TI introduces tiny USB power management switches with adjustable current limit
(Technology News, 06 Mar 2008 )
Texas Instruments Incorporated (TI) has introduced power distribution switches with an integrated FET that can be set to support a 100-mA to 1.1-A current limit range for a standard USB port or other applications requiring a current limited switch. The power management integrated circuit (IC) efficiently protects an input voltage supply against potential short-circuit conditions that may occur when using a USB connection in a mobile phone, notebook computer, LCD TV, set-top box, gaming system or IP phone.
TI’s TPS2550 and TPS2551 power switches incorporate an 85-milliohm, N-channel MOSFET in a 2 mm x 2 mm SON or a SOT-23 6-pin package. The devices operate from a wide 2.5 V to 6.5 V input and minimize current surges during heavy capacitance loads by controlling rise and fall times.
The TPS2550 and TPS2551 offer several protection features. The devices’ fast, 2 micro-second (uS) over-current response limits the output current to a safe level by switching into a constant-current mode when the output load exceeds the current-limit threshold or a short circuit is present. The devices also feature an internal reverse-voltage blocking function to disable the power switch in case the output voltage is driven higher than the input voltage to protect the application’s system on the input side of the switch. In addition, a /FAULT logic output asserts at low condition during over-current and reverse-voltage conditions.
