
SFDR (dBFS)
–3.0
–100
–4.5
OUTPUT CODE
Figure 15. Two-Tone SFDR/IMD3 vs. Input Amplitude (AIN) with
fIN1 = 70.5 MHz and fIN2 = 72.5 MHz, fSAMPLE = 125 MSPS, VREF = 1.0 V
Figure 18. INL, fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.0 V
Rev. 0 | Page 15 of 40
10538-018
60000
54000
48000
42000
36000
30000
24000
–10
18000
–30
12000
–50
INPUT AMPLITUDE (dBFS)
6000
–70
0
–120
–90
10538-015
IMD3 (dBFS)
AD9653
Data Sheet
100
0.8
SFDR (dBc)
0.6
SNR/SFDR (dBFS/dBc)
80
0.4
DNL (LSB)
0.2
0
–0.2
–0.4
–0.6
SNR (dBFS)
60
40
20
60000
20
40
10538-019
54000
48000
42000
36000
30000
24000
18000
12000
6000
0
0
OUTPUT CODE
60
80
100
120
SAMPLE RATE (MSPS)
Figure 19. DNL, fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.0 V
10538-022
–0.8
Figure 22. SNR/SFDR vs. Sample Rate, fIN = 9.7 MHz, VREF = 1.0 V
160000
100
2.7 LSB RMS
SFDR (dBc)
140000
80
SNR/SFDR (dBFS/dBc)
NUMBER OF HITS
120000
100000
80000
60000
SNR (dBFS)
60
40
40000
20
0
20
CODE
Figure 20. Input-Referred Noise Histogram, fSAMPLE = 125 MSPS, VREF = 1.0 V
90
DRVDD
80
60
50
40
AVDD
30
20
10
10
70
FREQUENCY (MHz)
10538-021
PSRR (dB)
70
1
60
80
100
120
Figure 23. SNR/SFDR vs. Sample Rate, fIN = 64 MHz, Clock Divider = 4, VREF =
1.0 V
100
0
40
SAMPLE RATE (MSPS)
10538-020
N – 12
N – 11
N – 10
N–9
N–8
N–7
N–6
N–5
N–4
N–3
N–2
N–1
N
N+1
N+2
N+3
N+4
N+5
N+6
N+7
N+8
N+9
N + 10
N + 11
N + 12
N + 13
0
10538-023
20000
Figure 21. PSRR vs. Frequency, fSAMPLE = 125 MSPS, VREF = 1.0 V
Rev. 0 | Page 16 of 40
Data Sheet
AD9653
VREF = 1.3 V
0
0
125MSPS
9.7MHz AT –1dBFS
SNR = 79.1dB (80.1dBFS)
SFDR = 93.5dBc
–30
–45
–60
–75
–90
3
2
+
–45
–60
–75
+
6
5
4
–105
6
4
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
–135
10538-024
6
0
6
0
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
Figure 24. Single-Tone 16k FFT with fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
10538-027
–120
–135
Figure 27. Single-Tone 16k FFT with fIN = 70 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
0
0
125MSPS
15MHz AT –1dBFS
SNR = 78.3dB (79.3dBFS)
SFDR = 94.5dBc
–30
–30
–45
–60
–75
–90
3
+
2
–105
6
125MSPS
128MHz AT –1dBFS
SNR = 73.5dB (74.5dBFS)
SFDR = 86.7dBc
–15
AMPLITUDE (dBFS)
–15
4
5
–45
–60
–75
+
2
–90
3
4
–105
5 6
–120
–120
0
6
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
–135
10538-025
–135
0
6
12
18
24
30
36
42
48
54
60
FREQUENCY (MHz)
10538-028
AMPLITUDE (dBFS)
5
–105
–120
Figure 28. Single-Tone 16k FFT with fIN = 128 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
Figure 25. Single-Tone 16k FFT with fIN = 15 MHZ,
fSAMPLE = 125 MSPS, VREF = 1.3 V
0
0
125MSPS
64MHz AT –1dBFS
SNR = 76.9dB (77.9dBFS)
SFDR = 82.6dBc
–30
–30
–45
–60
–75
3
2
–90
4 6
+ 5
–45
–60
–75
–120
–135
18
24
30
36
42
48
54
FREQUENCY (MHz)
60
10538-026
–120
12
2 +
6
5
–105
6
3
–90
–105
0
125MSPS
200.5MHz AT –1dBFS
SNR = 71.1dB (72.1dBFS)
SFDR = 73.7dBc
–15
AMPLITUDE (dBFS)
–15
AMPLITUDE (dBFS)
3
2
–90
4
–135
0
6
12
18
24
30
36
42
48
54
FREQUENCY (MHz)
Figure 29. Single-Tone 16k FFT with fIN = 200.5 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
Figure 26. Single-Tone 16k FFT with fIN = 64 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
Rev. 0 | Page 17 of 40
60
10538-029
AMPLITUDE (dBFS)
–30
125MSPS
70MHz AT –1dBFS
SNR = 76.7dB (77.7dBFS)
SFDR = 82.1dBc
–15
AMPLITUDE (dBFS)
–15
AD9653
Data Sheet
0
0
80MSPS
15MHz AT –1dBFS
SNR = 79.0dB (80.0dBFS)
SFDR = 90.5dBc
–30
–45
–60
–75
3
–90
–105
5
+
4
6
2
–60
–75
2F1 + F2
2F2 + F1
–90
F2 – F1
F1 + F2
2F2 – F1
+ 2F1 – F2
–105
–120
–120
0
4
12
8
16
20
24
28
32
36
40
FREQUENCY (MHz)
–135
10538-030
–135
Figure 30. Single-Tone 16k FFT with fIN = 15 MHz,
fSAMPLE = 80 MSPS, VREF = 1.3 V
0
6
18
12
24
30
36
42
48
54
60
FREQUENCY (MHz)
Figure 33. Two-Tone 16k FFT with fIN1 = 70.5 MHz and fIN2 = 72.5 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
0
0
80MSPS
15MHz AT –1dBFS
SNR = 76.7dB (77.7dBFS)
SFDR = 82.1dBc
–30
–20
SFDR/IMD3 (dBc/dBFS)
–15
AMPLITUDE (dBFS)
–45
10538-033
AMPLITUDE (dBFS)
–30
–15
AMPLITUDE (dBFS)
–15
–45
–60
–75
3
–90
+
5
–105
6
2
–40
SFDR (dBc)
IMD3 (dBc)
–60
–80
SFDR (dBFS)
4
–100
–120
4
8
12
16
20
24
28
32
36
40
FREQUENCY (MHz)
10538-031
0
–120
–90
–70
–50
–30
–10
INPUT AMPLITUDE (dBFS)
Figure 31. Single-Tone 16k FFT with fIN = 64.5 MHz,
fSAMPLE = 80 MSPS, VREF = 1.3 V
10538-034
IMD3 (dBFS)
–135
Figure 34. Two-Tone SFDR/IMD3 vs. Input Amplitude (AIN) with
fIN1 = 70.5 MHz and fIN2 = 72.5 MHz, fSAMPLE = 125 MSPS, VREF = 1.3 V
100
120
SFDRFS
SFDR (dBc)
90
100
80
SNR/SFDR (dBFS/dBc)
60
SFDR
40
20
SNR
70
SNR (dBFS)
60
50
40
30
20
0
–20
–100
–90
–80
–70
–60
–50
–40
–30
–20
–10
0
INPUT AMPLITUDE (dBFS)
Figure 32. SNR/SFDR vs. Input Amplitude (AIN), fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
0
0
20
40
60
80
100
120
140
INPUT FREQUENCY (MHz)
160
180
200
10538-035
10
10538-032
SNR/SFDR (dBFS/dBc)
SNRFS
80
Figure 35. SNR/SFDR vs. fIN, fSAMPLE = 125 MSPS, Clock Divider = 8, VREF = 1.3 V
Rev. 0 | Page 18 of 40
Data Sheet
AD9653
200000
94
2.1 LSB RMS
180000
160000
SFDR (dBc)
90
NUMBER OF HITS
SNR/SFDR (dBFS/dBc)
92
88
86
84
140000
120000
100000
80000
60000
82
40000
SNR (dBFS)
80
20000
N+9
10538-039
N + 10
N+8
N+7
N+6
N+5
N+4
N+3
N+2
N
N+1
N–1
N–2
N–3
N–4
TEMPERATURE (°C)
0
N–5
80
N–6
60
N–7
40
N–8
20
N–9
0
10538-036
78
CODE
Figure 39. Input-Referred Noise Histogram, fSAMPLE = 125 MSPS, VREF = 1.3 V
Figure 36. SNR/SFDR vs. Temperature, fIN = 9.7 MHz,
fSAMPLE = 125 MSPS, VREF = 1.3 V
100
90
4.5
DRVDD
80
3.0
70
PSRR (dB)
INL (LSB)
1.5
0
–1.5
60
50
40
AVDD
30
–3.0
20
–4.5
OUTPUT CODE
1
10
FREQUENCY (MHz)
Figure 37. INL, fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.3 V
70
10538-040
0
10538-037
60000
54000
48000
42000
36000
30000
24000
18000
12000
6000
0
10
Figure 40. PSRR vs. Frequency, fSAMPLE = 125 MSPS, VREF = 1.3 V
100
0.8
SFDR (dBc)
0.6
SNR/SFDR (dBFS/dBc)
80
0.2
0
–0.2
–0.4
–0.6
SNR (dBFS)
60
40
20
OUTPUT CODE
20
40
60
80
100
120
SAMPLE RATE (MSPS)
Figure 41. SNR/SFDR vs. Sample Rate, fIN = 9.7 MHz, VREF = 1.3 V
Figure 38. DNL, fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.3 V
Rev. 0 | Page 19 of 40
10538-041
0
10538-038
60000
54000
48000
42000
36000
30000
24000
18000
12000
6000
–0.8
0
DNL (LSB)
0.4
AD9653
Data Sheet
100
SFDR (dBc)
SNR/SFDR (dBFS/dBc)
80
SNR (dBFS)
60
40
0
20
40
60
80
SAMPLE RATE (MSPS)
100
120
10538-042
20
Figure 42. SNR/SFDR vs. Sample Rate, fIN = 64 MHz, Clock Divider = 4, VREF = 1.3 V
Rev. 0 | Page 20 of 40
Data Sheet
AD9653
EQUIVALENT CIRCUITS
AVDD
AVDD
350Ω
SCLK/DTP, SYNC,
AND PDWN
30kΩ
10538-047
10538-043
VIN±x
Figure 43. Equivalent Analog Input Circuit
Figure 47. Equivalent SCLK/DTP, SYNC, and PDWN Input Circuit
AVDD
10Ω
CLK+
AVDD
15kΩ
0.9V
AVDD
15kΩ
10538-048
10538-044
CLK–
375Ω
RBIAS
AND VCM
10Ω
Figure 44. Equivalent Clock Input Circuit
