AD7156 Analog Devices, AD7156 Datasheet - Page 14
![no-image](/images/manufacturer_photos/0/0/56/analog_devices_sml.jpg)
AD7156
Manufacturer Part Number
AD7156
Description
Manufacturer
Analog Devices
Datasheet
1.AD7156.pdf
(28 pages)
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AD7156ASTZF16
Manufacturer:
HITACHI
Quantity:
8
Part Number:
AD7156BCPZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
AD7156
AUTO-DAC ADJUSTMENT
In adaptive threshold mode, the part can dynamically adjust the
CAPDAC to keep the CDC in an optimal operating capacitive
range. When the auto-DAC function is enabled, the CAPDAC
value is automatically incremented when the data average
exceeds ¾ of the CDC full range (average > 0xA800), and
the CAPDAC value is decremented when the data average
goes below ¼ of the CDC full range (average < 0x5800).
The auto-DAC increment or decrement step depends on
the selected CDC capacitive input range (see the Setup Registers
section).
When the CAPDAC value reaches 0, the ¼ threshold for further
decrementing is ignored. Similarly, when the CAPDAC value
reaches its full range, the ¾ threshold is ignored. The CDC and
the rest of the algorithm are continuously working, and they are
functional down to a capacitance input of 0 pF or as high as the
capacitance input of (CAPDAC full range + CDC full range),
respectively.
Rev. 0 | Page 14 of 28
POWER-DOWN TIMER
In power sensitive applications, the AD7156 can be set to
automatically enter power-down mode after a programmed
period of time in which the outputs have not been activated.
The AD7156 can then be returned to a normal operational
mode either via the serial interface or by the power supply
off/on sequence.