Bias Voltage Regulation Circuit for Switch-Mode Power Supplies

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Solution Overview

Problem

Conventional power conversion circuits face inefficiencies in generating and maintaining auxiliary bias power, particularly when the input voltage drops below a threshold, leading to reduced performance and potential disruptions in switch-mode power supplies.

Innovation Solution

A power conversion circuit with a voltage boost circuit, a boost controller, and a bias voltage generation circuit that regulates bias voltage levels by detecting input voltage thresholds, using a comparator and pulse width modulation signals to control switches and maintain optimal voltage and current levels, ensuring efficient operation of the high voltage switch in a switched mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the input voltage drops below the threshold voltage level, then the bias voltage generation becomes insufficient, but increasing the bias voltage requires additional circuit complexity

Engineering Contradiction:
Improvebias voltage generation reliabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bias voltage generation circuit automatically detects when input voltage drops below the threshold and self-regulates by adjusting the duty cycle of the control signal to the first switch, maintaining adequate bias voltage without external intervention or complex control circuits

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The comparator continuously monitors the input voltage level and provides feedback to the bias voltage generation circuit, enabling automatic adjustment of the bias voltage when the input voltage falls below the threshold, ensuring reliable operation without manual intervention

Inventive Principle:
Principle #23Feedback

2Reliability

If the first switch is kept on continuously to maintain bias voltage, then the bias voltage remains stable, but the power consumption increases

Engineering Contradiction:
Improvebias voltage stabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The first switch is controlled with a periodic duty cycle rather than being continuously on, allowing the bias voltage to be replenished in pulses during each switching cycle, maintaining stability while reducing average power consumption

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The duty cycle of the control signal is dynamically adjusted based on the input voltage level, changing the on-time parameter of the first switch to optimize the balance between bias voltage stability and power consumption

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution ensures stable and efficient generation of bias voltage, maintaining high voltage switch operation in a switched mode, reducing inefficiencies and disruptions, and enhancing the overall performance of switch-mode power supplies by periodically recharging the bias voltage and synchronizing recharge cycles with input voltage characteristics.

Implementation Method 1

A switched-mode power supply may include a switch that, when switching on and off, stores energy in an inductor and discharges the stored energy to an output of the switched mode power supply

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The boost controller may be configured to generate a pulse width modulation signal that controls operation of a switch in the voltage boost circuit. The bias voltage generation circuit may be configured to detect the level of the input voltage by measuring an on-time of the pulse width modulation signal

Methodology Applied
Scientific EffectPulse width modulation:

Implementation Method 3

the bias voltage generation circuit may include a comparator that is configured to compare a level of the input voltage with the threshold voltage level

Methodology Applied
Scientific EffectVoltage comparison:

Data Source

PatentEP2915243B1Power converter with bias voltage regulation circuit
Publication Date: 2019.05.08 WOLFSPEED INC
  • EP2915243B1 patent drawingFigure 1
  • EP2915243B1 patent drawingFigure 2~3
  • EP2915243B1 patent drawingFigure 4

AI summary

A power conversion circuit includes a voltage boost circuit configured to generate an output voltage in response to an input voltage, a boost controller configured to control operation of the voltage boost circuit, and a bias voltage generation circuit configured to generate a bias voltage. The bias generation circuit is configured to regulate a level of the bias voltage in response to a level of the input voltage.