ADC07D1520
Low Power, 7-Bit, Dual 1.5 GSPS or Single 3.0 GSPS A/D Converter
General Description
Features
The ADC07D1520 is a dual, low power, high performance
CMOS analog-to-digital converter. The ADC07D1520 digitizes signals to 7 bits of resolution at sample rates up to 1.5
GSPS. Its features include a test pattern output for system
debug, a clock phase adjust, and selectable output demultiplexer modes. This device is guaranteed to have no missing
codes over the full operating temperature range. The unique
folding and interpolating architecture, the fully differential
comparator design, the innovative design of the internal sample-and-hold amplifier and the self-calibration scheme enable
a very flat response of all dynamic parameters beyond
Nyquist, producing a high 6.8 Effective Number of Bits
(ENOB) with a 748 MHz input signal and a 1.5 GHz sample
rate while providing a 10-18 Code Error Rate (C.E.R.) Output
formatting is offset binary and the Low Voltage Differential
Signaling (LVDS) digital outputs are compatible with IEEE
1596.3-1996, with the exception of an adjustable common
mode voltage between 0.8V and 1.2V.
Each converter has a selectable output demultiplexer which
feeds two LVDS buses. If the 1:2 Demultiplexed Mode is selected, the output data rate is reduced to half the input sample
rate on each bus. When Non-Demultiplexed Mode is selected,
the output data rate on channels DI and DQ is at the same
rate as the input sample clock. The two converters can be
interleaved and used as a single 3 GSPS ADC.
The converter typically consumes less than 3.5 mW in the
Power Down Mode and is available in a leaded or lead-free,
128-pin, thermally enhanced, exposed pad LQFP and operates over the Industrial (-40°C ≤ TA ≤ +85°C) temperature
range.
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Single +1.9V ±0.1V Operation
Interleave Mode for 2x Sample Rate
Multiple ADC Synchronization Capability
Adjustment of Input Full-Scale Range, Clock Phase, and
Offset
Choice of SDR or DDR Output Clocking
1:1 or 1:2 Selectable Output Demux
Second DCLK Output
Duty Cycle Corrected Sample Clock
Test pattern
Key Specifications
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Resolution
Max Conversion Rate
Code Error Rate
ENOB @ 748 MHz Input
DNL
Power Consumption (Non-DES Mode)
— Operating in 1:2 Demux Mode
— Power Down Mode
7 Bits
1.5 GSPS (max)
10-18 (typ)
6.8 Bits (typ)
±0.15 LSB (typ)
1.9 W (typ)
2.5 mW (typ)
Applications
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Direct RF Down Conversion
Digital Oscilloscopes
Satellite Set-top boxes
Communications Systems
Test Instrumentation
Ordering Information
Industrial Temperature Range (-40°C < TA < +85°C)
NS Package
ADC07D1520CIYB/NOPB
Lead-free 128-Pin Exposed Pad LQFP
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.
301941 SLAS881A
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Block Diagram
30194153
2
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Pin Configuration
30194101
Note: The exposed pad on the bottom of the package must be soldered to a ground plane to ensure rated performance.
Copyright © 1999-2012, Texas Instruments Incorporated
3
ADC07D1520
Pin Descriptions and Equivalent Circuits
Pin Functions
Pin No.
3
OutV / SCLK
29
PDQ
Equivalent Circuit
Description
Output Voltage Amplitude and Serial Interface Clock. Tie this
pin logic high for normal differential DCLK and data
amplitude. Ground this pin for a reduced differential output
amplitude and reduced power consumption. See 1.1.6 The
LVDS Outputs. When the Extended Control Mode is
enabled, this pin functions as the SCLK input which clocks
in the serial data. See 1.2 NON-EXTENDED AND
EXTENDED CONTROL MODE for details on the Extended
Control Mode. See 1.3 THE SERIAL INTERFACE for
description of the serial interface.
Power Down Q-channel. A logic high on the PDQ pin puts
only the Q-channel into the Power Down Mode.
OutEdge / DDR /
SDATA
DCLK Edge Select, Double Data Rate Enable and Serial
Data Input. This input sets the output edge of DCLK+ at
which the output data transitions. See 1.1.5.2 OutEdge and
Demultiplex Control Setting. When this pin is floating or
connected to 1/2 the supply voltage, DDR clocking is
enabled. When the Extended Control Mode is enabled, this
pin functions as the SDATA input. See 1.2 NON-EXTENDED
AND EXTENDED CONTROL MODE for details on the
Extended Control Mode. See 1.3 THE SERIAL
INTERFACE for description of the serial interface.
15
DCLK_RST /
DCLK_RST+
DCLK Reset. When single-ended DCLK_RST is selected by
floating or setting pin 52 logic high, a positive pulse on this
pin is used to reset and synchronize the DCLK outputs of
multiple converters. See 1.5 MULTIPLE ADC
SYNCHRONIZATION for detailed description. When
differential DCLK_RST is selected by setting pin 52 logic low,
this pin receives the positive polarity of a differential pulse
signal used to reset and synchronize the DCLK outputs of
multiple converters.
26
PD
Power Down Pins. A logic high on the PD pin puts the entire
device into the Power Down Mode.
CAL
Calibration Cycle Initiate. A minimum tCAL_L input clock
cycles logic low followed by a minimum of tCAL_H input clock
cycles high on this pin initiates the self calibration sequence.
See 2.4.2 Calibration for an overview of calibration and
2.4.2.2 On-Command Calibration for a description of oncommand calibration. The calibration cycle may similarly be
initiated via the CAL bit in the Calibration register (0h).
4
30
4
Symbol
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Pin Functions
Pin No.
14
127
18
19
Symbol
Equivalent Circuit
Description
FSR/ALT_ECE/
DCLK_RST-
Full Scale Range Select, Alternate Extended Control Enable
and DCLK_RST-. This pin has three functions. It can
conditionally control the ADC full-scale voltage, enable the
Extended Control Mode, or become the negative polarity
signal of a differential pair in differential DCLK_RST mode.
If pin 52 is floating or at logic high and pin 41 is floating, this
pin can be used to set the full-scale-range or can be used as
an alternate Extended Control Mode enable pin. When used
as the FSR pin, a logic low on this pin sets the full-scale
differential input range to a reduced VIN input level . A logic
high on this pin sets the full-scale differential input range to
a higher VIN input level. See Converter Electrical
Characteristics. To enable the Extended Control Mode,
whereby the serial interface and control registers are
employed, allow this pin to float or connect it to a voltage
equal to VA/2. See 1.2 NON-EXTENDED AND EXTENDED
CONTROL MODE for information on the Extended Control
Mode. Note that pin 41 overrides the Extended Control Mode
enable of this pin. When pin 52 is held at logic low, this pin
acts as the DCLK_RST- pin. When in differential DCLK_RST
mode, there is no pin-controlled FSR and the full-scale-range
is defaulted to the higher VIN input level.
(Note 17)
CalDly / DES / SCS
Calibration Delay, Dual Edge Sampling and Serial Interface
Chip Select. In non-extended control mode, this pin functions
as the Calibration Delay select. A logic high or low the
number of input clock cycles after power up before
calibration begins (See 1.1.1 Calibration). When this pin is
floating or connected to a voltage equal to VA/2, DES (Dual
Edge Sampling) Mode is selected where the I-channel is
sampled at twice the input clock rate and the Q-channel is
ignored. See 1.1.5.1 Dual-Edge Sampling. In extended
control mode, this pin acts as the enable pin for the serial
interface input and the CalDly value becomes "0" (short
delay with no provision for a long power-up calibration delay).
(Note 17)
CLK+
CLK-
Differential clock input pins for the ADC. The differential clock
signal must be a.c. coupled to these pins. The input signal is
sampled on the falling edge of CLK+. See 1.1.2 Acquiring
the Input for a description of acquiring the input and 2.3 THE
CLOCK INPUTS for an overview of the clock inputs.
Copyright © 1999-2012, Texas Instruments Incorporated
5
ADC07D1520
Pin Functions
Pin No.
Equivalent Circuit
Description
VINIVINI+
VINQ+
VINQ−
Analog signal inputs to the ADC. The differential full-scale
input range of this input is programmable using the FSR pin
14 in Non-Extended Control Mode and the Input Full-Scale
Voltage Adjust register in the Extended Control Mode. Refer
to the VIN specification in the Converter Electrical
Characteristics for the full-scale input range in the NonExtended Control Mode. Refer to 1.4 REGISTER
DESCRIPTION for the full-scale input range in the Extended
Control Mode.
7
VCMO
Common Mode Voltage. This pin is the common mode
output in d.c. coupling mode and also serves as the a.c.
coupling mode select pin. When d.c. coupling is used at the
analog inputs, the voltage output at this pin is required to be
the common mode input voltage at VIN+ and VIN−. When a.c.
coupling is used, this pin should be grounded. This pin is
capable of sourcing or sinking 100 μA. See 2.2 THE
ANALOG INPUT.
31
VBG
Bandgap output voltage. This pin is capable of sourcing or
sinking 100 μA and can drive a load up to 80 pF.
126
CalRun
32
REXT
10
11
22
23
34
35
41
6
Symbol
Calibration Running indication. This pin is at a logic high
when calibration is running.
(Note 17)
External bias resistor connection. Nominal value is 3.3 kΩ
(±0.1%) to ground. See 1.1.1 Calibration.
Tdiode_P
Tdiode_N
Temperature Diode Positive (Anode) and Negative
(Cathode). These pins may be used for die temperature
measurements, however no specified accuracy is implied or
guaranteed. Noise coupling from adjacent output data
signals has been shown to affect temperature
measurements using this feature. See 2.6.2 Thermal
Management.
ECE
Extended Control Enable. This pin always enables or
disables Extended Control Mode. When this pin is set logic
high, the Extended Control Mode is inactive and all control
of the device must be through control pins only . When it is
set logic low, the Extended Control Mode is active. This pin
overrides the Extended Control Enable signal set using pin
14.
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Pin Functions
Pin No.
Symbol
Equivalent Circuit
Description
52
DRST_SEL
DCLK_RST select. This pin selects whether the DCLK is
reset using a single-ended or differential signal. When this
pin is floating or logic high, the DCLK_RST operation is
single-ended and pin 14 functions as FSR/ALT_ECE. When
this pin is logic low, the DCLK_RST operation becomes
differential with functionality on pin 15 (DCLK_RST+) and pin
14 (DCLK_RST-). When in differential DCLK_RST mode,
there is no pin-controlled FSR and the full-scale-range is
defaulted to the higher VIN input level. When pin 41 is set
logic low, the Extended Control Mode is active and the FullScale Voltage Adjust registers can be programmed.
(Note 17)
83 / 78
84 / 77
85 / 76
86 / 75
89 / 72
90 / 71
91 / 70
92 / 69
93 / 68
94 / 67
95 / 66
96 / 65
100 / 61
101 / 60
DI6− / DQ6−
DI6+ / DQ6+
DI5− / DQ5−
DI5+ / DQ5+
DI4− / DQ4−
DI4+ / DQ4+
DI3− / DQ3−
DI3+ / DQ3+
DI2− / DQ2−
DI2+ / DQ2+
DI1− / DQ1−
DI1+ / DQ1+
DI0− / DQ0−
DI0+ / DQ0+
I- and Q-channel LVDS Data Outputs that are not delayed in
the output demultiplexer. Compared with the DId and DQd
outputs, these outputs represent the later time samples.
These outputs should always be terminated with a 100Ω
differential resistor.
In Non-demultiplexed Mode, only these outputs are active.
104 / 57
105 / 56
106 / 55
107 / 54
111 / 50
112 / 49
113 / 48
114 / 47
115 / 46
116 / 45
117 / 44
118 / 43
122 / 39
123 / 38
DId6− / DQd6−
DId6+ / DQd6+
DId5− / DQd5−
DId5+ / DQd5+
DId4− / DQd4−
DId4+ / DQd4+
DId3− / DQd3−
DId3+ / DQd3+
DId2− / DQd2−
DId2+ / DQd2+
DId1− / DQd1−
DId1+ / DQd1+
DId0− / DQd0−
DId0+ / DQd0+
I- and Q-channel LVDS Data Outputs that are delayed by
one CLK cycle in the output demultiplexer. Compared with
the DI and DQ outputs, these outputs represent the earlier
time sample. These outputs should always be terminated
with a 100Ω differential resistor.
In Non-demultiplexed Mode, these outputs are disabled and
are high impedance. When disabled, these outputs must be
left floating.
OR+/DCLK2+
OR-/DCLK2-
Out Of Range, second Data Clock output. When functioning
as OR+/-, a differential high at these pins indicates that the
differential input is out of range (outside the range ±VIN/2 as
programmed by the FSR pin in Non-extended Control Mode
or the Input Full-Scale Voltage Adjust register setting in the
Extended Control Mode). This single out of range indication
is for both the I- and Q-channels, unless PDQ is asserted, in
which case it only applies to the I-channel input. When
functioning as DCLK2+/-, DCLK2 is the exact replica of
DCLK and outputs the same signal at the same rate. The
functionality of these pins is selectable in Extended Control
Mode only; default is OR+/-.
79
80
Copyright © 1999-2012, Texas Instruments Incorporated
7
ADC07D1520
Pin Functions
Pin No.
8
Symbol
Equivalent Circuit
Description
Data Clock. Differential Clock outputs used to latch the
output data. Delayed and non-delayed data outputs are
supplied synchronously to this signal. In 1:2 Demux Mode,
this signal is at 1/2 the input clock rate in SDR mode and at
1/4 the input clock rate in the DDR mode. In the Non-demux
Mode, DCLK can only be in DDR mode and is at 1/2 the input
clock rate. By default, the DCLK outputs are not active during
the termination resistor trim section of the calibration cycle.
If a system requires DCLK to run continuously during a
calibration cycle, the termination resistor trim portion of the
cycle can be disabled by setting the Resistor Trim Disable
(RTD) bit to logic high in the Extended Configuration
Register. This disables all subsequent termination resistor
trims after the initial trim which occurs during power-on
calibration. This output is not recommended as a system
clock unless the resistor trim is disabled.
81
82
DCLKDCLK+
2, 5, 8, 13,
16, 17, 20,
25, 28, 33,
128
VA
Analog power supply pins. Bypass these pins to ground.
40, 51, 62,
73, 88, 99,
110, 121
VDR
Output Driver power supply pins. Bypass these pins to DR
GND.
1, 6, 9, 12,
21, 24, 27
GND
Ground return for VA.
42, 53, 64,
74, 87, 97,
108, 119
DR GND
Ground return for VDR.
63, 98, 109,
120
NC
36 / 37
58 / 59
103 / 102
125 / 124
RSV+ / RSV-
No Connection. Make no connection to these pins.
Reserved. These pins may be left unconnected and floating,
or as recommended in 2.5.1 Terminating RSV Pins.
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Absolute Maximum Ratings
(Note 1, Note 2)
If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for
availability and specifications.
