12-Bit, 65 MSPS, Dual ADC
AD15252
FUNCTIONAL BLOCK DIAGRAM
FEATURES
AD15252
12-bit, 65 MSPS dual ADC
Differential input with 100 Ω input impedance
Full-scale analog input: 296 mV p-p
170 MHz, 3 dB bandwidth
SNR (−9 dBFS): 64 dBFS (70 MHz AIN), 64 dBFS (140 MHz AIN)
SFDR (−9 dBFS): 77 dBFS (70 MHz AIN), 73 dBFS (140 MHz AIN)
435 mW per channel
Dual parallel output buses
Out-of-range indicators
Independent clocks
Duty cycle stabilizer
Twos complement or offset binary data format
OTR_A
PDWNA
CLKA
INA
LPF
OBS
OEB_A
DFS
PDWNB
CLKB
OLE
DATA
BUS B
INB
LPF
05154-001
APPLICATIONS
DATA
BUS A
OEB_B
OTR_B
Antijam GPS receivers
Wireless and wired broadband communications
Communications test equipment
TE
Figure 1.
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD15252 is a dual, 12-bit, 65 MSPS, analog-to-digital
converter (ADC). It features a differential front-end
amplification circuit followed by a sample-and-hold amplifier
and multistage pipeline ADC. It is designed to operate with a
3.3 V analog supply and a 2.5 V/3.3 V digital supply. Each input
is fully differential, ac-coupled, and terminated in 100 Ω input
impedances. The full-scale differential signal input range is
296 mV p-p.
1.
Dual 12-bit, 65 MSPS ADC with integrated analog signal
conditioning optimized for antijam global positioning
system receiver (AJ-GPS) applications.
2.
Operates from a single 3.3 V power supply and features a
separate digital output driver supply to accommodate 2.5 V
and 3.3 V logic families.
3.
Packaged in a space-saving 8 mm × 8 mm chip scale
package ball grid array (CSP_BGA) and is specified over
the industrial temperature range (–40°C to +85°C).
Two parallel, 12-bit digital output buses provide data flow from
the ADCs. The digital output data is presented in either straight
binary or twos complement format. Out-of-range (OTR) signals
indicate an overflow condition, which can be used with the
most significant bit to determine low or high overflow. Dual
single-ended clock inputs control all internal conversion cycles.
A duty cycle stabilizer allows wide variations in the clock duty
cycle while maintaining excellent performance. The AD15252 is
optimized for applications in antijam global positioning
receivers and is well suited for communications applications.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
© 2005 Analog Devices, Inc. All rights reserved.
AD15252
TABLE OF CONTENTS
Electrical Characteristics ................................................................. 3
Clock Input and Considerations .............................................. 11
Absolute Maximum Ratings............................................................ 5
Power Dissipation and Standby Mode .................................... 11
ESD Caution.................................................................................. 5
Digital Outputs ........................................................................... 12
Pin Configuration and Function Descriptions............................. 6
Timing ......................................................................................... 12
Typical Performance Characteristics ............................................. 8
Data Format ................................................................................ 12
Theory of Operation ...................................................................... 11
PCB and Evaluation Board............................................................ 13
OBS
Analog Input ............................................................................... 11
Outline Dimensions ....................................................................... 19
Voltage Reference ....................................................................... 11
Ordering Guide .......................................................................... 19
REVISION HISTORY
8/05—Revision 0: Initial Version
OLE
TE
Rev. 0 | Page 2 of 20
AD15252
ELECTRICAL CHARACTERISTICS
AVDD = 3.3 V, DRVDD = 2.5 V, encode = 65 MSPS, CLK_A = CLK_B, AIN = −9 dBFS differential input, TA= 25°C, unless otherwise
noted.
Table 1.
