High resolution resistive bridge sensor signal conditioning chip

The JHM1400 is a high accuracy signal conditioning IC designed for differential resistive bridge sensor signals. The differential voltage signal output by the bridge sensor can be converted to a digital signal with high accuracy and then digitally compensated by the JHM1400. The final measurement can be read out through an I²C or SPI interface.

A low-noise instrumentation amplifier with gain and offset tuning capability amplifies the input bridge signal to a level which fits the input range of a 24-bit delta-sigma A/D converter. The digitized input is compensated for thermal drifts of offset and gain as well as non-linearity in digital domain. A temperature signal from an on-chip sensor is digitized and fed to the compensation circuit, too. The compensation coefficients can be written to the on-chip programmable non-volatile memory (MTP).

The JHM140X 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

JHM1400 QFN16

• 24-bit ADC

• Built-in 32 level FIFO

• Built-in IIR filter

• Optional I ² C or SPI communication protocol

• CYC mode supporting periodic work

• Integrated nonlinear and temperature compensation algorithm

• The zero temperature drift, sensitivity temperature drift and nonlinearity of the sensor can be compensated at the same time

• With non-volatile memory (OTP)

• The calibration parameters of the sensor can be saved. Up to two calibrations are supported

• Standby current < 0.1μA

• Average current≈ 4μA@1Hz ODR

• Absolute precision of compensated bridge ≈ 0.1%FSO

JHM1400 Block Diagram

Applications