A/DD/A CPU 4-20 mA TRIM Analog Signal From Sensor Digital Conversion To CPU Analog Signal Out Digital Signal To Converter Improved I/O Characteristics -Eliminate ‘Trim’ Analog signal from sensor is converted to digital signal for CPU processing. CPU samples input and performs linearization and temperature/pressure characterizations. CPU output is converted to analog signal for 4-20 mA. Errors between CPU input and D/A converter output result due to poor resolution between signals. 4-20 mA ‘TRIM’ is required as a result.