The FPF2140/42/43/44/46/47 is a series of load switches which provides full protection to systems and loads which may encounter large current conditions. These devices contain a 0.11Ω current-limited P-channel MOSFET which can operate over an input voltage range of 1.8-5.5V. Internally, current is prevented from flowing when the MOSFET is off and the output voltage is higher than the input voltage. Switch control is by a logic input (ON) capable of interfacing directly with low voltage control signals. Each part contains thermal shutdown protection which shuts off the switch to prevent damage to the part when a continuous over-current condition causes excessive heating.

When the switch current reaches the current limit, the part operates in a constant-current mode to prohibit excessive currents from causing damage. For the FPF2140/42/44/46, if the constant current condition still persists after 30ms, the part will shut off the switch and pull the fault signal pin (FLAGB) low. The FPF2140/44 have an auto-restart feature which will turn the switch on again after 450ms if the ON pin is still active. The FPF2142/46 do not have this auto-restart feature so the switch will remain off until the ON pin is cycled. For the FPF2143/47, a current limit condition will immediately pull the fault signal pin low and the part will remain in the constant-current mode until the switch current falls below the current limit. The minimum current limit is 200mA for the FPF2140/42/43 while that for the FPF2144/46/47 is 400mA.

These parts are available in a space-saving 6 pin 2X2 MLP package.