High resolution capacitive sensor signal conditioning IC JHM2031

JHM2031 is a low-power, high-precision signal conditioning IC for capacitive sensors.The capacitance to be measured is directly connected with the chip, and is controlled by the high-precision 24 bit sigmaΔ. JHM2031 supports single capacitor, differential capacitor and full bridge capacitor.The default differential capacitor input range is±14 PF, which can be expanded to the maximum±3.15pF. Programmable digital to capacitance converter can offset the input common mode capacitance, allowing the sensor's common mode capacitance value up to 18pF.

JHM2031 supports single measurement mode and automatic periodic measurement mode, with built-in temperature sensor with high linearity and temperature resolution up to 0.003°C. The absolute accuracy can be reached after calibration±zero point five°C. The chip supports the function of digital compensation, which can calibrate and compensate the nonlinearity, sensitivity temperature drift and zero temperature drift of the capacitive sensor at the same time. The coefficients of the compensation algorithm are saved by the integrated programmable memory (OTP).

Features

• Integrated IIR filter 

• I²C or SPI communication protocol can be selected

• Support single capacitance, differential capacitance and full bridge capacitance sensor

• Measurement range of differential capacitance:±14 PF, and the measurement range can reach 1±3.15pF / ±0.38pF

• Allowable input common mode capacitance range: up to 18pF, 54pf after range expansion

• Integrating nonlinearity and temperature compensation, it can simultaneously compensate the zero temperature drift, sensitivity temperature drift and nonlinearity of the sensor

• With non-volatile memory (OTP), it can save the calibration parameters of the sensor and support up to two calibrations

• The capacitance resolution of CDC circuit is up to 1.65af, the effective resolution is up to 20.4bit, and the linearity is up to 1.65af±0.01%.