AN701 - Vishay Siliconix

AN701 Designing High-Frequency DC-to-DC Converters With the Si9114A Switchmode Controller

OF THE SI9114A BID/CMOS PWM CONTROLLER The Si9114A controller is similar in configuration to the Si9110. It uses a traditional constant frequency current mode control, the most commonly used architecture. The duty cycle is limited to less than 50% to avoid problems with core reset. Current mode control is presently the de-facto standard for PWM control circu.

Features

including a power MOSFET, high-voltage start circuitry, and low power consumption. The Si9114A controller pushes the limits for high-frequency power conversion by further reducing delay times and adding additional features. As a result, dc-to-dc converters can be designed for frequencies up to 1 MHz with simple PWM topologies instead of the complex resonant ones. S reduce the size of energy storage components S increase reliability by using ceramic capacitors S produce an all-surface-mount assembly solution S lower system costs S simplify the implementation of a distributed power architecture.