A variable frequency pulse width modulation (PWM) controller IC from Supertex Inc. targets automotive LED lighting among other applications.
The HV9930 is designed to control an LED lamp using a low-noise boost-buck topology that can step input or output voltage up or down automatically. Patent-pending hysteretic current mode control regulates input and input currents for fast transient response without the need for loop compensation and external components, according to Ahmed Masood, director of marketing. “Input and output current control protects against a short circuit, and capacitive isolation of the boost-buck topology protects LED lamps from failure of the switching MOSFET,” he said.
The device features a dc input range of 8 V to 200 V. It provides PWM dimming capability with a duty cycle ratio of 0% to100%, and enables LED lamp efficiency of better than 85%. The HV9930 is available in an eight-pin DIP or an eight-pin SOIC, priced at $0.87 and $0.91 respectively in 1,000-piece quantity. Deliveries are four to five weeks.