Supply Voltage (VA, VDR)
2.2V
Supply Difference
VDR - VA
0V to 100 mV
Voltage on Any Input Pin
(Except VIN+, VIN- )
−0.15V to (VA +0.15V)
Voltage on VIN+, VIN(Maintaining Common Mode)
Ground Difference
|GND - DR GND|
Input Current at Any Pin (Note 3)
Package Input Current (Note 3)
-0.15V to 2.5V
0V to 100 mV
±25 mA
±50 mA
Maximum Package Power Dissipation at TA ≤ 85°C
2.35 W
ESD Susceptibility (Note 4)
Human Body Model
Machine Model
Charged Device Model
2500V
250V
1000V
−65°C to +150°C
Storage Temperature
Operating Ratings
(Note 1, Note 2)
−40°C ≤ TA ≤ +85°C
Ambient Temperature Range
Supply Voltage (VA)
+1.8V to +2.0V
+1.8V to VA
Driver Supply Voltage (VDR)
Analog Input Common Mode Voltage
VCMO ±50 mV
VIN+, VIN- Voltage Range (Maintaining Common Mode)
0V to 2.15V
(100% duty cycle)
0V to 2.5V
(10% duty cycle)
Ground Difference
(|GND - DR GND|)
CLK Pins Voltage Range
0V
0V to VA
Differential CLK Amplitude
0.4VP-P to 2.0VP-P
Package Thermal Resistance
Package
θJA
θJC
Top of Package
θJC
Thermal Pad
128-Lead,
Exposed Pad LQFP
26°C / W
10°C / W
2.8°C / W
For soldering information please refer to http://www.ti.com/lit/an/snoa549c/snoa549c.pdf.(Note 5)
Copyright © 1999-2012, Texas Instruments Incorporated
9
ADC07D1520
Converter Electrical Characteristics
The following specifications apply after calibration for VA = VDR = +1.9V; OutV = 1.9V; VIN FSR (a.c. coupled) = differential 870
mVP-P; CL = 10 pF; Differential, a.c. coupled Sine Wave Input Clock, fCLK = 1.5 GHz at 0.5 VP-P with 50% duty cycle; VBG = Floating;
Non-extended Control Mode; SDR Mode; REXT = 3300 Ω ±0.1%; Analog Signal Source Impedance = 100 Ω Differential; 1:2 Demultiplex Mode; Duty Cycle Stabilizer on. Boldface limits apply for TA = TMIN to TMAX. All other limits TA = 25°C, unless otherwise
noted. (Note 6, Note 7, Note 16, Note 18)
Symbol
Parameter
Conditions
Typical
(Note 8)
Limits
Units
(Limits)
STATIC CONVERTER CHARACTERISTICS
INL
Integral Non-Linearity
(Best fit)
DC Coupled, 1 MHz Sine Wave Overranged
±0.3
±0.9
LSB (max)
DNL
Differential Non-Linearity
DC Coupled, 1 MHz Sine Wave Overranged
±0.15
±0.6
LSB (max)
7
Bits
Resolution with No Missing
Codes
VOFF
Offset Error
VOFF_ADJ
Input Offset Adjustment Range Extended Control Mode
PFSE
Positive Full-Scale Error
(Note 9)
±25
mV (max)
NFSE
Negative Full-Scale Error
(Note 9)
±25
mV (max)
FS_ADJ
Full-Scale Adjustment Range
Extended Control Mode
±15
%FS
−0.75
LSB
±45
mV
±20
1:2 DEMUX NON-DES MODE, DYNAMIC CONVERTER CHARACTERISTICS; FCLK = 1.5 GHZ
FPBW
Full Power Bandwidth
C.E.R.
Code Error Rate
Gain Flatness
Non-DES Mode
2.0
GHz
10−18
Error/Sample
d.c. to 748 MHz
±0.5
dBFS
d.c. to 1.5 GHz
±1.0
fIN = 373 MHz, VIN = FSR − 0.5 dB
6.8
ENOB
Effective Number of Bits
fIN = 748 MHz, VIN = FSR − 0.5 dB
6.8
SINAD
Signal-to-Noise Plus Distortion fIN = 373 MHz, VIN = FSR − 0.5 dB
Ratio
fIN = 748 MHz, VIN = FSR − 0.5 dB
43
SNR
Signal-to-Noise Ratio
THD
Total Harmonic Distortion
2nd Harm
Second Harmonic Distortion
3rd Harm
SFDR
IMD
Third Harmonic Distortion
Spurious-Free Dynamic Range
Intermodulation Distortion
Out of Range Output Code
dBFS
6.3
Bits (min)
39.5
dB (min)
40.8
dB (min)
Bits
43
dB
fIN = 373 MHz, VIN = FSR − 0.5 dB
43.2
fIN = 748 MHz, VIN = FSR − 0.5 dB
43.2
fIN = 373 MHz, VIN = FSR − 0.5 dB
−55
fIN = 748 MHz, VIN = FSR − 0.5 dB
−60
dB
fIN = 373 MHz, VIN = FSR − 0.5 dB
−63
dB
fIN = 748 MHz, VIN = FSR − 0.5 dB
−63
dB
fIN = 373 MHz, VIN = FSR − 0.5 dB
−58
dB
fIN = 748 MHz, VIN = FSR − 0.5 dB
−67
fIN = 373 MHz, VIN = FSR − 0.5 dB
57
fIN = 748 MHz, VIN = FSR − 0.5 dB
61
dB
−50
dB
fIN1 = 365 MHz, VIN = FSR − 7 dB
fIN2 = 375 MHz, VIN = FSR − 7 dB
dB
-47
dB (max)
dB
45.5
(VIN+) − (VIN−) > + Full Scale
127
(VIN+) − (VIN−) < − Full Scale
0
dB (min)
1:4 DEMUX DES MODE, DYNAMIC CONVERTER CHARACTERISTICS; FCLK = 1.5 GHZ
FPBW
Full Power Bandwidth
DES Mode
1.3
GHz
ENOB
Effective Number of Bits
fIN = 748 MHz, VIN = FSR − 0.5 dB
6.7
Bits
SINAD
Signal to Noise Plus Distortion
fIN = 748 MHz, VIN = FSR − 0.5 dB
Ratio
42
dB
SNR
Signal to Noise Ratio
fIN = 748 MHz, VIN = FSR − 0.5 dB
43
dB
THD
Total Harmonic Distortion
fIN = 748 MHz, VIN = FSR − 0.5 dB
−52
dB
2nd Harm
Second Harmonic Distortion
fIN = 748 MHz, VIN = FSR − 0.5 dB
−57
dB
10
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Symbol
Parameter
Conditions
Typical
(Note 8)
Limits
Units
(Limits)
3rd Harm
Third Harmonic Distortion
fIN = 748 MHz, VIN = FSR − 0.5 dB
−57
dB
SFDR
Spurious Free Dynamic Range fIN = 748 MHz, VIN = FSR − 0.5 dB
52
dB
ANALOG INPUT AND REFERENCE CHARACTERISTICS
VIN
Full Scale Analog Differential
Input Range
VCMI
Common Mode Input Voltage
CIN
Analog Input Capacitance,
Normal operation
(Note 10, Note 11)
RIN
FSR pin 14 Low
(Note 12)
650
FSR pin 14 High
870
VCMO
590
mVP-P (min)
730
mVP-P (max)
800
mVP-P (min)
940
mVP-P (max)
VCMO − 0.05
V (min)
VCMO + 0.05
V (max)
Differential
0.02
pF
Each input pin to ground
1.6
pF
Differential
Analog Input Capacitance,
DES Mode (Note 10, Note 11) Each input pin to ground
0.08
pF
2.2
pF
Differential Input Resistance
100
94
Ω (min)
106
Ω (max)
0.95
1.45
V (min)
V (max)
ANALOG OUTPUT CHARACTERISTICS
VCMO
Common Mode Output Voltage ICMO = ±100 µA
1.26
TC VCMO
Common Mode Output Voltage
TA = −40°C to +85°C
Temperature Coefficient
118
ppm/°C
VCMO_LVL
VCMO input threshold to set D.C. VA = 1.8V
Coupling mode
VA = 2.0V
0.60
V
0.66
V
CLOAD VCMO
Maximum VCMO Load
Capacitance
VBG
Bandgap Reference Output
Voltage
IBG = ±100 µA
TC VBG
Bandgap Reference Voltage
Temperature Coefficient
TA = −40°C to +85°C,
IBG = ±100 µA
CLOAD VBG
Maximum Bandgap Reference
load Capacitance
1.26
80
pF
1.20
1.34
V (min)
V (max)
28
ppm/°C
80
pF
CHANNEL-TO-CHANNEL CHARACTERISTICS
Offset Match
1
LSB
1
LSB
Positive Full-Scale Match
Zero offset selected in Control Register
Negative Full-Scale Match
Zero offset selected in Control Register
1
LSB
Phase Matching (I, Q)
fIN = 1.5 GHz
<1
Degree
X-TALK
Crosstalk from I-channel
(Aggressor) to Q-channel
(Victim)
Aggressor = 867 MHz F.S.
Victim = 100 MHz F.S.
−65
dB
X-TALK
Crosstalk from Q-channel
(Aggressor) to I-channel
(Victim)
Aggressor = 867 MHz F.S.
Victim = 100 MHz F.S.
−65
dB
LVDS CLK INPUT CHARACTERISTICS (Typical specs also apply to DCLK_RST)
VID
Input Offset Voltage
CIN
Input Capacitance
(Note 10, Note 11)
VP-P (min)
2.0
VP-P (max)
0.6
Square Wave Clock
0.6
1.2
V
Differential
0.02
pF
Each input to ground
1.5
pF
Differential Clock Input Level
VOSI
0.4
Sine Wave Clock
Copyright © 1999-2012, Texas Instruments Incorporated
0.4
VP-P (min)
2.0
VP-P (max)
11
ADC07D1520
Symbol
Limits
Units
(Limits)
OutV, DCLK_RST, PD, PDQ, CAL, ECE,
DRST_SEL
0.69 x VA
V (min)
OutEdge, FSR, CalDly
0.79 x VA
V (min)
OutV, DCLK_RST, PD, PDQ, CAL
0.28 x VA
V (max)
OutEdge, FSR, CalDly, ECE, DRST_SEL
0.21 x VA
V (max)
Parameter
Typical
(Note 8)
Conditions
DIGITAL CONTROL PIN CHARACTERISTICS
VIH
Logic High Input Voltage
VIL
Logic Low Input Voltage
CIN
Input Capacitance
(Note 11, Note 13)
Each input to ground
1.2
Measured differentially, OutV = VA,
VBG = Floating (Note 15)
660
Measured differentially, OutV = GND, VBG
= Floating (Note 15)
580
pF
DIGITAL OUTPUT CHARACTERISTICS
VOD
LVDS Differential Output
Voltage
460
mVP-P (min)
975
mVP-P (max)
300
mVP-P (min)
740
mVP-P (max)
ΔVO DIFF
Change in LVDS Output Swing
Between Logic Levels
VOS
Output Offset Voltage
See Figure 1
ΔVOS
Output Offset Voltage Change
Between Logic Levels
IOS
Output Short Circuit Current
ZO
Differential Output Impedance
VOH
CalRun H level output
IOH = −400 µA (Note 12)
1.65
1.5
V
VOL
CalRun L level output
IOH = 400 µA (Note 12)
0.15
0.3
V
Analog Supply Current
1:2 Demux Mode; fCLK = 1.5 GHz
PD = PDQ = Low
PD = Low, PDQ = High
PD = PDQ = High
810
560
1.3
930
630
mA (max)
mA (max)
mA
Output Driver Supply Current
1:2 Demux Mode; fCLK = 1.5 GHz
PD = PDQ = Low
PD = Low, PDQ = High
PD = PDQ = High
190
107
0.025
295
163
mA (max)
mA (max)
mA
PD
Power Consumption
1:2 Demux Mode; fCLK = 1.5 GHz
PD = PDQ = Low
PD = Low, PDQ = High
PD = PDQ = High
1.9
1.25
2.5
2.33
1.53
W (max)
W (max)
mW
PSRR1
D.C. Power Supply Rejection
Ratio
Change in Full Scale Error with change in
VA from 1.8V to 2.0V
±1
mV
VBG = Floating
800
mV
VBG = VA (Note 15)
1175
mV
±1
mV
±4
mA
Output+ and Output−
connected to 0.8V
100
Ohms
POWER SUPPLY CHARACTERISTICS (NON-DES MODE)
IA
IDR
12
-30
dB
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Limits
Units
(Limits)
Demux Mode (DES or Non-DES Mode)
1.5
GHz
1:2 Demux Non-DES Mode
200
MHz
1:4 Demux DES Mode
500
MHz
Input Clock Duty Cycle
fCLK(min) ≤ fCLK ≤ 1.5 GHz
(Note 12)
50
20
% (min)
80
% (max)
tCL
Input Clock Low Time
(Note 11)
333
133
ps (min)
tCH
Input Clock High Time
(Note 11)
333
133
ps (min)
45
55
% (min)
% (max)
Symbol
Parameter
Conditions
Typical
(Note 8)
A.C. ELECTRICAL CHARACTERISTICS
fCLK (max)
Maximum Input Clock
Frequency
fCLK (min)
Minimum Input Clock
Frequency
DCLK Duty Cycle
(Note 11)
50
tSR
Setup Time DCLK_RST±
(Note 12)
90
ps
tHR
Hold Time DCLK_RST±
(Note 12)
30
ps
tPWR
Pulse Width DCLK_RST±
(Note 11)
tLHT
Differential Low-to-High
Transition Time
10% to 90%, CL = 2.5 pF
150
ps
tHLT
Differential High-to-Low
Transition Time
10% to 90%, CL = 2.5 pF
150
ps
tOSK
DCLK-to-Data Output Skew
50% of DCLK transition to 50% of Data
transition, SDR Mode
and DDR Mode, 0° DCLK (Note 11)
±50
ps (max)
tSU
Data-to-DCLK Set-Up Time
DDR Mode, 90° DCLK (Note 11)
400
ps
tH
DCLK-to-Data Hold Time
DDR Mode, 90° DCLK (Note 11)
560
ps
tAD
Sampling (Aperture) Delay
Input CLK+ Fall to Acquisition of Data
1.6
ns
tAJ
Aperture Jitter
0.4
ps (rms)
tOD
Input Clock-to Data Output
Delay (in addition to Pipeline
Delay)
4.0
ns
50% of Input Clock transition to 50% of Data
transition
DI Outputs
13
DId Outputs
14
Pipeline Delay (Latency) in 1:2
Demux Mode
DQ Outputs
(Note 11, Note 14)
DQd Outputs
Pipeline Delay (Latency) in
Non-Demux Mode
(Note 11, Note 14)
Over Range Recovery Time
4
Non-DES Mode
13
DES Mode
13.5
Non-DES Mode
DES Mode
14.5
13
Non-DES Mode
13
DES Mode
Differential VIN step from ±1.2V to 0V to get
accurate conversion
Input Clock
Cycles
14
DI Outputs
DQ Outputs
Input Clock
Cycles (min)
13.5
Input Clock
Cycles
1
Input Clock
Cycle
500
ns
tWU
PD low to Rated Accuracy
Conversion (Wake-Up Time)
Non-DES Mode (Note 11)
DES Mode (Note 11)
1
µs
fSCLK
Serial Clock Frequency
(Note 11)
15
MHz
tSSU
Serial Data to Serial Clock
Rising Setup Time
(Note 11)
2.5
ns (min)
tSH
Serial Data to Serial Clock
Rising Hold Time
(Note 11)
1
ns (min)
tSCS
CS to Serial Clock Rising Setup
Time
2.5
ns
Copyright © 1999-2012, Texas Instruments Incorporated
13
ADC07D1520
Symbol
tHCS
Parameter
Conditions
CS to Serial Clock Falling Hold
Time
Typical
(Note 8)
Limits
1.5
Units
(Limits)
ns
Serial Clock Low Time
30
Serial Clock High Time
30
ns (min)
tCAL
Calibration Cycle Time
tCAL_L
CAL Pin Low Time
See Figure 10 (Note 11)
1280
Clock Cycles
(min)
tCAL_H
CAL Pin High Time
See Figure 10 (Note 11)
1280
Clock Cycles
(min)
CalDly = Low
See 1.1.1 Calibration, Figure 10,
(Note 11)
226
Clock Cycles
(max)
CalDly = High
See 1.1.1 Calibration, Figure 10,
(Note 11)
232
Clock Cycles
(max)
tCalDly
14
Calibration delay determined
by CalDly (pin 127)
1.4 x 106
ns (min)
Clock Cycles
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. There is no guarantee of operation at the Absolute Maximum
Ratings. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications
and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics
may degrade when the device is not operated under the listed test conditions.
