© 2002 Microchip Technology Inc.

DS21349B-page 3

TC105

2.0

PIN DESCRIPTIONS

Thedescriptionsof the pins arelistedinTable2-1.

TABLE 2-1:

PIN FUNCTION TABLE

Pin No.

(5-Pin SOT-23A)

Symbol

Description

1

EXT

Switch transistor control output. This terminal connects to the gate of an external P-channel

MOSFET (or to the base of an external PNP transistor through a current limiting resistor).

Power supply voltage input.

3

GND

Ground terminal.

4

SHDN

Shutdown input (active low). The device enters a low power shutdown state when this input is

brought low. During shutdown, regulator action is suspended, and supply current is reduced to

less than 0.5

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

Voltage sense input. This input senses output voltage for regulation and must be connected to the

output voltage node as shown in the application schematic in this data sheet.