103 Multi-Channel Constant Current LED Driver with PWM Boost Converter

This Paper presents an integrated LED driver with boost converter designed with standard CMOS technology considering Lithium-Ion battery used to drive LED strings that provides overall maximum efficiency of 85% and current error accuracy of 0.0046%. The boost converter operates in PWM voltage mode at 600kHz with stable output voltage as a voltage source to LED driver. A dimmable LED driver with a dimming frequency up to 10MHz is implemented for the application of constant current driving capability for LED displays and LCD backlighting that is used in many portable devices with advanced video and image processing operating at low voltage. A current balance circuit is applied having two or three channels that act as a constant current source for the series connection of LED strings and also used to control the amount of driving current for regulating the constant light luminance of LEDs. The design is simulated with tsmc 0.351m process with an effective layout area of 2.279967 1 2.39105mm2 and a power consumption lower than 1W.