Ideal Diode Control Circuit for Dynamic Current Adjustment

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Solution Overview

Problem

Conventional control circuits for ideal diodes experience increased current consumption in standby states due to the need for high drive capability to prevent backflow, especially when handling light loads.

Innovation Solution

A control circuit that dynamically adjusts the operating current of a field effect transistor by using multiple current sources and a differential amplifier to control the gate voltage, reducing current consumption during light loads and increasing it during heavy loads, thereby optimizing power usage while maintaining diode functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high drive capability is used to control gate voltage to prevent backflow, then backflow prevention is improved, but current consumption increases in standby state

Engineering Contradiction:
Improvebackflow preventionVSAvoidcurrent consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control circuit dynamically adjusts the operating current of the transistor controller based on load conditions. A current controller monitors the gate voltage and adjusts the operating current accordingly: reducing it when the transistor current is below a predetermined threshold (light load/standby state), and increasing it when the transistor current exceeds the threshold (heavy load state). This dynamic adjustment maintains backflow prevention capability while reducing current consumption during standby.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operating current parameter of the transistor controller based on the voltage at the gate terminal. By detecting the gate voltage level, the system determines the appropriate operating current level and switches between low current (for light loads) and high current (for heavy loads), thereby optimizing the trade-off between backflow prevention and power consumption.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If operating current is reduced for light load, then current consumption decreases, but drive capability may be insufficient for heavy load

Engineering Contradiction:
Improvecurrent consumptionVSAvoiddrive capability
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The control circuit transitions from a static high drive capability design to a dynamic design that adapts to load conditions. The current controller continuously monitors the gate voltage and adjusts the operating current in real-time, providing low current during light loads to save power and high current during heavy loads to maintain sufficient drive capability for backflow prevention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system periodically evaluates the gate voltage and adjusts the operating current accordingly. The current controller switches between different current levels based on the detected load condition, creating a periodic adjustment cycle that optimizes power consumption while maintaining the necessary drive capability when needed.

Inventive Principle:
Principle #19Periodic action

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 effectively reduces current consumption in standby states while ensuring the ideal diode function is maintained, by adjusting the operating current based on load conditions, thus enhancing energy efficiency.

Implementation Method 1

a field effect transistor as an ideal diode... controls a gate voltage in accordance with a comparison result of the comparator, thereby controlling the field effect transistor to operate as a diode

Methodology Applied
Scientific EffectField effect transistor operation: Conduction (electrical)

Implementation Method 2

the transistor controller may include a differential amplifier circuit that controls the voltage at the gate terminal in accordance with the difference in voltage between the drain terminal and the source terminal

Methodology Applied
Scientific EffectDifferential amplification:

Implementation Method 3

a first current source that supplies a constant current serving as a reference for the operating current... a second current source that adds and supplies an additional constant current

Methodology Applied
Scientific EffectCurrent source operation: Conduction (electrical)

Data Source

PatentEP3648330B1Control circuit and ideal diode circuit
Publication Date: 2022.04.27 SHINDENGEN ELECTRIC MANUFACTURING CO LTD
  • EP3648330B1 patent drawingFigure 1
  • EP3648330B1 patent drawingFigure 2
  • EP3648330B1 patent drawingFigure 3~4

AI summary

A control circuit includes: a transistor controller that controls a voltage at a gate terminal of a field effect transistor in accordance with a difference in voltage between a source terminal and a drain terminal of the field effect transistor connected so that a body diode is in a forward direction; and a current controller that reduces an operating current for operating the transistor controller when a load connected via the source terminal of the field effect transistor is light, and increases the operating current when the load is heavy.