AD9238

–6–

PIN FUNCTION DESCRIPTIONS

Pin Number

Mnemonic

Description

2

VIN+_A

Analog Input Pin (+) for Channel A

3

VIN–_A

Analog Input Pin (–) for Channel A

15

VIN+_B

Analog Input Pin (+) for Channel B

14

VIN–_B

Analog Input Pin (–) for Channel B

6

REFT_A

Differential Reference (+) for Channel A

7

REFB_A

Differential Reference (–) for Channel A

11

REFT_B

Differential Reference (+) for Channel B

10

REFB_B

Differential Reference (–) for Channel B

8

VREF

Voltage Reference Input/Output

9

SENSE

Reference Mode Selection

18

CLK_B

Clock Input Pin for Channel B

63

CLK_A

Clock Input Pin for Channel A

19

DCS

Enable Duty Cycle Stabilizer (DCS) Mode

20

DFS

Data Output Format Select Bit (Low for Offset Binary, High for Twos Complement)

21

PDWN_B

Power-Down Function Selection for Channel B (Active High)

60

PDWN_A

Power-Down Function Selection for Channel A (Active High)

22

OEB_B

Output Enable Bit for Channel B

59

OEB_A

Output Enable Bit for Channel A (Low Setting Enables Channel A Output Data Bus)

44–51, 54–57

D0_A (LSB)–D11_A (MSB) Channel A Data Output Bits

25–27, 30–38

D0_B (LSB)–D11_B (MSB)

Channel B Data Output Bits

39

OTR_B

Out-of-Range Indicator for Channel B

58

OTR_A

Out-of-Range Indicator for Channel A

62

SHARED_REF

Shared Reference Control Bit (Low for Independent Reference Mode,

High for Shared Reference Mode)

61

MUX_SELECT

Data Multiplexed Mode. (See description for how to enable; high setting disables

output data Multiplexed mode).

5, 12, 17, 64

AVDD

Analog Power Supply

1, 4, 13, 16

AGND

Analog Ground

28, 40, 53

DRGND

Digital Output Ground

29, 41, 52

DRVDD

Digital Output Driver Supply. Must be decoupled to DRGND with a minimum

0.1 µF capacitor. Recommended decoupling is 0.1 µF capacitor in parallel with 10 µF.

23, 24, 42, 43

DNC

Do Not Connect Pins. Should be left floating.

PIN CONFIGURATION

1

2

3

4

5

6

7

8

9

10

11

13

14

15

16

12

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

48

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

64 63 62 61 60

55 54 53 52 51 50 49

59 58 57 56

PIN 1

IDENTIFIER

64-LEAD LQFP

TOP VIEW

(Not to Scale)

D4_A

D3_A

D2_A

D1_A

D0_A

DNC

DNC

DRGND

OTR_B

D11_B (MSB)

D10_B

D9_B

D8_B

D7_B

D6_B

AD9238

AGND

AVDD

REFT_A

REFB_A

VREF

SENSE

REFB_B

AGND

VIN–_B

VIN+_B

VIN+_A

VIN–_A

AVDD

REFT_B

AGND

AGND

DRVDD

DNC = DO NOT CONNECT

REV. A