AD AD9731BRS

a
FEATURES
170 MSPS Update Rate
TTL/High-Speed CMOS-Compatible Inputs
Wideband SFDR: 66 dB @ 2 MHz/50 dB @ 65 MHz
Pin-Compatible, Lower Cost Replacement for
Industry Standard AD9721 DAC
Low Power: 439 mW @ 170 MSPS
Fast Settling: 3.8 ns to 1/2 LSB
Internal Reference
Two Package Styles: 28-Lead SOIC and SSOP
APPLICATIONS
Digital Communications
Direct Digital Synthesis
Waveform Reconstruction
High Speed Imaging
5 MHz–65 MHz HFC Upstream Path
GENERAL DESCRIPTION
The AD9731 is a 10-bit, 170 MSPS, bipolar D/A converter that
is optimized to provide high dynamic performance, yet offer
lower power dissipation and more economical pricing than
afforded by previous bipolar high performance DAC solutions.
The AD9731 was designed primarily for demanding communications systems applications where wideband spurious-free
dynamic range (SFDR) requirements are strenuous and could
previously only be met by using a high performance DAC such
as the industry-standard AD9721. The proliferation of digital
communications into basestation and high volume subscriberend markets has created a demand for excellent DAC performance delivered at reduced levels of power dissipation and cost.
The AD9731 is the answer to that demand.
10-Bit, 170 MSPS
D/A Converter
AD9731
FUNCTIONAL BLOCK DIAGRAM
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
ANALOG
RETURN
TTL
DRIVE
LOGIC
DECODERS
AND
DRIVERS
REGISTER
SWITCH
NETWORK
IOUT
IOUT
REF IN
CLOCK
CONTROL
AMP
INTERNAL VOLTAGE
REFERENCE
RSET
REF OUT
CONTROL
AMP IN
AMP OUT
DIGITAL DIGITAL ANALOG
–VS
+VS
–VS
Optimized for direct digital synthesis (DDS) waveform reconstruction, the AD9731 provides 50 dB of wideband harmonic
suppression over a dc-to-65 MHz analog output bandwidth.
This signal bandwidth addresses the transmit spectrum in many
of the emerging digital communications applications where
signal purity is critical. Narrowband, the AD9731 provides an
SFDR of greater than 79 dB. This excellent wideband and
narrowband ac performance, coupled with a lower pricing structure, make the AD9731 the optimum high performance DAC
value.
The AD9731 is packaged in 28-lead SOIC (same footprint
as the industry standard AD9721) and super space-saving
28-lead SSOP; both are specified to operate over the extended
industrial temperature range of –40°C to +85°C.
REV. A
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
5/27/99 8 PM
(+VS = +5 V, –VS = –5.2 V, CLOCK = 125 MHz, RSET = 1.96 k⍀ for 20.4 mA IOUT,
REF = –1.25 V, unless otherwise noted.)
