Digital Control of Power Converters

Abstract

A system and method for controlling a power converter is presented. An embodiment comprises an analog differential circuit connected to an analog-to-digital converter, a digital pulse generator, and a pre-driver to control the power converter. Another embodiment also includes a digital filter as part of the control loop that may be used to control the loop characteristics of the control circuit. Yet another embodiment replaces the differential circuit with a sigma-delta analog-to-digital modulator and a decimator.

Description

[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 038,348, filed on Mar. 20, 2008, entitled “Digital Control of Power Converters,” which application is hereby incorporated herein by reference.TECHNICAL FIELD[0002]The present invention relates generally to a system and method for power conversion, and more particularly to a system and method for controlling the output voltage of DC / DC converters.BACKGROUND[0003]Generally, today's devices have systems with multiple power requirements, but which run off of a smaller number of, or even a single, power supplies, such as batteries. This is especially true of system-on-chip (SOC) devices, which contain multiple sections with different power requirements, but contain few connections to different power supplies. This is also true of portable devices that run off a single battery (such as a cellular phone). These devices and SOCs utilize power converters to take a single power source and convert the power to the...

AI Technical Summary

Benefits of technology

The present invention provides a control circuit for a power converter that can accurately control the output voltage. This is achieved by using a differential circuit, an analog-to-digital converter, and a digitally controlled PWM generator to generate control pulses for the transistors in the power converter. Additionally, a digital filter can be included to filter the digital signal. The control circuit can also operate at different clock frequencies and can be reprogrammed easily, making it easier to control the loop dynamics of the system. Overall, the present invention allows for greater control and flexibility in power conversion systems.

Problems solved by technology

One disadvantage of the analog control circuit 103 is the difficulty in implementing a precise ramp generator 123.

Further, it is difficult to control the loop response and dynamic performance of the control circuit 103 and power converter 101 using an analog system because the frequency response of the control loop can only be modified by changing the frequency response of the analog components, requiring a redesign and rebuild.

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