TPS2560

TPS2561

SLVS930 – DECEMBER 2009

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DETAILED DESCRIPTION

OVERVIEW

The TPS2560/61 is a dual-channel, current-limited power-distribution switch using N-channel MOSFETs for

applications where short circuits or heavy capacitive loads will be encountered. This device allows the user to

program the current-limit threshold between 250 mA and 2.8 A (typ) per channel via an external resistor. This

device incorporates an internal charge pump and gate drive circuitry necessary to drive the N-channel

MOSFETs. The charge pump supplies power to the driver circuit for each channel and provides the necessary

voltage to pull the gate of the MOSFET above the source. The charge pump operates from input voltages as low

as 2.5 V and requires little supply current. The driver controls the gate voltage of the power switch. The driver

incorporates circuitry that controls the rise and fall times of the output voltage to limit large current and voltage

surges and provides built-in soft-start functionality. Each channel of the TPS2560/61 limits the output current to

pump voltage driving the N-channel MOSFET and operating it in the linear range of operation. The result of

longer fully enhanced.

OVERCURRENT CONDITIONS

overcurrent condition is detected, the device maintains a constant output current and reduces the output voltage

accordingly. Two possible overload conditions can occur.

The first condition is when a short circuit or partial short circuit is present when the device is powered-up or

enabled. The output voltage is held near zero potential with respect to ground and the TPS2560/61 ramps the

or the device begins to thermal cycle.

The second condition is when a short circuit, partial short circuit, or transient overload occurs while the device is

current-sense amplifier is overdriven during this time and momentarily disables the internal current-limit

cycle.

The TPS2560/61 thermal cycles if an overload condition is present long enough to activate thermal limiting in any

of the above cases. The device turns off when the junction temperature exceeds 135°C (min) while in current

limit. The device remains off until the junction temperature cools 20°C (typ) and then restarts. The TPS2560/61

cycles on/off until the overload is removed (see Figure 9) .

10

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Product Folder Link(s): TPS2560 TPS2561