AD9731–SPECIFICATIONS V
Parameter
Temp
Test Level
Min
RESOLUTION
THROUGHPUT RATE
Max
Units
10
Bits
170
MHz
+25°C
IV
+25°C
Full
+25°C
Full
I
VI
I
VI
0.25
0.35
0.6
0.7
1
1.5
1
1.5
LSB
LSB
LSB
LSB
+25°C
Full
+25°C
Full
I
VI
I
VI
V
35
40
2.5
2.5
0.04
70
100
5
5
µA
µA
% FS
% FS
µA/°C
REFERENCE/CONTROL AMP
Internal Reference Voltage2
Internal Reference Voltage Drift
Internal Reference Output Current3
Amplifier Input Impedance
Amplifier Bandwidth
+25°C
Full
Full
+25°C
+25°C
I
IV
VI
V
V
–1.25
100
–1.15
50
2.5
V
µV/°C
µA
kΩ
MHz
REFERENCE INPUT4
Reference Input Impedance
Reference Multiplying Bandwidth5
+25°C
+25°C
V
V
4.6
75
kΩ
MHz
OUTPUT PERFORMANCE
Output Current4, 6
Output Compliance
Output Resistance
Output Capacitance
Voltage Settling Time to 1/2 LSB (tST)7
Propagation Delay (tPD)8
Glitch Impulse9
Output Slew Rate10
Output Rise Time10
Output Fall Time10
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
V
IV
V
V
V
V
V
V
V
V
Full
Full
Full
+25°C
+25°C
+25°C
Full
+25°C
Full
+25°C
+25°C
IV
VI
VI
VI
VI
IV
IV
IV
IV
IV
IV
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
V
V
V
V
V
V
DC ACCURACY
Differential Nonlinearity
Integral Nonlinearity
INITIAL OFFSET ERROR
Zero-Scale Offset Error
Full-Scale Gain Error1
Offset Drift Coefficient
DIGITAL INPUTS
Input Capacitance
Logic “1” Voltage
Logic “0” Voltage
Logic “1” Current
Logic “0” Current
Minimum Data Setup Time (tS)11
Minimum Data Hold Time (tH)12
Clock Pulsewidth Low (pwMIN)
Clock Pulsewidth High (pwMAX)
SFDR PERFORMANCE (Wideband) 13
2 MHz AOUT
10 MHz AOUT
20 MHz AOUT
40 MHz AOUT
65 MHz AOUT (Clock = 170 MHz)
70 MHz AOUT (Clock = 170 MHz)
–2–
165
Typ
–1.35
–50
+500
20
–1.5
+3
240
5
3.8
2.9
4.1
400
1
1
2
2.0
8
30
1.2
1.5
0.1
0.1
2
2
66
62
61
55
50
47
0.8
50
100
2
2.5
1.0
1.0
mA
V
Ω
pF
ns
ns
pVs
V/µs
ns
ns
pF
V
V
µA
µA
ns
ns
ns
ns
ns
ns
dB
dB
dB
dB
dB
dB
REV. A
5/27/99 8 PM
AD9731
Parameter
Temp
Test Level
Min
Typ
Max
Units
SFDR PERFORMANCE (Narrowband)
2 MHz; 2 MHz Span
25 MHz, 2 MHz Span
10 MHz, 5 MHz Span (Clock = 170 MHz)
+25°C
+25°C
+25°C
V
V
V
79
61
73
dB
dB
dB
INTERMODULATION DISTORTION14
F1 = 800 kHz, F2 = 900 kHz
+25°C
V
58
dB
+25°C
Full
+25°C
Full
+25°C
Full
+25°C
Full
+25°C
I
VI
I
VI
I
VI
V
V
V
27
27
45
45
13
15
439
449
100
13
15
POWER SUPPLY
Digital –V Supply Current
Analog –V Supply Current
Digital +V Supply Current
Power Dissipation
PSRR
37
42
53
66
20
22
mA
mA
mA
mA
mA
mA
mW
mW
µA/V
NOTES
1
Measured as an error in ratio of full-scale current to current through R SET (640 µA nominal); ratio is nominally 32. DAC load is virtual ground.
2
Internal reference voltage is tested under load conditions specified in Internal Reference Output current specification.
3
Internal reference output current defines load conditions applied during Internal Reference Voltage test.
4
Full-scale current variations among devices are higher when driving REFERENCE IN directly.
5
Frequency at which a 3 dB change in output of DAC is observed; R L = 50 Ω; 100 mV modulation at midscale.
6
Based on IFS = 32 (CONTROL AMP IN/R SET) when using internal control amplifier. DAC load is virtual ground.
7
Measured as voltage settling at midscale transition to ± 0.1%; RL = 50 Ω.
8
Measured from 50% point of rising edge of CLOCK signal to 1/2 LSB change in output signal.
9
Peak glitch impulse is measured as the largest area under a single positive or negative transient.
