AD7152 datasheet(22/24 Pages) AD

22 / 24 page

AD7152/AD7153

Rev. 0 | Page 22 of 24

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

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.

TYPICAL APPLICATION DIAGRAM

SCL

VDD

GND

AD7153

SDA

3.3V

VSUPPLY

1kΩ

0.1µF

10µF

1µF

CIN1(+)

CSENS1

CSENS2

CIN1(–)

EXC1

47pF

10kΩ

ADP1720-3.3

HOST

SYSTEM

GND

Figure 41. Basic Application Diagram for a Differential Capacitive Sensor

AD7152 Arkusz danych(PDF) 22 Page - Analog Devices

AD7152 Arkusz danych(HTML) 22 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Arkusz danych Pobierz

Link URL