Note 2: All voltages are measured with respect to GND = DR GND = 0V, unless otherwise specified.
Note 3: When the input voltage at any pin exceeds the power supply limits (that is, less than GND or greater than VA), the current at that pin should be limited to
25 mA. The 50 mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 25 mA to
two. This limit is not placed upon the power, ground and digital output pins.
Note 4: Human body model is 100 pF capacitor discharged through a 1.5 kΩ resistor. Machine model is 220 pF discharged through ZERO Ohms. Charged device
model simulates a pin slowly acquiring charge (such as from a device sliding down the feeder in an automated assembler) then rapidly being discharged.
Note 5: Reflow temperature profiles are different for lead-free and non-lead-free packages.
Note 6: The analog inputs are protected as shown below. Input voltage magnitudes beyond the Absolute Maximum Ratings may damage this device.
30194104
Note 7: To guarantee accuracy, it is required that VA and VDR be well bypassed. Each supply pin must be decoupled with separate bypass capacitors. Additionally,
achieving rated performance requires that the backside exposed pad be well grounded.
Note 8: Typical figures represent most likely parametric norms at TA = 25°C and nominal supply voltages at the time of product characterization and are not
guaranteed.
Note 9: Calculation of Full-Scale Error for this device assumes that the actual reference voltage is exactly its nominal value. Full-Scale Error for this device,
therefore, is a combination of Full-Scale Error and Reference Voltage Error. See Figure 2. For relationship between Gain Error and Full-Scale Error, see
Specification Definitions for Gain Error.
Note 10: The analog and clock input capacitances are die capacitances only. Additional package capacitances of 0.65 pF differential and 0.95 pF each pin to
ground are isolated from the die capacitances by lead and bond wire inductances.
Note 11: This parameter is guaranteed by design and is not tested in production.
Note 12: This parameter is guaranteed by design and/or characterization and is not tested in production.
Note 13: The digital control pin capacitances are die capacitances only. Additional package capacitance of 1.6 pF each pin to ground are isolated from the die
capacitances by lead and bond wire inductances.
Note 14: The ADC07D1520 has two LVDS output buses, each of which clocks data out at one half the sample rate. The second bus (D0 through D6) has a
pipeline latency that is one clock cycle less than the latency of the first bus (Dd0 through Dd6).
Note 15: Tying VBG to the supply rail will increase the output offset voltage (VOS) by 400mv (typical), as shown in the VOS specification above. Tying VBG to the
supply rail will also affect the differential LVDS output voltage (VOD), causing it to increase by 40mV (typical).
Note 16: The maximum clock frequency for Non-Demux Mode is 1 GHz.
Note 17: This feature is not tested for performance or functionality in production.
Note 18: Production test coverage does not guarantee all possible combinations of Non-Extended and/or Extended mode device configuration settings.
Copyright © 1999-2012, Texas Instruments Incorporated
15
ADC07D1520
Specification Definitions
APERTURE (SAMPLING) DELAY is the amount of delay, measured from the sampling edge of the CLK input, after which the
signal present at the input pin is sampled inside the device.
APERTURE JITTER (tAJ) is the variation in aperture delay from sample to sample. Aperture jitter shows up as input noise.
CODE ERROR RATE (C.E.R.) is the probability of error and is defined as the probable number of word errors on the ADC output
per unit of time divided by the number of words seen in that amount of time. A C.E.R. of 10-18 corresponds to a statistical error in
one word about every four (4) years.
CLOCK DUTY CYCLE is the ratio of the time that the clock waveform is at a logic high to the total time of one clock period.
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of the maximum deviation from the ideal step size of 1 LSB. Measured
at sample rate = 500 MSPS with a 1MHz input sine wave.
EFFECTIVE NUMBER OF BITS (ENOB, or EFFECTIVE BITS) is another method of specifying Signal-to-Noise and Distortion
Ratio, or SINAD. ENOB is defined as (SINAD − 1.76) / 6.02 and says that the converter is equivalent to a perfect ADC of this
(ENOB) number of bits.
FULL POWER BANDWIDTH (FPBW) is a measure of the frequency at which the reconstructed output fundamental drops 3 dB
below its low frequency value for a full-scale input.
GAIN ERROR is the deviation from the ideal slope of the transfer function. It can be calculated from Offset and Full-Scale Errors:
Positive Gain Error = Offset Error − Positive Full-Scale Error
Negative Gain Error = −(Offset Error − Negative Full-Scale Error)
Gain Error = Negative Full-Scale Error − Positive Full-Scale Error = Positive Gain Error + Negative Gain Error
INTEGRAL NON-LINEARITY (INL) is a measure of worst case deviation of the ADC transfer function from an ideal straight line
drawn through the ADC transfer function. The deviation of any given code from this straight line is measured from the center of
that code value step. The best fit method is used.
INTERMODULATION DISTORTION (IMD) is the creation of additional spectral components as a result of two sinusoidal frequencies being applied to the ADC input at the same time. It is defined as the ratio of the power in the second and third order
intermodulation products to the power in one of the original frequencies. IMD is usually expressed in dBFS.
LSB (LEAST SIGNIFICANT BIT) is the bit that has the smallest value or weight of all bits. This value is
VFS / 2N
where VFS is the differential full-scale amplitude VIN as set by the FSR input and "N" is the ADC resolution in bits, which is 7 for the
ADC07D1520.
LOW VOLTAGE DIFFERENTIAL SIGNALING (LVDS) DIFFERENTIAL OUTPUT VOLTAGE (VID and VOD) is two times the absolute value of the difference between the VD+ and VD - signals; each measured with respect to Ground.
30194146
FIGURE 1. LVDS Output Signal Levels
LVDS OUTPUT OFFSET VOLTAGE (VOS) is the midpoint between the D+ and D- pins output voltage with respect to ground; i.e.,
[(VD+) +( VD-)]/2. See Figure 1.
MISSING CODES are those output codes that are skipped and will never appear at the ADC outputs. These codes cannot be
reached with any input value.
MSB (MOST SIGNIFICANT BIT) is the bit that has the largest value or weight. Its value is one half of full scale.
NEGATIVE FULL-SCALE ERROR (NFSE) is a measure of how far the first code transition is from the ideal 1/2 LSB above a
differential −VIN/2 with the FSR pin low. For the ADC07D1520 the reference voltage is assumed to be ideal, so this error is a
combination of full-scale error and reference voltage error.
OFFSET ERROR (VOFF) is a measure of how far the mid-scale point is from the ideal zero voltage differential input.
Offset Error = Actual Input causing average of 8k samples to result in an average code of 127.5.
OUTPUT DELAY (tOD) is the time delay (in addition to Pipeline Delay) after the falling edge of CLK+ before the data update is
present at the output pins.
OVER-RANGE RECOVERY TIME is the time required after the differential input voltages goes from ±1.2V to 0V for the converter
to recover and make a conversion with its rated accuracy.
16
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
PIPELINE DELAY (LATENCY) is the number of input clock cycles between initiation of conversion and when that data is presented
to the output driver stage. New data is available at every clock cycle, but the data lags the conversion by the Pipeline Delay plus
the tOD.
POSITIVE FULL-SCALE ERROR (PFSE) is a measure of how far the last code transition is from the ideal 1-1/2 LSB below a
differential +VIN/2. For the ADC07D1520 the reference voltage is assumed to be ideal, so this error is a combination of full-scale
error and reference voltage error.
POWER SUPPLY REJECTION RATIO (PSRR) can be one of two specifications. PSRR1 (D.C. PSRR) is the ratio of the change
in full-scale error that results from a power supply voltage change from 1.8V to 2.0V. PSRR2 (A.C. PSRR) is a measure of how
well an a.c. signal riding upon the power supply is rejected from the output and is measured with a 248 MHz, 50 mVP-P signal riding
upon the power supply. It is the ratio of the output amplitude of that signal at the output to its amplitude on the power supply pin.
PSRR is expressed in dB.
SIGNAL TO NOISE RATIO (SNR) is the ratio, expressed in dB, of the rms value of the input signal at the output to the rms value
of the sum of all other spectral components below one-half the sampling frequency, not including harmonics or d.c.
SIGNAL TO NOISE PLUS DISTORTION (S/(N+D) or SINAD) is the ratio, expressed in dB, of the rms value of the input signal at
the output to the rms value of all of the other spectral components below half the input clock frequency, including harmonics but
excluding d.c.
SPURIOUS-FREE DYNAMIC RANGE (SFDR) is the difference, expressed in dB, between the rms values of the input signal at
the output and the peak spurious signal, where a spurious signal is any signal present in the output spectrum that is not present
at the input, excluding d.c.
TOTAL HARMONIC DISTORTION (THD) is the ratio expressed in dB, of the rms total of the first nine harmonic levels at the output
to the level of the fundamental at the output. THD is calculated as
where Af1 is the RMS power of the fundamental (output) frequency and Af2 through Af10 are the RMS power of the first 9 harmonic
frequencies in the output spectrum.
– Second Harmonic Distortion (2nd Harm) is the difference, expressed in dB, between the RMS power in the input frequency
seen at the output and the power in its 2nd harmonic level at the output.
– Third Harmonic Distortion (3rd Harm) is the difference expressed in dB between the RMS power in the input frequency seen
at the output and the power in its 3rd harmonic level at the output.
Copyright © 1999-2012, Texas Instruments Incorporated
17
ADC07D1520
Transfer Characteristic
30194122
FIGURE 2. Input / Output Transfer Characteristic
18
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Timing Diagrams
30194114
FIGURE 3. SDR Clocking in 1:2 Demultiplexed Non-DES Mode
30194159
FIGURE 4. DDR Clocking in 1:2 Demultiplexed Non-DES Mode
Copyright © 1999-2012, Texas Instruments Incorporated
19
ADC07D1520
30194160
FIGURE 5. DDR Clocking in Non-Demultiplexed Non-DES Mode
30194119
FIGURE 6. Serial Interface Timing
30194120
FIGURE 7. Clock Reset Timing in DDR Mode
20
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
30194123
FIGURE 8. Clock Reset Timing in SDR Mode with OUTEDGE Low
30194124
FIGURE 9. Clock Reset Timing in SDR Mode with OUTEDGE High
30194125
FIGURE 10. Power-on and On-Command Calibration Timing
Copyright © 1999-2012, Texas Instruments Incorporated
21
ADC07D1520
Typical Performance Characteristics VA = VDR = 1.9V, fCLK = 1500 MHz, fIN = 748 MHz, TA= 25°C, I
channel, 1:2 Demux Mode (1:1 Demux Mode has similar performance), unless otherwise stated.
ENOB vs. TEMPERATURE
2.5
7.0
2.0
6.9
ENOB
POWER (W)
POWER CONSUMPTION vs. CLOCK FREQUENCY
1.5
6.8
1.0
6.7
0
500
1000
CLOCK FREQUENCY (MHz)
1500
-50
0
50
TEMPERATURE (°C)
100
30194181
30194196
ENOB vs. SUPPLY VOLTAGE
7.0
ENOB vs. CLOCK FREQUENCY
7.0
I Channel
Q Channel
ENOB
6.9
ENOB
6.9
I-Channel
Q-Channel
6.8
6.8
6.7
6.7
1.80
1.85
1.90
VA (V)
1.95
2.00
0
500
1000
CLOCK FREQUENCY (MHz)
1500
30194177
30194178
ENOB vs. INPUT FREQUENCY
7.0
SNR vs. TEMPERATURE
45
I-Channel
Q-Channel
44
SNR (dB)
ENOB
6.8
6.6
6.4
43
42
6.2
6.0
41
0
500
1000
INPUT FREQUENCY (MHz)
1500
30194179
22
-50
0
50
TEMPERATURE (°C)
100
30194168
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
SNR vs. SUPPLY VOLTAGE
45
SNR vs. CLOCK FREQUENCY
45
I-Channel
Q-Channel
44
SNR (dB)
SNR (dB)
44
I-Channel
Q-Channel
43
43
42
42
41
41
1.80
1.85
1.90
VA (V)
1.95
2.00
0
500
1000
CLOCK FREQUENCY (MHz)
1500
30194169
30194170
SNR vs. INPUT FREQUENCY
45
THD vs. TEMPERATURE
-40
I-Channel
Q-Channel
-45
THD (dB)
SNR (dB)
44
43
42
-50
-55
41
-60
0
500
1000
INPUT FREQUENCY (MHz)
1500
-50
0
50
TEMPERATURE (°C)
100
30194171
30194172
THD vs. SUPPLY VOLTAGE
-40
THD vs. CLOCK FREQUENCY
-40
I-Channel
Q-Channel
-45
THD (dB)
THD (dB)
-45
-50
-55
-50
-55
-60
1.80
I-Channel
Q-Channel
-60
1.85
1.90
VA (V)
1.95
2.00
30194173
Copyright © 1999-2012, Texas Instruments Incorporated
0
500
1000
CLOCK FREQUENCY (MHz)
1500
30194174
23
ADC07D1520
THD vs. INPUT FREQUENCY
-40
SFDR vs. TEMPERATURE
65
I-Channel
Q-Channel
60
SFDR (dB)
THD (dB)
-45
-50
55
-55
50
-60
45
0
500
1000
INPUT FREQUENCY (MHz)
1500
-50
0
50
TEMPERATURE (°C)
100
30194175
30194185
SFDR vs. SUPPLY VOLTAGE
65
SFDR vs. CLOCK FREQUENCY
65
I-Channel
Q-Channel
60
SFDR (dB)
SFDR (dB)
60
I-Channel
Q-Channel
55
50
55
50
45
45
1.80
1.85
1.90
VA (V)
1.95
2.00
0
500
1000
CLOCK FREQUENCY (MHz)
1500
30194184
30194182
SFDR vs. INPUT FREQUENCY
65
Spectral Response at FIN = 373 MHz
0
I-Channel
Q-Channel
-10
MAGNITUDE (dBFS)
SFDR (dB)
60
55
50
-20
-30
-40
-50
-60
-70
45
-80
0
500
1000
INPUT FREQUENCY (MHz)
1500
30194183
24
0
250
500
FREQUENCY (MHz)
750
30194187
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Spectral Response at FIN = 748 MHz
CROSSTALK vs. SOURCE FREQUENCY
0
MAGNITUDE (dBFS)
-10
-20
-30
-40
-50
-60
-70
-80
0
250
500
FREQUENCY (MHz)
750
30194188
FULL POWER BANDWIDTH (NON-DES MODE)
30194186
Copyright © 1999-2012, Texas Instruments Incorporated
30194163
GAIN STABILITY vs. DIE TEMPERATURE
30194195
25
ADC07D1520
1.0 Functional Description
The ADC07D1520 is a versatile A/D Converter with an innovative architecture permitting very high speed operation. The controls
available ease the application of the device to circuit solutions. Optimum performance requires adherence to the provisions discussed here and in the Applications Information Section.
