USB Power Manager Reduces Battery Charging Time

USB Power Manager Reduces Battery Charging Time
MILPITAS, CA ?February 4, 2003 ?Linear Technology Corporation introduces the LTC4410, a USB power manager IC in a ThinSOT™ package, which enables simultaneous battery charging and system operation of a Li-Ion powered USB peripheral from a USB host. Compared to conventional methods, the LTC4410 powers the system load directly from USB 5V supply instead of the battery 3.6V terminal, allowing the battery to charge up to 39% faster. More charging current reduces the battery charging time and ensures a full charge while the peripheral is connected to the USB host device. By managing the total current consumption, the IC permits a 1-cell Li-Ion battery powered USB peripheral to charge its battery and operate its system circuitry without exceeding a user set current limit. Applications include USB certified Li-Ion powered devices such as portable printers, digital cameras, cell phones, and PDAs.

The LTC4410 ensures that a portable device is in compliance with USB overcurrent specifications by keeping the total current constant from the USB port. This is accomplished by adjusting the charge current relative to the amount of current demanded by the system load. Immediately after the USB cable is detached from the peripheral device, the LTC4410 routes the system load to the battery for seamless and continuous operation of the end-device. The LTC4410抯 solution uses 15 fewer components than comparable solutions and fits into one fourth the board area. The LTC4410 is offered in a 6-lead ThinSOT package and is used with the LTC4053 Li-Ion battery charger for USB applications or LTC1733 for general purpose Li-Ion battery charging. Pricing for the LTC4410 starts at $1.20 each in 1,000-piece quantities.

Summary of Features: LTC4410
Manages Total Power between a USB Peripheral and Battery Charger
Reduces Charging Time by Directing More Current to Battery Charger
Minimal Voltage Drop of 100mV at 500mA
Ultra Low Battery Drain of 1µA
Reverse Current Blocking Diode Not Required
Compatible with LTC linear battery chargers: LTC4053 and LTC1733
Overtemperature Protected
ThinSOT 6-lead package