Figure 48. Equivalent RBIAS and VCM Circuit
AVDD
AVDD
400Ω
SDIO/OLM
30kΩ
31kΩ
10538-049
10538-045
CSB
350Ω
Figure 45. Equivalent SDIO/OLM Input Circuit
Figure 49. Equivalent CS Input Circuit
DRVDD
AVDD
V
D0–x, D1–x
V
V
D0+x, D1+x
V
375Ω
VREF
10538-050
10538-046
7.5kΩ
Figure 46. Equivalent Digital Output Circuit
Figure 50. Equivalent VREF Circuit
Rev. 0 | Page 21 of 40
AD9653
Data Sheet
THEORY OF OPERATION
The AD9653 is a multistage, pipelined ADC. Each stage
provides sufficient overlap to correct for flash errors in the
preceding stage. The quantized outputs from each stage are
combined into a final 16-bit result in the digital correction
logic. The serializer transmits this converted data in a 16-bit
output. The pipelined architecture permits the first stage to
operate with a new input sample while the remaining stages
operate with preceding samples. Sampling occurs on the rising
edge of the clock.
Each stage of the pipeline, excluding the last, consists of a low
resolution flash ADC connected to a switched-capacitor DAC
and an interstage residue amplifier (for example, a multiplying
digital-to-analog converter (MDAC)). The residue amplifier
magnifies the difference between the reconstructed DAC output
and the flash input for the next stage in the pipeline. One bit of
redundancy is used in each stage to facilitate digital correction
of flash errors. The last stage simply consists of a flash ADC.
The output staging block aligns the data, corrects errors, and
passes the data to the output buffers. The data is then serialized
and aligned to the frame and data clocks.
ANALOG INPUT CONSIDERATIONS
The analog input to the AD9653 is a differential switchedcapacitor circuit designed for processing differential input
signals. This circuit can support a wide common-mode range
while maintaining excellent performance. By using an input
common-mode voltage of midsupply, users can minimize
signal-dependent errors and achieve optimum performance.
the output stage of the driving source. In addition, low Q inductors
or ferrite beads can be placed on each leg of the input to reduce
high differential capacitance at the analog inputs and therefore
achieve the maximum bandwidth of the ADC. Such use of low
Q inductors or ferrite beads is required when driving the converter
front end at high IF frequencies. Either a differential capacitor or
two single-ended capacitors can be placed on the inputs to
provide a matching passive network. This ultimately creates a
low-pass filter at the input to limit unwanted broadband noise.
See the AN-742 Application Note, the AN-827 Application Note,
and the Analog Dialogue article “Transformer-Coupled FrontEnd for Wideband A/D Converters” (Volume 39, April 2005) for
more information. In general, the precise values depend on the
application.
Input Common Mode
The analog inputs of the AD9653 are not internally dc-biased.
Therefore, in ac-coupled applications, the user must provide
this bias externally. Setting the device so that VCM = AVDD/2 is
recommended for optimum performance, but the device can
function over a wider range with reasonable performance, as
shown in Figure 52 and Figure 53.
An on-chip, common-mode voltage reference is included in the
design and is available from the VCM pin. The VCM pin must
be bypassed to ground by a 0.1 µF capacitor, as described in the
Applications Information section.
Maximum SNR performance is achieved by setting the ADC to
the largest span in a differential configuration. In the case of the
AD9653, the input span is dependent on the reference voltage
(see Table 11).
110
H
SFDR (dBc)
100
CPAR
H
90
S
S
S
S
SNR/SFDR (dBFS/dBc)
CSAMPLE
CSAMPLE
VIN–x
H
10538-051
H
CPAR
SNRFS (dBFS)
80
70
60
50
40
Figure 51. Switched-Capacitor Input Circuit
30
The clock signal alternately switches the input circuit between
sample mode and hold mode (see Figure 51). When the input
circuit is switched to sample mode, the signal source must be
capable of charging the sample capacitors and settling within
one-half of a clock cycle. A small resistor in series with each
input can help reduce the peak transient current injected from
Rev. 0 | Page 22 of 40
20
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
COMMON-MODE VOLTAGE (V)
Figure 52. SNR/SFDR vs. Common-Mode Voltage,
fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.0 V
1.3
10538-052
VIN+x
Data Sheet
AD9653
Internal Reference Connection
110
A comparator within the AD9653 detects the potential at the
SENSE pin and configures the reference into one of three
possible modes, which are summarized in Table 11. If SENSE is
grounded, the reference amplifier switch is connected to the
internal resistor divider (see Figure 54), setting the voltage at the
VREF pin, VREF, to 1.0 V. If SENSE is connected to an external
resistor divider (see Figure 55), VREF is defined as
SFDR (dBc)
100
SNR/SFDR (dBFS/dBc)
90
SNRFS (dBFS)
80
70
60
50
R2 
VREF = 0.5 × 1 +

R1 

40
30
where:
0.7
0.8
0.9
1.0
1.1
1.2
COMMON-MODE VOLTAGE (V)
1.3
10538-053
20
0.6
7 kΩ ≤ (R1 + R2) ≤ 10 kΩ
Figure 53. SNR/SFDR vs. Common-Mode Voltage,
fIN = 9.7 MHz, fSAMPLE = 125 MSPS, VREF = 1.3 V
VIN+A
VIN–A
Differential Input Configurations
ADC
CORE
There are several ways to drive the AD9653 either actively or
passively. However, optimum performance is achieved by driving
the analog inputs differentially. Using a differential double balun
configuration to drive the AD9653 provides excellent performance
and a flexible interface to the ADC (see Figure 56) for baseband
applications.
VREF
1.0µF
0.1µF
SELECT
LOGIC
SENSE
For applications where SNR is a key parameter, differential transformer coupling is the recommended input configuration (see
Figure 57), because the noise performance of most amplifiers is
not adequate to achieve the true performance of the AD9653.
10538-054
0.5V
AD9653
Figure 54. 1.0 V Internal Reference Configuration
Regardless of the configuration, the value of the shunt capacitor,
C, is dependent on the input frequency and may need to be
reduced or removed.
VIN+A
VIN–A
It is not recommended to drive the AD9653 inputs single-ended.
ADC
CORE
VOLTAGE REFERENCE
A stable and accurate voltage reference is built into the AD9653.
VREF can be configured using either the internal 1.0 V reference, an externally applied 1.0 V to 1.3 V reference voltage, or
using an external resistor divider applied to the internal reference to produce a reference voltage of the user’s choice. The
various reference modes are summarized in the Internal Reference
Connection section and the External Reference Operation
section. The VREF pin should be externally bypassed to ground
with a low ESR, 1.0 μF capacitor in parallel with a low ESR,
0.1 μF ceramic capacitor.
