DC-to-DC Converter Control Circuit for Transient Response

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Solution Overview

Problem

Traditional DC-to-DC converters experience ringback and undershoot during load transients due to slow response times, affecting the performance of connected load circuits like CPUs, as the output voltage drops faster than the reference voltage, leading to instability.

Innovation Solution

A control circuit with a load transient detector that increases the operation frequency of the converter during load transients, utilizing a quick response signal to adjust the sampling frequency and drive channels to reduce the falling speed of the output voltage, thereby minimizing ringback and undershoot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the operation frequency is increased during load transients, then the transient response speed is improved, but the device complexity increases due to the need for frequency modulation control

Engineering Contradiction:

Improvetransient response speedVSAvoidcontrol circuit complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The control circuit dynamically adjusts the operation frequency based on load transient detection. When a load transient is detected, the controller increases the operation frequency to improve transient response, and reduces it to normal frequency when stable, optimizing performance across varying conditions without requiring permanently complex hardware

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameter (frequency) in response to detected conditions. The controller monitors load changes and adjusts the switching frequency parameter to match system requirements, achieving fast transient response only when needed rather than operating at high frequency continuously

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the sampling frequency is increased during load transients, then the control precision is improved, but the energy consumption increases

Engineering Contradiction:

Improvecontrol precisionVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The control circuit employs periodic sampling at normal frequency during stable operation and switches to high-frequency sampling only during detected load transients. This periodic adjustment of sampling rate provides precise control when needed while minimizing energy consumption during normal operation

Inventive Principle:

Principle #19Periodic action

3Speed

If the operation frequency is continuously high, then the transient response is always fast, but the loss of energy increases due to unnecessary high-frequency switching

Engineering Contradiction:

Improvetransient response speedVSAvoidswitching loss

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The system dynamically adjusts switching frequency based on actual load conditions. High frequency is applied only during transient events when fast response is needed, while normal operation uses lower frequency to minimize switching losses and energy consumption

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7701190B2Control circuit and method for a DC-to-DC converter to improve transient response thereof

Publication Date: 2010.04.20 RICHTEK TECH

AI summary

For a DC-to-DC converter including a plurality of channels for converting an input voltage to an output voltage, a control circuit comprises a load transient detector to detect the output voltage to provide a quick response signal. In a load transient, the quick response signal triggers a quick transient response period to increase the operational frequency of the converter.