10
Measured with RL = 50 Ω and DAC operating in latched mode.
11
Data must remain stable for specified time prior to rising edge of CLOCK.
12
Data must remain stable for specified time after rising edge of CLOCK.
13
SFDR is defined as the difference in signal energy between the full-scale fundamental signal and worst case spurious frequencies in the output spectrum window.
The frequency span is dc-to-Nyquist unless otherwise noted.
14
Intermodulation distortion is the measure of the sum and difference products produced when a two-tone input is driven into the DAC. The distortion products
created will manifest themselves at sum and difference frequencies of the two tones.
15
Supply voltages should remain stable within ± 5% for nominal operation.
Specifications subject to change without notice.
pw MIN
pw MAX
CLOCK
tS
tH
CODE 1
DATA
DATA
CODE 2
DATA
CODE 3
DATA
CODE 4
DATA
CODE 2
CODE 4
ANALOG OUTPUT
CODE 1
CODE 3
DETAIL OF SETTLING TIME
GLITCH AREA =
1/2 HEIGHT 3 WIDTH
CLOCK
SPECIFIED
ERROR BAND
t PD
H
ANALOG OUTPUT
W
t ST
Figure 1. Timing Diagrams
REV. A
–3–
AD9731
ABSOLUTE MAXIMUM RATINGS*
EXPLANATION OF TEST LEVELS
Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . –VS to +VS
+VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +6 V
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . –0.7 V to +VS
–VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –7 V
Analog Output Current . . . . . . . . . . . . . . . . . . . . . . . . 30 mA
Control Amplifier Input Voltage Range . . . . . . . . . 0 V to –4 V
Reference Input Voltage Range . . . . . . . . . . . . . . . . 0 V to –VS
Maximum Junction Temperature . . . . . . . . . . . . . . . . +150°C
Operating Temperature Range . . . . . . . . . . . –40°C to +85°C
Internal Reference Output Current . . . . . . . . . . . . . . . 500 µA
Lead Temperature (10 sec Soldering) . . . . . . . . . . . . . +300°C
Storage Temperature . . . . . . . . . . . . . . . . . . –65°C to +165°C
Control Amplifier Output Current . . . . . . . . . . . . . ± 2.5 mA
Test Level
Definition
I
II
100% Production Tested.
The parameter is 100% production tested at
+25°C; sampled at temperature production.
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 devices.
III
IV
V
VI
*Absolute maximum ratings are limiting values, to be applied individually, and
beyond which the serviceability of the circuit may be impaired. Functional
operability under any of these conditions is not necessarily implied. Exposure of
absolute maximum rating conditions for extended periods of time may affect
device reliability.
ORDERING GUIDE
Model
Temperature
Range
Package
Description
Package
Options
AD9731BR
AD9731BRS
AD9731-PCB
–40°C to +85°C
–40°C to +85°C
0°C to +70°C
28-Lead Wide Body (SOIC)
28-Lead Shrink Small (SSOP)
PCB
R-28
RS-28
CAUTION
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 the AD9731 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.
–4–
WARNING!
ESD SENSITIVE DEVICE
REV. A
AD9731
PIN FUNCTION DESCRIPTION
Pin #
Pin Name
Pin Description
1
2–9
10
11
12, 13
14
15, 18, 28
16
17
D9(MSB)
D8–D1
D0(LSB)
CLOCK
NC
DIGITAL +VS
GND
DIGITAL –VS
RSET
19
ANALOG RETURN
20
IOUT
21
IOUTB
22
23
ANALOG –VS
REF IN
24
CONTROL AMP OUT
25
REF OUT
26
27
CONTROL AMP IN
DIGITAL –VS
Most significant data bit of digital input word.
Eight bits of 10-bit digital input word.
Least significant data bit of digital input word.
TTL-compatible edge-triggered latch enable signal for on-board registers.
No internal connection to this pin.
