AD7156 Analog Devices, AD7156 Datasheet - Page 16

• Manufacturer Part Number: AD7156
• Manufacturer: Analog Devices

Specifications of AD7156

• Resolution (bits): 12bit
• # Chan: 2
• Sample Rate: 100SPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: Capacitive
• Ain Range: 0.5 pF,1 pF,2 pF,4 pF
• Pkg Type: CSP

AD7156
STATUS REGISTER
Address Pointer 0x00
8 Bits, Read Only
Default Value 0x53 Before Conversion, 0x54 After Conversion
The status register indicates the status of the part. The register can be read via the 2-wire serial interface to query the status of the outputs,
check the CDC finished conversion, and check whether the CAPDAC has been changed by the auto-DAC function.
Table 6. Status Register Bit Map
Bit 7
PwrDown
(0)
1
Table 7. Status Register Bit Descriptions
Bit
7
6
5
4
3
2
1
0
The default values are given in parentheses.
Mnemonic
PwrDown
DacStep2
OUT2
DacStep1
OUT1
C1/C2
RDY2
RDY1
Bit 6
DacStep2
(1)
Description
PwrDown = 1 indicates that the part is in a power-down.
DacStep2 = 0 indicates that the Channel 2 CAPDAC value was changed after the last CDC conversion as part of
the auto-DAC function. The bit value is updated after each finished CDC conversion on this channel.
OUT2 = 1 indicates that the Channel 2 data (CIN2 capacitance) crossed the threshold, according to the selected
comparator mode of operation. The bit value is updated after each finished CDC conversion on this channel.
DacStep1 = 0 indicates that the Channel 1 CAPDAC value was changed during the last conversion as part of the
auto-DAC function. The bit value is updated after each finished CDC conversion on this channel.
OUT1 = 1 indicates that the Channel 1 data (CIN1 capacitance) crossed the threshold, according to the selected
comparator mode of operation. The bit value is updated after each finished CDC conversion on this channel.
C1/C2 = 0 indicates that the last finished CDC conversion was on Channel 1.
C1/C2 = 1 indicates that the last finished CDC conversion was on Channel 2.
RDY2 = 0 indicates a finished CDC conversion on Channel 2. The bit is reset back to 1 when the Channel 2 data
register is read via the serial interface or after a part reset or power-up.
RDY1 = 0 indicates a finished CDC conversion on Channel 1. The bit is reset back to 1 when the Channel 1 data
register is read via serial interface or after a part reset or power-up.
1
Bit 5
OUT2
(0)
Bit 4
DacStep1
(1)
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Bit 3
OUT1
(0)
Bit 2
C1/C2
(0)
Bit 1
RDY2
(1)
Bit 0
RDY1
(1)