© 2002 Microchip Technology Inc.

DS21355B-page 3

TC110

2.0

PIN DESCRIPTIONS

Thedescriptionsof the pins arelistedinTable2-1.

TABLE 2-1:

PIN FUNCTION TABLE

Pin No.

(5-Pin SOT-23A)

Symbol

Description

Internal device power and voltage sense input. This dual function input provides both feedback

voltage sensing and internal chip power. It should be connected to the regulator output. (See

Section 4.0, Applications).

Power supply voltage input.

3

SHDN/SS

Shutdown input. A logic low on this input suspends device operation and supply current is

reducedtolessthan0.5

µA. The device resumes normal operation when SHDN is again brought

high. An RC circuit connected to this input also determines the soft-start time.

4

GND

Ground terminal.

5

EXT

External switch transistor drive complimentary output. This pin drives the external switching

transistor. It may be connected to the base of the external bipolar transistor or gate of the external

N-channel MOSFET. (See Section 4.0, Applications).