While it is generally poor practice to allow an active pin to float, pins 4, 14, 52 and 127 of the ADC07D1520 are designed to be left
floating without jeopardy. In all discussions for pins 4, 14, and 127, whenever a function is called by allowing these control pins to
float, connecting that pin to a potential of one half the VA supply voltage will have the same effect as allowing it to float.
1.1 OVERVIEW
The ADC07D1520 uses a calibrated folding and interpolating architecture that achieves 6.8 effective bits. The use of folding amplifiers greatly reduces the number of comparators and power consumption. Interpolation reduces the number of front-end amplifiers
required, minimizing the load on the input signal and further reducing power requirements. In addition to correcting other nonidealities, on-chip calibration reduces the INL bow often seen with folding architectures. The result is an extremely fast, high
performance, low power converter.
The analog input signal that is within the converter's input voltage range is digitized to seven bits at speeds of 200 MSPS to 1.5
GSPS. Differential input voltages below negative full-scale will cause the output word to consist of all zeroes. Differential input
voltages above positive full-scale will cause the output word to consist of all ones. Either of these conditions at either the I- or Qchannel will cause the Out of Range (OR) output to be activated. This single OR output indicates when the output code from one
or both of the channels is below negative full scale or above positive full scale. When PDQ is asserted, the OR indication applies
to the I channel only.
For Non-DES Modes, each converter has a selectable output demultiplexer which feeds two LVDS buses. If the 1:2 Demux Mode
is selected, the output data rate is reduced to half the input sample rate on each bus. When Non-demux Mode is selected, the
output data rate on channels DI and DQ are at the same rate as the input sample clock.
The output levels may be selected to be normal or reduced. Using reduced levels saves power but could result in erroneous data
capture of some or all of the bits, especially at higher sample rates and in marginally designed systems.
1.1.1 Calibration
A calibration is performed upon power-up and can also be invoked by the user upon command. Calibration trims the 100Ω analog
input differential termination resistor and minimizes full-scale error, offset error, DNL and INL, resulting in maximizing SNR, THD,
SINAD (SNDR) and ENOB. Internal bias currents are also set during the calibration process. All of this is true whether the calibration
is performed upon power up or is performed upon command. Running the calibration is required for proper operation and to obtain
the ADC's specified performance. In addition to the requirement to be run at power-up, an on-command calibration must be run
whenever the sense of the FSR pin is changed. For best performance, it is recommend that an on-command calibration be run 20
seconds or more after application of power and whenever the operating temperature changes significantly, relative to the specific
system performance requirements. See 2.4.2.2 On-Command Calibration for more information. Calibration cannot be initiated or
run while the device is in the power-down mode. See 1.1.7 Power Down for information on the interaction between Power Down
and Calibration.
In normal operation, calibration is performed just after application of power and whenever a valid calibration command is given,
which may be accomplished one of two ways, via the CAL pin (30) or the Calibration register (Addr: 0h, Bit 15). The calibration
command is achieved by holding the CAL pin low for at least tCAL_L clock cycles, and then holding it high for at least another
tCAL_H clock cycles, as defined in the Converter Electrical Characteristics. The time taken by the calibration procedure is specified
as tCALin Converter Electrical Characteristics. Holding the CAL pin high upon power up will prevent the calibration process from
running until the CAL pin experiences the above-mentioned tCAL_L clock cycles followed by tCAL_H clock cycles.
CalDly (pin 127) is used to select one of two delay times that take place from the application of power to the start of calibration.
This calibration delay time is dependent on the setting of the CalDly pin and is specified as tCalDly in the Converter Electrical
Characteristics. These delay values allow the power supply to come up and stabilize before calibration takes place. If the PD pin
is high upon power-up, the calibration delay counter will be disabled until the PD pin is brought low. Therefore, holding the PD pin
high during power up will further delay the start of the power-up calibration cycle. The best setting of the CalDly pin depends upon
the power-on settling time of the power supply.
1.1.2 Acquiring the Input
In 1:2 Demux Non-DES Mode, data is acquired at the falling edge of CLK+ (pin 18) and the digital equivalent of that data is available
at the digital outputs 13 input clock cycles later for the DI and DQ output buses and 14 input clock cycles later for the DId and DQd
output buses. See Pipeline Delay in the Converter Electrical Characteristics. There is an additional internal delay called tOD before
the data is available at the outputs. See the Timing Diagrams. The ADC07D1520 will convert as long as the input clock signal is
present. The fully differential comparator design and the innovative design of the sample-and-hold amplifier, together with self
calibration, enables a very flat SINAD/ENOB response beyond 1.5 GHz. The ADC07D1520 output data signaling is LVDS and the
output format is offset binary.
1.1.3 Control Modes
Much of the user control can be accomplished with several control pins that are provided. Examples include initiation of the calibration cycle, power down mode and full scale range setting. However, the ADC07D1520 also provides an Extended Control Mode
whereby a serial interface is used to access register-based control of several advanced features. The Extended Control Mode is
not intended to be enabled and disabled dynamically. Rather, the user is expected to employ either the Non-extended Control
Mode or the Extended Control Mode at all times. When the device is in the Extended Control Mode, pin-based control of several
26
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
features is replaced with register-based control and those pin-based controls are disabled. These pins are OutV (pin 3), OutEdge/
DDR (pin 4), FSR (pin 14) and CalDly/DES (pin 127). See 1.2 NON-EXTENDED AND EXTENDED CONTROL MODE for details
on the Extended Control Mode.
1.1.4 The Analog Inputs
The ADC07D1520 must be driven with a differential input signal. Operation with a single-ended signal is not recommended. It is
important that the inputs either be a.c. coupled to the inputs with the VCMO (pin 7) grounded, or d.c. coupled with the VCMO pin left
floating. An input common mode voltage equal to the VCMO output must be provided as the common mode input voltage to VIN+
and VIN- when d.c. coupling is used.
Two full-scale range settings are provided via pin 14 (FSR). In Non-extended Control Mode, a logic high on pin 14 causes an input
full-scale range setting of a normal VIN input level, while a logic low on pin 14 causes an input full-scale range setting of a reduced
VIN input level. The full-scale range setting operates on both ADCs.
In the Extended Control Mode, programming the Input Full-Scale Voltage Adjust register allows the input full-scale range to be
adjusted as described in 1.4 REGISTER DESCRIPTION and 2.2 THE ANALOG INPUT.
1.1.5 Clocking
The ADC07D1520 must be driven with an a.c. coupled, differential clock signal. 2.3 THE CLOCK INPUTS describes the use of the
clock input pins. A differential LVDS output clock is available for use in latching the ADC output data into whatever device is used
to receive the data.
The ADC07D1520 offers output clocking options: two of these options are Single Data Rate (SDR) and Double Data Rate (DDR).
In SDR mode, the user has a choice of which Data Clock (DCLK) edge, rising or falling, the output data transitions on.
The ADC07D1520 also has the option to use a duty cycle corrected clock receiver as part of the input clock circuit. This feature is
enabled by default and provides improved ADC clocking, especially in the Dual-Edge Sampling (DES) Mode. This circuitry allows
the ADC to be clocked with a signal source having a duty cycle ratio of 20%/80% (worst case) for both the Non-DES and the DES
Modes.
1.1.5.1 Dual-Edge Sampling
The Dual-Edge Sampling (DES) Mode allows either of the ADC07D1520's inputs (I- or Q-channel) to be sampled by both ADCs.
One ADC samples the input on the rising edge of the input clock and the other ADC samples the same input on the falling edge of
the input clock. A single input is thus sampled twice per input clock cycle, resulting in an overall sample rate of twice the input clock
frequency, or 3 GSPS with a 1.5 GHz input clock.
In this mode, the outputs must be carefully interleaved to reconstruct the sampled signal. If the device is programmed into the 1:4
Demux DES Mode, the data is effectively demultiplexed by 1:4. If the input clock is 1.5 GHz, the effective sampling rate is doubled
to 3 GSPS and each of the 4 output buses has an output rate of 750 MHz. All data is available in parallel. To properly reconstruct
the sampled waveform, the four bytes of parallel data that are output with each clock are in the following sampling order, from the
earliest to the latest, and must be interleaved as such: DQd, DId, DQ, DI. Table 1 indicates what the outputs represent for the
various sampling possibilities. If the device is programmed into the Non-demux DES Mode, two bytes of parallel data are output
with each edge of the clock in the following sampling order, from the earliest to the latest: DQ, DI. See Table 2.
In the Non-extended Control and DES Mode of operation, only the I-channel can be sampled. In the Extended Control Mode of
operation, the user can select which input is sampled.
The ADC07D1520 also includes an automatic clock phase background adjustment in DES Mode to automatically and continuously
adjust the clock phase of the I- and Q-channels. This feature removes the need to adjust the clock phase setting manually and
provides optimal DES Mode performance.
TABLE 1. Input Channel Samples Produced at Data Outputs in 1:2 Demultiplexed Mode**
Data Outputs
(Always sourced with
respect to fall of DCLK+)
Dual-Edge Sampling (DES) Mode
Non-DES Sampling Mode
I-Channel Selected
Q-Channel Selected *
DI
I-channel sampled with fall of CLK,
13 cycles earlier.
I-channel sampled with fall
of CLK,
13 cycles earlier.
Q-channel sampled with fall
of CLK,
13 cycles earlier.
DId
I-channel sampled with fall of CLK,
14 cycles earlier.
I-channel sampled with fall
of CLK,
14 cycles earlier.
Q-channel sampled with fall
of CLK,
14 cycles earlier.
DQ
I-channel sampled with rise Q-channel sampled with rise
Q-channel sampled with fall of CLK,
of CLK,
of CLK,
13 cycles earlier.
13.5 cycles earlier.
13.5 cycles earlier.
DQd
I-channel sampled with rise Q-channel sampled with rise
Q-channel sampled with fall of CLK,
of CLK,
of CLK,
14 cycles earlier.
14.5 cycles earlier.
14.5 cycles earlier.
* Note that, in DES Mode and Non-extended Control Mode, only the I-channel is sampled. In DES Mode and Extended Control Mode, the I- or Q-channel can be
sampled.
** Note that, in the Non-demux Mode (DES and Non-DES Mode), the DId and DQd outputs are disabled and are high impedance.
Copyright © 1999-2012, Texas Instruments Incorporated
27
ADC07D1520
TABLE 2. Input Channel Samples Produced at Data Outputs in Non-Demux Mode
Data Outputs
(Always sourced with
respect to fall of DCLK+)
Dual-Edge Sampling (DES) Mode
Non-DES Sampling Mode
I-Channel Selected
Q-Channel Selected
DI
I-channel sampled with fall of CLK,
14 cycles earlier.
I-channel sampled with fall
of CLK,
14 cycles earlier.
Q-channel sampled with fall
of CLK,
13.5 cycles earlier.
DId
No output;
high impedance.
No output;
high impedance.
No output;
high impedance.
DQ
I-channel sampled with rise Q-channel sampled with rise
Q-channel sampled with fall of CLK,
of CLK,
of CLK,
13.5 cycles earlier.
13.5 cycles earlier.
13.5 cycles earlier.
DQd
No output;
high impedance.
No output;
high impedance.
No output;
high impedance.
1.1.5.2 OutEdge and Demultiplex Control Setting
To help ease data capture in the Single Data Rate (SDR) mode, the output data may be caused to transition on either the positive
or the negative edge of the output data clock (DCLK). In the Non-extended Control Mode, this is selected by OutEdge (pin 4). A
logic high on the OutEdge input pin causes the output data to transition on the rising edge of DCLK+, while a logic low causes the
output to transition on the falling edge of DCLK+. See 2.4.3 Output Edge Synchronization. When in the Extended Control Mode,
the OutEdge is selected using the OED bit in the Configuration Register. This bit has two functions. In the SDR mode, the bit
functions as OutEdge and selects the DCLK edge with which the data transitions. In the Double Data Rate (DDR) mode, this bit
selects whether the device is in Non-demux or Demux Mode. In the DDR case, the DCLK has a 0° phase relationship with the
output data, independent of the demultiplexer selection. For 1:2 Demux DDR 0° Mode, there are four, as opposed to three cycles
of CLK delay from the deassertion of DCLK_RST to the Synchronizing Edge. See 1.5 MULTIPLE ADC SYNCHRONIZATION for
more information.
1.1.5.3 Double Data Rate and Single Data Rate
A choice of Single Data Rate (SDR) or Double Data Rate (DDR) output is offered. With SDR, the output clock (DCLK) frequency
is the same as the data rate of the two output buses. With DDR, the DCLK frequency is half the data rate and data is sent to the
outputs on both edges of DCLK. DDR clocking is enabled in Non-extended Control Mode by allowing pin 4 to float or by biasing it
to half the supply.
1.1.5.4 Clocking Summary
The chip may be in one of four modes, depending on the Dual-Edge Sampling (DES) selection and the demultiplex selection. For
the DES selection, there are two possibilities: Non-DES Mode and DES Mode. In Non-DES Mode, each of the channels (I-channel
and Q-channel) functions independently, i.e. the chip is a dual 1.5 GSPS A/D converter. In DES Mode, the I- and Q-channels are
interleaved and function together as one 3.0 GSPS A/D converter. For the demultiplex selection, there are also two possibilities:
Demux Mode and Non-Demux Mode. The I-channel has two 7-bit output busses associated with it: DI and DId. The Q-channel
also has two 7-bit output busses associated with it: DQ and DQd. In Demux Mode, the channel is demultiplexed by 1:2. In NonDemux Mode, the channel is not demultiplexed. Note that Non-Demux Mode is also sometimes referred to as 1:1 Demux Mode.
For example, if the I-channel was in Non-Demux Mode, the corresponding digital output data would be available on only the DI
bus. If the I-channel was in Demux Mode, the corresponding digital output data would be available on both the DI and DId busses,
but at half the rate of Non-Demux Mode.
Given that there are two DES Mode selections (DES Mode and Non-DES Mode) and two demultiplex selections (Demux Mode
and Non-Demux Mode), this yields a total of four possible modes: (1) Non-Demux Non-DES Mode, (2) Non-Demux DES Mode,
(3) 1:2 Demux Non-DES Mode, and (4) 1:4 Demux DES Mode. The following is a brief explanation of the terms and modes:
1. Non-Demux Non-DES Mode: This mode is when the chip is in Non-Demux Mode and Non-DES Mode. The I- and Q- channels
function independently of one another. The digital output data is available for the I-channel on DI, and for the Q-channel on
DQ.
2. Non-Demux DES Mode: This mode is when the chip is in Non-Demux Mode and DES Mode. The I- and Q- channels are
interleaved and function together as one channel. The digital output data is available on the DI and DQ busses because
although the chip is in Non-Demux Mode, both I- and Q-channels are functioning and passing data.
3. 1:2 Demux Non-DES Mode: This mode is when the chip is in Demux Mode and Non-DES Mode. The I- and Q- channels
function independently of one another. The digital output data is available for the I-channel on DI and DId, and for the Q-channel
on DQ and DQd. This is because each channel (I-channel and Q-channel) is providing digital data in a demultiplexed manner.
4. 1:4 Demux DES Mode: This mode is when the chip is in Demux Mode and DES Mode. The I- and Q- channels are interleaved
and function together as one channel. The digital output data is available on the DI, DId, DQ and DQd busses because although
the chip is in Demux Mode, both I- and Q-channels are functioning and passing data. To avoid confusion, this mode is labeled
1:4 because the analog input signal is provided on one channel and the digital output data is provided on four busses.