VREF
1.0µF
+
0.1µF
SELECT
LOGIC
R2
SENSE
R1
AD9653
10538-055
0.5V
Figure 55. Programmable Internal Reference Configuration
Table 11. Reference Configuration Summary
Selected Mode
Fixed Internal Reference
Programmable Internal Reference
Fixed External Reference
1
SENSE Voltage (V)
AGND to 0.2
Tie to external R-divider
(see Figure 55)
AVDD
Resulting VREF (V)
1.0 internal
0.5 × (1 + R2/R1), example: R1 = 3.5 kΩ,
R2 = 5.6 kΩ for VREF = 1.3 V 1
1.0 to 1.3 applied to external VREF pin1
Normal operation for VREF = 1.3 V is supported over the 0°C to 85°C temperature range.
Rev. 0 | Page 23 of 40
Resulting Differential Span
(V p-p)
2.0
2 × VREF
2.0 to 2.6
AD9653
Data Sheet
0.1µF
0.1µF
R
C
33Ω
33Ω
2V p-p
*C1
C
VIN+x
ADC
5pF
33Ω
0.1µF
R
VCM
VIN–x
ET1-1-I3
33Ω
C
*C1
200Ω
0.1µF
C
0.1µF
*C1 IS OPTIONAL
10538-056
R
Figure 56. Differential Double Balun Input Configuration for Baseband Applications
ADT1-1WT
1:1 Z RATIO
R
*C1
VIN+x
33Ω
2V p-p
49.9Ω
C
ADC
5pF
R
33Ω
VIN–x
VCM
*C1
0.1µF
0.1μF
*C1 IS OPTIONAL
10538-057
200Ω
Figure 57. Differential Transformer-Coupled Configuration
for Baseband Applications
0
–0.5
–1.0
–1
–2
INTERNAL VREF = 1.3V
INTERNAL VREF = 1.0V
–3
–4
–5
–6
–7
–2.0
–8
–2.5
–9
0
–3.0
0.5
1.0
1.5
2.0
2.5
LOAD CURRENT (mA)
3.0
10538-059
–1.5
Figure 59. VREF =1.3 V Error vs. Load Current
–3.5
–4.0
External Reference Operation
–4.5
The use of an external reference may be necessary to enhance
the gain accuracy of the ADC or improve thermal drift characteristics. Figure 60 and Figure 61 show the typical drift characteristics of the internal reference in 1.0 V mode and programmable
1.3 V mode, respectively.
–5.0
0
0.5
1.0
1.5
2.0
2.5
LOAD CURRENT (mA)
Figure 58. VREF = 1.0 V Error vs. Load Current
3.0
10538-058
VREF ERROR (%)
0
VREF ERROR (%)
If the internal reference of the AD9653 is used to drive multiple
converters to improve gain matching, the loading of the reference
by the other converters must be considered. Figure 58 and
Figure 59 show how the internal reference voltage is affected by
loading.
Rev. 0 | Page 24 of 40
Data Sheet
AD9653
The RF balun configuration is recommended for clock frequencies
between 125 MHz and 1 GHz, and the RF transformer is recommended for clock frequencies from 20 MHz to 200 MHz. The
back-to-back Schottky diodes across the transformer/balun
secondary winding limit clock excursions into the AD9653 to
approximately 0.8 V p-p differential.
4
0
–2
–4
–8
–40
–15
10
35
10538-060
–6
85
60
TEMPERATURE (°C)
This limit helps prevent the large voltage swings of the clock
from feeding through to other portions of the AD9653 while
preserving the fast rise and fall times of the signal that are critical
to achieving low jitter performance. However, the diode capacitance comes into play at frequencies above 500 MHz. Care must be
taken in choosing the appropriate signal limiting diode.
Mini-Circuits®
ADT1-1WT, 1:1 Z
Figure 60. Typical VREF = 1.0 V Drift
0.1µF
CLOCK
INPUT
10
XFMR
0.1µF
CLK+
100Ω
50Ω
CLK–
0
10538-062
SCHOTTKY
DIODES:
HSMS2822
0.1µF
Figure 62. Transformer-Coupled Differential Clock (Up to 200 MHz)
–5
0.1µF
CLOCK
INPUT
–10
0.1µF
CLK+
50Ω
ADC
0.1µF
0.1µF
–20
0
20
40
60
80
TEMPERATURE (°C)
SCHOTTKY
DIODES:
HSMS2822
10538-061
–15
–40
CLK–
10538-063
VREF ERROR (mV)
ADC
0.1µF
5
Figure 63. Balun-Coupled Differential Clock (Up to 1 GHz)
Figure 61. Typical VREF = 1.3 V Drift
When the SENSE pin is tied to AVDD, the internal reference is
disabled, allowing the use of an external reference. An internal
reference buffer loads the external reference with an equivalent
7.5 kΩ load (see Figure 50). The internal buffer generates the
positive and negative full-scale references for the ADC core.
It is not recommended to leave the SENSE pin floating.
CLOCK INPUT CONSIDERATIONS
For optimum performance, clock the AD9653 sample clock
inputs, CLK+ and CLK−, with a differential signal. The signal
is typically ac-coupled into the CLK+ and CLK− pins via a
transformer or capacitors. These pins are biased internally
(see Figure 44) and require no external bias.
Clock Input Options
The AD9653 has a flexible clock input structure. The clock input
can be a CMOS, LVDS, LVPECL, or sine wave signal. Regardless of the type of signal being used, clock source jitter is of the
most concern, as described in the Jitter Considerations section.
Figure 62 and Figure 63 show two preferred methods for clocking the AD9653 (at clock rates up to 1 GHz prior to internal clock
divider). A low jitter clock source is converted from a singleended signal to a differential signal using either an RF transformer
or an RF balun.
If a low jitter clock source is not available, another option is to
ac couple a differential PECL signal to the sample clock input
pins, as shown in Figure 64. The AD9510/AD9511/AD9512/
AD9513/AD9514/AD9515/AD9516/AD9517 clock drivers offer
excellent jitter performance.
A third option is to ac couple a differential LVDS signal to the
sample clock input pins, as shown in Figure 65. The AD9510/
AD9511/AD9512/AD9513/AD9514/AD9515/AD9516/AD9517
clock drivers offer excellent jitter performance.
In some applications, it may be acceptable to drive the sample
clock inputs with a single-ended 1.8 V CMOS signal. In such
applications, drive the CLK+ pin directly from a CMOS gate, and
bypass the CLK− pin to ground with a 0.1 μF capacitor (see
Figure 66).
0.1µF
0.1µF
CLOCK
INPUT
CLK+
0.1µF
CLOCK
INPUT
Rev. 0 | Page 25 of 40
AD951x
PECL DRIVER
100Ω
ADC
0.1µF
CLK–
50kΩ
50kΩ
240Ω
240Ω
Figure 64. Differential PECL Sample Clock (Up to 1 GHz)
10538-064
VREF ERROR (mV)
2
AD9653
Data Sheet
84
0.1µF
0.1µF
CLOCK
INPUT
AD951x
LVDS DRIVER
100Ω
ADC
80
0.1µF
50kΩ
10538-065
CLK–
50kΩ
Figure 65. Differential LVDS Sample Clock (Up to 1 GHz)
SNR (dBFS)
0.1µF
CLOCK
INPUT
82
CLK+
SNRFS (DCS ON)
78
SNRFS (DCS OFF)
76
74
VCC
50Ω1
1kΩ
AD951x
CMOS DRIVER
OPTIONAL
0.1µF
100Ω
1kΩ
72
CLK+
ADC
70
40
45
CLK–
150Ω RESISTOR IS OPTIONAL.
55
60
Figure 67. SNR vs. DCS On/Off, VREF = 1.0 V
10538-066
0.1µF
50
DUTY CYCLE (%)
10538-076
0.1µF
CLOCK
INPUT
84
Figure 66. Single-Ended 1.8 V CMOS Input Clock (Up to 200 MHz)
82
Input Clock Divider
SNRFS (DCS ON)
The AD9653 clock divider can be synchronized using the
external SYNC input. Bit 0 and Bit 1 of Register 0x109 allow the
clock divider to be resynchronized on every SYNC signal or
only on the first SYNC signal after the register is written. A
valid SYNC causes the clock divider to reset to its initial state.
This synchronization feature allows multiple parts to have their
clock dividers aligned to guarantee simultaneous input sampling.
SNRFS (DCS OFF)
78
76
74
72
70
40
45
Clock Duty Cycle
50
55
DUTY CYCLE (%)
Typical high speed ADCs use both clock edges to generate a variety of internal timing signals and, as a result, may be sensitive to
clock duty cycle. Commonly, a ±5% tolerance is required on the
clock duty cycle to maintain dynamic performance characteristics.
