AD7747

Preliminary Technical Data

Rev. PrC | Page 16 of 20

CONFIGURATION REGISTER

Address Pointer 0x0A, Default Value 0xA0

Converter update rate and mode of operation setup.

Table 17. Configuration Register Bit Map

Bit

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Mnemonic

VTF1

VTF0

CAPF2

CAPF1

CAPF0

MD2

MD1

MD0

Default

0

0

0

0

0

0

0

0

Table 18.

Bit

Mnemonic

Description

Voltage/temperature channel digital filter setup—conversion time/update rate setup.

VTCHOP = 1

VTF1

VTF0

Conversion Time (ms)

Update Rate (Hz)

–3 dB Frequency (Hz)

0

0

20.1

49.8

26.4

0

1

32.1

31.2

15.9

1

0

62.1

16.1

8.0

7

6

VTF1

VTF0

1

1

122.1

8.2

4.0

Capacitive channel digital filter setup—conversion time/update rate setup.

CAP CHOP = 0

CAPF2

CAPF1

CAPF0

Conversion Time (ms)

Update Rate

–3 dB Frequency (Hz)

0

0

0

22.0

45.5

0

0

1

23.9

41.9

0

1

0

40.0

25.0

0

1

1

76.0

13.2

1

0

0

124.0

8.1

1

0

1

154.0

6.5

1

1

0

184.0

5.5

5

4

3

CAPF2

CAPF1

CAPF0

1

1

1

219.3

4.6

Converter mode of operation setup.

MD2

MD1

MD0

Mode

0

0

0

Idle

0

0

1

Continuous conversion

0

1

0

Single conversion

0

1

1

Power-Down

1

0

0

-

1

0

1

Capacitance system offset calibration

1

1

0

Capacitance or voltage system gain calibration

2

1

0

MD2

MD1

MD0

1

1

1