+5 V supply voltage for digital circuitry.
Converter Ground.
–5.2 V supply voltage for digital circuitry.
Connection for external reference set resistor; nominal 1.96 kΩ. Full-scale output current =
32 (Control Amp in V/RSET).
Analog Return. This point and the reference side of the DAC load resistors should be connected to the same potential (nominally ground).
Analog current output; full-scale current occurs with a digital word input of all “1s.” With
external load resistor, output voltage = IOUT (RLOAD储RINTERNAL). RINTERNAL is nominally
240 Ω.
Complementary analog current output; full-scale current occurs with a digital word input
of all “0s.”
Negative analog supply, nominally –5.2 V.
Normally connected to CONTROL AMP OUT (Pin 24). Direct line to DAC current
source network. Voltage changes (noise) at this point have a direct effect on the full-scale
output current of the DAC. Full-scale current output = 32 (CONTROL AMP IN/RSET)
when using the internal amplifier. DAC load is virtual ground.
Normally connected to REF IN (Pin 23). Output of internal control amplifier which provides a reference for the current switch network.
Normally connected to CONTROL AMP IN (Pin 26). Internal voltage reference, nominally –1.25 V.
Normally connected to REF Out (Pin 25) if not connected to external reference.
Negative digital supply, nominally –5.2 V.
PIN CONFIGURATION
D9(MSB) 1
28
GND
D8 2
27
DIGITAL –VS
D7 3
26
CONTROL AMP IN
D6 4
25
REF OUT
D5 5
24
CONTROL AMP OUT
23
REF IN
D4 6
AD9731
D3 7
22
D0(LSB) 10
19
ANALOG RETURN
CLOCK 11
18
GND
NC 12
17
RSET
NC 13
16
DIGITAL –VS
DIGITAL +VS 14
15
GND
ANALOG –VS
TOP VIEW
D2 8 (Not to Scale) 21 IOUTB
20 I
D1 9
OUT
NC = NO CONNECT
REV. A
–5–
AD9731–Typical Performance Characteristics
60
80
75
55
SFDR – dB
SFDR – dB
70
65
50
60
45
55
50
10
40
20
30
40
50
AOUT – MHz
60
70
80
20
18
16
14
10
12
IOUT – mA
8
6
4
2
Figure 5. SFDR vs. IOUT (Clock =125 MHz/AOUT = 40 MHz)
Figure 2. Narrowband SFDR (Clock = 170 MHz) vs.
AOUT Frequency
0.4
85
0.3
80
0.2
75
LSB
SFDR – dB
0.1
70
0
65
–0.1
60
–0.2
55
–0.3
–0.4
50
10
20
30
40
AOUT – MHz
50
60
Figure 6. Typical Differential Nonlinearity Performance
(DNL)
Figure 3. Narrowband SFDR (Clock = 125 MHz) vs.
