Datasheet
AD9761
–6–
AD9761
–7–
PIN FUNCTION DESCRIPTIONS
Pin No. Mnemonic Description
1 DB9 Most Signicant Data Bit (MSB).
2–9 DB8–DB1 Data Bits 1–8.
10 DB0 Least Signicant Data Bit (LSB).
11 CLOCK Clock Input. Both DACs’ outputs updated on positive edge of clock and digital lters read respective
input registers.
12 WRITE Write Input. DAC input registers latched on positive edge of write.
13 SELECT Select Input. Select high routes input data to I DAC; select low routes data to Q DAC.
14 DVDD Digital Supply Voltage (2.7 V to 5.5 V).
15 DCOM Digital Common.
16 COMP3 Internal Bias Node for Switch Driver Circuitry. Decouple to ACOM with 0.1 µF capacitor.
17 QOUTA Q DAC Current Output. Full-scale current when all data bits are 1s.
18 QOUTB Q DAC Complementary Current Output. Full-scale current when all data bits are 0s.
19 REFLO Reference Ground when Internal 1.2 V Reference Used. Connect to AVDD to disable internal reference.
20 REFIO Reference Input/Output. Serves as reference input when internal reference disabled. Serves as 1.2 V
reference output when internal reference activated. Requires 0.1 µF capacitor to ACOM when internal
reference activated.
21 FSADJ Full-Scale Current Output Adjust. Resistance to ACOM sets full-scale output current.
22 COMP2 Bandwidth/Noise Reduction Node. Add 0.1 µF to AVDD for optimum performance.
23 AVDD Analog Supply Voltage (3 V to 5.5 V).
24 ACOM Analog Common.
25 IOUTB I DAC Complementary Current Output. Full-scale current when all data bits are 0s.
26 IOUTA I DAC Current Output. Full-scale current when all data bits are 1s.
27 COMP1 Internal Bias Node for Switch Driver Circuitry. Decouple to AGND with 0.1 µF capacitor.
28 RESET/SLEEP Power-Down Control Input if Asserted for Four Clock Cycles or Longer. Reset control input if
asserted for less than four clock cycles. Active high. Connect to DCOM if not used. Refer to RESET/
SLEEP Mode Operation section.
PIN CONFIGURATION
14
13
12
11
17
16
15
20
19
18
10
9
8
1
2
3
4
7
6
5
TOP VIEW
(Not to Scale)
28
27
26
25
24
23
22
21
AD9761
(MSB) DB9
IOUTB
IOUTA
COMP1
RESET/SLEEP
DB8
DB7
DB6
COMP2
AVDD
ACOM
DB5
DB4
DB3
DB2
DB1
(LSB) DB0 REFLO
REFIO
FSADJ
CLOCK
WRITE
SELECT
DVDD
QOUTB
DCOM
COMP3
QOUTA
REV. C
REV. C