onsemi (Ansemi)

SOT-23-6

taping

3000

The FAN4149 is a low-power controller that detects dangerous ground and ground-to-neutral fault current paths. The FAN4149 application circuit opens the load contacts before hazardous electrical shock occurs. The FAN4149 combined with the FAN41501 self-monitoring digital controller meets the 2015 UL943 self-test requirements for permanently coupled GFCI products. The FAN4149 detects and protects against hot-to-ground fault and neutral-to-line/load short conditions. FAN41501 regularly monitors FAN4149 and critical GFI components for compliance with 2015 UL943 requirements. Minimal component count and small 6-pin encapsulation enable a high-density, flexible application solution. The FAN4149 contains a precision bandgap 14 V shunt regulator, precision low VOS sense amplifier, time delay squelch filter, window detection comparator and SCR driver. The shunt regulator operates with low quiescent current, enabling high value, low power series supply resistors. An internal temperature compensated shunt regulator, sense amplifier and bias circuit provide accurate ground fault detection. This allows the use of larger component sizes, so there is no need to limit or fine-tune external components. A typical ±50 µV VOS sense amplifier offset allows direct DC coupling of the sense coil. Therefore, no large AC-coupling capacitors are required. An internal delay filter suppresses high frequency noise spikes common to inductive loads. False nuisance trips are thus reduced. The SCR driver adds current and temperature compensation, enabling a wider selection of external SCRs. Few external components and 6-pin SOT23 encapsulation enable low-cost, compact design and layout.