AOUT Frequency
0.6
65
0.4
60
LSB
SFDR – dB
0.2
55
0
50
–0.2
45
40
10
–0.4
–0.6
20
30
40
50
60
AOUT – MHz
70
80
90
Figure 7. Typical Integral Nonlinearity Performance (INL)
Figure 4. Wideband SFDR (170 MHz Clock) vs. AOUT
–6–
REV. A
AD9731
1
1
–10
–10
ENCODE = 125MHz
AOUT = 2MHz
SPAN = 62.5MHz
–20
–20
–30
–30
1AP
–40
1AP
–40
–50
–50
–60
–60
1
1
–70
–70
–80
–80
–90
–90
–100
–100
0Hz
START
6.25MHz
62.5MHz
STOP
0Hz
START
Figure 8. Wideband SFDR 2 MHz AOUT; 125 MHz Clock
–10
ENCODE = 125MHz
AOUT = 40MHz
SPAN = 62.5MHz
6.25MHz
Figure 11. Wideband SFDR 40 MHz AOUT; 125 MHz Clock
1
0
ENCODE = 125MHz
AOUT = 10MHz
SPAN = 62.5MHz
–20
1
–10
–30
–20
1AP
–40
–30
–50
1AP
–40
–60
1
–50
PRN
–70
–60
–80
–70
–90
–80
–100
1
–90
0Hz
START
6.25MHz
62.5MHz
STOP
0Hz
START
Figure 9. Wideband SFDR 10 MHz AOUT; 125 MHz Clock
8.5MHz
1
–20
–30
ENCODE = 170MHz
AOUT = 70MHz
SPAN = 85MHz
–30
1AP
–40
1AP
–40
–50
–50
–60
1
–60
1
–70
–70
–80
–80
–90
–90
–100
–100
6.25MHz
62.5MHz
STOP
0Hz
START
Figure 10. Wideband SFDR 20 MHz AOUT; 125 MHz Clock
REV. A
1
–10
ENCODE = 125MHz
AOUT = 20MHz
SPAN = 62.5MHz
–20
85MHz
STOP
Figure 12. Wideband SFDR 65 MHz AOUT; 170 MHz Clock
–10
0Hz
START
62.5MHz
STOP
8.5MHz
85MHz
STOP
Figure 13. Wideband SFDR 70 MHz AOUT; 170 MHz Clock
–7–
AD9731
The on-board register is rising-edge triggered and should be
used to synchronize data to the current switches by applying a
pulse with proper data setup and hold times as shown in the
timing diagram. Although the AD9731 is designed to provide
isolation of the digital inputs to the analog output, some coupling of digital transitions is inevitable. Digital feedthrough can
be minimized by forming a low-pass filter at the digital input by
using a resistor in series with the capacitance of each digital
input. This common high speed DAC application technique has
the effect of isolating digital input noise from the analog output.
1
–10
ENCODE = 125MHz
AOUT1 = 800kHz
AOUT2 = 900kHz
SPAN = 2MHz
–20
–30
–40
1AP
–50
–60
1
–70
–80
References
The internal bandgap reference, control amplifier and reference
input are pinned out to provide maximum user flexibility in
configuring the reference circuitry for the AD9731. When using
the internal reference, REF OUT (Pin 25) should be connected
to CONTROL AMP IN (Pin 26). CONTROL AMP OUT (Pin
24) should be connected to REF IN (Pin 23). A 0.1 µF ceramic
capacitor connected from Pin 23 to Analog –VS (Pin 22) improves settling time by decoupling switching noise from the
current sink baseline. A reference current cell provides feedback
to the control amplifier by sinking current through RSET (Pin 17).
–90
–100
0Hz
START
200kHz
2MHz
STOP
Figure 14. Wideband Intermodulation Distortion
F1 = 800 kHz; F2 = 900 kHz; 125 MHz Clock; Span = 2 MHz
1
–10
–20
–30
ENCODE = 125MHz
AOUT1 = 800kHz
AOUT2 = 900kHz
SPAN = 62.5MHz
–40
Full-scale current is determined by CONTROL AMP IN and
RSET according to the following equation:
1AP
IOUT (FS) = 32(CONTROL AMP IN/RSET)
PRN
The internal reference is nominally –1.25 V with a tolerance of
± 8% and typical drift over temperature of 100 ppm/°C. If
greater accuracy or temperature stability is required, an external
reference can be used. The AD589 reference features 10 ppm/°C
drift over the 0°C to +70°C temperature range.
–50
–60
–70
1
–80
Two modes of multiplying operation are possible with the
AD9731. Signals with bandwidths up to 2.5 MHz and input
swings from –0.6 V to –1.2 V can be applied to the CONTROL
AMP IN pin as shown in Figure 16. Because the control amplifier is internally compensated, the 0.1 µF capacitor discussed
above can be reduced to maximize the multiplying bandwidth.
However, it should be noted that output settling time, for
changes in the digital word, will be degraded.
