Switching Power Supply Dynamic Frequency Control

Solution Overview

Problem

Conventional switching power supplies experience increased switching loss and current imbalance among inductors during high frequency load transient conditions, leading to electrical and thermal stress.

Innovation Solution

A switching power supply design that includes a signal generator, controller, and power converter, utilizing a frequency detector and ramp generator to adjust the modulation signal frequency, maintaining it proximate to the nominal operating frequency by filtering the comparison signal and adjusting the threshold voltage, thereby reducing switching loss and current imbalance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the switching frequency increases to respond to high frequency load transient conditions, then the power supply responds faster to load changes, but the switching loss of the switching elements increases

Engineering Contradiction:

Improveresponse speed to load transientVSAvoidswitching loss

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The patent implements dynamic frequency adjustment by detecting load transient conditions and modulating the switching frequency accordingly. The controller dynamically changes the switching frequency from the nominal frequency to a higher frequency during load transients, then returns to nominal frequency when transients subside, optimizing both response speed and efficiency.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the switching frequency parameter in response to detected load transient conditions. By adjusting this key operational parameter dynamically based on system state, the patent achieves fast response during transients while maintaining low switching loss during steady-state operation.

Inventive Principle:

Principle #35Parameter changes

2Speed

If the switching frequency increases during high frequency load transient conditions, then the power supply responds faster to load changes, but current imbalance among inductors occurs leading to electrical and thermal stress

Engineering Contradiction:

Improveresponse speed to load transientVSAvoidelectrical and thermal stress on inductors

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent implements dynamic frequency adjustment by detecting load transient conditions and modulating the switching frequency accordingly. The controller dynamically changes the switching frequency from the nominal frequency to a higher frequency during load transients, then returns to nominal frequency when transients subside, optimizing both response speed and efficiency.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs feedback control through a transient detector that monitors load conditions and provides feedback to the controller. This feedback mechanism enables the controller to adjust the switching frequency in response to detected transients, coordinating multiple inductors to maintain current balance and reduce stress during high-frequency operation.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10033273B1System and method for controlling switching power supply

Publication Date: 2018.07.24 SEMICON COMPONENTS IND LLC

AI summary

A switching power supply includes a signal generator providing a selected signal according to a first signal and a second signal, a controller generating a modulation signal in response to the selected signal, and a power converter converting an input signal into an output signal in response to the modulation signal. The first signal has a first ripple amplitude, and the second signal has a second ripple amplitude less than the first ripple amplitude.