The AD9653 contains a duty cycle stabilizer (DCS) that retimes
the nonsampling (falling) edge, providing an internal clock
signal with a nominal 50% duty cycle. This feature minimizes
performance degradation in cases where the clock input duty
cycle deviates from 50% greater than the specified ±5%. Noise and
distortion performance are nearly flat for a wider range of duty
cycles with the DCS on, as shown in Figure 67 and Figure 68.
60
10538-077
The AD9653 contains an input clock divider with the ability
to divide the input clock by integer values between 1 and 8.
SNR (dBFS)
80
Figure 68. SNR vs. DCS On/Off, VREF = 1.3 V
Jitter in the rising edge of the input is still of concern and is not
easily reduced by the internal stabilization circuit. The duty
cycle control loop does not function for clock rates less than
20 MHz, nominally. The loop has a time constant associated
with it that must be considered in applications in which the
clock rate can change dynamically. A wait time of 1.5 µs to 5 µs
is required after a dynamic clock frequency increase or decrease
before the DCS loop is relocked to the input signal.
Jitter Considerations
High speed, high resolution ADCs are sensitive to the quality of the
clock input. The degradation in SNR at a given input frequency
(fA) due only to aperture jitter (tJ) can be calculated by

1
 2π × f A × t J
SNR Degradation = 20 log10 




In this equation, the rms aperture jitter represents the root mean
square of all jitter sources, including the clock input, analog input
signal, and ADC aperture jitter specifications. IF undersampling
applications are particularly sensitive to jitter (see Figure 69).
The clock input should be treated as an analog signal in cases
where aperture jitter may affect the dynamic range of the AD9653.
Power supplies for clock drivers should be separated from the
Rev. 0 | Page 26 of 40
Data Sheet
AD9653
ADC output driver supplies to avoid modulating the clock signal
with digital noise. Low jitter, crystal-controlled oscillators make
the best clock sources. If the clock is generated from another
type of source (by gating, dividing, or other methods), it should
be retimed by the original clock at the last step.
Refer to the AN-501 Application Note and the AN-756
Application Note for more in-depth information about jitter
performance as it relates to ADCs.
130
RMS CLOCK JITTER REQUIREMENT
120
110
Low power dissipation in power-down mode is achieved by
shutting down the reference, reference buffer, biasing networks,
and clock. Internal capacitors are discharged when entering
power-down mode and then must be recharged when returning
to normal operation. As a result, wake-up time is related to the
time spent in power-down mode, and shorter power-down
cycles result in proportionally shorter wake-up times. When
using the SPI port interface, the user can place the ADC in
power-down mode or standby mode. Standby mode allows the
user to keep the internal reference circuitry powered when
faster wake-up times are required. See the Memory Map section
for more details on using these features.
16 BITS
DIGITAL OUTPUTS AND TIMING
90
14 BITS
The AD9653 differential outputs conform to the ANSI-644 LVDS
standard on default power-up. This can be changed to a low power,
reduced signal option (similar to the IEEE 1596.3 standard) via the
SPI. The LVDS driver current is derived on chip and sets the
output current at each output equal to a nominal 3.5 mA. A 100 Ω
differential termination resistor placed at the LVDS receiver
inputs results in a nominal 350 mV swing (or 700 mV p-p
differential) at the receiver.
SNR (dB)
100
80
12 BITS
70
10 BITS
60
0.125ps
0.25ps
0.5ps
1.0ps
2.0ps
8 BITS
50
40
1
10
100
ANALOG INPUT FREQUENCY (MHz)
10538-067
30
1000
Figure 69. Ideal SNR vs. Input Frequency and Jitter
POWER DISSIPATION AND POWER-DOWN MODE
As shown in Figure 70, the power dissipated by the AD9653 is
proportional to its sample rate. The digital power dissipation
does not vary significantly because it is determined primarily by
the DRVDD supply and bias current of the LVDS output drivers.
0.60
ANALOG CORE POWER (W)
0.55
0.50
0.45
VREF = 1.3V
VREF = 1.0V
0.40
When operating in reduced range mode, the output current is
reduced to 2 mA. This results in a 200 mV swing (or 400 mV p-p
differential) across a 100 Ω termination at the receiver.
The AD9653 LVDS outputs facilitate interfacing with LVDS
receivers in custom ASICs and FPGAs for superior switching
performance in noisy environments. Single point-to-point net
topologies are recommended with a 100 Ω termination resistor
placed as close to the receiver as possible. If there is no far-end
receiver termination or there is poor differential trace routing,
timing errors may result. To avoid such timing errors, it is
recommended that the trace length be less than 24 inches and
that the differential output traces be close together and at equal
lengths. An example of the FCO and data stream with proper
trace length and position is shown in Figure 71. Figure 72 shows
the LVDS output timing example in reduced range mode.
0.35
0.30
0.20
20
40
60
80
SAMPLE RATE (MSPS)
100
120
10538-068
0.25
The AD9653 is placed in power-down mode either by the SPI
port or by asserting the PDWN pin high. In this state, the ADC
typically dissipates 2 mW. During power-down, the output
drivers are placed in a high impedance state. Asserting the
PDWN pin low returns the AD9653 to its normal operating
mode. Note that PDWN is referenced to the digital output
driver supply (DRVDD) and should not exceed that supply
voltage.
D0 500mV/DIV
D1 500mV/DIV
DCO 500mV/DIV
FCO 500mV/DIV
4ns/DIV
10538-069
Figure 70. Analog Core Power vs. fSAMPLE for fIN = 9.7 MHz, Four Channels
Figure 71. LVDS Output Timing Example in ANSI-644 Mode (Default)
Rev. 0 | Page 27 of 40
AD9653
Data Sheet
500
EYE: ALL BITS
ULS: 8000/414024
EYE DIAGRAM VOLTAGE (mV)
400
300
200
100
0
–100
–200
–300
–400
–500
–0.8ns
10538-070
4ns/DIV
D0 400mV/DIV
D1 400mV/DIV
DCO 400mV/DIV
FCO 400mV/DIV
–0.4ns
0ns
0.4ns
–0.8ns
12k
Figure 72. LVDS Output Timing Example in Reduced Range Mode
500
EYE: ALL BITS
ULS: 7000/400354
300
200
6k
4k
2k
100
0
0k
–800ps –600ps –400ps –200ps
–100
0ps
200ps
400ps
600ps
Figure 74. Data Eye for LVDS Outputs in ANSI-644 Mode with Trace Lengths
Greater than 24 Inches on Standard FR-4 Material, External 100 Ω Far-End
Termination Only
–200
–300
–400
Figure 74 shows an example of trace lengths exceeding 24 inches
on standard FR-4 material. Notice that the TIE jitter histogram
reflects the decrease of the data eye opening as the edge deviates
from the ideal position.
It is the user’s responsibility to determine if the waveforms
meet the timing budget of the design when the trace lengths
exceed 24 inches. Additional SPI options allow the user to further
increase the internal termination (increasing the current) of all
four outputs to drive longer trace lengths. This can be achieved
by programming Register 0x15. Even though this produces
sharper rise and fall times on the data edges and is less prone to
bit errors, the power dissipation of the DRVDD supply increases
when this option is used.
–500
–0.8ns
–0.4ns
0ns
0.4ns
0.8ns
7k
6k
TIE JITTER HISTOGRAM (Hits)
8k
10538-072
EYE DIAGRAM VOLTAGE (mV)
400
10k
TIE JITTER HISTOGRAM (Hits)
An example of the LVDS output using the ANSI-644 standard
(default) data eye and a time interval error (TIE) jitter histogram with trace lengths less than 24 inches on standard FR-4
material is shown in Figure 73.
5k
4k
3k
2k
0
200ps
250ps
300ps
350ps
400ps
450ps
500ps
10538-071
1k
Figure 73. Data Eye for LVDS Outputs in ANSI-644 Mode with Trace Lengths
Less than 24 Inches on Standard FR-4 Material, External 100 Ω Far-End
Termination Only
The format of the output data is twos complement by default.
An example of the output coding format can be found in Table 12.
To change the output data format to offset binary, see the
Memory Map section.
Data from each ADC is serialized and provided on a separate
channel in two lanes in DDR mode. The data rate for each serial
stream is equal to 16 bits times the sample clock rate, with a
maximum of 500 Mbps/lane [(16 bits × 125 MSPS)/(2 × 2) =
500 Mbps/lane]. The lowest typical conversion rate is 20 MSPS.
See the Memory Map section for details on enabling this feature.
Rev. 0 | Page 28 of 40
Data Sheet
AD9653
Two output clocks are provided to assist in capturing data from
the AD9653. The DCO is used to clock the output data and is
equal to four times the sample clock (CLK) rate for the default
mode of operation. Data is clocked out of the AD9653 and must
be captured on the rising and falling edges of the DCO that
supports double data rate (DDR) capturing. The FCO is used to
signal the start of a new output byte and is equal to the sample
clock rate in 1× frame mode. See the Timing Diagrams section
for more information.
