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.
|Capacitance measurement range
|Capacitance measurement frequency
|Built-in temperature sensor resolution
|Built-in temperature sensor accuracy(after cailbration)
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