TPS2010, TPS2011, TPS2012, TPS2013

POWER-DISTRIBUTION

SLVS097A – DECEMBER 1994 – REVISED AUGUST 1995

3

POST OFFICE BOX 655303

detailed description (continued)

driver

The driver controls the gate voltage of the power switch. To limit large current surges and reduce the associated

electromagnetic interference (EMI) produced, the driver incorporates circuitry that controls the rise times and

fall times of the output voltage. The rise and fall times are typically in the 2-ms to 4-ms range instead of the

microsecond or nanosecond range for a standard FET.

enable (EN)

A logic high on the EN input turns off the power switch and the bias for the charge pump, driver, and other circuitry

to reduce the supply current to less than 10

µA. A logic zero input restores bias to the drive and control circuits

and turns the power on. The enable input is compatible with both TTL and CMOS logic levels.

current sense

A sense FET monitors the current supplied to the load. The sense FET is a much more efficient way to measure

current than conventional resistance methods. When an overload or short circuit is encountered, the

current-sense circuitry sends a control signal to the driver. The driver in turn reduces the gate voltage and drives

the power FET into its linear region, which switches the output into a constant current mode and simply holds

the current constant while varying the voltage on the load.

thermal sense

An internal thermal-sense circuit shuts the power switch off when the junction temperature rises to

approximately 180

°C. Hysteresis is built into the thermal sense, and after the device has cooled approximately

20 degrees, the switch turns back on. The switch continues to cycle off and on until the fault is removed.

TPS201xY chip information

This chip, when properly assembled, displays characteristics similar to the TPS201xC. Thermal compression

or ultrasonic bonding may be used on the doped aluminum bonding pads. The chip may be mounted with

conductive epoxy or a gold-silicon preform.