AD8108/AD8109

–7–

REV. 0

PIN FUNCTION DESCRIPTIONS

Pin Name

Pin Numbers

Pin Description

INxx

1, 3, 5, 7, 9, 11, 13, 15

Analog Inputs; xx = Channel Numbers 00 Through 07.

DATA IN

57

Serial Data Input, TTL Compatible.

CLK

58

Clock, TTL Compatible. Falling Edge Triggered.

DATA OUT

59

Serial Data Out, TTL Compatible.

UPDATE

56

Enable (Transparent) “Low.” Allows serial register to connect directly to switch

matrix. Data latched when “High.”

RESET

61

Disable Outputs, Active “Low.”

CE

60

Chip Enable, Enable “Low.” Must be “low” to clock in and latch data.

SER/PAR

55

Selects Serial Data Mode, “Low” or Parallel Data Mode, “High.” Must be connected.

OUTyy

41, 38, 35, 32, 29, 26, 23, 20

Analog Outputs yy = Channel Numbers 00 Through 07.

AGND

2, 4, 6, 8, 10, 12, 14, 16, 46

Analog Ground for Inputs and Switch Matrix.

DVCC

63, 79

+5 V for Digital Circuitry.

DGND

62, 80

Ground for Digital Circuitry.

AVEE

17, 45

–5 V for Inputs and Switch Matrix.

AVCC

18, 44

+5 V for Inputs and Switch Matrix

AGNDxx

42, 39, 36, 33, 30, 27, 24, 21

Ground for Output Amp, xx = Output Channel Numbers 00 Through 07. Must be connected.

AVCCxx/yy

43, 37, 31, 25, 22, 19

+5 V for Output Amplifier that is shared by Channel Numbers xx and yy. Must be connected.

AVEExx/yy

40, 34, 28, 22

–5 V for Output Amplifier that is shared by Channel Numbers xx and yy. Must be connected.

A0

54

Parallel Data Input, TTL Compatible (Output Select LSB).

A1

53

Parallel Data Input, TTL Compatible (Output Select).

A2

52

Parallel Data Input, TTL Compatible (Output Select MSB).

D0

51

Parallel Data Input, TTL Compatible (Input Select LSB).

D1

50

Parallel Data Input, TTL Compatible (Input Select).

D2

49

Parallel Data Input, TTL Compatible (Input Select MSB).

D3

48

Parallel Data Input, TTL Compatible (Output Enable).

NC

47, 64–78

Not Connected.

Figure 5. I/O Schematics

d. Logic Input

e. Logic Output

ESD

ESD

INPUT

AVEE

ESD

ESD

OUTPUT

AVEE

1k

(AD8109 ONLY)

ESD

ESD

RESET

20k

DGND

ESD

ESD

INPUT

DGND

ESD

ESD

OUTPUT

DGND

2k

a. Analog Input

c. Reset Input

b. Analog Output