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1/12/2005 Rev.2.11

SS8014G

PIN DESCRIPTION

PIN

NAME

FUNCTION

1

IN

Regulator Input. Supply voltage can range from +2.5V to +5.5V. Bypass with 1µF to GND

2

GND

Ground. This pin also functions as a heatsink. Solder to large pads or the circuit board ground plane to maxi-

mize thermal dissipation.

3

SHDN

Active-Low Shutdown Input. A logic low reduces the supply current to less than 1

µA. Connect to IN for

normal operation.

4

ADJ

Adjust (Input): Adjustable regulator feedback input. It can connect to an external resistor divider for adjust-

able output voltage. A ceramic capacitor of at least 470pF must be connected from ADJ pin to GND

to reduce output noise.

5

OUT

Regulator Output. Fixed or adjustable from +2.5V to +5.5V. Sources up to 150mA. Bypass with a

capacitor of 1µF, < 0.2

Ω typical ESR to GND.

APPLICATIONS INFORMATION

The block diagram of the SS8014 is shown in Figure 1.

It consists of an error amplifier,1.25V bandgap reference,

PMOS output transistor, shutdown logic, over-current

protection circuit, and over-temperature protection cir-

cuit.

The SS8014 can be adjusted to a specific output voltage

by using two external resistors (Figure 2). The resis-

tors set the output voltage based on the following

equation:

R2

R1

+ 1

Note that the bandgap voltage is relative to the output,

as seen in the block diagram. Because traditional

regulators normally have the reference voltage relative

values are not critical because ADJ (adjust) has a high

input impedance, but for best results use resistors of

470k

Ω or less. A capacitor from ADJ to ground pro-

vides greatly improved noise performance.

Figure 1. Functional Diagram

SHDN

IN

OUT

SHUTDOWN

LOGIC

1.25V

ref

ERROR

AMP.

+

GND

OVER TEMP. &

OVER CURRENT

PROTECTION

ADJ

SHDN

IN

OUT

SHUTDOWN

LOGIC

1.25V

ref

ERROR

AMP.

+

GND

OVER TEMP. &

OVER CURRENT

PROTECTION

ADJ