The MIC3263 is Micrel's six-way white LED (WLED) driver with high-efficiency PWM boost switching technology, ideal for constant-current WLED backlighting. Each current is matched at ±3% and current is programmable from 15mA to 30mA. Input voltage from 6V to 40V, each channel can drive up to 10 WLEDs, dimming ratio between 1% and 100%, efficiency up to 90%, mainly used in notebook computers, LCD screens and monitors, multimedia players, Navigation equipment, game consoles, etc. This article describes the main features of the MIC3263, functional block diagrams, typical application circuits, and the MIC3263 evaluation board circuit diagram and bill of materials (BOM). PWM driver for white LED: http:// Vent spacer,stator core vent spacer lamination,stator core vent spacer,vent plates Henan Yongrong Power Technology Co., Ltd , https://www.hnyongrongglobal.com
MIC3263; Six-Channel WLED Driver for Backlighting Applications with Flicker-Free Dimming
The MIC3263 is a high-efficiency Pulse Width Modulation (PWM) boost switching regulator that is optimized for constant-current WLED driver backlighting applications. The MIC3263 drives six channels of up to ten WLEDs per channel. Each channel is matched in current to within ± 3% for constant brightness across the screen and can be programmed from 15mA to 30mA.
The MIC3263 provides a very flexible dimming control scheme with better accuracy and noise immunity. The dimming frequency can be set to any value between 100Hz and 20kHz by an external resistor. The dimming ratio is determined by the duty cycle of a dimming ratio control input signal And can be set to one of 16 levels with a minimum ratio of 1%. The LED dimming current is set by an external resistor to allow programming of LED current between 15mA and 30mA.
The dimming ratio of the MIC3263 is fixed to 16 log levels to better match the sensitivity of the human eye. Each of the dimming levels has hysteresis to avoid skipping between levels and allow for high noise immunity. The MIC3263 has a programmable PWM switching frequency from The 6V to 40V wide input voltage range of MIC3263 allows direct operation from 6V or high cell count Li-Ion batteries commonly found in notebook computers. The MIC3263 is available in a low-profile 24 -pin 4mm x 4mm MLF® package and has a junction temperature range of –40°C to -125°C.
Main features of MIC3263:
6V to 40V wide input voltage range
Drives 6 channels of up to 10 white LEDs
Programmable WLED current from 15mA to 30mA
Highly reliable operation with open and short LEDs
Accurate 16 dimming log levels sets the dimming ratio from 1% to 100%
Flicker-Free Dimming filters the jitter from the dimming control input signal and eliminates dimming flicker
Allows external dimming control
Accurate LED channel current matching ±3%
Accurate initial LED current setting ±2%
Programmable switching frequency from 400kHz to 1.8MHz
High efficiency up to 90%
Low (<40μA) shutdown current over temperature
Over temperature protection
Programmable over-voltage protection
–40°C to -125°C junction temperature range
Available in 24-pin 4mm x 4mm MLF® package
MIC3263 application:
• White LED driver for backlighting
• Notebooks
• LCD Panels and Monitors
• Multimedia players
• Navigation equipment
• Gaming systems
• Video poker
• Slot machines 
Figure 1. Functional block diagram of the MIC3263