Parameter
RESOLUTION
ACCURACY
No Missing Codes
Offset Error
Gain Error
Differential Nonlinearity (DNL)
Integral Nonlinearity (INL)
TEMPERATURE DRIFT
Offset Error
Gain Error
MATCHING CHARACTERISTICS
Offset Error
Gain Error
Input Referred Noise
ANALOG INPUT
Input Range
Input Resistance (RIN) 1
Input Capacitance (CIN)1
CLOCK INPUTS
High Level Input Voltage (VIH)
Low Level Input Voltage (VIL)
High Level Input Current (IIH)
Low Level Input Current (IIL)
Input Capacitance (CIN)
LOGIC OUTPUTS
High Level Output Voltage (VOH)
Low Level Output Voltage (VOL)
INTERFACE TIMING
Maximum Conversion Rate
Minimum Conversion Rate
Clock Period (tC)
Clock Width High (tCH)
Clock Width Low (tCL)
Clock to Data (tOD)
Pipeline Delay (Latency)
POWER SUPPLIES
Supply Voltages
AVDD
DRVDD
Supply Currents
AVDD
DRVDD
Total Power Dissipation
OBS
Temp
Test Level
Min
25°C
25°C
25°C
Full
Full
IV
I
I
V
V
Full
Full
V
V
±9
±172
ppm/°C
ppm/°C
Full
Full
Full
V
V
V
±2.0
±1.0
0.87
% FSR
% FSR
LSB rms
Full
25°C
25°C
IV
V
V
296
100
1.8
Full
Full
Full
Full
Full
IV
IV
IV
IV
V
Full
Full
IV
IV
2.49
Full
Full
Full
Full
Full
Full
Full
VI
IV
V
IV
IV
IV
V
65
Full
Full
IV
IV
Full
Full
Full
VI
VI
VI
−6
−12.5
Typ
12
Guaranteed
±1.7
±2.0
±0.35
±0.8
Max
Unit
Bits
+6
+12.5
% FSR
% FSR
LSB
LSB
OLE
Rev. 0 | Page 3 of 20
2.0
TE
mV p-p
Ω
pF
0.8
+10
+10
−10
−10
2
0.2
1
15.4
6.2
6.2
2
6
7
3.0
2.25
V
V
μA
μA
pF
V
V
MSPS
MSPS
ns
ns
ns
ns
Cycles
3.3
2.5
3.6
3.6
V
V
254
12
0.87
280
15
1.0
mA
mA
W
AD15252
Parameter
SIGNAL-TO-NOISE RATIO (SNR)
fINPUT = 70 MHz
fINPUT = 110 MHz
fINPUT = 140 MHz
SINAD
fINPUT = 70 MHz
fINPUT = 110 MHz
fINPUT = 140 MHz
THD
fINPUT = 70 MHz
fINPUT = 110 MHz
fINPUT = 140 MHz
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
fINPUT = 70 MHz
fINPUT = 110 MHz
fINPUT = 140 MHz
CROSSTALK
Temp
Test Level
Min
Typ
25°C
25°C
25°C
I
V
I
62.7
64.2
64.1
64
dBFS
dBFS
dBFS
25°C
25°C
25°C
I
V
I
63.9
63.7
63.3
dBFS
dBFS
dBFS
Full
Full
Full
V
V
V
−76
−74
−72
dBFS
dBFS
dBFS
25°C
25°C
25°C
25°C
I
V
I
V
77.8
75.9
73.8
−70
dBFS
dBFS
dBFS
dB
OBS
1
Input resistance and capacitance shown as differential.
Table 2. Explanation of Test Levels
Test Level
I
II
III
IV
V
VI
62.5
62.4
61.9
72.7
OLE
Max
68
Unit
TE
Description
100% production tested.
100% production tested at 25°C, and sample tested at specified temperatures.
Sample tested only.
Parameter is guaranteed by design and characterization testing.
Parameter is a typical value only.
All devices are 100% production tested at 25°C, guaranteed by design and characterization testing for industrial
temperature range; 100% production tested at temperature extremes for military devices.
Rev. 0 | Page 4 of 20
AD15252
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
AVDD to AGND
DRVDD to DRGND
DRGND to AGND
DRVDD to AVDD
Analog Inputs
Digital Outputs
CLK
Operational Case Temperature
Storage Temperature Range
Lead Temperature: Infrared, 15 sec
Rating
−0.3 V, +3.9 V
−0.3 V, +3.9 V
−0.3 V, +0.3 V
−3.9 V, +3.9 V
−0.3 V, AVDD + 0.3 V
−0.3 V, DRVDD + 0.3 V
−0.3 V, AVDD + 0.3 V
−40°C to 85°C
−65°C to 150°C
230°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
OBS
ESD CAUTION
OLE
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
TE
Rev. 0 | Page 5 of 20
AD15252
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
8
7
6
5
4
3
2
1
A
B
C
D
E
F
H
BOTTOM VIEW
(Not to Scale)
05154-003
G
OBS
Figure 2. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
A1
Mnemonic
VINA
Description
Analog Input Pin (+) for Channel A.
A2
H1
VINA
VINB
Analog Input Pin (−) for Channel A.
Analog Input Pin (+) for Channel B.
H2
VINB
Analog Input Pin (−) for Channel B.
B4
CLK_A
Clock Input Pin for Channel A.
G4
CLK_B
Clock Input Pin for Channel B.
C4
PDWN_A
Power-Down Function Selection for Channel A (Active High).
F4
PDWN_B
Power-Down Function Selection for Channel B (Active High).
A4
OTR_A
Out-of-Range Indicator for Channel A.
E8
OTR_B
Out-of-Range Indicator for Channel B.
OLE
TE
A3
VCM_A
Channel A Common Mode.
H3
VCM_B
Channel B Common Mode.
D4
OEB_A
Output Enable for Channel A. Logic 0 enables Data Bus A; Logic 1 sets outputs to high-Z.
