High-precision Capacitor Sensor Signal Conditioning IC JHM2000

JHM2000 is a high-resolution signal conditioning IC for capacitive sensor. The capacitance to be measured is connected directly to the device inputs. The integrated 24-bit sigma-delta capacitance-to-digital converter features inherent high resolution (10aF, 19.5bit ENOB), high linearity (±0.01%).

The capacitance to be measured can be configured to be single-ended, differential or full-bridge style. The capacitance input range is ±5pF while it can accept up to ±19pF common-mode capacitance, or even up to ±25pF by extending the excitation amplitude. A temperature signal from an on-chip sensor is digitized with resolution of 0.01℃ and accuracy of ±1℃ after calibration.

The digitized capacitance measurement is compensated for thermal drifts of offset and gain as well as non-linearity in digital domain. The compensation coefficients can be written to the on-chip programmable non-volatile memory. The final measurement can be read out through an I2C or SPI interface.

The JHM2000 supports automatic periodic mode. The integrated IIR low-pass filter and 32-level FIFO can be enabled in this mode, which facilitate low-power application and greatly reduces the workload of the external MCU.

Features

JHM2000 QFN16(4*4)

• Integrated digital compensation function

• Measurement linearity: 0.01%

• Communication mode: I2C or SPI

• Capacitance resolution 10aF,ENOB 19.5bit

• Allowable input common mode capacitance range:up to 19pF, 95pF after range expansion

• With non-volatile memory (OTP) for saving calibration parameters

• CYC mode supporting periodic operation,IIR digital filtering

• The operating current depends on the specific setting

• The average current at the highest update rate is about 0.7mA single ended capacitance

• Half bridge or full bridge differential capacitor

JHM200X Block Diagram

Applications