The Trends for using PWM Controllers and Its Impact in High Performance Switching Mode Power Supply Designs

This paper will discuss an industry trend towards the integration of a Pulse Width Modulation mode (PWM) controller in applying advanced technologies for cost-effective high performance switching power supply applications. In recent years, with the onset of more sophisticated CAD design tools, better process technology, progressive third party suppliers, demanding circuit application design criteria and high competition among manufacturers has promoted chip makers to produce cost effective high performance controllers for switching mode power supply applications. This trend for devices with much higher energy conversion efficiency using minimum external components at reducing total cost will be discussed. PFM as the alternative with high efficiency for a low current load will also be discussed. The discussion will be placed on developing a higher integrated controller with the following features: Adjustable Dead Time Control (DTC), Under Voltage Lockout (VULO) protection, Short Circuit Protection (SCP), variable oscillation frequency, and on-chip high precision voltage reference The result is a flexible device that can support a wide range of switching mode power supply designs at a costeffective price.