AD7747 View Datasheet(PDF) - Analog Devices

Part Name

Description

MFG CO.

AD7747

24-Bit Capacitance-to-Digital Converter with Temperature Sensor

Analog Devices 

AD7747

REGISTER DESCRIPTIONS

The master can write to or read from all of the AD7747 registers

except the address pointer register, which is a write-only

register. The address pointer register determines which register

the next read or write operation accesses. All communications

with the part through the bus start with an access to the address

pointer register. After the part has been accessed over the bus

and a read/write operation is selected, the address pointer

register is set up. The address pointer register determines from

or to which register the operation takes place. A read/write

operation is performed from/to the target address, which then

increments to the next address until a stop command on the bus

is performed.

Table 8. Register Summary

Address

Pointer

Bit 7

Register

(Dec) (Hex) Dir

Status

0

0x00 R –

0

Cap Data H 1

0x01 R

Cap Data M 2

0x02 R

Cap Data L 3

0x03 R

VT Data H

4

0x04 R

VT Data M

5

0x05 R

VT Data L

6

0x06 R

Cap Setup

7

0x07 R/W CAPEN

0

VT Setup

8

0x08 R/W VTEN

0

EXC Setup

9

0x09 R/W –

0

Configuration 10

0x0A R/W VTFS1

1

Cap DAC A 11

0x0B R/W DACAENA

0

Cap DAC B

12

0x0C R/W DACBENB

0

Cap Offset H 13

0x0D R/W

Cap Offset L 14

0x0E R/W

Cap Gain H 15

0x0F R/W

Cap Gain L

16

0x10 R/W

Volt Gain H 17

0x11 R/W

Volt Gain L 18

0x12 R/W

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Default Value

–

–

–

–

RDY

RDYVT

0

0

0

0

1

1

Capacitive channel data—high byte, 0x00

Capacitive channel data—middle byte, 0x00

Capacitive channel data—low byte, 0x00

Voltage/temperature channel data—high byte, 0x00

Voltage/temperature channel data—middle byte, 0x00

Voltage/temperature channel data—low byte, 0x00

–

CAPDIFF –

–

–

–

0

0

0

0

0

0

VTMD1 VTMD0 EXTREF –

–

VTSHORT

0

0

0

0

0

0

–

–

–

EXCDAC EXCEN EXCLVL1

0

0

0

0

0

1

VTFS0 CAPFS2 CAPFS1 CAPFS0 MD2

MD1

0

1

0

0

0

0

–

DACA—6-Bit Value

0

0x00

–

DACB—6-Bit Value

0

0x00

Capacitive offset calibration—high byte, 0x80

Capacitive offset calibration—low byte, 0x00

Capacitive gain calibration—high byte, factory calibrated

Capacitive gain calibration—low byte, factory calibrated

Voltage gain calibration—high byte, factory calibrated

Voltage gain calibration—low byte, factory calibrated

Bit 0

RDYCAP

1

–

0

VTCHOP

0

EXCLVL0

1

MD0

0

Rev. 0 | Page 14 of 28

Share Link: