AD7745/AD7746

Rev. 0 | Page 18 of 28

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.

The conversion times in this table are valid for the CLKCTRL = 0 in the EXC SETUP register. The conversion

times are longer by a factor of two for the CLKCTRL = 1.

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.

The conversion times in this table are valid for the CLKCTRL = 0 in the EXC SETUP register.

The conversion times are longer by factor of two for the CLKCTRL = 1.

CAP CHOP = 0

CAPF2

CAPF1

CAPF0

Conversion Time (ms)

Update Rate

–3 dB Frequency (Hz)

0

0

0

11.0

90.9

87.2

0

0

1

11.9

83.8

79.0

0

1

0

20.0

50.0

43.6

0

1

1

38.0

26.3

21.8

1

0

0

62.0

16.1

13.1

1

0

1

77.0

13.0

10.5

1

1

0

92.0

10.9

8.9

5

4

3

CAPF2

CAPF1

CAPF0

1

1

1

109.6

9.1

8.0

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