The LTC4410 enables simultaneous battery charging and operation of portable USB 1.0 and 2.0 compliant devices while they are connected to a USB port. As the USB peripheral load increases, the LTC4410 proportionally reduces the battery charge current to keep the total current less than 500mA or 100mA, depending on the state of the MODE pin. The LTC4410 includes a USB present output that drives an external P-channel MOSFET to disconnect the battery from the USB peripheral when the USB power is valid. This allows device operation when connected to the USB port, even when the battery is deeply discharged. Other features include reverse current blocking, thermal shutdown and low quiescent current (80µA in 500mA MODE) that is compliant with USB Suspend Mode. The LTC4410 is available in the low profile (1mm) SOT-23 (ThinSOT™) package.
