AD7153 Analog Devices, AD7153 Datasheet - Page 22

• Manufacturer Part Number: AD7153
• Description: 12-Bit Capacitance-to-Digital Converter (1 Capacitance Input Channel)
• Manufacturer: Analog Devices

Specifications of AD7153

• Resolution (bits): 12bit
• # Chan: 1
• Sample Rate: 200SPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: Capacitive
• Ain Range: ±0.25 pF to ±2 pF Diff,0.5 pF to 4 pF SE
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

AD7152/AD7153
The offset register of the AD7152/AD7153 allows for offset
calibration over the full capacitive input range. However, the
user must ensure that the offset to be removed is within 40% of
the full scale range; this can be achieved by using the CAPCAC
to perform a coarse offset calibration and use the system offset
calibration then to compensate for an offset within the 40% of
full-scale range pF of the CAPDAC.
The offset calibration register is reloaded by the default value
0x8000 at power-on or after reset. Therefore, if the offset
calibration is not repeated after each system power-up, the
TYPICAL APPLICATION DIAGRAM
C
SENS1
C
R1
R3
SENS2
10kΩ
C1
C3
R2
R4
Figure 41. Basic Application Diagram for a Differential Capacitive Sensor
47pF
CIN1(+)
CIN1(–)
EXC1
C2
C4
AD7153
VDD
GND
Rev. 0 | Page 22 of 24
0.1µF
SDA
SCL
10µF
1kΩ
calibration coefficient value should be stored by the host
controller and reloaded as part of the AD7152/AD7153 setup.
Note that the AD7152/AD7153 zero scale for differential mode
is around 0x8000; therefore, the offset register also needs a
value of around 0x8000, where the zero scale in single-ended
mode is 0x0000, with a required offset register value of 0x3000.
For more detailed information, see the Data Registers section.
1kΩ
1kΩ
1µF
3.3V
SYSTEM
HOST
GND
ADP1720-3.3
1µF
V
SUPPLY