–90
–100
0Hz
START
6.25MHz
62.5MHz
STOP
Figure 15. Wideband Intermodulation Distortion F1 =
800 kHz; F2 = 900 kHz; 125 MHz Clock; Span = 62.5 MHz
THEORY AND APPLICATIONS
The AD9731 high speed digital-to-analog converter utilizes
most significant bit decoding and segmentation techniques to
reduce glitch impulse and deliver high dynamic performance
on lower power consumption than previous bipolar DAC
technologies.
RSET
The design is based on four main subsections: the decoder/
driver circuits, the edge-triggered data register, the switch network and the control amplifier. An internal bandgap reference is
included to allow operation of the device with minimum external support components.
AD9731
RSET
CONTROL
AMP IN
–0.6 TO –1.2V
2.5MHz TYPICAL
RT
CONTROL
AMP OUT
Digital Inputs/Timing
REFERENCE IN
The AD9731 has TTL/high speed CMOS-compatible singleended inputs for data inputs and clock. The switching threshold
is +1.5 V.
0.1mF
ANALOG –VS
In the decoder/driver section, the three MSBs are decoded to
seven “thermometer code” lines. An equalizing delay is included
for the seven least significant bits and the clock signals. This
delay minimizes data skew and data setup and hold times at the
register inputs.
Figure 16. Low Frequency Multiplying Circuit
–8–
REV. A
AD9731
An operational amplifier can also be used to perform the I-to-V
conversion of the DAC output. Figure 18 shows an example of a
circuit that uses the AD9617, a high speed, current feedback
amplifier. The resistor values in Figure 18 provide a 4.096 V
swing, centered at ground, at the output of the AD9617 amplifier.
The REFERENCE IN pin can also be driven directly for wider
bandwidth multiplying operation. The analog signal for this mode
of operation must have a signal swing in the range of –3.3 V to
–4.25 V. This can be implemented by capacitively coupling into
REFERENCE IN a signal with a dc bias of –3.3 V (IOUT ≈
22.5 mA) to –4.25 V (IOUT ≈ 3 mA), as shown in Figure 17, or
by dividing REFERENCE IN with a low impedance op amp
whose signal swing is limited to the stated range.
10kV
1/2
AD708
NOTE: When using an external reference, the external reference voltage must be applied prior to applying –VS.
10kV
1/2
AD708
IFS
R1
200V
R2
100V
AD9731
REF CONTROL
AMP IN
OUT
APPROX
–3.8V
IOUT
RFF
25V
IFS
RL
25V
RFB
400V
±2048V
AD9617
VOUT
AD9731
REFERENCE IN
–VS
IOUTB
–VS
25V
Figure 17. Wideband Multiplying Circuit
Figure 18. I-to-V Conversion Using a Current Feedback
Amplifier
Analog Output
The switch network provides complementary current outputs
IOUT and IOUTB. The design of the AD9731 is based on statistical current source matching, which provides a 10-bit linearity
without trim. Current is steered to either IOUT or IOUTB in proportion to the digital input word. The sum of the two currents is
always equal to the full-scale output current minus 1 LSB. The
current can be converted to a voltage by resistive loading as
shown in the block diagram. Both IOUT and IOUTB should be
equally loaded for best overall performance. The voltage that is
developed is the product of the output current and the value of
the load resistor.
REV. A
EVALUATION BOARD
The performance characteristics of the AD9731 make it ideally
suited for direct digital synthesis (DDS) and other waveform
synthesis applications. The AD9731 evaluation board provides a
platform for analyzing performance under optimum layout conditions. The AD9731 also provides a reference for high speed
circuit board layout techniques.
