The FAN4146 is a low-power controller for AC outlet appliance leakage circuit interrupters (ALCI) and two-wire residual current devices (RCD). The FAN4146 detects hazardous grounding conditions and open circuits the line before a harmful shock occurs.Internally, the FAN4146 contains a diode rectifier, precision bandgap 12V shunt regulator, precision low VOS offset-sense amplifier, time delay noise filter, window-detection comparators, and an SCR driver. With the addition of a minimum number of external components, the FAN4146 detects and protects against a hot-wire-to-ground fault. The minimum number of components and the small SuperSOT™ package allow for a small-form-factor, low-cost application solution.The FAN4146 circuitry has a built-in rectifier and shunt regulator that operates with a low quiescent current. This allows for a high-value, low-wattage-series supply resistor. The internal temperature compensated shunt regulator, sense amplifier, and bias circuitry provide for precision ground-fault detection. The low VOSoffset-sense amplifier allows direct coupling of the sense coil to the amplifier’s feedback signal. This eliminates the large 50/60Hz AC-coupling capacitor. The internal delay filter rejects high-frequency noise spikes common with inductive loads. This decreases false nuisance tripping. The internal SCR driver is temperature compensated and designed to satisfy the current requirements for a wide selection of external SCRs.The minimum number of external components and the 6-pin SuperSOT™ package enable for a low-cost, compact design and layout. The FAN4146ESX is an enhanced temperature range device.