www.fairchildsemi.com

REV. 1.0.6 2/14/03

Features

• Ultra Low Power Consumption

• 50 mV dropout voltage at 50 mA

• 25 µA ground current at 50 mA

• Enable/Shutdown Control

• SOT23-5 package

• Thermal limiting

• 300 mA peak current

Applications

• Cellular Phones and accessories

•PDAs

• Portable cameras and video recorders

• Laptop, notebook and palmtop computers

Description

The FAN2508/09 family of micropower low-dropout voltage

regulators utilize CMOS technology to offer a new level of

cost-effective performance in GSM and TDMA cellular

handsets, Laptop and Notebook portable computers, and

other portable devices. Features include extremely low

power consumption and low shutdown current, low dropout

voltage, exceptional loop stability able to accommodate a

wide variety of external capacitors, and the compact SOT23-5

surface-mount package. The FAN2508/09 family of products

offer significant improvements over older BiCMOS designs

and are pin-compatible with many popular devices. The

output is thermally protected against overload.

The FAN2508 and FAN2509 devices are distinguished by

the assignment of pin 4:

FAN2508: pin 4 – ADJ, allowing the user to adjust the

output voltage over a wide range using an external voltage

divider.

FAN2508-XX: pin 4 – BYP, to which a bypass capacitor

may be connected for optimal noise performance. Output

voltage is fixed, indicated by the suffix XX.

FAN2509-XX: pin 4 – ERR, a flag which indicates that the

output voltage has dropped below the specified minimum

due to a fault condition.

The standard fixed output voltages available are 2.5V, 2.6V,

2.7V, 2.8V, 2.85V, 3.0V, and 3.3V. Custom output voltage are

also available: please contact your local Fairchild Sales

Office for information.

FAN2508, FAN2509

50 mA CMOS LDO Regulators

Block Diagrams

FAN2508

EN

ADJ

GND

Thermal

Sense

p

VIN

VOUT

Bandgap

Error

Amplifier

FAN2508-XX

EN

BYP

GND

GND

Bandgap

Thermal

Sense

p

Error

Amplifier

VIN

VOUT

FAN2509-XX

EN

ERR

Bandgap

Thermal

Sense

p

Error

Amplifier

VIN

VOUT