When the SPI is used, the DCO phase can be adjusted in 60°
increments relative to the data edge. This enables the user to
refine system timing margins if required. The default DCO+
and DCO− timing, as shown in Figure 2, is 90° relative to the
output data edge.
In default mode, as shown in Figure 2, the MSB is first in the
data output serial stream. This can be inverted so that the LSB
is first in the data output serial stream by using the SPI.
There are 12 digital output test pattern options available that
can be initiated through the SPI. This is a useful feature when
validating receiver capture and timing. Refer to Table 13 for the
output bit sequencing options available. Some test patterns have
two serial sequential words and can be alternated in various
ways, depending on the test pattern chosen. Note that some
patterns do not adhere to the data format select option. In
addition, custom user-defined test patterns can be assigned in
the 0x19, 0x1A, 0x1B, and 0x1C register addresses.
Table 12. Digital Output Coding
Input (V)
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
Condition (V)
<−VREF − 0.5 LSB
−VREF
0V
+VREF − 1.0 LSB
>+VREF − 0.5 LSB
Offset Binary Output Mode
0000 0000 0000 0000
0000 0000 0000 0000
1000 0000 0000 0000
1111 1111 1111 1111
1111 1111 1111 1111
Twos Complement Mode
1000 0000 0000 0000
1000 0000 0000 0000
0000 0000 0000 0000
0111 1111 1111 1111
0111 1111 1111 1111
Table 13. Flexible Output Test Modes
Output Test
Mode Bit
Sequence
0000
0001
Pattern Name
Off (default)
Midscale short
Digital Output Word 1
N/A
1000 0000 0000 0000 (16-bit)
Digital Output Word 2
N/A
N/A
Subject to
Data Format
Select
N/A
Yes
0010
+Full-scale short
0000 0000 0000 0000 (16-bit)
N/A
Yes
0011
−Full-scale short
0000 0000 0000 0000 (16-bit)
N/A
Yes
0100
0101
Checkerboard
PN sequence long
1010 1010 1010 1010 (16-bit)
N/A
0101 0101 0101 0100 (16-bit)
N/A
No
Yes
0110
PN sequence short
N/A
N/A
Yes
0111
111 1111 1111 1100 (16-bit)
0000 0000 0000 0000 (16-bit)
No
1000
1001
1010
1011
One-/zero-word
toggle
User input
1-/0-bit toggle
1× sync
One bit high
Register 0x19 to Register 0x1A
1010 1010 1010 1000 (16-bit)
0000 0001 1111 1100 (16-bit)
1000 0000 0000 0000 (16-bit)
Register 0x1B to Register 0x1C
N/A
N/A
N/A
No
No
No
No
1100
Mixed frequency
1010 0001 1001 1100 (16-bit)
N/A
No
Rev. 0 | Page 29 of 40
Notes
Offset binary
code shown
Offset binary
code shown
Offset binary
code shown
PN23
ITU 0.150
X23 + X18 + 1
PN9
ITU 0.150
X9 + X5 + 1
Pattern
associated with
the external pin
AD9653
Data Sheet
The PN sequence short pattern produces a pseudorandom bit
sequence that repeats itself every 29 − 1 or 511 bits. A description of the PN sequence and how it is generated can be found in
Section 5.1 of the ITU-T 0.150 (05/96) standard. The seed value
is all 1s (see Table 14 for the initial values). The output is a
parallel representation of the serial PN9 sequence in MSB-first
format. The first output word is the first 14 bits of the PN9
sequence in MSB aligned form.
The PN sequence long pattern produces a pseudorandom bit
sequence that repeats itself every 223 − 1 or 8,388,607 bits. A
description of the PN sequence and how it is generated can be
found in Section 5.6 of the ITU-T 0.150 (05/96) standard. The
seed value is all 1s (see Table 14 for the initial values) and the
AD9653 inverts the bit stream with relation to the ITU standard.
The output is a parallel representation of the serial PN23 sequence
in MSB-first format. The first output word is the first 14 bits of the
PN23 sequence in MSB aligned form
Table 14. PN Sequence
Sequence
PN Sequence Short
PN Sequence Long
Initial
Value
0x1FE0
0x1FFF
First Three Output Samples
(MSB First) Twos Complement
0x1DF1, 0x3CC8, 0x294E
0x1FE0, 0x2001, 0x1C00
Consult the Memory Map section for information on how to
change these additional digital output timing features through
the SPI.
SDIO/OLM Pin
For applications that do not require SPI mode operation, the
CSB pin is tied to AVDD, and the SDIO/OLM pin controls the
output lane mode according to Table 15.
Note that, when the CSB pin is tied to AVDD, the AD9653 DCS
is on by default and remains on unless the part is placed in SPI
mode and controlled via the SPI. Refer to the Clock Duty Cycle
section for more information on the DCS.
For applications where the SDIO/OLM pin is not used, CSB
should be tied to AVDD. When using the one-lane mode, the
conversion rate should be ≤62.5 MSPS to meet the maximum
output rate of 1 Gbps.
Table 15. Output Lane Mode Pin Settings
OLM Pin
Voltage
AVDD (Default)
GND
Output Mode
Two-lane. 1× frame, 16-bit serial output
One-lane. 1× frame, 16-bit serial output
SCLK/DTP Pin
The SCLK/DTP pin is used to select the digital test pattern
(DTP) for applications that do not require SPI mode operation.
This pin can enable a single digital test pattern if it and the CSB
pin are held high during device power-up. When SCLK/DTP is
tied to AVDD, the ADC channel outputs shift out the following
pattern: 1000 0000 0000 0000. The FCO and DCO function
normally while all channels shift out the repeatable test pattern.
This pattern allows the user to perform timing alignment
adjustments among the FCO, DCO, and output data. This pin has
an internal 10 kΩ resistor to GND. It can be left unconnected.
Table 16. Digital Test Pattern Pin Settings
Selected DTP
Normal Operation
DTP
DTP Voltage
10 kΩ to AGND
AVDD
Resulting
D0±x and D1±x
Normal operation
1000 0000 0000 0000
Additional and custom test patterns can also be observed when
commanded from the SPI port. Consult the Memory Map
section for information about the options available.
CSB Pin
The CSB pin should be tied to AVDD for applications that do
not require SPI mode operation. By tying CSB high, all SCLK
and SDIO information is ignored.
Note that, when the CSB pin is tied to AVDD, the AD9653 DCS
is on by default and remains on unless the part is placed in SPI
mode and controlled via the SPI. Refer to the Clock Duty Cycle
section for more information on the DCS.
RBIAS Pin
To set the internal core bias current of the ADC, place a
10.0 kΩ, 1% tolerance resistor to ground at the RBIAS pin.
OUTPUT TEST MODES
The output test options are described in Table 13 and controlled by
the output test mode bits at Address 0x0D. When an output test
mode is enabled, the analog section of the ADC is disconnected
from the digital back-end blocks and the test pattern is run
through the output formatting block. Some of the test patterns
are subject to output formatting, and some are not. The PN
generators from the PN sequence tests can be reset by setting
Bit 4 or Bit 5 of Register 0x0D. These tests can be performed
with or without an analog signal (if present, the analog signal is
ignored), but they do require an encode clock. For more
information, see the AN-877 Application Note, Interfacing to
High Speed ADCs via SPI.
Rev. 0 | Page 30 of 40
Data Sheet
AD9653
SERIAL PORT INTERFACE (SPI)
The AD9653 serial port interface (SPI) allows the user to configure
the converter for specific functions or operations through a
structured register space provided inside the ADC. The SPI
offers the user added flexibility and customization, depending on
the application. Addresses are accessed via the serial port and
can be written to or read from via the port. Memory is organized
into bytes that can be further divided into fields, which are documented in the Memory Map section. For detailed operational
information, see the AN-877 Application Note, Interfacing to
High Speed ADCs via SPI.
The falling edge of the CSB, in conjunction with the rising edge
of the SCLK, determines the start of the framing. An example of
the serial timing and its definitions can be found in Figure 75
and Table 7.
CONFIGURATION USING THE SPI
During an instruction phase, a 16-bit instruction is transmitted.
Data follows the instruction phase, and its length is determined
by the W0 and W1 bits.
Other modes involving the CSB are available. The CSB can be
held low indefinitely, which permanently enables the device;
this is called streaming. The CSB can stall high between bytes to
allow for additional external timing. When CSB is tied high, SPI
functions are placed in high impedance mode. This mode turns
on any SPI pin secondary functions.