E4
OEB_B
Output Enable for Channel B. Logic 0 enables Data Bus B; Logic 1 sets outputs to high-Z.
C5
D11_A(MSB)
Channel A Data Output Bit 11 (MSB).
A5
D10_A
Channel A Data Output Bit 10.
B5
D09_A
Channel A Data Output Bit 9.
A6
D08_A
Channel A Data Output Bit 8.
B6
D07_A
Channel A Data Output Bit 7.
A7
D06_A
Channel A Data Output Bit 6.
B7
D05_A
Channel A Data Output Bit 5.
A8
D04_A
Channel A Data Output Bit 4.
C6
D03_A
Channel A Data Output Bit 3.
B8
D02_A
Channel A Data Output Bit 2.
C7
D01_A
Channel A Data Output Bit 1.
C8
D00_A(LSB)
Channel A Data Output Bit 0 (LSB).
E3
DFS
Data Output Format Select Bit (Logic 0 for offset binary, Logic 1 for twos complement).
E7
D11_B(MSB)
Channel B Data Output Bit 11 (MSB).
F8
D10_B
Channel B Data Output Bit 10.
F7
D09_B
Channel B Data Output Bit 9.
G8
D08_B
Channel B Data Output Bit 8.
Rev. 0 | Page 6 of 20
AD15252
Pin No.
F6
Mnemonic
D07_B
Description
Channel B Data Output Bit 7.
H8
D06_B
Channel B Data Output Bit 6.
G7
D05_B
Channel B Data Output Bit 5.
H7
D04_B
Channel B Data Output Bit 4.
G6
D03_B
Channel B Data Output Bit 3.
H6
D02_B
Channel B Data Output Bit 2.
G5
D01_B
Channel B Data Output Bit 1.
H5
D00_B
Channel B Data Output Bit 0 (LSB).
C1 to C3, F1 to F3
AVDD
Analog Power Supply.
OBS
B1 to B3, D3, G1 to G3
AGND
Analog Ground.
D6, E6
DRVDD
Digital Output Driver Supply.
D5, E5
DRGND
Digital Output Ground.
E1
REFT
Differential Reference (+).
E2
REFB
Differential Reference (−).
D1
VREF
Voltage Reference.
OLE
D2
REF_RTN
Voltage Reference Return
H4, F5, D7, D8
DNC1 to DNC4
No Connect.
TE
Rev. 0 | Page 7 of 20
AD15252
TYPICAL PERFORMANCE CHARACTERISTICS
0
90
–1
–2
85
–4
80
SFDR (dBFS)
ATTENUATION (dB)
–3
–5
–6
–7
–8
75
70
–9
OBS
–10
–12
10
60
–15 –14 –13 –12 –11 –10 –9 –8 –7 –6 –5 –4 –3 –2 –1
1000
100
FREQUENCY (MHz)
0
–0.25
–0.75
Figure 6. Single-Tone SFDR vs. AIN with fIN = 70 MHz
90
TE
85
80
–1.00
SFDR (dBFS)
–1.25
–1.50
–1.75
75
70
–2.00
–2.25
05154-005
65
–2.50
130
135
140
145
150
155
60
–16
160
05154-008
30MHz FLATNESS (dB)
–0.50
125
0
INPUT AMPLITUDE (dBFS)
OLE
Figure 3. Gain Flatness
–2.75
120
05154-007
05154-004
65
–11
–14
–12
FREQUENCY (MHz)
–10
–8
–6
–4
–2
0
INPUT AMPLITUDE (dBFS)
Figure 4. Gain Flatness fIN =125MHz to 155 MHz
Figure 7. Single-Tone SFDR vs. AIN with fIN = 110 MHz
0
90
–10
85
–30
SFDR (dBFS)
80
–40
–50
–60
75
70
–70
–80
–90
1
10
100
60
–16
1000
FREQUENCY (MHz)
05154-009
65
05154-006
CROSSTALK (dBFS)
–20
–14
–12
–10
–8
–6
–4
–2
INPUT AMPLITUDE (dBFS)
Figure 8. Single-Tone SFDR vs. AIN with fIN = 140 MHz
Figure 5. Typical Crosstalk
Rev. 0 | Page 8 of 20
0
AD15252
0.4
85
0.3
80
0.1
75
(DNL)
SFDR/SNR (dBFS)
0.2
SFDR
70
0
–0.1
–0.2
65
SNR
–0.4
140
110
05154-014
05154-010
OBS
60
70
–0.3
0
512
1024
1536
FREQUENCY (MHz)
Figure 9. Single-Tone SNR/SFDR vs. fIN
2560
3072
3584
4096
Figure 12. Typical DNL
OLE
64.4
64.2
0.6
0.5
0.4
63.8
TE
0.3
0.2
(INL)
64.0
0.7
0.1
0
–0.1
63.6
–0.2
–0.3
63.4
–0.4
–0.5
05154-011
63.2
63.0
70
110
–0.6
–0.7
0
140
512
1024
1536
FREQUENCY (MHz)
Figure 10. Single-Tone SINAD vs. fIN
2048
CODE
2560
3072
3584
05154-019
64.6
SINAD (dBFS)
2048
CODE
4096
Figure 13. Typical INL
–68
0
1
–10
–70
–20
–30
MAGNITUDE (dB)
–74
–76
–78
–40
–50
–60
–70
–80
2
–90
–80
3
4
5
6
–100
–110
–84
70
110
–120
–130
140
0
FREQUENCY (MHz)
Figure 11. Single-Tone THD vs. fIN
05154-023
–82
05154-012
THD (dBFS)
–72
3.25
6.50
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