The choice of Dual Data Rate (DDR) and Single Data Rate (SDR) will only affect the speed of the output Data Clock (DCLK). Once
the DES Modes and Demux Modes have been chosen, the data output rate is also fixed. In the case of SDR, the DCLK runs at
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
the same rate as the output data; output data may transition with either the rising or falling edge of DCLK. In the case of DDR, the
DCLK runs at half the rate of the output data; the output data transitions on both rising and falling edges of the DCLK.
1.1.6 The LVDS Outputs
The Data, Out Of Range (OR+/-), and Data Clock (DCLK+/-) outputs are LVDS. The electrical specifications of the LVDS outputs
are compatible with typical LVDS receivers available on ASIC and FPGA chips; but they are not IEEE or ANSI communications
standards compliant due to the low +1.9V supply used on this chip. The user is given the choice of a lower signal amplitude via the
OutV control pin or the OV control register bit. For short LVDS lines and low noise systems, satisfactory performance may be
realized with the OutV input low, which results in lower power consumption. If the LVDS lines are long and/or the system in which
the ADC07D1520 is used is noisy, it may be necessary to tie the OutV pin high.
The LVDS data outputs have a typical common mode voltage of 800 mV when the VBG pin is unconnected and floating. If a higher
common mode is required, this common mode voltage can be increased to 1175 mV by tying the VBG pin to VA .
IMPORTANT NOTE: Tying the VBG pin to VA will also increase the differential LVDS output voltage by up to 40mV.
1.1.7 Power Down
The ADC07D1520 is in the active state when the Power Down pin (PD) is low. When the PD pin is high, the device is in the power
down mode. In this mode, the data output pins (both positive and negative) are put into a high impedance state and the device's
power consumption is reduced to a minimal level.
A logic high on the Power Down Q-channel (PDQ) pin will power down the Q-channel and leave the I-channel active. There is no
provision to power down the I-channel independently of the Q-channel. Upon return to normal operation, the pipeline will contain
meaningless information.
If the PD input is brought high while a calibration is running, the device will not go into power down until the calibration sequence
is complete. However, if power is applied and PD is already high, the device will not begin the calibration sequence until PD is
brought low. If a manual calibration is requested while the device is powered down, the calibration will not take place at all. That
is, the manual calibration input is completely ignored in the power down state. Calibration will function with the Q-channel powered
down, but that channel will not be calibrated if PDQ is high. If the Q-channel is subsequently to be used, it is necessary to perform
a calibration after PDQ is brought low.
1.2 NON-EXTENDED AND EXTENDED CONTROL MODE
Note: Production test coverage does not guarantee all possible combinations of Non-Extended and/or Extended mode device
configuration settings.
The ADC07D1520 may be operated in one of two control modes: Non-extended Control Mode or Extended Control Mode. In the
simpler Non-extended Control Mode, the user affects available configuration and control of the device through several control pins.
The Extended Control Mode provides additional configuration and control options through a serial interface and a set of 9 registers.
Extended Control Mode is selected by setting pin 41 to logic low. If pin 41 is floating and pin 52 is floating or logic high, pin 14 can
alternately be used to enable the Extended Control Mode. The choice of control modes is required to be a fixed selection and is
not intended to be switched dynamically while the device is operational.
Table 3 shows how several of the device features are affected by the control mode chosen.
TABLE 3. Features and Modes
Feature
Non-Extended Control Mode
Extended Control Mode
SDR or DDR Clocking
Selected with pin 4
Selected with nDE in the Configuration
Register (Addr-1h; bit-10).
DDR Clock Phase
Not Selectable (0° Phase Only)
Selected with DCP in the Configuration
Register (Addr-1h; bit-11).
SDR Data transitions with rising or
falling DCLK edge
SDR Data transitions with rising edge of
DCLK+ when pin 4 is logic high and on
falling edge when low.
Selected with OED in the Configuration
Register (Addr-1h; bit-8).
LVDS output level
Normal differential data and DCLK
amplitude selected when pin 3 is logic
high and reduced amplitude selected
when low.
Selected with OV in the Configuration
Register (Addr-1h; bit-9).
Power-On Calibration Delay
Short delay selected when pin 127 is logic
Short delay only.
low and longer delay selected when high.
Full-Scale Range
Normal input full-scale range selected
when pin 14 is logic high and reduced
range when low. Selected range applies
to both channels.
Copyright © 1999-2012, Texas Instruments Incorporated
Up to 512 step adjustments over a
nominal range specified in 1.4
REGISTER DESCRIPTION. Separate
range selected for I- and Q-channels.
Selected using Full Range Registers
(Addr-3h and Bh; bit-7 through 15).
29
ADC07D1520
512 steps of adjustment using the Input
Offset register specified in 1.4
REGISTER DESCRIPTION for each
channel using Input Offset Registers
(Addr-2h and Ah; bit-7 thru 15).
Input Offset Adjust
Not possible
Dual Edge Sampling Selection
Enabled by programming DEN in the
Enabled with pin 127 floating or tied to half
Extended Configuration Register
the supply
(Addr-9h; bit-13).
Dual Edge Sampling Input Channel
Selection
Only I-channel Input can be used
Either I- or Q-channel input may be
sampled by both ADCs.
Not possible
A test pattern can be made present at
the data outputs by setting TPO to 1b in
Extended Configuration Register
(Addr-9h; bit-15).
Not possible
The DCLK outputs will continuously be
present when RTD is set to 1b in
Extended Configuration Register
(Addr-9h; bit-14 to 7).
Not possible
If the device is set in DDR, the output can
be programmed to be nondemultiplexed. When OED in
Configuration Register is set 1b
(Addr-1h; bit-8), this selects nondemultiplex. If OED is set 0b, this selects
1:2 demultiplex.
Not possible
The OR outputs can be programmed to
become a second DCLK output when
nSD is set 0b in Configuration Register
(Addr-1h; bit-13).
Not possible
The sampling clock phase can be
manually adjusted through the Coarse
and Intermediate Register (Addr-Fh;
bit-15 to 7) and Fine Register (Addr-Eh;
bit-15 to 8).
Test Pattern
Resistor Trim Disable
Selectable Output Demultiplexer
Second DCLK Output
Sampling Clock Phase Adjust
The default state of the Extended Control Mode is set upon power-on reset (internally performed by the device) and is shown in
Table 4.
TABLE 4. Extended Control Mode Operation
(Pin 41 Logic Low or Pin 52 Logic High or Floating and Pin 14 Floating or VA/2)
30
Feature
Extended Control Mode Default State
SDR or DDR Clocking
DDR Clocking
DDR Clock Phase
Data changes with DCLK edge (0° phase)
LVDS Output Amplitude
Normal amplitude
(See VOD in Converter Electrical Characteristics)
Calibration Delay
Short Delay
(See tCalDly in Converter Electrical Characteristics)
Full-Scale Range
Normal range for both channels
(See VIN in Converter Electrical Characteristics)
Input Offset Adjust
No adjustment for either channel
Dual Edge Sampling (DES)
Not enabled
Test Pattern
Not present at output
Resistor Trim Disable
Trim enabled, DCLK not continuously present at output
Selectable Output Demultiplexer
1:2 Demultiplex
Second DCLK Output
Not present, pin 79 and 80 function as OR+ and OR-, respectively
Sampling Clock Phase Adjust
No adjustment for fine, intermediate or coarse
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
1.3 THE SERIAL INTERFACE
IMPORTANT NOTE: During the initial write using the serial interface, all nine registers must be written with desired or default
values. Subsequent writes to single registers are allowed.
Note: Production test coverage does not guarantee all possible combinations of Non-Extended and/or Extended mode device
configuration settings.
The 3-pin serial interface is enabled only when the device is in the Extended Control Mode. The pins of this interface are Serial
Clock (SCLK), Serial Data (SDATA) and Serial Interface Chip Select (SCS). Nine write only registers are accessible through this
serial interface.
SCS: This signal should be asserted low while accessing a register through the serial interface. Setup and hold times with respect
to the SCLK must be observed.
SCLK: Serial data input is accepted at the rising edge of this signal. There is no minimum frequency requirement for SCLK.
SDATA: Each register access requires a specific 32-bit pattern at this input. This pattern consists of a header, register address
and register value. The data is shifted in MSB first. Setup and hold times with respect to the SCLK must be observed.
Each Register access consists of 32 bits, as shown in Figure 6 of the Timing Diagrams. The fixed header pattern is 0000 0000
0001 (eleven zeros followed by a 1). The loading sequence is such that a "0" is loaded first. These 12 bits form the header. The
next 4 bits are the address of the register that is to be written to and the last 16 bits are the data written to the addressed register.
The addresses of the various registers are indicated in Table 5.
Refer to 1.4 REGISTER DESCRIPTION for information on the data to be written to the registers.
Subsequent register accesses may be performed immediately, starting with the 33rd SCLK. This means that the SCS input does
not have to be de-asserted and asserted again between register addresses. It is possible, although not recommended, to keep the
SCS input permanently enabled (logic low) when using Extended Control Mode.
Control register contents are retained when the device is put into power-down mode.
IMPORTANT NOTE: Do not write to the Serial Interface when calibrating the ADC. Doing so will impair the performance of the
device until it is re-calibrated correctly. Programming the serial registers will also reduce dynamic performance of the ADC for the
duration of the register access time.
TABLE 5. Register Addresses
4-Bit Address
Loading Sequence:
A3 loaded after Fixed Header pattern, A0 loaded last
A3 A2 A1
A0 Hex
Register Addressed
0
0
0
0
0h
Calibration
0
0
0
1
1h
Configuration
0
0
1
0
2h
I-channel Offset
0
0
1
1
3h
I-channel Full-Scale Voltage Adjust
0
1
0
0
4h
Reserved
0
1
0
1
5h
Reserved
0
1
1
0
6h
Reserved
0
1
1
1
7h
Reserved
1
0
0
0
8h
Reserved
1
0
0
1
9h
Extended Configuration
1
0
1
0
Ah
Q-channel Offset
1
0
1
1
Bh
Q-channel Full-Scale Voltage Adjust
1
1
0
0
Ch
Reserved
1
1
0
1
Dh
Reserved
1
1
1
0
Eh
Sampling Clock Phase Fine Adjust
1
1
1
1
Fh
Sample Clock Phase Intermediate and Coarse Adjust
Copyright © 1999-2012, Texas Instruments Incorporated
31
ADC07D1520
1.4 REGISTER DESCRIPTION
Nine write-only registers provide several control and configuration options in the Extended Control Mode. These registers have no
effect when the device is in the Non-extended Control Mode. Each register description below also shows the Power-On Reset
(POR) state of each control bit.
Calibration Register
Addr: 0h (0000b)
Write only (0x7FFF)
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
CAL
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Bit 15
Bits 14:0
CAL: Calibration Enable. When this bit is set 1b, an on-command calibration cycle is initiated. This function
is exactly the same as issuing an on-command calibration using the CAL pin. This bit is OR'd with the
CAL pin (30).
POR State: 0b
Must be set to 1b
Configuration Register
Addr: 1h (0001b)
Write only (0xB2FF)
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
1
0
nSD
DCS DCP
nDE
OV
OED
1
1
1
1
1
1
1
1
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bits 7:0
Must be set to 1b
Must be set to 0b
nSD: Second DCLK Output. When this bit is 1b, the device only has one DCLK output and one OR output.
When this output is 0b, the device has two identical DCLK outputs and no OR output.
POR State: 1b
DCS: Duty Cycle Stabilizer. When this bit is set to 1b, a duty cycle stabilization circuit is applied to the
clock input. When this bit is set to 0b the stabilization circuit is disabled.
POR State: 1b
DCP: DDR Clock Phase. This bit only has an effect in the DDR mode. When this bit is set to 0b, the DCLK
edges are time-aligned with the data bus edges ("0° Phase"). When this bit is set to 1b, the DCLK edges
are placed in the middle of the data bit-cells ("90° Phase"), using the one-half speed DCLK shown in
Figure 4 as the phase reference.
POR State: 0b
nDE: DDR Enable. When this bit is set to 0b, data bus clocking follows the DDR mode whereby a data
word is output with each rising and falling edge of DCLK. When this bit is set to a 1b, data bus clocking
follows the SDR mode whereby each data word is output with either the rising or falling edge of DCLK,
as determined by the OutEdge bit.
POR State: 0b
OV: Output Voltage. This bit determines the LVDS outputs' voltage amplitude and has the same function
as the OutV pin that is used in the Non-extended Control Mode. When this bit is set to 1b, the normal
output amplitude is used. When this bit is set to 0b, the reduced output amplitude is used. See VOD in
Converter Electrical Characteristics.
POR State: 1b
OED: Output Edge and Demultiplex Control. This bit has two functions. When the device is in SDR mode,
this bit selects the DCLK edge with which the data words transition and has the same effect as the OutEdge
pin in the Non-extended Control Mode. When this bit is set to 1b, the data outputs change with the rising
edge of DCLK+. When this bit is set to 0b, the data output changes with the falling edge of DCLK+. When
the device is in DDR mode, this bit selects the Non-demultiplexed Mode when set to 1b. When the bit set
to 0b, the device is programmed into the Demultiplexed Mode. If the device is in DDR and NonDemultiplexed Mode, then the DCLK has a 0° phase relationship with the data; it is not possible to select
the 90° phase relationship.
POR State: 0b
Must be set to 1b
IMPORTANT NOTE: It is recommended that this register should only be written upon power-up initialization as writing it may cause
disturbance on the DCLK output as this signal's basic configuration is changed.
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
I-Channel Offset
Addr: 2h (0010b)
D15
D14
D13
(MSB)
Bits 15:8
Bit 7
Bit 6:0
Write only (0x007F)
D12
D11
D10
D9
Offset Value
D8
D7
(LSB) Sign
D6
D5
D4
D3
D2
D1
D0
1
1
1
1
1
1
1
Offset Value. The input offset of the I-channel ADC is adjusted linearly and monotonically by the value in
this field. 00h provides a nominal value of zero offset, while FFh provides a nominal value of 45 mV of
offset. Thus, each code step provides 0.176 mV of offset.
POR State: 0000 0000 b
Sign bit. 0b gives positive offset, 1b gives negative offset, resulting in total offset adjustment of ±45 mV.
POR State: 0b
Must be set to 1b
I-Channel Full-Scale Voltage Adjust
Addr: 3h (0011b)
D15
D14
D13
Write only (0x807F)
D12
(MSB)
Bit 15:7
Bits 6:0
D11
D10
Adjust Value
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
(LSB)
1
1
1
1
1
1
1
Full Scale Voltage Adjust Value. The input full-scale voltage or gain of the I-channel is adjusted linearly
and monotonically with a 9 bit data value. The adjustment range is ±20% of the nominal 700 mVP-P
differential value.
0000 0000 0
560mVP-P
1000 0000 0 Default Value
700mVP-P
1111 1111 1
840mVP-P
For best performance, it is recommended that the value in this field be limited to the range of 0110 0000
0b to 1110 0000 0b, i.e., limit the amount of adjustment to ±15%. The remaining ±5% headroom allows
for the ADC's own full scale variation. A gain adjustment does not require ADC re-calibration.