Three pins define the SPI of this ADC: the SCLK pin, the SDIO
pin, and the CSB pin (see Table 17). The SCLK (a serial clock) is
used to synchronize the read and write data presented from and
to the ADC. The SDIO (serial data input/output) is a dualpurpose pin that allows data to be sent to and read from the
internal ADC memory map registers. The CSB (chip select bar)
is an active low control that enables or disables the read and
write cycles.
In addition to word length, the instruction phase determines
whether the serial frame is a read or write operation, allowing
the serial port to be used both to program the chip and to read
the contents of the on-chip memory. The first bit of the first byte in
a multibyte serial data transfer frame indicates whether a read
command or a write command is issued. If the instruction is a
readback operation, performing a readback causes the serial
data input/output (SDIO) pin to change direction from an input to
an output at the appropriate point in the serial frame.
Table 17. Serial Port Interface Pins
Pin
SCLK
SDIO
CSB
Function
Serial clock. The serial shift clock input, which is used to
synchronize serial interface reads and writes.
Serial data input/output. A dual-purpose pin that
typically serves as an input or an output, depending on
the instruction being sent and the relative position in the
timing frame.
Chip select bar. An active low control that gates the read
and write cycles.
tHIGH
tDS
tS
tDH
All data is composed of 8-bit words. Data can be sent in MSBfirst mode or in LSB-first mode. MSB-first mode is the default
on power-up and can be changed via the SPI port configuration
register. For more information about this and other features,
see the AN-877 Application Note, Interfacing to High Speed
ADCs via SPI.
tCLK
tH
tLOW
CSB
SDIO DON’T CARE
DON’T CARE
R/W
W1
W0
A12
A11
A10
A9
A8
A7
D5
Figure 75. Serial Port Interface Timing Diagram
Rev. 0 | Page 31 of 40
D4
D3
D2
D1
D0
DON’T CARE
10538-073
SCLK DON’T CARE
AD9653
Data Sheet
HARDWARE INTERFACE
The pins described in Table 17 comprise the physical interface
between the user programming device and the serial port of the
AD9653. The SCLK pin and the CSB pin function as inputs
when using the SPI interface. The SDIO pin is bidirectional,
functioning as an input during write phases and as an output
during readback.
pattern, and power-down feature control. In this mode, CSB
should be connected to AVDD, which disables the serial port
interface.
Note that, when the CSB pin is tied to AVDD, the AD9653 DCS
is on by default and remains on unless the part is placed in SPI
mode and controlled via the SPI. Refer to the Clock Duty Cycle
section for more information on the DCS.
The SPI interface is flexible enough to be controlled by either
FPGAs or microcontrollers. One method for SPI configuration
is described in detail in the AN-812 Application Note, Microcontroller-Based Serial Port Interface (SPI) Boot Circuit.
When the device is in SPI mode, the PDWN pin (if enabled)
remains active. For SPI control of power-down, the PDWN pin
should be set to its default state.
The SPI port should not be active during periods when the full
dynamic performance of the converter is required. Because the
SCLK signal, the CSB signal, and the SDIO signal are typically
asynchronous to the ADC clock, noise from these signals can
degrade converter performance. If the on-board SPI bus is used for
other devices, it may be necessary to provide buffers between
this bus and the AD9653 to prevent these signals from transitioning at the converter inputs during critical sampling periods.
Table 18 provides a brief description of the general features that
are accessible via the SPI. These features are described in detail
in the AN-877 Application Note, Interfacing to High Speed ADCs
via SPI. The AD9653 part-specific features are described in detail
following Table 19, the external memory map register table.
Some pins serve a dual function when the SPI interface is not
being used. When the pins are strapped to DRVDD or ground
during device power-on, they are associated with a specific
function. Table 15 and Table 16 describe the strappable
functions supported on the AD9653.
SPI ACCESSIBLE FEATURES
Table 18. Features Accessible Using the SPI
Feature Name
Power Mode
Clock
Offset
CONFIGURATION WITHOUT THE SPI
Test I/O
In applications that do not interface to the SPI control registers,
the SDIO/OLM pin, the SCLK/DTP pin, and the PDWN pin
serve as standalone CMOS-compatible control pins. When the
device is powered up, it is assumed that the user intends to use the
pins as static control lines for the output lane mode, digital test
Output Mode
Output Phase
Rev. 0 | Page 32 of 40
Description
Allows the user to set either power-down mode
or standby mode
Allows the user to set the clock divider, set the
clock divider phase, and enable the sync
Allows the user to digitally adjust the
converter offset
Allows the user to set test modes to have
known data on output bits
Allows the user to set the output mode
Allows the user to set the output clock polarity
Data Sheet
AD9653
MEMORY MAP
READING THE MEMORY MAP REGISTER TABLE
Default Values
Each row in the memory map register table has eight bit locations.
The memory map is roughly divided into three sections: the chip
configuration registers (Address 0x00 to Address 0x02); the device
index and transfer registers (Address 0x05 and Address 0xFF);
and the global ADC functions registers, including setup, control,
and test (Address 0x08 to Address 0x109).
After the AD9653 is reset, critical registers are loaded with
default values. The default values for the registers are given in
the memory map register table, Table 19.
The memory map register table (see Table 19) lists the default
hexadecimal value for each hexadecimal address shown. The
column with the heading Bit 7 (MSB) is the start of the default
hexadecimal value given. For example, Address 0x05, the device
index register, has a hexadecimal default value of 0x3F. This
means that in Address 0x05, Bits[7:6] = 0, and the remaining
Bits[5:0] = 1. This setting is the default channel index setting.
The default value results in both ADC channels receiving the
next write command. For more information on this function
and others, see the AN-877 Application Note, Interfacing to High
Speed ADCs via SPI. This application note details the functions
controlled by Register 0x00 to Register 0xFF. The remaining
registers are documented in the Memory Map Register
Descriptions section.
Open Locations
All address and bit locations that are not included in Table 19
are not currently supported for this device. Unused bits of a
valid address location should be written with 0s. Writing to these
locations is required only when part of an address location is
open (for example, Address 0x05). If the entire address location
is open or not listed in Table 19 (for example, Address 0x13), this
address location should not be written.
Logic Levels
An explanation of logic level terminology follows:
•
•
“Bit is set” is synonymous with “bit is set to Logic 1” or
“writing Logic 1 for the bit.”
“Clear a bit” is synonymous with “bit is set to Logic 0” or
“writing Logic 0 for the bit.”
Channel-Specific Registers
Some channel setup functions, such as the signal monitor
thresholds, can be programmed differently for each channel. In
these cases, channel address locations are internally duplicated
for each channel. These registers and bits are designated in
Table 19 as local. These local registers and bits can be accessed
by setting the appropriate data channel bits (A, B, C, or D) and
the clock channel DCO bit (Bit 5) and FCO bit (Bit 4) in
Register 0x05. If all the bits are set, the subsequent write affects
the registers of all channels and the DCO/FCO clock channels.
In a read cycle, only one of the channels (A, B, C, or D) should
be set to read one of the four registers. If all the bits are set
during a SPI read cycle, the part returns the value for Channel A.
Registers and bits designated as global in Table 19 affect the
entire part or the channel features for which independent
settings are not allowed between channels. The settings in
Register 0x05 do not affect the global registers and bits.
Rev. 0 | Page 33 of 40
AD9653
Data Sheet
MEMORY MAP REGISTER TABLE
The AD9653 uses a 3-wire interface and 16-bit addressing and,
therefore, Bit 0 and Bit 7 in Register 0x00 are set to 0, and Bit 3
and Bit 4 are set to 1. When Bit 5 in Register 0x00 is set high,
the SPI enters a soft reset, where all of the user registers revert
to their default values and Bit 2 is automatically cleared.
Table 19.
ADDR
(Hex)
Parameter Name
Chip Configuration Registers
SPI port
0x00
configuration
0x01
Chip ID (global)
0x02
Chip grade
(global)
Bit 7
(MSB)
0=
SDO
active
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB first
Soft
reset
1=
16-bit
address
1=
16-bit
address
Soft
reset
LSB first
Bit 0
(LSB)
0 = SDO
active
8-bit chip ID, Bits[7:0]
AD9653 0xB5 = quad, 16-bit, 125 MSPS serial LVDS
Open
Speed grade ID[6:4]
110 = 125 MSPS
Default
Value
(Hex)
0x18
0xB5
Open
Open
Open
Open
Device Index and Transfer Registers
0x05
Device index
Open
Open
Clock
Channel
DCO
Clock
Channel
FCO
Data
Channel
D
Data
Channel
C
Data
Channel
B
Data
Channel
A
0x3F
0xFF
Open
Open
Open
Open
Open
Open
Open
Initiate
override
0x00
Global ADC Function Registers
Power modes
0x08
Open
(global)
Open
Open
Open
0x09
Open
External
powerdown
pin
function
0 = full
powerdown
1=
standby
Open
Open
Open
Transfer
Clock (global)
Open
Rev. 0 | Page 34 of 40
Open
Open
Power mode
00 = chip run
01 = full powerdown
10 = standby
11 = reset
Open
Duty
cycle
stabilize
0 = on
1 = off
Comments
The nibbles
are mirrored
so that LSBfirst or MSBfirst mode
registers
correctly. The
default for
ADCs is 16-bit
mode.