Figure 14. Single-Tone FFT of Channel A Digitizing fIN = 70 MHz @ −9 dBFS
While Channel B Digitizes fIN = 70 MHz @ −9 dBFS
Rev. 0 | Page 9 of 20
AD15252
0
1
–10
–20
–20
–30
–30
–40
–40
MAGNITUDE (dB)
–50
–60
–70
–80
3
2
–90
6
5
4
–60
–70
2
6
–80
4
5
3
–100
05154-024
–120
OBS
–130
0
3.25
6.50
–120
–130
0
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
Figure 15. Single-Tone FFT of Channel B Digitizing fIN = 70 MHz @ −9 dBFS
While Channel A Digitizes fIN = 70 MHz @ −9 dBFS
1
–20
–30
–40
–50
–60
–70
–80
3
–90
2
6
4
3.25
6.50
OLE
0
1
–10
–20
TE
–30
5
–40
–50
–60
–70
6
–80
5
–90
–100
–100
–110
05154-025
–110
–120
–130
0
3.25
6.50
–120
–130
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
0
Figure 16. Single-Tone FFT of Channel A Digitizing fIN = 110 MHz @ −9 dBFS
While Channel B Digitizes fIN = 110 M z @ −9 dBFS
1
–20
–30
–40
–50
–60
–70
2
–80
3
–90
6
4
5
–100
05154-026
–110
–120
–130
0
3.25
6.50
2
4
3
3.25
6.50
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
Figure 19. Single-Tone FFT of Channel B Digitizing fIN = 140 MHz @ −9 dBFS
While Channel A Digitizes fIN = 140 MHz @ −9dBFS
0
–10
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
Figure 18. Single-Tone FFT of Channel A Digitizing fIN = 140 MHz @ −9 dBFS
While Channel B Digitizes fIN = 140 MHz @ −9 dBFS
MAGNITUDE (dB)
0
–10
05154-021
–110
–110
MAGNITUDE (dB)
–50
–90
–100
MAGNITUDE (dB)
1
05154-022
MAGNITUDE (dB)
0
–10
9.75 13.00 16.25 19.50 22.75 26.00 29.25 32.50
FREQUENCY (MHz)
Figure 17. Single-Tone FFT of Channel B Digitizing fIN = 110 MHz @ −9 dBFS
While Channel A Digitizes fIN = 110 MHz @ −9 dBFS
Rev. 0 | Page 10 of 20
AD15252
THEORY OF OPERATION
The AD15252 consists of two high performance ADC channels.
The dual ADC paths are independent, except for a shared
internal band gap reference source, VREF. Each path consists of
a differential front end amplification circuit followed by a
sample-and-hold amplifier and multistage pipeline ADC.
High speed, high resolution ADCs are sensitive to the quality of
the clock input. The degradation in SNR at a given full-scale
input frequency (fINPUT) due only to aperture jitter (tJ) can be
calculated by
The output-staging block aligns the data, carries out the error
correction, and passes the data to the output buffers. The output
buffers are powered from a separate supply, allowing adjustment
of the output voltage swing.
In the equation, the rms aperture jitter, tJ, represents the rootsum square of all jitter sources, which includes the clock input,
analog input signal, and ADC aperture jitter specification.
OBS
ANALOG INPUT
Each analog input is fully differential, allowing sampling of
differential input signals. The differential input signals are accoupled and terminated in 100 Ω input impedances. The fullscale differential signal input range is 296 mV p-p.
VOLTAGE REFERENCE
SNR Degradation = 20 × log 10 (1/2 × p × f INPUT × tJ)
Undersampling applications are particularly sensitive to jitter.
For optimal performance, especially in cases where aperture
jitter can affect the dynamic range of the AD15252, it is
important to minimize input clock jitter. The clock input
circuitry should use stable references, for example, using analog
power and ground planes to generate the valid high and low
digital levels for the AD15252 clock input. Power supplies for
clock drivers should be separated from the ADC output driver
supplies to avoid modulating the clock signal with digital noise.
