The HV9930 is a variable frequency PWM controller IC designed to control an LED lamp driver using a low noise boost-buck (Cuk) topology. The HV9930 uses hystereticcurrent mode control to regulate both the input and the output currents. This enables fast transient response (required for PWM dimming) without the necessity for complex loop compensation. Input current control enables current limiting during startup and output overload conditions. Capacitive isolation protects the LED Lamp from failure of the switching MOSFET. HV9930 provides a low-frequency PWM dimming input that can accept an external control signal with a duty ratio of 0-100%.