POR State: 1000 0000 0b (no adjustment)
Must be set to 1b
Copyright © 1999-2012, Texas Instruments Incorporated
33
ADC07D1520
Extended Configuration Register
Addr: 9h (1001b)
Write only (0x03FF)
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
TPO
RTD
DEN
IS
0
DLF
1
1
1
1
1
1
1
1
1
1
Bit 15
TPO: Test Pattern Output. When this bit is set 1b, the ADC is disengaged and a test pattern generator is
connected to the outputs including OR. This test pattern will work with the device in the SDR, DDR and
the Non-demux Modes (DES and Non-DES).
POR State: 0b
Bit 14
RTD: Resistor Trim Disable. When this bit is set to 1b, the input termination resistor is not trimmed during
the calibration cycle and the DCLK output remains enabled. Note that the ADC is calibrated regardless
of this setting.
POR State: 0b
Bit 13
DEN: DES Enable. Setting this bit to 1b enables the Dual Edge Sampling Mode. In this mode, the ADCs
in this device are used to sample and convert the same analog input in a time-interleaved manner,
accomplishing a sample rate of twice the input clock rate. When this bit is set to 0b, the device operates
in the Non-DES Modes.
POR State: 0b
Bit 12
IS: Input Select. When this bit is set to 0b the I-channel is operated upon by both ADCs. When this bit is
set to 1b the Q-channel is operated on by both ADCs.
POR State: 0b
Bit 11
Must be set to 0b
Bit 10
DLF: DES Low Frequency. When this bit is set 1b, the dynamic performance of the device is improved
when the input clock is less than 900 MHz.
POR State: 0b
Bits 9:0
34
Must be set to 1b
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Q-Channel Offset
Addr: Ah (1010b)
D15
D14
D13
(MSB)
Bit 15:8
Bit 7
Bit 6:0
Write only (0x007F)
D12
D11
D10
D9
Offset Value
D8
D7
(LSB) Sign
D6
D5
D4
D3
D2
D1
D0
1
1
1
1
1
1
1
Offset Value. The input offset of the Q-channel ADC is adjusted linearly and monotonically by the value
in this field. 00h provides a nominal zero offset, while FFh provides a nominal 45 mV of offset. Thus, each
code step provides about 0.176 mV of offset.
POR State: 0000 0000 b
Sign bit. 0b gives positive offset, 1b gives negative offset.
POR State: 0b
Must be set to 1b
Q-Channel Full-Scale Voltage Adjust
Addr: Bh (1011b)
D15
D14
D13
Write only (0x807F)
D12
(MSB)
Bit 15:7
Bits 6:0
D11
D10
Adjust Value
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
(LSB)
1
1
1
1
1
1
1
Full Scale Voltage Adjust Value. The input full-scale voltage or gain of the Q-channel ADC is adjusted
linearly and monotonically with a 9 bit data value. The adjustment range is ±20% of the nominal 700
mVP-P differential value.
0000 0000 0
560 mVP-P
1000 0000 0 Default Value
700 mVP-P
1111 1111 1
840 mVP-P
For best performance, it is recommended that the value in this field be limited to the range of 0110 0000
0b to 1110 0000 0b, i.e., limit the amount of adjustment to ±15%. The remaining ±5% headroom allows
for the ADC's own full scale variation. A gain adjustment does not require ADC re-calibration.
POR State: 1000 0000 0b (no adjustment)
Must be set to 1b
Copyright © 1999-2012, Texas Instruments Incorporated
35
ADC07D1520
Sample Clock Phase Fine Adjust
Addr: Eh (1110b)
D15
D14
D13
(MSB)
Bits 15:8
Write only (0x00FF)
D12
D11
D10
D9
Fine Phase Adjust
D8
D7
D6
D5
D4
D3
D2
D1
D0
(LSB)
1
1
1
1
1
1
1
1
Fine Phase Adjust. The phase of the ADC sampling clock is adjusted linearly and monotonically by the
value in this field. 00h provides a nominal zero phase adjustment, while FFh provides a nominal 50 ps of
delay. Thus, each code step provides about 0.2 ps of delay.
POR State: 0000 0000b
Bits 7:0
Must be set to 1b
Sample Clock Phase Intermediate/Coarse Adjust
Addr: Fh (1111b)
D15
POL
Bit 15
D14
D13
Write only (0x007F)
D12
D11
Coarse Phase Adjust
D10
D9
D8
D7
Int Phase Adjust
D6
D5
D4
D3
D2
D1
D0
1
1
1
1
1
1
1
Polarity Select. When this bit is selected, the polarity of the ADC sampling clock is inverted.
POR State: 0b
Bits 14:10 Coarse Phase Adjust. Each code value in this field delays the sample clock by approximately 65 ps. A
value of 00000b in this field causes zero adjustment.
POR State: 00000b
Bits 9:7
Intermediate Phase Adjust. Each code value in this field delays the sample clock by approximately 11 ps.
A value of 000b in this field causes zero adjustment. Maximum combined adjustment using Coarse Phase
Adjust and Intermediate Phase adjust is approximately 2.1ns.
POR State: 000b
Bits 6:0
Must be set to 1b
1.4.1 Clock Phase Adjust
This is a feature intended to help the system designer remove small imbalances in clock distribution traces at the board level when
multiple ADCs are used. However, enabling this feature will reduce the dynamic performance (ENOB, SNR, SFDR) some finite
amount. The amount of degradation increases with the amount of adjustment applied. The user is strongly advised to (a) use the
minimal amount of adjustment; and (b) verify the net benefit of this feature in his system before relying on it.
1.4.2 DCLK Output During Register Programming
When programming the Configuration register, the DCLK output may be disrupted and is invalid. The DCLK output is not valid until
the register data has not been completely shifted and latched into the register and the register is in a known programmed state.
To minimize disrupting the DCLK output, it is recommend that the Configuration Register only be programmed when necessary.
For example, if a user wishes to enable the test pattern, only the Test Pattern register should be programmed. A user should avoid
developing software routines which program all the registers when the data contents of only one register is being modified.
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
1.5 MULTIPLE ADC SYNCHRONIZATION
The ADC07D1520 has the capability to precisely reset its sampling clock input to DCLK output relationship as determined by the
user-supplied DCLK_RST pulse. This allows multiple ADCs in a system to have their DCLK (and data) outputs transition at the
same time with respect to the shared CLK input that all the ADCs use for sampling.
The DCLK_RST signal must observe some timing requirements that are shown in Figure 7, Figure 8 and Figure 9 of the Timing
Diagrams. The DCLK_RST pulse must be of a minimum width and its deassertion edge must observe setup and hold times with
respect to the CLK input rising edge. These timing specifications are listed as tPWR, tRS and tRH in the Converter Electrical Characteristics.
The DCLK_RST signal can be asserted asynchronously to the input clock. If DCLK_RST is asserted, the DCLK output is held in a
designated state. The state in which DCLK is held during the reset period is determined by the mode of operation (SDR or DDR)
and the setting of the Output Edge configuration pin or bit. (Refer to Figure 7, Figure 8 and Figure 9 for the DCLK reset state
conditions). Therefore, depending upon when the DCLK_RST signal is asserted, there may be a narrow pulse on the DCLK line
during this reset event. When the DCLK_RST signal is de-asserted in synchronization with the CLK rising edge, there are three or
four CLK cycles of systematic delay and the next CLK falling edge synchronizes the DCLK output with those of other ADC07D1520s
in the system. The DCLK output is enabled again after a constant delay (relative to the input clock frequency) which is equal to the
CLK input to DCLK output delay (tOD). The device always exhibits this delay characteristic in normal operation. The user has the
option of using a single-ended DCLK_RST signal, but a differential DCLK_RST is strongly recommended due to its superior timing
specifications.
As shown in Figure 7, Figure 8, and Figure 9 of the Timing Diagrams, there is a delay from the deassertion of DCLK_RST to the
reappearance of DCLK, which is equal to several CLK cycles of delay plus tOD. Note that the deassertion of DCLK_RST is not
latched in until the next falling edge of CLK. For 1:2 Demux 0° Mode, there are four CLK cycles of delay; for all other modes, there
are three CLK cycles of delay.
If the device is not programmed to allow DCLK to run continuously, DCLK will become inactive during a calibration cycle. Therefore,
it is strongly recommended that DCLK only be used as a data capture clock and not as a system clock.
The DCLK_RST pin should NOT be brought high while the calibration process is running (while CalRun is high). Doing so could
cause a glitch in the digital circuitry, resulting in corruption and invalidation of the calibration.
1.6 ADC TEST PATTERN
To aid in system debug, the ADC07D1520 has the capability of providing a test pattern at the four output ports completely independent of the input signal. The ADC is disengaged and a test pattern generator is connected to the outputs, including OR+/-. The
test pattern output is the same in DES Mode and Non-DES Mode. Each port is given a 7-bit word, alternating between 1's and 0's
as described in the Table 6 and Table 7.
TABLE 6. Test Pattern by Output Port
in 1:2 Demultiplex Mode
Time
Qd
Id
Q
I
OR
T0
00h
01h
01h
02h
0
T1
7Fh
7Eh
7Eh
7Dh
1
T2
00h
01h
01h
02h
0
T3
7Fh
7Eh
7Eh
7Dh
1
T4
00h
01h
01h
02h
0
T5
00h
01h
01h
02h
0
T6
7Fh
7Eh
7Eh
7Dh
1
T7
00h
01h
01h
02h
0
T8
7Fh
7Eh
7Eh
7Dh
1
T9
00h
01h
01h
02h
0
T10
00h
01h
01h
02h
0
T11
...
...
...
...
...
Comments
Pattern
Sequence
n
Pattern
Sequence
n+1
Pattern
Sequence n+2
With the part programmed into the Non-demultiplex Mode, the test pattern’s order will be as described in Table 7.
Copyright © 1999-2012, Texas Instruments Incorporated
37
ADC07D1520
TABLE 7. Test Pattern by Output Port in
Non-demultiplex Mode
Time
Q
I
OR
T0
00h
01h
0
T1
7Fh
7Eh
1
T2
00h
01h
0
T3
00h
01h
0
T4
7Fh
7Eh
1
T5
7Fh
7Eh
1
T6
00h
01h
0
T7
00h
01h
0
T8
7Fh
7Eh
1
T9
00h
01h
0
T10
00h
01h
0
T11
7Fh
7Eh
1
T12
00h
01h
0
T13
00h
01h
0
T14
7Fh
7Eh
1
T15
...
...
...
Comments
Pattern
Sequence
n
Pattern
Sequence
n+1
Depending upon how it is initiated, the I- and the Q- channels' test patterns may or may not be synchronized. Either I and Id or Q
and Qd patterns may be behind by one DCLK.
To ensure that the test pattern starts synchronously in each port, set DCLK_RST while writing the Test Pattern Output bit in the
Extended Configuration Register. The pattern appears at the data output ports when DCLK_RST is cleared low. The test pattern
will work at speed and with the device in the SDR, DDR and the Non-demux Modes (DES and Non-DES).
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
2.0 Applications Information
2.1 THE REFERENCE VOLTAGE
The reference voltage for the ADC07D1520 is derived from a 1.254V bandgap reference, a buffered version of which, is made
available at VBG (pin 31) for the user.
This output has an output current capability of ±100 μA and should be buffered if more current than this is required.
The internal bandgap-derived reference voltage has a nominal value of VIN , as determined by the FSR pin and described in1.1.4
The Analog Inputs.
There is no provision for the use of an external reference voltage, but the full-scale input voltage can be adjusted through a
Configuration Register in the Extended Control Mode, as explained in 1.2 NON-EXTENDED AND EXTENDED CONTROL
MODE.
Differential input signals up to the chosen full-scale level will be digitized to 7 bits. Signal excursions beyond the full-scale range
will be clipped at the output. These large signal excursions will also activate the OR output for the time that the signal is out of
range. See 2.2.3 Out Of Range Indication.
One extra feature of the VBG pin is that it can be used to raise the common mode voltage level of the LVDS outputs. The output
offset voltage (VOS) is typically 800 mV when the VBG pin is used as an output or left floating. To raise the LVDS offset voltage to
the typical value, the VBG pin can be connected directly to the supply rail.
2.2 THE ANALOG INPUT
The analog input is differential and the signal source may be a.c. or d.c. coupled. In the Non-extended Control Mode, the full-scale
input range is selected using the FSR pin as specified in the Converter Electrical Characteristics. In the Extended Control Mode,
the full-scale input range is selected by programming the Full-Scale Voltage Adjust register through the Serial Interface. For best
performance when adjusting the input full-scale range in the Extended Control Mode, refer to 1.4 REGISTER DESCRIPTION for
guidelines on limiting the amount of adjustment.
Table 8 gives the input to output relationship with the FSR pin high when the Non-extended Control Mode is used. With the FSR
pin grounded, the millivolt values in Table 8 are reduced to 75% of the values indicated. In the Extended Control Mode, these values
will be determined by the full scale range and offset settings in the Control Registers.
TABLE 8. Differential Input To Output Relationship
(Non-Extended Control Mode, FSR High)
VIN+
VIN−
Output Code
VCM − 217.5 mV
VCM + 217.5 mV
000 0000
VCM − 109 mV
VCM + 109 mV
010 0000
VCM
VCM
011 1111 /
100 0000
VCM + 109 mV
VCM −109 mV
110 0000
VCM + 217.5 mV
VCM − 217.5 mV
111 1111
The buffered analog inputs simplify the task of driving these inputs so that the RC pole which is generally used at sampling ADC
inputs is not required. If the user desires to place an amplifier circuit before the ADC, care should be taken in choosing an amplifier
with adequate noise and distortion performance, and adequate gain at the frequencies used for the application.
Note that a precise d.c. common mode voltage must be present at the ADC inputs. This common mode voltage, VCMO, is provided
on-chip when a.c. input coupling is used and the input signal is a.c. coupled to the ADC.
When the inputs are a.c. coupled, the VCMO output must be grounded, as shown in Figure 11. This causes the on-chip VCMO voltage
to be connected to the inputs through on-chip 50 kΩ resistors.
IMPORTANT NOTE: An analog input channel that is not used (e.g. in DES Mode) should be connected to a.c. ground (i.e., capacitors to ground) when the inputs are a.c. coupled. Do not connect an unused analog input directly to ground.
30194144
FIGURE 11. VCMO Drive for A.C. Coupled Differential Input
Copyright © 1999-2012, Texas Instruments Incorporated
39
ADC07D1520
When the d.c. coupled mode is used, a common mode voltage must be provided at the differential inputs. This common mode
voltage should track the VCMO output pin. Note that the VCMO output potential will change with temperature. The common mode
output of the driving device should track this change.
IMPORTANT NOTE: An analog input channel that is not used (e.g. in DES Mode) should be tied to the VCMO voltage when the
inputs are d.c. coupled. Do not connect unused analog inputs to ground.
Full-scale distortion performance falls off rapidly as the input common mode voltage deviates from VCMO. This is a direct
result of using a very low supply voltage to minimize power. Keep the input common voltage within 50 mV of VCMO.
Performance is as good in the d.c. coupled mode as it is in the a.c. coupled mode, provided the input common mode voltage at
both analog inputs remains within 50 mV of VCMO.
2.2.1 Single-Ended Input Signals
There is no provision for the ADC07D1520 to adequately process single-ended input signals. The best way to handle single-ended
signals is to convert them to differential signals before presenting them to the ADC. The easiest way to accomplish single-ended
to differential signal conversion is with an appropriate balun-connected transformer, as shown in Figure 12.