Unique chip
ID used to
differentiate
devices; read
only.
Unique
speed grade
ID used to
differentiate
graded
devices; read
only.
Bits are set to
determine
which device
on chip
receives the
next write
command.
The default is
all devices on
chip.
Set sample
rate override.
0x00
Determines
various
generic
modes of chip
operation.
0x01
Turns duty
cycle stabilizer
on or off.
Data Sheet
ADDR
(Hex)
0x0B
Parameter Name
Clock divide
(global)
0x0C
Enhancement
control
0x0D
Test mode (local
except for PN
sequence resets)
0x10
0x14
Offset adjust
(local)
Output mode
0x15
Output adjust
0x16
Output phase
AD9653
Bit 7
(MSB)
Open
Bit 0
(LSB)
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Clock divide ratio[2:0]
Open
Open
Open
Open
000 = divide by 1
001 = divide by 2
010 = divide by 3
011 = divide by 4
100 = divide by 5
101 = divide by 6
110 = divide by 7
111 = divide by 8
Chop
Open
Open
Open
Open
Open
Open
Open
mode
0 = off
1 = on
Reset
Reset PN
Output test mode[3:0] (local)
User input test mode
PN long
short
0000 = off (default)
00 = single
gen
gen
0001 = midscale short
01 = alternate
0010 = positive FS
10 = single once
0011 = negative FS
11 = alternate once
0100 = alternating checkerboard
(affects user input test
0101 = PN 23 sequence
mode only,
0110 = PN 9 sequence
Bits[3:0] = 1000)
0111 = one/zero word toggle
1000 = user input
1001 = 1-/0-bit toggle
1010 = 1× sync
1011 = one bit high
1100 = mixed bit frequency
8-bit device offset adjustment [7:0] (local)
Offset adjust in LSBs from +127 to −128 (twos complement format)
LVDS-ANSI/
Output
Output
Open
Open
Open
Open
Open
LVDS-IEEE
invert
format
option
0=
(local)
0 = LVDSoffset
ANSI
binary
1 = LVDS1=
IEEE
twos
reduced
complerange link
ment
(global)
(global)
see
Table 20
Output driver
Output
Open
Open
Open
Open
Open
termination[1:0]
drive
0 = 1×
00 = none
drive
01 = 200 Ω
1 = 2×
10 = 100 Ω
drive
11 = 100 Ω
Output clock phase adjust[3:0]
Open
Input clock phase adjust[6:4]
(0000 through 1011)
(value is number of input clock
see Table 22
cycles of phase delay)
see Table 21
Rev. 0 | Page 35 of 40
Default
Value
(Hex)
0x00
Comments
0x00
Enables/
disables chop
mode.
0x00
When set, the
test data is
placed on the
output pins in
place of
normal data.
0x00
Device offset
trim.
Configures
the outputs
and the
format of the
data.
0x01
0x00
Determines
LVDS or other
output
properties.
0x03
On devices
that use
global clock
divide,
determines
which phase
of the divider
output is used
to supply the
output clock.
Internal
latching is
unaffected.
AD9653
ADDR
(Hex)
0x18
0x19
0x1A
0x1B
0x1C
0x21
Parameter Name
VREF
USER_PATT1_LSB
(global)
USER_PATT1_MSB
(global)
USER_PATT2_LSB
(global)
USER_PATT2_MSB
(global)
Serial output data
control (global)
Data Sheet
Bit 6
Open
Bit 5
Open
Bit 4
Open
Bit 3
Open
B7
B6
B5
B4
B3
Bit 1
VREF adjustment
digital scheme[2:0]
000 = 1.0 V p-p (1.3 V p-p)
001 = 1.14 V p-p (1.48 V p-p)
010 = 1.33 V p-p (1.73 V p-p)
011 = 1.6 V p-p (2.08 V p-p)
100 = 2.0 V p-p (2.6 V p-p)
B2
B1
B0
B15
B14
B13
B12
B11
B10
B9
B8
0x00
B7
B6
B5
B4
B3
B2
B1
B0
0x00
B15
B14
B13
B12
B11
B10
B9
B8
0x00
LVDS
output
LSB
first
SDR/DDR one-lane/two-lane,
bitwise/bytewise[6:4]
000 = SDR two-lane, bitwise
001 = SDR two-lane, bytewise
010 = DDR two-lane, bitwise
011 = DDR two-lane, bytewise
100 = DDR one-lane, wordwise
Open
Open
Open
Open
Select
2×
frame
Open
Open
0
Open
Bit 2
0x22
Serial channel
status (local)
Open
0x100
Sample rate
override
Open
Sample
rate
override
enable
0x101
User I/O Control 2
Open
Open
Open
Open
Open
Open
0x102
User I/O Control 3
Open
Open
Open
Open
Open
0x109
Sync
Open
Open
Open
Open
VCM
powerdown
Open
0
Rev. 0 | Page 36 of 40
Bit 0
(LSB)
Default
Value
(Hex)
0x04
Bit 7
(MSB)
Open
Open
Serial output
number of bits
00 = 16 bits
Channel
output
reset
Channel
powerdown
Sample rate
000 = 20 MSPS
001 = 40 MSPS
010 = 50 MSPS
011 = 65 MSPS
100 = 80 MSPS
101 = 105 MSPS
110 = 125 MSPS
SDIO
Open
pulldown
Open
Open
Sync
next
only
Enable
sync
0x00
0x30
0x00
0x00
Comments
Selects
internal VREF.
Values shown
are for VREF =
1.0 V (1.3 V).
User Defined
Pattern 1 LSB.
User Defined
Pattern 1 MSB.
User Defined
Pattern 2 LSB.
User Defined
Pattern 2 MSB.
Serial stream
control.
Default causes
MSB first and
the native bit
stream.
Used to
power down
individual
sections of a
converter.
Sample rate
override
(requires
transfer
register, 0xFF).
0x00
Disables SDIO
pull-down.
0x00
VCM control.
0x00
Data Sheet
AD9653
MEMORY MAP REGISTER DESCRIPTIONS
For additional information about functions controlled in
Register 0x00 to Register 0xFF, see the AN-877 Application Note,
Interfacing to High Speed ADCs via SPI.
Device Index (Register 0x05)
There are certain features in the map that can be set independently for each channel, whereas other features apply
globally to all channels (depending on context) regardless of
which are selected. The first four bits in Register 0x05 can be
used to select which individual data channels are affected. The
output clock channels can be selected in Register 0x05 as well.
A smaller subset of the independent feature list can be applied
to those devices.
Transfer (Register 0xFF)
All registers except Register 0x100 are updated the moment
they are written. Setting Bit 0 of this transfer register high
initializes the settings in the sample rate override register
(Address 0x100).
For applications that are sensitive to offset voltages and other
low frequency noise, such as homodyne or direct conversion
receivers, chopping in the first stage of the AD9653 is a feature
that can be enabled by setting Bit 2. In the frequency domain,
chopping translates offsets and other low frequency noise to
fCLK/2 where it can be filtered.
Bits[1:0]—Open
Output Mode (Register 0x14)
Bit 7—Open
Bit 6—LVDS-ANSI/LVDS-IEEE Option
Setting this bit chooses LVDS-IEEE (reduced range) option.
The default setting is LVDS-ANSI. As described in Table 20,
when LVDS-ANSI or LVDS-IEEE reduced range link is selected,
the user can select the driver termination. The driver current
is automatically selected to give the proper output swing.
Table 20. LVDS-ANSI/LVDS-IEEE Options
Output
Mode,
Bit 6
0
Power Modes (Register 0x08)
Bits[7:6]—Open
Output
Mode
LVDS-ANSI
Bit 5—External Power-Down Pin Function
If set, the external PDWN pin initiates standby mode. If cleared,
the external PDWN pin initiates power-down mode.
Bits[4:2]—Open
Setting this bit inverts the output bit stream.
In power-down mode (Bits[1:0] = 01), the digital datapath clocks
are disabled while the digital datapath is reset. Outputs are
disabled.
In standby mode (Bits[1:0] = 10), the digital datapath clocks
and the outputs are disabled.
During a digital reset (Bits[1:0] = 11), all the digital datapath
clocks and the outputs (where applicable) on the chip are reset,
except the SPI port. Note that the SPI is always left under
control of the user; that is, it is never automatically disabled or
in reset (except by power-on reset).
