
Micrel
General Description
The MIC3291 is a PWM switching boost regulator that is optimized for constant current white LED (WLED) driver applications. The MIC3291 features an internal Schottky diode, allowing an efficient DC/DC solution that requires only four external components.
FEATUREs
• Single wire combines 16 level linear brightness and shutdown control
• 18V / 25V OVP options supports up to four and six WLEDs
• Startup in any one of 16 brightness levels
• Internal Schottky diode
• 2.5V to 6.5V input voltage
• 1.2MHz PWM operation
• Over 500mA switch current
• 250mV reference voltage
• ±5% LED current accuracy
• <1µA shutdown current
• UVLO and over-temperature protection
• Thin SOT23-6L package option
• 2mm × 2mm leadless MLF® package option
• –40°C to +125°C junction temperature range
APPLICATIONs
• Mobile handsets
• LCD handset backlighting
• Digital cameras
• Portable media players/MP3 players
• Portable applications