30194143
FIGURE 12. Single-Ended to Differential Signal Conversion Using a Balun
Figure 12 is a generic depiction of a single-ended to differential signal conversion using a balun. The circuitry specific to the balun
will depend upon the type of balun selected and the overall board layout. It is recommended that the system designer contact the
manufacturer of the balun in order to aid in designing the best performing single-ended to differential conversion circuit.
When selecting a balun, it is important to understand the input architecture of the ADC. There are specific balun parameters, of
which the system designer should be mindful. The impedance of the analog source should be matched to the ADC07D1520's onchip 100Ω differential input termination resistor. The range of this termination resistor is described in the Converter Electrical
Characteristics as the specification RIN.
Also, the phase and amplitude balance are important. The lowest possible phase and amplitude imbalance is desired when selecting
a balun. The phase imbalance should be no more than ±2.5° and the amplitude imbalance should be limited to less than 1dB at
the desired input frequency range. Finally, when selecting a balun, the VSWR (Voltage Standing Wave Ratio), bandwidth and
insertion loss of the balun should also be considered. The VSWR aids in determining the overall transmission line termination
capability of the balun when interfacing to the ADC input. The insertion loss should be considered so that the signal at the balun
output is within the specified input range of the ADC; see VIN in the Converter Electrical Characteristics.
2.2.2. D.C. Coupled Input Signals
When d.c. coupling to the ADC07D1520 analog inputs, single-ended to differential conversion may be easily accomplished with
the LMH6555, as shown in Figure 13. In such applications, the LMH6555 performs the task of single-ended to differential conversion
while delivering low distortion and noise, as well as output balance, that supports the operation of the ADC07D1520. Connecting
the ADC07D1520 VCMO pin to the VCM_REF pin of the LMH6555, via an appropriate buffer, will ensure that the common mode input
voltage meets the requirements for optimum performance of the ADC07D1520. The LMV321 was chosen to buffer VCMD for its low
voltage operation and reasonable offset voltage.
The output current from the ADC07D1520 VCMO pin should be limited to 100 μA.
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
30194155
FIGURE 13. Example of Using LM6555 for D.C. Coupled Input
In Figure 13, RADJ- and RADJ+ are used to adjust the differential offset that can be measured at the ADC inputs VIN+ and VIN- with
the LMH6555's input terminated to ground as shown, but not driven and with no RADJ resistors present. An unadjusted positive
offset with reference to VIN- greater than |15mV| should be reduced with a resistor in the RADJ- position. Likewise, an unadjusted
negative offset with reference to VIN- greater than |15mV| should be reduced with a resistor in the RADJ+ position. Table 9 gives
suggested RADJ- and RADJ+ values for various unadjusted differential offsets to bring the VIN+ and VIN- offset back to within
|15mV|.
TABLE 9. Resistor Values for Offset Adjustment
Unadjusted Offset Reading
Resistor Value
0mV to 10mV
no resistor needed
11mV to 30mV
20.0kΩ
31mV to 50mV
10.0kΩ
51mV to 70mV
6.81kΩ
71mV to 90mV
4.75kΩ
91mV to 110mV
3.92kΩ
2.2.3 Out Of Range Indication
When the conversion result is clipped, the Out of Range (OR) output is activated such that OR+ goes high and OR- goes low. This
output is active as long as accurate data on either or both of the buses would be outside the range of 00h to FFh. When the device
is programmed to provide a second DCLK output, the OR signals become DCLK2. Refer to 1.4 REGISTER DESCRIPTION.
2.2.4 Full-Scale Input Range
As with all A/D Converters, the input range is determined by the value of the ADC's reference voltage. The reference voltage of
the ADC07D1520 is derived from an internal band-gap reference. The FSR pin controls the effective reference voltage of the
ADC07D1520 such that the differential full-scale input range at the analog inputs is a normal amplitude with the FSR pin high, or
a reduced amplitude with FSR pin low; see VIN in the Converter Electrical Characteristics. The best SNR is obtained with FSR high,
but better distortion and SFDR are obtained with the FSR pin low. The LMH6555 of Figure 13 is suitable for any Full Scale Range.
2.3 THE CLOCK INPUTS
The ADC07D1520 has differential LVDS clock inputs, CLK+ and CLK-, which must be driven with an a.c. coupled, differential clock
signal. Although the ADC07D1520 is tested and its performance is guaranteed with a differential 1.5 GHz clock, it will typically
function well with input clock frequency range; see fCLK(min) and fCLK(max) in the Converter Electrical Characteristics. The clock
inputs are internally terminated and biased. The input clock signal must be capacitively coupled to the clock pins as indicated in
Figure 14.
Operation up to the sample rates indicated in the Converter Electrical Characteristics is typically possible if the maximum ambient
temperatures indicated are not exceeded. Operating at higher sample rates than indicated for the given ambient temperature may
result in reduced device reliability and product lifetime. This is because of the higher power consumption and die temperatures at
high sample rates. Important also for reliability is proper thermal management. See 2.6.2 Thermal Management.
Copyright © 1999-2012, Texas Instruments Incorporated
41
ADC07D1520
30194147
FIGURE 14. Differential (LVDS) Input Clock Connection
The differential input clock line pair should have a characteristic impedance of 100Ω and (when using a balun), be terminated at
the clock source in that (100Ω) characteristic impedance. The input clock line should be as short and as direct as possible. The
ADC07D1520 clock input is internally terminated with an untrimmed 100Ω resistor.
Insufficient input clock levels will result in poor dynamic performance. Excessively high input clock levels could cause a change in
the analog input offset voltage. To avoid this, keep the input clock level (VID) within the range specified in the Converter Electrical
Characteristics.
The low and high times of the input clock signal can affect the performance of any A/D Converter. The ADC07D1520 features a
duty cycle clock correction circuit which can maintain performance over the 20%-to-80% specified duty cycle range, even in DES
Mode. The ADC will meet its performance specification if the input clock high and low times are maintained within the duty cycle
range; see the Converter Electrical Characteristics.
High speed, high performance ADCs such as the ADC07D1520 require a very stable input clock signal with minimum phase noise
or jitter. ADC jitter requirements are defined by the ADC resolution (number of bits), maximum ADC input frequency and the input
signal amplitude relative to the ADC input full scale range. The maximum jitter (the sum of the jitter from all sources) allowed to
prevent a jitter-induced reduction in SNR is found to be
tJ(MAX) = ( VINFSR/ VIN(P-P)) x (1/(2(N+1) x π x fIN))
where tJ(MAX) is the rms total of all jitter sources in seconds, VIN(P-P) is the peak-to-peak analog input signal, VINFSR is the full-scale
range of the ADC, "N" is the ADC resolution in bits and fIN is the maximum input frequency, in Hertz, at the ADC analog input.
Note that the maximum jitter described above is the RSS sum of the jitter from all sources, including that in the ADC input clock,
that added by the system to the ADC input clock and input signals and that added by the ADC itself. Since the effective jitter added
by the ADC is beyond user control, the best the user can do is to keep the sum of the externally added input clock jitter and the
jitter added by the analog circuitry to the analog signal to a minimum.
Input clock amplitudes above those specified in the Converter Electrical Characteristics may result in increased input offset voltage.
This would cause the converter to produce an output code other than the expected 63/64 when both input pins are at the same
potential.
2.4 CONTROL PINS
Six control pins (without the use of the serial interface) provide a wide range of possibilities in the operation of the ADC07D1520
and facilitate its use. These control pins provide Full-Scale Input Range setting, Calibration, Calibration Delay, Output Edge Synchronization choice, LVDS Output Level choice and a Power Down feature.
2.4.1 Full-Scale Input Range Setting
The input full-scale range can be selected with the FSR control input (pin 14) in the Non-extended Control Mode of operation. The
input full-scale range is specified as VIN in the Converter Electrical Characteristics. In the Extended Control Mode, the input fullscale range may be programmed using the Full-Scale Adjust Voltage register. See 2.2 THE ANALOG INPUT for more information.
2.4.2 Calibration
The ADC07D1520 calibration must be run to achieve specified performance. The calibration procedure is run automatically upon
power-up and can be run any time on-command via the CAL pin (30) or the Calibration register (Addr: 0h, Bit 15). The calibration
procedure is exactly the same whether there is an input clock present upon power up or if the clock begins some time after
application of power. The CalRun output indicator is high while a calibration is in progress. Note that the DCLK outputs are not
active during a calibration cycle by default, therefore it is not recommended to use these signals as a system clock unless the
Resistor Trim Disable feature is used (Reg. 9h). The DCLK outputs are continuously present at the output only when the Resistor
Trim Disable is active.
2.4.2.1 Power-On Calibration
Power-on calibration begins after a time delay following the application of power. This time delay is determined by the setting of
CalDly.
The calibration process will be not be performed if the CAL pin is high at power up. In this case, the calibration cycle will not begin
until the on-command calibration conditions are met. The ADC07D1520 will function with the CAL pin held high at power up, but
no calibration will be done and performance will be impaired. A manual calibration, however, may be performed after powering up
with the CAL pin high. See 2.4.2.2 On-Command Calibration.
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Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
The internal power-on calibration circuitry comes up in an unknown logic state. If the input clock is not running at power up and the
power on calibration circuitry is active, it will hold the analog circuitry in power down and the power consumption will typically be
less than 200 mW. The power consumption will be normal after the clock starts.
2.4.2.2 On-Command Calibration
To initiate an on-command calibration, either bring the CAL pin high for a minimum of tCAL_H input clock cycles after it has been
low for a minimum of tCAL_L input clock cycles or perform the same operation via the CAL bit in the Calibration register. Holding the
CAL pin high upon power up will prevent execution of power-on calibration until the CAL pin is low for a minimum of tCAL_L input
clock cycles, then brought high for a minimum of another tCAL_H input clock cycles. The calibration cycle will begin tCAL_H input clock
cycles after the CAL pin is thus brought high. The CalRun signal should be monitored to determine when the calibration cycle has
completed.
The minimum tCAL_L and tCAL_H input clock cycle sequences are required to ensure that random noise does not cause a calibration
to begin when it is not desired. For best performance, a calibration should be performed 20 seconds or more after power up and
repeated when the operating temperature changes significantly, relative to the specific system design performance requirements.
By default, on-command calibration also includes calibrating the input termination resistance and the ADC. However, since the
input termination resistance, once trimmed at power-up, changes marginally with temperature, the user has the option to disable
the input termination resistor trim, which will guarantee that the DCLK is continuously present at the output during subsequent
calibration. The Resistor Trim Disable (RTD) can be programmed in register 9h when in the Extended Control Mode. Refer to 1.4
REGISTER DESCRIPTION for register programming information.
2.4.2.3 Calibration Delay
The CalDly input (pin 127) is used to select one of two delay times after the application of power to the start of calibration, as
described in 1.1.1 Calibration. The calibration delay values allow the power supply to come up and stabilize before calibration takes
place. With no delay or insufficient delay, calibration would begin before the power supply is stabilized at its operating value and
result in non-optimal calibration coefficients. If the PD pin is high upon power-up, the calibration delay counter will be disabled until
the PD pin is brought low. Therefore, holding the PD pin high during power up will further delay the start of the power-up calibration
cycle. The best setting of the CalDly pin depends upon the power-on settling time of the power supply.
Note that the calibration delay selection is not possible in the Extended Control Mode and the short delay time is used.
2.4.3 Output Edge Synchronization
DCLK signals are available to latch the converter output data into external circuitry. The output data can be synchronized with either
edge of these DCLK signals. That is, the output data transition can be set to occur with either the rising edge or the falling edge of
the DCLK signal, so that either edge of that DCLK signal can be used to latch the output data into the receiving circuit.
When OutEdge (pin 4) is high, the output data is synchronized with the rising edge of the DCLK+ (pin 82). When OutEdge is low,
the output data is synchronized with the falling edge of DCLK+.
At the very high speeds, of which the ADC07D1520 is capable, slight differences in the lengths of the DCLK and data lines can
mean the difference between successful and erroneous data capture. The OutEdge pin may be used to capture data on the DCLK
edge that best suits the application circuit and layout.
2.4.4 LVDS Output Level Control
The output level can be set to one of two levels with OutV (pin 3). The strength of the output drivers is greater with OutV logic high.
With OutV logic low, there is less power consumption in the output drivers, but the lower output level means decreased noise
immunity.
For short LVDS lines and low noise systems, satisfactory performance may be realized with the OutV input low. If the LVDS lines
are long and/or the system in which the ADC07D1520 is used is noisy, it may be necessary to tie the OutV pin high.
2.4.5 Dual Edge Sampling
The Dual Edge Sampling (DES) feature causes one of the two input pairs to be routed to both ADCs. The other input pair is
deactivated. One of the ADCs samples the input signal on the rising input clock edge (duty cycle corrected); the other ADC samples
the input signal on the falling input clock edge (duty cycle corrected). If the device is in the 1:4 Demux DES Mode, the result is an
output data rate 1/4 that of the interleaved sample rate, which is twice the input clock frequency. Data is presented in parallel on
all four output buses in the following order: DQd, DId, DQ, DI. If the device is the Non-demux DES Mode, the result is an output
data rate 1/2 that of the interleaved sample rate. Data is presented in parallel on two output buses in the following order: DQ, DI.
To use this feature in the Non-extended Control Mode, allow pin 127 to float and the signal at the I-channel input will be sampled
by both converters. The Calibration Delay will then only be a short delay.
In the Extended Control Mode, either input may be used for dual edge sampling. See 1.1.5.1 Dual-Edge Sampling.
2.4.6 Power Down Feature
The Power Down pins (PD and PDQ) allow the ADC07D1520 to be entirely powered down (PD) or the Q-channel to be powered
down and the I-channel to remain active (PDQ). See 1.1.7 Power Down for details on the power down feature.
The digital data output pins are put into a high impedance state when the PD pin for the respective channel is high. Upon return to
normal operation, the pipeline will contain meaningless information and must be flushed.
If the PD input is brought high while a calibration is running, the device will not go into power down until the calibration sequence
is complete. However, if power is applied and PD is already high, the device will not begin the calibration sequence until the PD
input goes low. If a manual calibration is requested while the device is powered down, the calibration will not begin at all. That is,
the manual calibration input is completely ignored in the power down state.
Copyright © 1999-2012, Texas Instruments Incorporated
43
ADC07D1520
2.5 THE DIGITAL OUTPUTS
The ADC07D1520 normally demultiplexes the output data of each of the two ADCs on the die onto two LVDS output buses (total
of four buses, two for each ADC). For each of the two converters, the results of successive conversions started on the odd falling
edges of the CLK+ pin are available on one of the two LVDS buses, while the results of conversions started on the even falling
edges of the CLK+ pin are available on the other LVDS bus. This means that, the word rate at each LVDS bus is 1/2 the ADC07D1520 input clock rate and the two buses must be multiplexed to obtain the entire 1.5 GSPS conversion result.
Since the minimum recommended input clock rate for this device is 200 MSPS (in 1:2 Demux Non-DES Mode), the effective rate
can be reduced to as low as 100 MSPS by using the results available on just one of the two LVDS buses and a 200 MHz input
clock, decimating the 200 MSPS data by two.
There is one LVDS output clock pair (DCLK+/-) available for use to latch the LVDS outputs on all buses. There is also a second
LVDS output clock pair (DCLK2+/-) which is optionally available for the same purpose. Whether the data is sent at the rising or
falling edge of DCLK is determined by the sense of the OutEdge pin, as described in 2.4.3 Output Edge Synchronization.
