© 2006 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FAN5099 Rev. 1.1.5

May 2008

FAN5099 — Wide Frequency Synchronous Buck PWM

& LDO Controller

Features

– 5V

– Shunt Regulator for 12V Operation

(50kHz to 600kHz)

Applications

– FPGA, DSP, Embedded Controllers, Graphic Card

Processor, and Communication Processors

Related Application Notes

Simulation Tools

Calculations with Excel Model

Description

The FAN5099 combines a high-efficiency pulse-width

modulated (PWM) controller and an LDO (low drop out)

linear regulator controller. The PWM controller is

designed to operate over a wide frequency range (50kHz

to 600kHz) to accommodate a variety of applications.

Synchronous rectification provides high efficiency over a

wide range of load currents. Efficiency is further

sense current. In addition, the capability to operate at low

switching frequencies provides opportunities to boost

power supply efficiency by reducing switching losses and

gain cost savings using low-cost materials, such as pow-

dered iron cores, on the output inductor.

Both the linear and PWM regulator soft-start are con-

trolled by a single external capacitor, to limit in rush cur-

rent from the supply when the regulators are first

enabled. Current limit for PWM is also programmable.

The FAN5099’s ability to handle wide input voltage

ranges makes this controller suitable for power solutions

in a wide range of applications involving conversion input

voltages from Silver box, battery, and adapters. The

PWM regulator employs a summing-current-mode con-

trol with external compensation to achieve fast load tran-

sient response and provide system design optimization.

FAN5099 is offered in both industrial temperature grade

(-40°C to +85°C) as well as commercial temperature

grade (-10°C to +85°C).

Ordering Information

All standard Fairchild Semiconductor products are RoHS compliant and many are also “GREEN” or going green. For Fairchild’s

definition of “green” please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.

Contact Fairchild sales for availability of other package options.

Part Number

Operating Temperature Range

Package

Packing Method

Qty/Reel

FAN5099MTCX

-10°C to +85°C

16-Lead TSSOP

Tape and Reel

2500

FAN5099EMTCX

-40°C to +85°C

16-Lead TSSOP

Tape and Reel

2500

FAN5099MX

-10°C to +85°C

16-Lead SOIC

Tape and Reel

2500

FAN5099EMX

-40°C to +85°C

16-Lead SOIC

Tape and Reel

2500