This reference design features multiple approaches for protecting AC or DC analog input, DC analog output, AC or DC binary input, digital output with a high-side or low-side driver, LCD bias supply, USB interfaces (power and data) and onboard power supplies with 24-, 12-, or 5-V input used in multiple grid applications against overvoltage, overload and transients (1.2/50 µs, 42-Ω) using bi-/uni-directional flat-clamp surge protection devices, ESD devices, eFuse or a load switch. The design monitors temperature, humidity, magnetic fields and power supplies for diagnostics.