Double Data Rate (DDR) clocking can also be used. In this mode, a word of data is presented with each edge of DCLK, reducing
the DCLK frequency to 1/4 the input clock frequency. See the Timing Diagrams for details.
The OutV pin is used to set the LVDS differential output levels. See 2.4.4 LVDS Output Level Control.
The output format is Offset Binary. Accordingly, a full-scale input level with VIN+ positive with respect to VIN− will produce an output
code of all ones; a full-scale input level with VIN− positive with respect to VIN+ will produce an output code of all zeros; when VIN+
and VIN− are equal, the output code will vary between codes 63 and 64. A non-demultiplexed mode of operation is available for
those cases where the digital ASIC is capable of higher speed operation.
2.5.1 Terminating RSV Pins
The RSV pins can be connected to allow a given hardware design to support both the ADC07D1520 as well as the ADC08D1020
and ADC08D1520. The components shown in the diagram below should be installed when using the ADC07D1520 to ensure the
data inputs to the capture device are set to a known logic state. When using either of the 8 bit ADCs the terminating resistors should
not be installed.
30194136
FIGURE 15. Terminating RSV+/− Pins
2.6 POWER CONSIDERATIONS
A/D converters draw sufficient transient current to corrupt their own power supplies if not adequately bypassed. A 33 µF capacitor
should be placed within an inch (2.5 cm) of the A/D converter power pins. A 0.1 µF capacitor should be placed as close as possible
to each VA pin, preferably within one-half centimeter. Leadless chip capacitors are preferred because they have low lead inductance.
The VA and VDR supply pins should be isolated from each other to prevent any digital noise from being coupled into the analog
portions of the ADC. A ferrite choke, such as the JW Miller FB20009-3B, is recommended between these supply lines when a
common source is used for them.
As is the case with all high speed converters, the ADC07D1520 should be assumed to have little power supply noise rejection. Any
power supply used for digital circuitry in a system where a lot of digital power is being consumed should not be used to supply
power to the ADC07D1520. The ADC supplies should be the same supply used for other analog circuitry, if not a dedicated supply.
2.6.1 Supply Voltage
The ADC07D1520 is specified to operate with a supply voltage of 1.9V ±0.1V. It is very important to note that, while this device will
function with slightly higher supply voltages, these higher supply voltages may reduce product lifetime.
No pin should ever have a voltage on it that is in excess of the supply voltage or below ground by more than 150 mV, not even on
a transient basis. This can be a problem upon application of power and power shut-down. Be sure that the supplies to circuits
driving any of the input pins, analog or digital, do not come up any faster than does the voltage at the ADC07D1520 power pins.
The Absolute Maximum Ratings should be strictly observed, even during power up and power down. A power supply that produces
a voltage spike at turn-on and/or turn-off of power can destroy the ADC07D1520. The circuit of Figure 16 will provide supply
overshoot protection.
44
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Many linear regulators will produce output spiking at power-on unless there is a minimum load provided. Active devices draw very
little current until their supply voltages reach a few hundred millivolts. The result can be a turn-on spike that can destroy the
ADC07D1520, unless a minimum load is provided for the supply. The 100Ω resistor at the regulator output provides a minimum
output current during power-up to ensure there is no turn-on spiking.
In the circuit of Figure 16, an LM317 linear regulator is satisfactory if its input supply voltage is 4V to 5V. If a 3.3V supply is used,
an LM1086 linear regulator is recommended.
30194154
FIGURE 16. Non-Spiking Power Supply
The output drivers should have a supply voltage, VDR, that is within the range specified in the Operating Ratings table. This voltage
should not exceed the VA supply voltage.
If the power is applied to the device without an input clock signal present, the current drawn by the device might be below 200 mA.
This is because the ADC07D1520 gets reset through clocked logic and its initial state is unknown. If the reset logic comes up in
the "on" state, it will cause most of the analog circuitry to be powered down, resulting in less than 100 mA of current draw. This
current is greater than the power down current because not all of the ADC is powered down. The device current will be normal after
the input clock is established.
2.6.2 Thermal Management
The ADC07D1520 is capable of impressive speeds and performance at very low power levels for its speed. However, the power
consumption is still high enough to require attention to thermal management. For reliability reasons, the die temperature should be
kept to a maximum of 130°C. That is, Ambient Temperature (TA) plus ADC power consumption times Junction to Ambient Thermal
Resistance (θJA) should not exceed 130°C. This is not a problem if TA is kept to a maximum of +85°C as specified in the Operating
Ratings section.
The following are general recommendations for mounting exposed pad devices onto a PCB. They should be considered the starting
point in PCB and assembly process development. It is recommended that the process be developed based upon past experience
in package mounting.
The package of the ADC07D1520 has an exposed pad on its back that provides the primary heat removal path as well as excellent
electrical grounding to the printed circuit board. The land pattern design for pin attachment to the PCB should be the same as for
a conventional LQFP, but the exposed pad must be attached to the board to remove the maximum amount of heat from the package,
as well as to ensure best product parametric performance.
To maximize the removal of heat from the package, a thermal land pattern must be incorporated on the PC board within the footprint
of the package. The exposed pad of the device must be soldered down to ensure adequate heat conduction out of the package.
The land pattern for this exposed pad should be at least as large as the 5 x 5 mm of the exposed pad of the package and be located
such that the exposed pad of the device is entirely over that thermal land pattern. This thermal land pattern should be electrically
connected to ground. A clearance of at least 0.5 mm should separate this land pattern from the mounting pads for the package
pins.
30194121
FIGURE 17. Recommended Package Land Pattern
Copyright © 1999-2012, Texas Instruments Incorporated
45
ADC07D1520
Since a large aperture opening may result in poor release, the aperture opening should be subdivided into an array of smaller
openings, similar to the land pattern of Figure 17.
To minimize junction temperature, it is recommended that a simple heat sink be built into the PCB. This is done by including a
copper area of about 2 square inches (6.5 square cm) on the opposite side of the PCB. This copper area may be plated or solder
coated to prevent corrosion, but should not have a conformal coating, which could provide some thermal insulation. Thermal vias
should be used to connect these top and bottom copper areas. These thermal vias act as "heat pipes" to carry the thermal energy
from the device side of the board to the opposite side of the board where it can be more effectively dissipated. The use of 9 to 16
thermal vias is recommended.
The thermal vias should be placed on a 1.2 mm grid spacing and have a diameter of 0.30 to 0.33 mm. These vias should be barrel
plated to avoid solder wicking into the vias during the soldering process as this wicking could cause voids in the solder between
the package exposed pad and the thermal land on the PCB. Such voids could increase the thermal resistance between the device
and the thermal land on the board, which would cause the device to run hotter.
If it is desired to monitor die temperature, a temperature sensor may be mounted on the heat sink area of the board near the thermal
vias. Allow for a thermal gradient between the temperature sensor and the ADC07D1520 die of θJ-PAD times typical power consumption = 2.8°C/W x 1.8W = 5°C. Allowing for 6°C, including some margin for temperature drop from the pad to the temperature
sensor, would mean that maintaining a maximum pad temperature reading of 124°C will ensure that the die temperature does not
exceed 130°C. This calculation assumes that the exposed pad of the ADC07D1520 is properly soldered down and the thermal vias
are adequate. (The inaccuracy of the temperature sensor is in addition to the above calculation).
2.7 LAYOUT AND GROUNDING
Proper grounding and proper routing of all signals are essential to ensure accurate conversion. A single ground plane should be
used, instead of splitting the ground plane into analog and digital areas.
Since digital switching transients are composed largely of high frequency components, the skin effect implies that the total ground
plane copper weight will have little effect upon the logic-generated noise. Total surface area is more important than is total ground
plane volume. Coupling between the typically noisy digital circuitry and the sensitive analog circuitry can lead to poor performance
that may seem impossible to isolate and remedy. The solution is to keep the analog circuitry well separated from the digital circuitry.
High power digital components should not be located on or near any linear component or power supply trace or plane that services
analog or mixed signal components, as the resulting common return current path could cause fluctuation in the analog input “ground”
return of the ADC, causing excessive noise in the conversion result.
Generally, it is assumed that analog and digital lines should cross each other at 90° to avoid getting digital noise into the analog
path. In high frequency systems, however, avoid crossing analog and digital lines altogether. The input clock lines should be isolated
from ALL other lines, analog AND digital. The generally accepted 90° crossing should be avoided, as even a little coupling can
cause problems at high frequencies. Best performance at high frequencies is obtained with a straight signal path.
The analog input should be isolated from noisy signal traces to avoid coupling of spurious signals into the input. This is especially
important with the low level drive required of the ADC07D1520. Any external component (e.g., a filter capacitor) connected between
the converter's input and ground should be connected to a very clean point in the analog ground plane. All analog circuitry (input
amplifiers, filters, etc.) should be separated from any digital components.
2.8 DYNAMIC PERFORMANCE
The ADC07D1520 is a.c. tested and its dynamic performance is guaranteed. To meet the published specifications and avoid jitterinduced noise, the clock source driving the CLK input must exhibit low rms jitter. The allowable jitter is a function of the input
frequency and the input signal level, as described in 2.3 THE CLOCK INPUTS.
It is good practice to keep the ADC input clock line as short as possible, to keep it well away from any other signals and to treat it
as a transmission line. Other signals can introduce jitter into the input clock signal. The clock signal can also introduce noise into
the analog path if not isolated from that path.
Best dynamic performance is obtained when the exposed pad at the back of the package has a good connection to ground. This
is because this path from the die to ground is a lower impedance than offered by the package pins.
2.9 USING THE SERIAL INTERFACE
The ADC07D1520 may be operated in the Non-extended Control Mode or in the Extended Control Mode. Table 10 and Table 11
describe the functions of pins 3, 4, 14 and 127 in the Non-extended Control Mode and the Extended Control Mode, respectively.
2.9.1 Non-Extended Control Mode Operation
Non-extended Control Mode operation means that the Serial Interface is not active and all controllable functions are controlled with
various pin settings. Pin 41 is the primary control of the Extended Control Mode enable function. When pin 41 is logic high, the
device is in the Non-extended Control Mode. If pin 41 is floating and pin 52 is floating or logic high, the Extended Control Enable
function is controlled by pin 14. The device has functions which are pin programmable when in the Non-extended Control Mode.
An example is the full-scale range; it is controlled in the Non-extended Control Mode by setting pin 14 logic high or low. Table 10
indicates the pin functions of the ADC07D1520 in the Non-extended Control Mode.
46
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
TABLE 10. Non-Extended Control Mode Operation
(Pin 41 Floating and Pin 52 Floating or Logic High)
Pin
Low
High
Floating
3
Reduced VOD
Normal VOD
N/A
DDR
4
OutEdge = Neg
OutEdge = Pos
127
CalDly Short
CalDly Long
DES
14
Reduced VIN
Normal VIN
Extended Control Mode
Pin 3 can be either logic high or low in the Non-extended Control Mode. Pin 14 must not be left floating to select this mode. See
1.2 NON-EXTENDED AND EXTENDED CONTROL MODE for more information.
Pin 4 can be logic high, logic low or left floating in the Non-extended Control Mode. In the Non-extended Control Mode, pin 4 logic
high or low defines the edge at which the output data transitions. See 2.4.3 Output Edge Synchronization for more information. If
this pin is floating, the output Data Clock (DCLK) is a Double Data Rate (DDR) clock (see 1.1.5.3 Double Data Rate and Single
Data Rate) and the output edge synchronization is irrelevant since data is clocked out on both DCLK edges.
Pin 127, if it is logic high or low in the Non-extended Control Mode, sets the calibration delay. If pin 127 is floating, the calibration
delay is short and the converter performs in DES Mode.
TABLE 11. Extended Control Mode Operation
(Pin 41 Logic Low or Pin 14 Floating and Pin 52 Floating or Logic High)
Pin
Function
3
SCLK (Serial Clock)
4
SDATA (Serial Data)
127
SCS (Serial Interface Chip Select)
2.10 COMMON APPLICATION PITFALLS
Failure to write all register locations when using extended control mode. When using the serial interface, all nine address
locations must be written at least once with the default or desired values before calibration and subsequent use of the ADC.
Driving the inputs (analog or digital) beyond the power supply rails. For device reliability, no input should go more than 150
mV below the ground pins or 150 mV above the supply pins. Exceeding these limits on even a transient basis may not only cause
faulty or erratic operation, but may impair device reliability. It is not uncommon for high speed digital circuits to exhibit undershoot
that goes more than a volt below ground. Controlling the impedance of high speed lines and terminating these lines in their characteristic impedance should control overshoot.
Care should be taken not to overdrive the inputs of the ADC07D1520. Such practice may lead to conversion inaccuracies and even
to device damage.
Incorrect analog input common mode voltage in the d.c. coupled mode. As discussed in 1.1.4 The Analog Inputs and 2.2 THE
ANALOG INPUT, the Input common mode voltage must remain within 50 mV of the VCMO output , which varies with temperature
and must also be tracked. Distortion performance will be degraded if the input common mode voltage is more than 50 mV from
VCMO .
Using an inadequate amplifier to drive the analog input. Use care when choosing a high frequency amplifier to drive the
ADC07D1520 as many high speed amplifiers will have higher distortion than the ADC07D1520, resulting in overall system performance degradation.
Driving the VBG pin to change the reference voltage. As mentioned in 2.1 THE REFERENCE VOLTAGE, the reference voltage
is intended to be fixed by FSR pin or Full-Scale Voltage Adjust register settings. Over driving this pin will not change the full scale
value, but can be used to change the LVDS common mode voltage from 0.8V to 1.2V by tying the VBG pin to VA.
Driving the clock input with an excessively high level signal. The ADC input clock level should not exceed the level described
in the Operating Ratings Table or the input offset could change.
Inadequate input clock levels. As described in 2.3 THE CLOCK INPUTS, insufficient input clock levels can result in poor performance. Excessive input clock levels could result in the introduction of an input offset.
Using a clock source with excessive jitter, using an excessively long input clock signal trace, or having other signals
coupled to the input clock signal trace. This will cause the sampling interval to vary, causing excessive output noise and a
reduction in SNR performance.
Failure to provide adequate heat removal. As described in 2.6.2 Thermal Management, it is important to provide adequate heat
removal to ensure device reliability. This can be done either with adequate air flow or the use of a simple heat sink built into the
board. The backside pad should be grounded for best performance.
Copyright © 1999-2012, Texas Instruments Incorporated
47
ADC07D1520
Physical Dimensions inches (millimeters) unless otherwise noted
NOTES: UNLESS OTHERWISE SPECIFIED
REFERENCE JEDEC REGISTRATION MS-026, VARIATION BFB.
128-Lead Exposed Pad LQFP
Order Number ADC07D1520CIYB
NS Package Number VNX128A
48
Copyright © 1999-2012, Texas Instruments Incorporated
ADC07D1520
Notes
Copyright © 1999-2012, Texas Instruments Incorporated
49
Notes
Copyright © 1999-2012, Texas Instruments
Incorporated
PACKAGE OPTION ADDENDUM
www.ti.com
12-Nov-2012
PACKAGING INFORMATION
Orderable Device
Status
(1)
ADC07D1520CIYB/NOPB
ACTIVE
Package Type Package Pins Package Qty
Drawing
HLQFP
NNB
128
60
Eco Plan
Lead/Ball Finish
(2)
Green (RoHS
& no Sb/Br)
Call TI
MSL Peak Temp
Samples
(3)
(Requires Login)
Level-3-260C-168 HR
(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.
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
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