MIC2843 Datasheet, PDF (1/15 Pages) Micrel Semiconductor – High-Efficiency 6-Channel Linear WLED Driver with Ultra-Fast PWM™ Control

MIC2843
High-Efficiency 6-Channel
Linear WLED Driver with
Ultra-Fast PWM™ Control
General Description
The MIC2843 is a high-efficiency linear white LED (WLED)
driver designed to drive up to six WLEDs, greatly
extending battery life for portable display backlighting,
keypad backlighting, and camera flash in mobile devices.
The MIC2843 provides the highest possible efficiency as
this architecture has no switching losses present in
traditional charge pumps or inductive boost circuits. The
MIC2843 provides six linear drivers which maintain
constant current for up to six WLEDs. It features a typical
dropout of less than 40mV at 20mA. This allows the
WLEDs to be driven directly from the battery eliminating
switching noise/losses present with the use of boost
circuitry.
The six channels are matched better than ±3% typical,
ensuring uniform display illumination under all conditions.
The brightness is controlled through an Ultra Fast PWM™
interface operating down to less than 1% duty cycle.
The MIC2843 is available in the 2mm x 2mm 10-pin Thin
MLF^® leadless package with a junction temperature range
of −40°C to +125°C.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• High efficiency (no voltage boost losses)
• Ultra Fast PWM™ control (200Hz to 500kHz)
• Input voltage range: 3.0V to 5.5V
• Dropout of less than 40mV at 20mA
• Matching better than ±3% (typical)
• Current accuracy better than ±1.5% (typical)
• Maintains proper regulation regardless of how many
channels are utilized
• Available in a 2mm x 2mm 10-pin Thin MLF^® package
Applications
• Mobile handsets
• Digital cameras
• Portable media/MP3 players
• Portable navigation devices (GPS)
• Portable applications
____________________________________________________________________________________________________________
Typical Application
LCD Display Backlight with Six WLEDs
High Current Flash Driver
Ultra Fast PWM is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademark Amkor Technology Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
November 2010
M9999-110810-B