Datasheet

AD7747
Rev. 0 | Page 16 of 28
CAP SETUP REGISTER
Address Pointer 0x07, Default Value 0x00
Capacitive channel setup.
Table 11. Cap Setup Register Bit Map
Bit Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Mnemonic CAPEN – CAPDIFF – – – – –
Default 0 0 0 0 0 0 0 0
Table 12.
Bit Mnemonic Description
7 CAPEN CAPEN = 1 enables capacitive channel for single conversion, continuous conversion, or calibration.
6 – This bit must be 0 for proper operation.
5 CAPDIFF This bit must be set to 1 for proper operation.
4 to 0 – These bits must be 0 for proper operation.
VT SETUP REGISTER
Address Pointer 0x08, Default Value 0x00
Voltage/Temperature channel setup.
Table 13. VT Setup Register Bit Map
Bit Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Mnemonic VTEN VTMD1 VTMD0 EXTREF – – VTSHORT VTCHOP
Default 0 0 0 0 0 0 0 0
Table 14.
Bit Mnemonic Description
7 VTEN VTEN = 1 enables voltage/temperature channel for single conversion, continuous conversion, or calibration.
Voltage/temperature channel input configuration.
VTMD1 VTMD0 Channel Input
0 0 Internal temperature sensor
0 1 External temperature sensor diode
1 0 V
DD
monitor
6
5
VTMD1
VTMD0
1 1 External voltage input (VIN)
4 EXTREF
EXTREF = 1 selects an external reference voltage connected to REFIN(+), REFIN(−) for the voltage input or the
V
DD
monitor.
EXTREF = 0 selects the on-chip internal reference. The internal reference must be used with the internal
temperature sensor for proper operation.
3 to 2 – These bits must be 0 for proper operation.
1 VTSHORT VTSHORT = 1 internally shorts the voltage/temperature channel input for test purposes.
0 VTCHOP = 1
VTCHOP = 1 sets internal chopping on the voltage/temperature channel.
The VTCHOP bit must be set to 1 for the specified voltage/temperature channel performance.