The KA7540 provides simple and high performance electronic ballast control functions. KA7540 is optimized for electronic ballast requiring a minimum board area, reduced component count and low power dissipation. Internal soft start circuitry eliminates the need for an external soft start PTC resistor. Voltage controlled dimming circuit is built into the IC to control the lighting output in a wide range. Protection circuitry has also been added to prevent switches from burning out in no lamp condition. Output gate drive circuit clamps power MOSFET gate voltage irrespective of supply voltage.