Sensor conditioning IC

ZMD has expanded its family of capacitive sensor signal conditioning devices with the wide dynamic range ZMD31210 cLite IC.

The design delivers 14-bit resolution and 0.5 % accuracy over a wide range of capacitances and temperatures.

The device has a low 60 µA current draw over a supply voltage range as low as 1.8 V or as high as 5.5 V.

The IC can be configured to interface with capacitive sensors from 2 to 260 pF with sensitivity as low as 125 atto-Farads (aF) per digital bit. The part accommodates both single and differential input sensor configurations. All calibration is digital and completed in one pass, eliminating the cost of laser trimming.

The device connects to micro-controllers but can also be used in stand-alone designs for transducer and switch applications. The mixed signal design offers 14-bit capacitive-to-digital conversion and full 14-bit compensation of sensor offset, sensitivity and temperature via an internal digital signal processor running a correction algorithm.

Calibration coefficients are stored in an onboard non-volatile EEPROM. The system interface offers 12C, SPI, PDM or alarm outputs.