July 2005

1

M9999-070105

MIC2292/93

Micrel, Inc.

MIC2292/93

High Frequency PWM White LED Drivers with

Internal Schottky Diode and OVP

General Description

The MIC2292 and MIC2293 are high frequency, Pulse Width

Modulator (PWM) boost regulators optimized for constant-

current, white LED driver applications. Because of their

constant PWM switching frequencies of 1.6MHz and 2MHz,

respectively, the MIC2292/93 can use the smallest external

components, allowing designers to avoid sensitive IF bands

in their RF applications.

The products feature an internal Schottky diode and two

levels of output overvoltage protection allowing a small size

and efficient DC/DC solution that requires only four external

components.

The 2.5V to 10V input voltage range of MIC2292/3

allows direct operation from 1- and 2-cell Li Ion as well as

3- to 4-cell NiCad/NiMH/Alkaline batteries. The MIC2292/3

products are available in a small size 2mm × 2mm 8-lead

MLF™ package and have a junction temperature range of

–40°C to +125°C.

All support documentation can be found on Micrel’s web site

at www.micrel.com.

Typical Application

1.6MHz PWM White LED Driver with 15V OVP

Features

• 2.5V to 10V input voltage

• Output voltage up to 34V

• Internal Schottky diode

• 1.6MHz PWM operation (MIC2292)

• 2.0MHz PWM operation (MIC2293)

• Stable with ceramic capacitors

• 15V and 34V output overvoltage protection options

• 500mA switch current rating

• 95mV feedback voltage

• <1% line and load regulation

• <1µA shutdown current

• Over-temperature protection

• UVLO

• 8-lead (2mm × 2mm) MLF™package

• –40°C to +125°C junction temperature range

Applications

• White LED driver for backlighting

– Cell phones

– PDAs

– GPS systems

– Digital cameras

– MP3 players

– IP phones

• Constant current power supplies

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc.

2MHz PWM White LED Driver with 15V OVP

15µH

0.22µF

16V

6.3Ω

95mV

Li Ion

1µF

MIC2292-15BML

VIN

EN

SW

FB

GND

OUT

10µH

0.22µF

16V

6.3Ω

95mV

Li Ion

1µF

MIC2293-15BML

VIN

EN

SW

FB

GND

OUT