AD7734

Rev. 0 | Page 14 of 32

REGISTER DESCRIPTION

Table 11. Register Summary

Register

Addr

Dir

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

(hex)

Default Value

Communications

00

W

0

R/W

6-Bit Register Address

I/O Port

01

R/W

P0

P1

P0 DIR

P1 DIR

RDYFN

0

0

SYNC

P0 Pin

P1 Pin

1

1

0

0

0

0

Revision

02

R

Chip Revision Code

Chip Generic Code

x

x

x

x

0

0

1

0

Test

03

R/W

24-Bit Manufacturing Test Register

ADC Status

04

R

–

–

–

–

RDY3

RDY2

RDY1

RDY0

0

0

0

0

0

0

0

0

Checksum

05

R/W

16-Bit Checksum Register

ADC Zero-Scale Calibration

06

R/W

24-Bit ADC Zero-Scale Calibration Register

800000h

ADC Full-Scale

07

R/W

24-Bit ADC Full-Scale Register

800000h

Channel Data1

08–0B

R

16-/24-Bit Data Registers

8000h

Channel Zero-Scale Cal.1

10–13

R/W

24-Bit Channel Zero-Scale Calibration Registers

800000h

Channel Full-Scale Cal. 1

18–1B

R/W

24-Bit Channel Full-Scale Calibration Registers

200000h

Channel Status1

20–23

R

0

CH1

CH0

0/P0

RDY/P1

NOREF

SIGN

OVR

Channel Number

0

0

0

0

0

Channel Setup1

28–2B

R/W

0

0

0

Stat OPT

ENABLE

0

RNG1

RNG0

0

0

0

0

0

0

0

0

Channel Conversion Time1

30–33

R/W

CHOP

FW (7-Bit Filter Word)

1

11h

Mode2

38–3B

R/W

MD2

MD1

MD0

CLKDIS

DUMP

Cont RD

24/16 BIT

CLAMP

0

0

0

0

0

0

0

0

the ADC channel on which the mode will be applied. Only address 38h must be used for reading from the mode register.

Table 12. Operational Mode Summary

MD2

MD1

MD0

Mode

0

0

0

Idle Mode

0

0

1

Continuous Conversion Mode

0

1

0

Single Conversion Mode

0

1

1

Power-Down (Standby) Mode

1

0

0

ADC Zero-Scale Self-Calibration

1

0

1

For Future Use

1

1

0

Channel Zero-Scale System Calibration

1

1

1

Channel Full-Scale System Calibration

Table 13. Input Range Summary

RNG1

RNG0

Nominal Input Voltage Range

0

0

±10 V

0

1

0 V to +10 V

1

0

±5 V

1

1

0 V to +5 V