GN54123A

GN54123A is a semiconductor IC with a built-in amplifier for high-speed ground fault circuit interrupters. The amplifier section consists of a differential amplifier, a latch circuit, and a voltage regulator. During normal operation, GN54123A should be connected to the secondary side of a zero current transformer (ZCT). The leakage current detected by the ZCT is applied to both inputs of the differential amplifier. The amplified signal is integrated by an external capacitor, and the integrated signal is fed to the input of the latch circuit, whose output characteristics are suited for high-speed residual current circuit breakers. The latch circuit holds a low output until the input voltage reaches the set threshold, at which point it switches high to drive subsequent circuitry.

Key features

• Excellent input sensitivity and current-temperature characteristics
• High input sensitivity: VT = 6.1 mV (typical)
• Minimal external components required
• High noise and surge immunity
• Low power consumption: PD = 5 mW (typical)
• Compatible with 100 V and 200 V operating voltages
• Wide operating temperature range: -40°C ~ +85°C