–9–
29
28
27
26
25
24
23
22
20
18
16
14
12
–10–
37
36
35
34
33
32
31
30
2
IEN
1
II
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
15
GND4
13
GND5
11
GND6
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
10
9
8
7
6
5
4
3
21
GND1
19
GND2
17
GND3
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
+5V1
+5V2
+12V
–12V
–5V
C37DRPF
CON1
DGND
DGND
E3
E1
E7
DGND
E9
E5
R11
4.9kV
+V DIG
BNC1
E4
E2
E6
R12
50V
Y1
DG2020 DATA
GENERATOR
E8 TO E10
EXT. CLK TO E7
J1 BNC
E6 TO E8
E6 TO E8
CON 1 PIN 10
E5 TO E7
EXT. GND TO E9
+V DIG
OPTIONAL
RP2 4.9kV
REMOVE R12
REMOVE Y1
–V DIG
DGND
+V DIG
U2
U3
U4
U5
U6
U7
U8
U9
U10
U11
DGND
C7
10mF
14
U21 1
U20 2
U19 3
U18 4
U17 5
U16 6
U15 7
U14 8
U13 9
U12 10
11
12
13
+V DIG
–V DIG
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
+V DIG
C8
0.1mF
GND3
DIGITAL –VS
DGND
GND
2
OUT
PWR
4
C9
0.1mF
–VA
DIGITAL –VS
GND
ANA RETURN
GND1
RSET
3
DGND
C6
0.1mF
+VD
R14
1960V
BNC1J2
R16
50V
DGND
C3
10mF
AGND
R15
25V
–V ANA
C2
10mF
AGND
AGND
–V DIG
AGND
C1
0.1mF
–V DIG
DGND
AGND
28
27
26
25
24
23
22
21
20
19
18
17
16
15
BNC
DGND
C5
0.1mF
CONTROL AMP IN
REF OUT
CONTROL AMP OUT
REF IN
ANALOG –VS
IOUT
IOUT
U1
AD9731
Y1
OSCILLATOR
OPTIONAL
D5
D6
D7
D8
D9
D10
DAC CLOCK
NC1
NC2
+5 DIG
D2
D3
D4
D1
–V
GND
+V
PWR3
NOTE: R1–R10 = 50V
+V DIG
COMPUTER PROVIDES CLOCK
NOTES
CLOCK SWITCH MATRIX
DGND
9
20
10
8
19
7
18
6
17
5
16
4
15
3
14
2
13
1
12
11
SOURCE
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
JUMPER
DGND
R13
50V
E10
E8
BNC
J1
DGND
–VD
+VD
OPTIONAL
RP1 4.9kV
C4
0.1mF
AD9731
Figure 19. AD9731-PCB Evaluation Board Schematic
REV. A
AD9731
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
28-Lead SOIC Wide Body (SOIC)
(R-28)
15
1
14
PIN 1
0.0118 (0.30)
0.0040 (0.10)
0.4193 (10.65)
0.3937 (10.00)
28
0.2992 (7.60)
0.2914 (7.40)
0.7125 (18.10)
0.6969 (17.70)
0.1043 (2.65)
0.0926 (2.35)
0.0500
(1.27)
BSC
0.0291 (0.74)
x 45°
0.0098 (0.25)
8°
0.0192 (0.49)
0°
SEATING 0.0125 (0.32)
0.0138 (0.35)
PLANE 0.0091 (0.23)
0.0500 (1.27)
0.0157 (0.40)
28-Lead Shrink Small Outline (SSOP)
(RS-28)
28
15
1
14
0.078 (1.98) PIN 1
0.068 (1.73)
0.008 (0.203) 0.0256
(0.65)
0.002 (0.050) BSC
REV. A
0.212 (5.38)
0.205 (5.21)
0.311 (7.9)
0.301 (7.64)
0.407 (10.34)
0.397 (10.08)
0.07 (1.79)
0.066 (1.67)
8°
0.015 (0.38)
SEATING 0.009 (0.229) 0°
0.010 (0.25)
PLANE
0.005 (0.127)
–11–
0.03 (0.762)
0.022 (0.558)