TPS76301, TPS76316, TPS76318, TPS76325, TPS76327

TPS76328, TPS76330, TPS76333, TPS76338, TPS76350

LOW POWER 150mA LOW DROPOUT LINEAR REGULATORS

SLVS181H − DECEMBER 1998 − REVISED JANUARY 2004

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12

APPLICATION INFORMATION

The TPS763xx low-dropout (LDO) regulators are new families of regulators which have been optimized for use in

battery-operated equipment and feature extremely low dropout voltages, low quiescent current (140

µA), and an enable

input to reduce supply currents to less than 2

µA when the regulator is turned off.

device operation

The TPS763xx uses a PMOS pass element to dramatically reduce both dropout voltage and supply current over more

conventional PNP pass element LDO designs. The PMOS pass element is a voltage-controlled device that, unlike a PNP

transistor, does not require increased drive current as output current increases. Supply current in the TPS763xx is

essentially constant from no-load to maximum load.

Current limiting and thermal protection prevent damage by excessive output current and/or power dissipation. The device

switches into a constant-current mode at approximately 1 A; further load reduces the output voltage instead of increasing

the output current. The thermal protection shuts the regulator off if the junction temperature rises above 165

°C. Recovery

is automatic when the junction temperature drops approximately 25

°C below the high temperature trip point. The PMOS

pass element includes a back diode that safely conducts reverse current when the input voltage level drops below the output

voltage level.

A logic low on the enable input, EN shuts off the output and reduces the supply current to less than 2

µA. EN should be

tied high in applications where the shutdown feature is not used.

A typical application circuit is shown in Figure 20.

C1

1

µF

(1) TPS76316, TPS76318, TPS76325, TPS76327, TPS76328,

TPS7630 TPS76333, TPS76338, TPS76350 (fixed-voltage options).

NC/FB

OUT

1

3

IN

EN

GND

2

4

5

VI

CSR = 1

Ω

VO

4.7

µF

+

TPS763xx(1)

Figure 20. Typical Application Circuit