MIC4801YM Microchip

MIC4801 High Efficiency 600mA Single Channel Linear WLED Driver with Ultra Fast PWM Control General Description Features The MIC4801 is a high efficiency White LED (WLED) High Efficiency (no Voltage Boost losses) driver designed to drive a single LED up to 600mA. The Ultra Fast PWM control (200Hz to 500kHz) MIC4801 constant current driver is designed to drive high Input voltage range: 3.0V to 5.5V power LEDs in various lighting applications. The MIC4801 Dropout of 130mV at 400mA provides the highest possible efficiency as this architecture has no switching losses present in traditional charge Programmable LED current with external resistor pumps or inductive boost circuits. It features a typical Current accuracy of 1% typical dropout of 130mV at 400mA. This allows the LEDs to be driven directly from the voltage source eliminating Applications switching noise/losses present with the use of boost Bill board displays circuitry. The high accuracy (1% typical) current regulated WLED channel ensures uniform display illumination under Marquee displays all conditions. The brightness is controlled through an Ultra Instrument displays Fast PWM Control interface operating down to less than Architectural lighting 1% duty cycle. The MIC4801 is available in an 8-pin SOIC package with a junction temperature range of -40 C to +125 C. Datasheets and support documentation can be found on Micrels web site at: www.micrel.com. Typical Application High Current Lighting Schematic Ultra Fast PWM is a trademark of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel Inc. MIC4801 Ordering Information Part Number Temperature Range Package MIC4801YM 40C to +125C 8-Pin SOIC Pin Configuration 8-Pin SOIC (M) (Top View) Pin Description Pin Number Pin Name Pin Function 1 VIN Voltage Input. Connect at least 2.2F ceramic capacitor between VIN and GND. 2 EN Enable LED drivers. This pin can be used as a PWM input for dimming of WLEDs. Do not leave floating. 3 RSET An internal 1.27V reference sets the nominal maximum WLED current. Example, apply a 12.1k resistor between RSET and GND to set LED current to 416mA at 100% duty cycle. 4 GND Ground. 5 D1 LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED. 6 D1 LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED. 7 D1 LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED. 8 D1 LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED. M9999-011811-A January 2011 2