Low jitter crystal-controlled oscillators make the best clock
sources. If the clock is generated from another type of source
(by gating, dividing, or other methods), it should be retimed by
the original clock at the last step.
OLE
The internal voltage reference of the ADC is pin strapped to a
fixed value of 0.5 V. A 10 μF capacitor should be used between
REFT and REFB.
CLOCK INPUT AND CONSIDERATIONS
Typical high speed ADCs use both clock edges to generate a
variety of internal timing signals and, as a result, can be
sensitive to clock duty cycle. Commonly, a 5% tolerance is
required on the clock duty cycle to maintain dynamic
performance characteristics.
TE
POWER DISSIPATION AND STANDBY MODE
The AD15252 provides separate clock inputs for each channel.
The optimum performance is achieved with the clocks operated
at the same frequency and phase. Clocking the channels
asynchronously can significantly degrade performance. In some
applications, it is desirable to skew the clock timing of adjacent
channels. The AD15252’s separate clock inputs allow clock
timing skew (typically ±1 ns) between the channels without
significant performance degradation.
The AD15252 contains two internal clock duty cycle stabilizers
(DCS), one for each converter, which retime the nonsampling
edge, providing an internal clock with a nominal 50% duty
cycle. Input clock rates of over 40 MHz can use the DCS so that
a wide range of input clock duty cycles can be accommodated.
Maintaining a 50% duty cycle clock is particularly important in
high speed applications, when proper track-and-hold times for
the converter are required to maintain high performance.
The duty cycle stabilizer uses a delay-locked loop to create the
nonsampling edge. As a result, any change to the sampling
frequency requires approximately 2 μs to 3 μs to allow the DLL
to acquire and settle to the new rate.
The power dissipated by the AD15252 is proportional to its
sampling rates. The digital (DRVDD) power dissipation is
determined primarily by the strength of the digital drivers and
the load on each output bit. The digital drive current can be
calculated by
IDRVDD = VDRVDD × CLOAD × fCLOCK × N
where:
N is the number of bits changing.
CLOAD is the average load on the digital pins that changed.
The analog circuitry is optimally biased so that each speed
grade provides excellent performance while affording reduced
power consumption. Each speed grade dissipates a baseline
power at low sample rates that increase with clock frequency.
Either channel of the AD15252 can be placed into standby mode
independently by asserting the PDWN_A or PDWN_B pins.
The minimum standby power is achieved when both channels
are placed into full power-down mode using PDWN_A =
PDWN_B = high. Under this condition, the internal references
are powered down. When either or both of the channel paths
are enabled after a power-down, the wake-up time is directly
related to the recharging of the REFT and REFB decoupling
capacitors and to the duration of the power-down. Typically, it
takes approximately 5 ms to restore full operation with fully
discharged 10 μF decoupling capacitors on REFT and REFB.
Rev. 0 | Page 11 of 20
AD15252
A single channel can be powered down for moderate power
savings. The powered-down channel shuts down internal
circuits, but both the reference buffers and shared reference
remain powered. Because the buffer and voltage reference
remain powered, the wake-up time is reduced to several clock
cycles.
The data format can be selected for either offset binary or twos
complement. This is discussed later in the Data Format section.
TIMING
The AD15252 provides latched data outputs with a pipeline
delay of seven clock cycles. Data outputs are available one
propagation delay (tPD) after the rising edge of the clock signal.
Refer to Figure 20 for a detailed timing diagram.
When using only one channel of the AD15252, the clock for the
disabled channel should also be disabled, or distortion occurs in
the channel in use.
The length of the output data lines and the loads placed on
them should be minimized to reduce transients within the
AD15252. These transients can detract from the converter’s
dynamic performance.
DIGITAL OUTPUTS
OBS
The AD15252 output drivers can be configured to interface
with 2.5 V or 3.3 V logic families by matching DRVDD to the
digital supply of the interfaced logic. The output drivers are
sized to provide sufficient output current to drive a wide variety
of logic families. However, large drive currents tend to cause
current glitches on the supplies, which can affect converter
performance. Applications requiring the ADC to drive large
capacitive loads or large fan-outs can require external buffers or
latches.
A–1
A1
A0
The lowest typical conversion rate of the AD15252 is 1 MSPS.
At clock rates below 1 MSPS, dynamic performance can degrade.
DATA FORMAT
OLE
A2
The AD15252 data output format can be configured for either
twos complement or offset binary. This is controlled by the data
format select pin (DFS). Connecting DFS to AGND produces
offset binary output data. Conversely, connecting DFS to AVDD
formats the output data as twos complement.
