14-bit 4-20mA loop-powered thermocouple temperature measurement system circuit diagram

Q3307LC41105900 14

One-piece inductor

The circuit shown is a complete loop-powered thermocouple temperature measurement system that uses a PWM function of a precision analog microcontroller to control the 4 mA to 20 mA output current.

This circuit provides a simple, highly integrated temperature solution that interfaces with a 4 mA to 20 mA host controller. Since most of the circuit functions are integrated into the precision analog microcontroller ADuC7060/ ADuC7061, it includes a dual 24-bit Σ-Δ ADC, an ARM7 processor core, and DAC/PWM characteristics for controlling the 4 mA to 20 mA feedback circuit. Therefore, this circuit is a very low cost temperature monitoring solution.