MIC2843A
High Efficiency 6 Channel Linear WLED
Driver with DAM™ and Ultra Fast
PWM™ Control
General Description
Features
The MIC2843A is a high efficiency linear White LED
•
High Efficiency (no Voltage Boost losses)
(WLED) driver designed to drive up to six WLEDs, greatly
•
Dynamic Average Matching (DAM™)
extending battery life for portable display backlighting
•
Ultra Fast PWM™ control (200Hz to 500kHz)
keypad backlighting, and camera flash in mobile devices.
•
Input voltage range: 3.0V to 5.5V
The MIC2843A provides the highest possible efficiency as
•
Dropout of 40mV at 20mA
this architecture has no switching losses present in
traditional charge pumps or inductive boost circuits. The
•
Matching better than ±1.5% (typical)
MIC2843A provides six linear drivers which maintain
•
Current Accuracy better than ±1.5% (typical)
constant current for up to six WLEDs. It features a typical
•
Maintains proper regulation regardless of how many
dropout of 40mV at 20mA. This allows the WLEDs to be
channels are utilized
driven directly from the battery eliminating switching
•
Available in a 10-pin 2mm x 2mm Thin MLF
®
package
noise/losses present with the use of boost circuitry.
The MIC2843A features Dynamic Average Matching™
Applications
(DAM™) which is specifically designed to provide optimum
matching across all WLEDs. The six channels are
•
Mobile handsets
matched better than ±1.5% typical, ensuring uniform
•
LCD Handset backlighting
display illumination under all conditions. The brightness is
•
Handset keypad backlighting
controlled through an Ultra Fast PWM™ interface
operating down to less than 1% duty cycle.
•
Digital cameras
The MIC2843A is available in the 10-pin 2mm x 2mm Thin
•
Portable media/MP3 players
®
MLF leadless package with a junction temperature range
•
Portable navigation devices (GPS)
of -40°C to +125°C.
•
Portable applications
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
____________________________________________________________________________________________________________
Typical Application
U1 MIC2843AYMT
U1 MIC2843AYMT
VIN
V
IN
Low
Dropout
Linear
Driver
PWM
Control
C1
RSET
C1
V
IN
R
SET
Low
Dropout
Linear
Driver
PWM
Control
END
END
LCD Display Backlight with Six WLEDs
Ultra Fast PWM, DAM and Dynamic Average Matching are trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are registered trademark Amkor Technology Inc.
High Current Flash Driver
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
June 2009
M9999-062909-C
MICREL [ MICREL SEMICONDUCTOR ]
