This reference design is the analog front end (AFE) for an electronic overload relay, used for monitoring and protecting motors from overcurrent or undercurrent events. It is an ideal tool for developers creating overload relays for sensitive AC motors in industrial applications. This programmable gain amplifier (PGA) based analog front end is intended to be an easy evaluation platform for an accurate, industry-leading 10:1 full load ampere (FLA) range and is repeatable over a -10 to +70°C temperature range.
- Wide FLA of 10:1 which dramatically reduces the number of units required on-hand
- Current measurement accuracies of <2% over entire 10:1 measurement range from no load to locked rotor current
- Ambient insensitivity from -10 to +70°C
- Robust design that prevents phase reversal in overdrive conditions and high electrostatic discharge (ESD) protection (3-kV HBM)