MIC4811YMM Microchip

MIC4811 High Current 6 Channel Linear WLED Driver with DAM and Ultra Fast PWM Control General Description Features The MIC4811 is a high efficiency linear White LED High Efficiency (no Voltage Boost losses) (WLED) driver designed to drive up to six high current Ultra Fast PWM control (200Hz to 500kHz) WLEDs for signage lighting. The MIC4811 provides the Input voltage range: 3.0V to 5.5V highest possible efficiency as this architecture has no LED current range up to 50mA per channel switching losses present in traditional charge pumps or inductive boost circuits. The MIC4811 provides six linear Programmable LED current with external resistor drivers which maintain constant current for up to six Dropout of 100mV at 50mA WLEDs. It features a typical dropout of 100mV at 50mA. Matching better than 1% (typical) The MIC4811 features Dynamic Average Matching Current Accuracy better than 1% (typical) (DAM) which is specifically designed to provide optimum Maintains proper regulation regardless of how many matching across all WLEDs. The high accuracy (1% channels are utilized typical) current regulated WLED channels ensure uniform 10-pin MSOP package display illumination under all conditions. The brightness is controlled through an Ultra Fast PWM interface Applications operating down to less than 1% duty cycle. The MIC4811 is available in an 10-pin MSOP package Billboard displays with a junction temperature range of -40 C to +125C. Marquee displays Datasheets and support documentation can be found on Instrument displays Micrels web site at: www.micrel.com. LCD display modules Typical Application High Current Lighting (Six WLEDs) Ultra Fast PWM, DAM and Dynamic Average Matching are 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. MIC4811 Ordering Information (1) Part Number Mark Code Junction Temperature Range Package MIC4811YMM 4811 40C to +125C 10-Pin MSOP Pin Configuration 10-Pin MSOP (MM) (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 16.5k resistor between RSET and GND to set LED current to 50mA at 100% duty cycle. 4 GND Ground. 5 D6 LED6 driver input. Connect LED anode to VIN and cathode to this pin. 6 D5 LED5 driver input. Connect LED anode to VIN and cathode to this pin. 7 D4 LED4 driver input. Connect LED anode to VIN and cathode to this pin. 8 D3 LED3 driver input. Connect LED anode to VIN and cathode to this pin. 9 D2 LED2 driver input. Connect LED anode to VIN and cathode to this pin. 10 D1 LED1 driver input. Connect LED anode to VIN and cathode to this pin. M9999-041411-B April 2011 2