Power switches protect USB connections

Protects an input voltage supply against potential short-circuit conditions that may occur when using a USB connection.

New power distribution switches with integrated FETs from Texas Instruments can be set to support a 100mA to 1.1A 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.

Each of TI's TPS2550 and TPS2551 power switches incorporates an 85mohm N-channel MOSFET in a 2 x 2mm SON or a SOT-23 6-pin package.

The devices operate from a wide 2.5 to 6.5V input and minimise current surges during heavy capacitance loads by controlling rise and fall times.

The TPS2550 and TPS2551 offer several protection features.

The devices' fast, 2us overcurrent 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 overcurrent and reverse-voltage conditions.

The TPS2550 and TPS2551 are available today in volume production from TI and its network of distributors.

Available in space-saving 6-pin 2 x 2mm SON or 6-pin SOT-23 packages, the devices' suggested retail price is US $0.70 each in 1000-piece quantities.

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