A4
B–1
B1
B0
TE
A7
A3
A6
A5
ANALOG INPUT
ADC A
A8
B8
B2
ANALOG INPUT
ADC B
B7
B3
B4
B6
B5
CLK_A = CLK_B =
MUX_SELECT
A–7
tODF
B–7
A–6
B–6
A–5
B–5
A–4
B–4
A–3
B–3
A–2
B–2
A–1
B–1
A0
B0
A1
D0_A
–D11_A
05154-002
B–8
tODR
Figure 20. Example of Multiplexed Data Format Using the Channel A Output and the Same Clock Tied to CLK_A, CLK_B, and MUX_SELECT
Rev. 0 | Page 12 of 20
AD15252
OBS
05154-027
OLE
TE
Figure 21. AD15252 Evaluation Board Top Silk
05154-029
PCB AND EVALUATION BOARD
Figure 22. AD15252 Evaluation Board Top Paste
05154-030
05154-028
Figure 23. AD15252 Evaluation Board Top Mask
Figure 24. AD15252 Evaluation Board Top Signal
Rev. 0 | Page 13 of 20
AD15252
OBS
05154-031
05154-033
OLE
Figure 27. AD15252 Evaluation Board Bottom Signal
Figure 25. AD15252 Evaluation Board Power Plane
05154-032
05154-034
TE
Figure 28. AD15252 Evaluation Board Bottom Mask
Figure 26. AD15252 Evaluation Board Ground Plane
Rev. 0 | Page 14 of 20
AD15252
OBS
05154-035
OLE
Figure 29. AD15252 Evaluation Board Bottom Paste
TE
Rev. 0 | Page 15 of 20
1
2
3
4
+VCC
AGND
AVDD
AGND
05154-036
AGND
R4
DNI
J2 Z = 50Ω
O
AGND
R1
DNI
6
6
T1
SEC
1
4
3
TC1-1-13M
T4
+
SEC
1
C28
10μF
L1
2
DGND
+ C7
10μF
DIGITAL
+2.5V
DGND
1
+VDD
4
3
TC1-1-13M
PRI
PRI
J1 Z = 50Ω
O
Z5.531.3425.0
J5
Z5.531.3425.0
+VDD
DGND
DRVDD
DGND
TC1-1-13M
3
4
AGND
AGND
R8
0Ω
R7
0Ω
AGND
R97
DNI
R10
0Ω
R9
0Ω
AGND
R96
DNI
C29
0.1μF
2
VIN+A
AGND
L2
VIN+B
VIN–A
R11
100Ω
+
VIN–B
R12
100Ω
C30
10μF
1
+VCC
AGND
AGND
DUTAVDD
LSB1_A
LSB0_A
LSB1_B
LSB0_B
C24
0.1μF
VIN+B
VIN–B
OEB_B
DUTCLK_B
PDWN_B
DFS
C23
0.1μF
VIN+A
VIN–A
C4
10μF
E2
D7
D8
F5
H4
H1
H2
H3
E1
E4
G4
F4
E3
D2
C3
10μF
A1
A2
A3
D1
D4
B4
C4
OEB_A
CLK_A
PDWN_A
C26
0.1μF
C1
0.1μF
L3
2
REFB
DNC
DNC
DNC
DNC
VINB
VINB
VCM_B
REFT
OEB_B
CLK_B
PDWN_B
DFS
AGND
C8
0.1μF
DUTAVDD
+ C13
10μF
REF_RTN
VINA
VINA
VCM_A
VREF
AGND
AGND
+
1
AVDD
C9
10μF
DUTAVDD
C31
0.1μF
OEB_A
DUTCLK_A
PDWN_A
AGND
+ C10
10μF
ANALOG
+3.3V
C27
0.1μF
+
1
+ C15
10μF
U1
AD15252
D11_B
D10_B
D09_B
D08_B
D07_B
D06_B
D05_B
D04_B
D03_B
D02_B
D01_B
D00_B
OTR_B
D11_A
D10_A
D09_A
D08_A
D07_A
D06_A
D05_A
D04_A
D03_A
D02_A
D01_A
D00_A
OTR_A
TE
AGND
DGND
E7
F8
F7
G8
F6
H8
G7
H7
G6
H6
G5
H5
E8
C5
A5
B5
A6
B6
A7
B7
A8
C6
B8
C7
C8
A4
D11_B
D10_B
D09_B
D08_B
D07_B
D06_B
D05_B
D04_B
D03_B
D02_B
D01_B
D00_B
OTR_B
D11_A
D10_A
D09_A
D08_A
D07_A
D06_A
D05_A
D04_A
D03_A
D02_A
D01_A
D00_A
OTR_A
LSB_B
MSB_B
LSB_A
MSB_A
DGND
C20
0.1μF
DUTDRVDD
DUTDVDD
L4
2
DGND
DRVDD
C2
10μF
AVDD
AVDD
AVDD
AVDD
AVDD
AVDD
DRVDD
DRVDD
1
2
3
4
