This is an example of a loop powered field instrument for pressure, temperature, or flow. In this example a sigma delta ADC is measuring a sensor or transducer. A microcontroller is used to process the ADC data and performs functions such as range setting, calibration, linearization, and creation of the serial output data. Analog Devices offers industry leading sigma delta ADC’s, such as the AD779X family and the ADuC7060, which includes an ARM7 microcontroller. Isolation is performed using an ADuM1401 or ADuM2401 and a DAC, such as the AD421 is used for current loop communication. The AD421 includes voltage regulators to power local devices from current loop.