Linear Technology Corp. (Milpitas, CA) announced its new LTC4412, a low-loss PowerPath controller that controls an external p-channel MOSFET to create a near-ideal diode function for power switchover or load sharing. When conducting, the voltage drop across the MOSFET is as low as 10mV compared to the traditional exponential curve of a comparable Schottky diode.
For applications with a wall adapter or other auxiliary power source, the load is automatically disconnected from the battery when the auxiliary source is connected. Furthermore, two or more LTC4412s can be interconnected to allow load sharing between multiple batteries or charging of multiple batteries from a single charger.
The LTC4412 has a wide supply operating range of 2.5V to 28V, which makes it suitable for use with one to six lithium-ion batteries, or most ac/dc adapters. The internal gate driver includes an internal voltage clamp for MOSFET protection and the low quiescent current of 11mA is independent of load current. Finally, a STAT pin can be used to enable an auxiliary p-channel MOSFET power switch when an auxiliary supply is detected or, alternatively, it could be used to indicate to a microcontroller that an auxiliary supply is connected.
The LTC4412 is housed in a small, low-profile (1mm maximum), six-pin, ThinSOT package and is characterized over the extended temperature range of -40 to +85 degrees C. Pricing starts at $1.30 each in 1,000-piece quantities.