TC1-1-13M
3
4
PRI
PRI
SEC
1
Figure 30. AD15252 Evaluation Board Schematic: Analog Front End ADC
SEC
6
T2
1
C1
C2
C3
F1
F2
F3
E6
D6
OLE
AGND
AGND
AGND
AGND
AGND
AGND
AGND
DRGND
DRGND
Rev. 0 | Page 16 of 20
6
T3
JP1
DFS
PDWN_B
OEB_B
OEB_A
DGND
JP2
JP4
OEB_B
JP3
OEB_A
JP5
DFS
PDWN_B
R2
5.1kΩ
ANALOG
+3.3V
R3
5.1kΩ
ANALOG
+3.3V
R5
5.1kΩ
ANALOG
+3.3V
R6
5.1kΩ
ANALOG
+3.3V
PDWN_A
R81
5.1kΩ
ANALOG
+3.3V
DGND
E11 E12
AGND
DGND
DGND
E10
E8
DGND
DGND
DRVDD
E9
E7
AGND
E6
E4
E2
+VCC
AGND
E5
AGND
E3
AGND
PDWN_A
JP9
JP10
E1
+VDD
AVDD
AGND
OBS
B1
B2
B3
D3
G1
G2
G3
D5
E5
J6
AGND
SHUNT
ON = GND
OFF = +3.3V
AD15252
AD15252
1
19
DATACLK_A
OTR_A
D06_A
D07_A
D08_A
D09_A
D10_A
D11_A
R13
150Ω
R14
150Ω
R20
150Ω
R19
150Ω
R18
150Ω
R17
150Ω
R16
150Ω
R15
150Ω
2
3
4
5
6
7
8
9
10
OE1
OE2
VCC
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
GND
O0
O1
O2
O3
O4
O5
O6
O7
R28
DNI
U3
OBS
LSB1_A
D00_A
D01_A
D02_A
D03_A
D04_A
D05_A
R27
DNI
R26
150Ω
R25
150Ω
R24
150Ω
R23
150Ω
R22
150Ω
R21
150Ω
C16
0.1μF
DGND
18
17
16
15
14
13
12
11
LSB1_AX
1
19
VCC
OE1
OE2
2
3
4
5
6
7
8
9
10
O0
O1
O2
O3
O4
O5
O6
O7
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
GND
R45
22.1Ω
R46
22.1Ω
R52
22.1Ω
R51
22.1Ω
R50
22.1Ω
R49
22.1Ω
R48
22.1Ω
R47
22.1Ω
DIGITAL
C17
+2.5V
0.1μF
20
R60
22.1Ω
R59
22.1Ω
DGND
R58
22.1Ω
R57
22.1Ω
R56
22.1Ω
R55
22.1Ω
74VHC541MTC
LSB0_AX
LSB0_A
20
18
17
16
15
14
13
12
11
DATACLK_A2
OTR_A2
D06_A2
D07_A2
D08_A2
D09_A2
D10_A2
D11_A2
LSB0_A2
LSB1_A2
D00_A2
D01_A2
TP5
D02_A2
TSW-140-08-S-D-RA
79
77
75
73
71
69
67
65
63
61
59
57
55
53
51
49
47
45
43
41
D03_A2
OLE
R54
22.1Ω
R53
22.1Ω
1
19
D05_B
D06_B
D07_B
D08_B
D09_B
D10_B
D11_B
OTR_B
R36
150Ω
R35
150Ω
R34
150Ω
R33
150Ω
R32
150Ω
R31
150Ω
R30
150Ω
R29
150Ω
2
3
4
5
6
7
8
9
10
OE1
OE2
VCC
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
GND
O0
O1
O2
O3
O4
O5
O6
O7
D00_B
D01_B
D02_B
D03_B
D04_B
LSB0_B
DATACLK_B
R42
DNI
R41
150Ω
R40
150Ω
R39
150Ω
R38
150Ω
U5
R37
150Ω
R43
DNI
R44
0Ω
LSB1_AX
20
18
17
16
15
14
13
12
11
DGND
1
19
2
3
4
5
6
7
8
9
10
DGND
OE1
OE2
VCC
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
GND
O0
O1
O2
O3
O4
O5
O6
O7
DIGITAL
C25
+2.5V
0.1μF
20
DGND
18
17
16
15
14
13
12
11
R68
22.1Ω
R67
22.1Ω
R66
22.1Ω
R65
22.1Ω
R64
22.1Ω
R63
22.1Ω
R62
22.1Ω
R61
22.1Ω
R74
22.1Ω
R73
22.1Ω
R72
22.1Ω
R71
22.1Ω
R70
22.1Ω
R69
22.1Ω
R75
22.1Ω
R76
22.1Ω
DATACLK_B2
OTR_B2
D06_B2
D07_B2
D08_B2
D09_B2
D10_B2
D11_B2
TSW-140-08-S-D-RA
39
37
35
33
31
29
27
25
23
21
19
17
15
13
11
9
7
5
3
1
TSW-140-08-S-D-RA
