JHM1501 is a high-precision signal conditioning circuit with digital compensation algorithm designed for Wheatstone bridge sensor signals, which compensates for offset, sensitivity, temperature drift and non-linearity of the sensor signal simultaneously. The calibration coefficients for the compensation algorithm are stored in an on-chip MTP.
The IC JHM150X is sensor signal processor designed to amplify and treat the signal of resistive bridges. It comprises wide programming range and comprehensive diagnostic features. 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 16-bit delta-sigma A/D converter. After low-pass filtering 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 correction engine can compensate non-linearity in the signal up to 3rd order. The compensated digital output is fed into a D/A converter driving an analogue voltage buffer providing a ratiometric output signal. Alternatively, a digital SENT output can be used instead of the analogue output.
In configuration mode the output pin is also used as single-wire serial data interface for calibration with only 3 wires to the outside. Calibration and configuration data for a specific sensor are stored in MTP. The IC includes self-test and diagnostics routines for the sensor bridge attached and IC itself. If faults occur, they are indicated at the output as distinctive failure states.
JHM150X supports over supply voltage protection as well as output short protection, which required by automotive application.
Features
| Voltage supply (digital) | 2.7~5.5V |
| Voltage supply (analog) | 4.0~5.5V |
| Operating temperature range | -40~125℃ |
| Operating current | 8 mA |
| Packaging specification | QFN16 |
Optimized to accommodate most of types of resistive sensor bridges
Low noise input amplifier and 16-bit sigma-delta ADC
Compensation of minimum sensor offset range up to ±250% FS
Configurable input signal range; ±3~±400mV
Configurable analogue gain; up to 411x
Configurable digital low pass filter
Precise compensation of sensor nonlinearity and thermal drift in sensor gain and offset up to 2nd order
On-chip MTP allows for up to 6 times calibration
Temperature acquisition by internal or external sensor
Configurable output for
§ Ratiometric voltage output through 12-bit DAC
§ SENT mode (SAE J2716, APR2016)
§ PWM
40V Over-voltage protection
Single-wire programming interface supports 3-wire sensor assembly
Wide range of diagnostic functions monitoring sensor and IC surveillance
JHM150X Block Diagram
