Circuit functions and advantages
This circuit shows how to use the precision analog microcontroller aducm360 / aducm361 in the application of precision thermocouple temperature monitoring. Aducm360 / aducm361 integrates dual channel 24 bit analog-to-digital converter (ADC), dual channel programmable current source, 12 bit analog-to-digital converter (DAC), 1.2 V internal reference voltage source, arm Cortex-M3 core, 126 KB flash memory, 8 KB SRAM and various digital peripherals, such as UART, timer, SPI and I2C interfaces.
In this circuit, aducm360 / aducm361 are connected to a thermocouple and a 100 platinum resistance temperature detector (RTD). RTD is used to perform cold junction compensation.
In the source code, the ADC sampling rate is 4 Hz. When the gain of ADC input programmable gain amplifier (PGA) is configured as 32, the noise free code resolution of aducm360 / aducm361 is greater than 18 bits.
Figure 1. Aducm360 / aducm361 is used as the interface between temperature monitoring controller and thermocouple (schematic diagram, not showing all connections)