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
DGND
DATACLK_B2
DGND
D11_B2
D10_B2
D09_B2
D08_B2
D07_B2
D06_B2
D05_B2
D04_B2
D03_B2
D02_B2
D01_B2
D00_B2
LSB1_B2
LSB0_B2
OTR_B2
DGND
LSB0_B2
TE
J7:A
J7:B
DGND
LSB1_B2
D00_B2
D01_B2
TP6
D02_B2
D03_B2
LSB1_AX
LSB0_AX
R77
0Ω
R78
0Ω
D04_B2
D05_B2
DGND
LSB1_BX
74VHC541MTC
LSB0_BX
R79
0Ω
R80
0Ω
DGND
Figure 31. AD15252 Evaluation Board Schematic: Digital Outputs
Rev. 0 | Page 17 of 20
J7:D
DGND
D05_A2
C22
0.1μF
74VHC541MTC
LSB0_AX
LSB1_B
DIGITAL
+2.5V
J7:C
D04_A2
74VHC541MTC
U4
TSW-140-08-S-D-RA
80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
DGND
DATACLK_A2
DGND
D11_A2
D10_A2
D09_A2
D08_A2
D07_A2
D06_A2
D05_A2
D04_A2
D03_A2
D02_A2
D01_A2
D00_A2
LSB1_A2
LSB0_A2
OTR_A2
DGND
05154-037
DIGITAL
+2.5V
U2
AD15252
5
U6:C
6
U6:D
8
9
74VHC04MTC
74VHC04MTC
AGND
ANALOG
+3.3V
C11
0.1μF
CLK_A
3
AGND
OBS
C14
0.1μF
JP8
AGND
XTAL
A = ENABLE
B = DISABLE
A
B
R98
100kΩ
AGND
1
7
C21
0.1μF
8
ANALOG
+3.3V
C12
0.1μF
DATACLK_A DELAY
A = 1 DELAY
B = 2 DELAY
AGND
1
U6:A
VCC
2
GND
U6:F
13
12
R85
0Ω
DUTCLK_A
TP8
AGND
OLE
ANALOG
+3.3V
C19
0.1μF
J4
R84
49.9Ω
R100
1kΩ
R82
0Ω
1
VCC
GND
R99
1kΩ
TP9
AGND
14
7
U7:A
2
13
U7:F
12
R87
DNI
74VHC04MTC 74VHC04MTC
AGND
CLK_B
3
R89
0Ω
U7:B
4
74VHC04MTC
U7:E
11
10
JP7 R95 TP10
DNI
A
B
74VHC04MTC
DATACLK_B
TE
DUTCLK_B
R91
DNI
AGND
AGND
DATACLK_A
R88
0Ω
AGND
C6
0.1μF
AGND
R92
DNI
74VHC04MTC 74VHC04MTC
7
R82
DNI
VF140SHHL-65MHz
74VHC04MTC
14
AGND
Y1 14
74VHC04MTC
DUTCLK_A
DUTCLK_B
DATACLK_B DELAY
A = 1 DELAY
B = 2 DELAY
5
U7:C
6
74VHC04MTC
U7:D
9
8
74VHC04MTC
AGND
Figure 32. AD15252 Evaluation Board Schematic: Encode
Rev. 0 | Page 18 of 20
05154-038
R83
49.9Ω
ANALOG
+3.3V
U6:E
11
10
ANALOG
+3.3V
C18
0.1μF
R90
100kΩ R94
0Ω
C5
0.1μF
J3
U6:B
4
TP7
JP6 R93
A 22.1Ω
B
AD15252
OUTLINE DIMENSIONS
8.10
8.00 SQ
7.90
8
7
6
5
4
3
2
1
A
BALL A1
CORNER
TOP VIEW
B
C
5.60
BSC SQ
D
0.80
BSC
E
F
G
H
OBS
1.70
1.55
1.35
BOTTOM VIEW
DETAIL A
1.31
1.21
1.10
DETAIL A
0.34 NOM
0.25 MIN
0.55
0.50
0.45
BALL DIAMETER
COPLANARITY
0.12
OLE
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-205-BA
Figure 33. 64-Lead Chip Scale Package Ball Grid Array [CSP_BGA]
(BC-64-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD15252BBC
AD15252/PCB
Temperature Range
−40°C to +85°C
TE
Package Description
64-Lead Chip Scale Package Ball Grid Array (CSP_BGA)
Evaluation Board
Rev. 0 | Page 19 of 20
Package Option
BC-64-1
AD15252
NOTES
OBS
OLE
TE
© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05154–0-–8/05(0)
Rev. 0 | Page 20 of 20