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USB power switch has adjustable current limit

Posted: 19 Feb 2008 ?? ?Print Version ?Bookmark and Share

Keywords:USB power switches? adjustable current limit? power management IC?

 TPS2550, TPS2551

Texas Instruments Inc. has introduced power distribution switches with an integrated FET that can be set to support a 100mA to 1.1 A current limit range for a standard USB port or other applications requiring a current limited switch. The power management IC protects an input voltage supply against potential short-circuit conditions that may occur when using a USB connection in a mobile phone, notebook, LCD TV, STB, gaming system or IP phone.

TI's TPS2550 and TPS2551 power switches incorporate an 85m, N-channel MOSFET in a 2mm x 2mm SON or a SOT-23 6-pin package. The devices operate from a wide 2.5V to 6.5V input and minimize current surges during heavy capacitance loads by controlling rise and fall times.

As with all power switches from TI, the TPS2550 and TPS2551 offer several protection features. The devices' 2?s 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 over-current and reverse-voltage conditions.

Key features of TPS2550/51 include adjustable current limit from 100mA to 1,100mA and fast overcurrent response of 2?s (typical). The devices also offer reverse I/O voltage protection, operating input range of 2.5-6.5V and deglitched fault report. Both devices offer 2?A maximum standby supply current and ambient temperature range of -40C to 85C. There is an enable active low input for TPS2550 and enable active high input for TPS2551.

The TPS2550 and TPS2551 are available in volume production. Housed in a space-saving 6-pin, 2mm x 2mm SON or 6-pin SOT-23 package, the devices' suggested retail price is 70 cents each in 1,000-piece quantities.

TI will be one of the exhibitors at IIC-China 2008.

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