Isolated amplifiers are widely used for voltage measurements in high-voltage applications that must be isolated from a low-voltage domain. A typical application is the sensing of the DC bus voltage in a frequency inverter.

With its wide, 5-V input voltage range, the AMC1351 is designed for isolated DC voltage-sensing applications where accurate voltage monitoring is required in high-noise environments.

Figure 8-1 shows a simplified schematic of the AMC1351 in a typical motor drive application. The DC bus voltage is divided down to an approximate 5-V level across the bottom resistor (RSNS) of a high-impedance resistor divider that is sensed by the AMC1351. The AMC1351 digitizes the analog input signal on the high-side, transfers the data across the isolation barrier to the low-side, and reconstructs an analog signal that is presented as a differential voltage on the output pins.

The high-impedance input and the high common-mode transient immunity (CMTI) of the AMC1351 ensure reliable and accurate operation even in high-noise environments.