ADS774H

PIN DESCRIPTIONS

PIN

NAME

NO.

I/O

DESCRIPTION

1

Power

5V digital logic supply

Data mode select

12/8

2

Input

'1' = read

'0' = convert

CS

3

Input

Chip select (active low)

4

Input

Byte address, short cycle

Read/Convert

R/C

5

Input

'1' = 12-bit

'0' = 8-bit

CE

6

Input

Chip enable (active high)

NC

7

Do not connect

Ref Out

8

Output

2.5V reference output

Analog Common

9

Power

Analog ground

Ref In

10

Input

2.5V reference input

11

Power

–15V to +5V analog supply

Connect this pin to REF OUT through a 50

Ω resistor for bipolar operation, or connect to Analog

Bipolar Offset

12

Input

Common for unipolar operation.

10V Range

13

Input

0V to 10V or ±5V input span. Do not connect if using a 20V range.

20V Range

14

Input

0V to 20V or ±10V input span. Do not connect if using a 10V range.

Digital Common

15

Power

Digital ground

DB0

16

Output

DB1

17

Output

disabled.

DB2

18

Output

DB3

19

Output

DB4

20

Output

DB5

21

Output

In 12-bit format, these pins output the middle four bits of data. In 8-bit format, they output the

DB6

22

Output

DB7

23

Output

DB8

24

Output

DB9

25

Output

In 12-bit format, these pins output the upper four bits of data. In 8-bit format, they output the upper

DB10

26

Output

DB11

27

Output

STATUS

28

Output

Active high when conversion is in progress; active low when complete.

8

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