The default state is Bit 0 = 1, duty cycle stabilizer off.
Note that, when the part is not in SPI mode, the duty cycle
stabilizer is on. Refer to the Configuration Without the SPI
section for more information.
Enhancement Control (Register 0x0C)
Bits[7:3]—Open
Bit 2—Chop Mode
User
selectable
Bit 2—Output Invert
In normal operation (Bits[1:0] = 00), all ADC channels are
active.
Bit 0—Duty Cycle Stabilize.
LVDS-IEEE
reduced
range link
Output Driver
Current
Automatically
selected to give
proper swing
Automatically
selected to give
proper swing
Bits[5:3]—Open
Bits[1:0]—Power Mode
Clock (Register 0x09)
Bits[7:1]—Open
1
Output
Driver
Termination
User
selectable
Bit 1—Open
Bit 0—Output Format
By default, this bit is set to send the data output in twos
complement format. Resetting this bit changes the output mode
to offset binary.
Output Adjust (Register 0x15)
Bits[7:6]—Open
Bits[5:4]—Output Driver Termination
These bits allow the user to select the internal termination
resistor.
Bits[3:1]—Open
Bit 0—Output Drive
Bit 0 of the output adjust register controls the drive strength on
the LVDS driver of the FCO and DCO outputs only. The default
values set the drive to 1× while the drive can be increased to 2×
by setting the appropriate channel bit in Register 0x05 and then
setting Bit 0. These features cannot be used with the output
driver termination select. The termination selection takes
precedence over the 2× driver strength on FCO and DCO when
both the output driver termination and output drive are selected.
Rev. 0 | Page 37 of 40
AD9653
Data Sheet
Output Phase (Register 0x16)
Bit 7—Open
Serial Output Data Control (Register 0x21)
Bits[6:4]—Input Clock Phase Adjust
Table 21. Input Clock Phase Adjust Options
Input Clock Phase
Adjust, Bits[6:4]
000 (Default)
001
010
011
100
101
110
111
Number of Input Clock Cycles of
Phase Delay
0
1
2
3
4
5
6
7
Bits[3:0]—Output Clock Phase Adjust
Table 22. Output Clock Phase Adjust Options
Output Clock (DCO),
Phase Adjust, Bits[3:0]
0000
0001
0010
0011 (Default)
0100
0101
0110
0111
1000
1001
1010
1011
DCO Phase Adjustment (Degrees
Relative to D0±x/D1±x Edge)
0
60
120
180
240
300
360
420
480
540
600
660
The serial output data control register is used to program the
AD9653 in various output data modes depending upon the data
capture solution. Table 23 describes the various serialization
options available in the AD9653.
Sample Rate Override (Register 0x100)
This register is designed to allow the user to downgrade the sample
rate. Settings in this register are not initialized until Bit 0 of the
transfer register (Register 0xFF) is written high.
User I/O Control 2 (Register 0x101)
Bits[7:1]—Open
Bit 0—SDIO Pull-Down
Bit 0 can be set to disable the internal 30 kΩ pull-down on the
SDIO pin, which can be used to limit the loading when many
devices are connected to the SPI bus.
User I/O Control 3 (Register 0x102)
Bits[7:4]—Open
Bit 3—VCM Power-Down
Bit 3 can be set high to power down the internal VCM
generator. This feature is used when applying an external
reference.
Bits[2:0]—Open
Table 23. SPI Register Options
Register 0x21
Contents
0x30
0x20
0x10
0x00
0x34
0x24
0x14
0x04
0x40
Serialization Options Selected
Serial Output Number
of Bits (SONB)
Frame Mode
Serial Data Mode
16-bit
1×
DDR two-lane, bytewise
16-bit
1×
DDR two-lane, bitwise
16-bit
1×
SDR two-lane, bytewise
16-bit
1×
SDR two-lane, bitwise
16-bit
2×
DDR two-lane, bytewise
16-bit
2×
DDR two-lane, bitwise
16-bit
2×
SDR two-lane, bytewise
16-bit
2×
SDR two-lane, bitwise
16-bit
1×
DDR one-lane, wordwise
Rev. 0 | Page 38 of 40
DCO Multiplier
4 × fS
4 × fS
8 × fS
8 × fS
4 × fS
4 × fS
8 × fS
8 × fS
8 × fS
Timing Diagram
Figure 2 (default setting)
Figure 2
Figure 2
Figure 2
Figure 3
Figure 3
Figure 3
Figure 3
Figure 4
Data Sheet
AD9653
APPLICATIONS INFORMATION
DESIGN GUIDELINES
VCM
Before starting design and layout of the AD9653 as a system,
it is recommended that the designer become familiar with these
guidelines, which describes the special circuit connections and
layout requirements that are needed for certain pins.
The VCM pin should be bypassed to ground with a 0.1 μF
capacitor.
When connecting power to the AD9653, it is recommended
that two separate 1.8 V supplies be used. Use one supply for
analog (AVDD); use a separate supply for the digital outputs
(DRVDD). For both AVDD and DRVDD, several different
decoupling capacitors should be used to cover both high and
low frequencies. Place these capacitors close to the point of
entry at the PCB level and close to the pins of the part, with
minimal trace length.
A single PCB ground plane should be sufficient when using the
AD9653. With proper decoupling and smart partitioning of the
PCB analog, digital, and clock sections, optimum performance
is easily achieved.
EXPOSED PAD THERMAL HEAT SLUG
RECOMMENDATIONS
It is required that the exposed pad on the underside of the ADC
be connected to analog ground (AGND) to achieve the best
electrical and thermal performance of the AD9653. An exposed
continuous copper plane on the PCB should mate to the
AD9653 exposed pad, Pin 0. The copper plane should have
several vias to achieve the lowest possible resistive thermal path
for heat dissipation to flow through the bottom of the PCB.
These vias should be solder-filled or plugged.
To maximize the coverage and adhesion between the ADC and
PCB, partition the continuous copper plane by overlaying a
silkscreen on the PCB into several uniform sections. This provides
several tie points between the ADC and PCB during the reflow
process, whereas using one continuous plane with no partitions
only guarantees one tie point. See Figure 76 for a PCB layout
example. For detailed information on packaging and the PCB
layout of chip scale packages, see the AN-772 Application Note,
A Design and Manufacturing Guide for the Lead Frame Chip
Scale Package (LFCSP), at www.analog.com.
The VREF pin should be externally bypassed to ground with a
low ESR, 1.0 μF capacitor in parallel with a low ESR, 0.1 μF
ceramic capacitor.
SPI PORT
The SPI port should not be active during periods when the full
dynamic performance of the converter is required. Because the
SCLK, CSB, and SDIO signals are typically asynchronous to the
ADC clock, noise from these signals can degrade converter
performance. If the on-board SPI bus is used for other devices,
it may be necessary to provide buffers between this bus and the
AD9653 to keep these signals from transitioning at the converter inputs during critical sampling periods.
CROSSTALK PERFORMANCE
The AD9653 is available in a 48-lead LFCSP package with the
input pairs on either corner of the chip. See Figure 6 for the pin
configuration. To maximize the crosstalk performance on the
board, add grounded filled vias in between the adjacent
channels as shown in Figure 77.
VIN
CHANNEL A
GROUNDED
FILLED VIAS
FOR ADDED
CROSSTALK
ISOLATION
10538-074
SILKSCREEN PARTITION
PIN 1 INDICATOR
Figure 76. Typical PCB Layout
Rev. 0 | Page 39 of 40
VIN
CHANNEL B
VIN
CHANNEL D
PIN 1
VIN
CHANNEL C
Figure 77. Layout Technique to Maximize Crosstalk Performance
10538-075
POWER AND GROUND RECOMMENDATIONS
REFERENCE DECOUPLING
AD9653
Data Sheet
OUTLINE DIMENSIONS
0.30
0.23
0.18
PIN 1
INDICATOR
37
36
48
1
0.50
BSC
TOP VIEW
0.80
0.75
0.70
0.45
0.40
0.35
EXPOSED
PAD
24
SEATING
PLANE
5.65
5.60 SQ
5.55
13
BOTTOM VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.20 REF
PIN 1
INDICATOR
0.20 MIN
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-220-WKKD.
02-14-2011-B
7.10
7.00 SQ
6.90
Figure 78. 48-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
7 mm × 7 mm Body, Very Very Thin Quad
(CP-48-13)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
AD9653BCPZ-125
AD9653BCPZRL7-125
AD9653-125EBZ
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
Package Description
48-Lead Lead Frame Chip Scale Package (LFCSP_WQ)
48-Lead Lead Frame Chip Scale Package (LFCSP_WQ)
Evaluation Board
Z = RoHS Compliant Part.
©2012 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D10538-0-5/12(0)
Rev. 0 | Page 40 of 40
Package Option
CP-48-13
CP-48-13