초록 ▼

A smart sensor module includes a microcontroller and a signal conditioning integrated circuit. In a preferred embodiment, the signal conditioning integrated circuit is a mixed signal application specific integrated circuit (ASIC) incorporating an instrumentation amplifier, offset correction, sensiti

A smart sensor module includes a microcontroller and a signal conditioning integrated circuit. In a preferred embodiment, the signal conditioning integrated circuit is a mixed signal application specific integrated circuit (ASIC) incorporating an instrumentation amplifier, offset correction, sensitivity correction, low pass filtering, an analog-to-digital converter (ADC), a temperature sensor, digital I/O interface, a crystal oscillator circuit, and power on reset open collector output. The ADC can be multiplexed to the transducer, the temperature sensor or an external input. All features of the ASIC can be dynamically reconfigured at any time by the microcontroller. Offset correction is implemented with a 4-bit coarse adjustment digital-to-analog converter (DAC) and a 7-bit fine adjustment DAC to control the instrumentation amplifier reference voltage. The coarse adjustment allows compensation of sensor-to-sensor offset variations, while the fine adjustment allows dynamic or real-time compensation of temperature-induced variations. The sensitivity correction is accomplished with a programmable system gain configured as a coarse gain adjustment and a fine gain adjustment. The coarse gain adjustment allows compensation of sensor-to-sensor sensitivity variations. The fine gain adjustment allows dynamic or real-time compensation of temperature-induced sensitivity variations. The smart sensor module allows very precise calibration of the sensor, signal processing capabilities, decision making capability and serial interface capability.

대표청구항 ▼

[ What is claimed is:] [1.] A smart sensor module for compensation of sensor-to-sensor and temperature-induced errors in the analog output of a sensor comprisinga temperature sensor providing an electrical output related to the temperature of the sensor;fine gain and offset correction storage for st

[ What is claimed is:] [1.] A smart sensor module for compensation of sensor-to-sensor and temperature-induced errors in the analog output of a sensor comprisinga temperature sensor providing an electrical output related to the temperature of the sensor;fine gain and offset correction storage for storing fine gain and offset corrections for a plurality of different temperatures and, responsive to said temperature sensor output, for providing a fine gain correction output and a fine offset correction output;coarse gain and offset correction storage for storing coarse gain and offset corrections and providing a coarse gain correction output and a coarse offset correction output;an analog amplifier, having a DC offset responsive to said coarse and fine offset correction outputs, for amplifying the analog sensor output and providing an amplified analog sensor output;a first low pass filter, having a filter gain responsive to said coarse gain correction output, for low pass filtering the amplified analog sensor output and providing a coarse gain corrected analog sensor output; anda second low pass filter, having a filter gain responsive to said fine gain correction output, for low pass filtering the coarse gain corrected analog sensor output and providing a fully conditioned analog sensor output.