AD7746_15 Datasheet, PDF (18/28 Pages) Analog Devices – 24-Bit Capacitance-to-Digital Converter with Temperature Sensor

AD7745/AD7746
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
7
VTF1
6
VTF0
5
CAPF2
4
CAPF1
3
CAPF0
2
MD2
1
MD1
0
MD0
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
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
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
1
1
1
Rev. 0 | Page 18 of 28