
Micrel
General Description
The MIC2841A is a high efficiency White LED (WLED) driver designed to drive up to four WLEDs, greatly extending battery life for portable display backlighting, keypad backlighting and camera flash in mobile devices. The MIC2841A provides the highest possible efficiency as this architecture has no switching losses present in traditional charge pumps or inductive boost circuits. The MIC2841A provides four linear driver channels which maintain constant current for up to four WLEDs. It features a typical dropout of 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.
FEATUREs
• High Efficiency (no Voltage Boost losses)
• Dynamic Average Matching™ (DAM™)
• Ultra Fast PWM™ control (200Hz to 500kHz)
• Input voltage range: 3.0V to 5.5V
• Dropout of 40mV at 20mA
• Matching better than ±1.5% (typical)
• Current accuracy better than ±1.5% (typical)
• Maintains proper regulation regardless of how many
channels are utilized
• Available in a 10-pin 2mm x 2mm Thin MLF® package
APPLICATIONs
• Mobile handsets
• Handset LCD backlighting
• Handset keypad backlighting
• Flash driver
• Digital cameras
• Portable media/MP3 players
• Portable navigation devices (GPS)
• Portable applications