Dynamic Bleeder Current Circuit for Voltage Regulator Overshoot

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Solution Overview

Problem

Voltage regulators face issues with increased leakage current and voltage overshoot due to shorter power MOSFET channel lengths and slow response times, leading to inefficient discharge of capacitors and potential power consumption problems.

Innovation Solution

A dynamic bleeder-current circuit is introduced, comprising a first bleeder-current circuit with a current comparator and output stage that determines whether to use a high or fixed current to discharge the load capacitor based on voltage overshoot conditions, allowing for efficient capacitor discharge without excessive power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed bleeder current is used to discharge the load capacitor, then the circuit structure is simple, but the voltage overshoot recovery time is prolonged and power consumption increases

Engineering Contradiction:

Improvecircuit structureVSAvoidvoltage overshoot recovery time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent applies dynamics by switching between two different bleeder current modes (first bleeder current and second bleeder current) based on the voltage overshoot condition. The circuit transitions from a static fixed current approach to a dynamic adaptive current approach, where the bleeder current magnitude changes according to the real-time voltage state, thereby reducing recovery time without excessive power consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of bleeder current from a fixed value to a variable value that adapts to different operating conditions. By adjusting the current magnitude between two predefined levels based on voltage overshoot detection, the system optimizes both recovery speed and power consumption, resolving the contradiction between simple structure and fast response.

Inventive Principle:

Principle #35Parameter changes

2Loss of time

If a high bleeder current is continuously applied to discharge the load capacitor, then the voltage overshoot recovery time is reduced, but the power consumption increases

Engineering Contradiction:

Improvevoltage overshoot recovery timeVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by alternately applying high bleeder current and low bleeder current based on the voltage overshoot condition. The high current is applied only during the critical recovery phase when voltage overshoot is detected, while the low current is used during normal operation, creating a periodic switching pattern that optimizes both response time and energy efficiency.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies partial action by using excessive current (first bleeder current) only when necessary for voltage overshoot recovery, rather than continuously. The system applies the higher current magnitude partially, only during the specific condition of voltage overshoot, thereby achieving fast recovery without the continuous power consumption penalty.

Inventive Principle:

Principle #16Partial or excessive action

3Speed

If the power MOSFET channel length is shortened to increase switching speed, then the response time is reduced, but the leakage current increases

Engineering Contradiction:

Improveresponse timeVSAvoidleakage current

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful leakage current effect into a beneficial detection signal. By monitoring the voltage overshoot caused by leakage current and backend component activation, the system triggers the dynamic bleeder current response, turning the harmful leakage effect into a useful indicator for activating the corrective bleeder current mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS10503189B1Voltage regulator and dynamic bleeder current circuit

Publication Date: 2019.12.10 WINBOND ELECTRONICS CORP

AI summary

A dynamic bleeder-current circuit for use in a voltage regulator is provided. The dynamic bleeder-current circuit includes a first bleeder-current circuit and a second bleeder-current circuit. The first bleeder-current circuit includes an input stage, a current comparator, and a bleeder-current output stage. The input stage maps a bias current in an operational amplifier in the voltage regulator with a predetermined ratio to generate a mapped current. The current comparator compares a pull current and a sink current generated by the mapped current. The bleeder-current output stage determines whether to use a first current to discharge the load capacitor of the voltage regulator according to a comparison result from the current comparator. The second bleeder-current circuit is configured to provide a second bleeder current to discharge the load capacitor. The first current is greater than the second current, and the pull current is equal to the second current.