AD7747

Rev. 0 | Page 17 of 28

EXC SETUP REGISTER

Address Pointer 0x09, Default Value 0x03

Capacitive channel excitation setup.

Table 15. EXC Setup Bit Map

Bit

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Mnemonic

–

–

–

–

EXCDAC

EXCEN

EXCLVL1

EXCLVL0

Default

0

0

0

0

0

0

1

1

Table 16.

Bit

Mnemonic

Description

7 to 4

–

These bits must be 0 for proper operation.

3

EXCDAC

CAPDAC excitation. This bit must be set to 1 for the proper capacitive channel operation.

2

EXCEN

CIN and AC SHLD excitation. This bit must be set to 1 for the proper capacitive channel operation.

EXCLVL1

EXCLVL0

Voltage on Cap

EXC Low Level

EXC High Level

0

0

0

1

1

0

1

0

EXCLVL1,

EXCLVL0

1

1

0