AD7634

Data Sheet

Rev. B | Page 8 of 32

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

AGND

AVDD

MODE0

MODE1

D0/OB/2C

D1/A0

D3

D4/DIVSCLK[0]

D5/DIVSCLK[1]

IMPULSE

WARP

BIPOLAR

CNVST

PD

RESET

CS

RD

TEN

NOTES

1. FOR THE LEAD FRAME CHIP SCALE PACKAGE (LFCSP), THE EXPOSED PAD

SHOULD BE CONNECTED TO VEE. THIS CONNECTION IS NOT REQUIRED TO

MEET THE ELECTRICAL PERFORMANCES.

BUSY

D17/SCCS

D16/SCCLK

D15/SCIN

D14/HW/SW

48 47 46 45 44 43 42 41 40 39 38 37

35

34

33

30

31

32

36

29

28

27

25

26

2

3

4

7

6

5

1

8

9

10

12

11

13 14 15 16 17 18 19 20 21 22 23 24

PIN 1

AD7634

TOP VIEW

(Not to Scale)

D2/A1

Figure 4. Pin Configuration

Table 6. Pin Function Descriptions

Pin No.

Mnemonic

Type1

Description

1, 42

AGND

P

Analog Power Ground Pins. Ground reference point for all analog I/O. All analog I/O should be refer-

enced to AGND and should be connected to the analog ground plane of the system. In addition, the

AGND, DGND, and OGND voltages should be at the same potential.

2, 44

AVDD

P

Analog Power Pins. Nominally 4.75 V to 5.25 V and decoupled with 10 μF and 100 nF capacitors.

3, 4

MODE[0:1]

DI

Data Input/Output Interface Mode Selection.

Interface Mode

MODE1

MODE0

Description

0

Low

Low

18-bit interface

1

Low

High

16-bit interface

2

High

Low

8-bit (byte) interface

3

High

High

Serial interface

5

D0/OB/2C

DI/O2

In 18-bit parallel mode, this output is used as Bit 0 of the parallel port data output bus and the data

coding is straight binary. In all other modes, this pin allows the choice of straight binary or twos

complement.

When OB/2C = high, the digital output is straight binary

When OB/2C = low, the MSB is inverted resulting in a twos complement output from its internal shift

register.

6

WARP

DI2

Conversion Mode Selection. See the Modes of Operation section for a more detailed description. Used

in conjunction with the IMPULSE input per the following:

Conversion Mode

WARP

IMPULSE

Normal

Low

Low

Impulse

Low

High

Warp

High

Low

Normal

High

High

7

IMPULSE

DI2

Conversion Mode Selection. See the WARP pin description in this table. See the Modes of Operation

section for a more detailed description.