Isolated Logarithmic Amp Leverages High-Linearity Optocouplers (.PDF Download)

Logarithmic amplifiers with their log functionality are useful for compressing wide dynamic-range signals whereby the measured quantities are in decibels (dB). They’re used in a wide variety of applications, such as video, medical, and test-and-measurement systems. Logarithmic amplifiers can be built to be compact, easy-to-use, and cost-effective circuits suitable for certain analog designs.

Because of the high-voltage presence in industrial applications, it’s necessary to protect equipment and personnel operating the motors using galvanic isolation. Here, HCNR201/200 analog optocouplers, developed by Broadcom, can be used for current sensing and voltage monitoring in motor-control drives, switching power supplies, and inverter systems.