Gate Drive Conversion Circuit for Negative Turn-Off at Start-Up
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Solution Overview
Problem
Current switching device driving circuits cannot produce a negative voltage to turn off a switching device before the initial start-up, leading to false turn-on issues during the initial start-up state.
Innovation Solution
A conversion circuit comprising a voltage supply circuit, a storage circuit, and a gate terminal, which outputs a negative voltage at the initial stage and adjusts the voltage range through a voltage clamp circuit to achieve gate-source voltage control of the main device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If general switching device driving circuits are used, then the circuit structure is simple, but negative voltage cannot be produced to turn off switching device before operating, causing false turn-on issues
Solution Approach 1:
The driving circuit is segmented into distinct functional modules: voltage supply circuit (with first and second voltage sources), storage circuit (with capacitor and switching elements), and clamping circuit (with diodes and resistors). Each module performs a specific function in generating the negative voltage, allowing for targeted design optimization and fault isolation while maintaining overall system reliability.
Solution Approach 2:
The storage circuit is pre-charged during the initial state before the main switching device operates. The capacitor in the storage circuit accumulates voltage in advance, enabling the circuit to immediately provide negative voltage for turning off the switching device when needed, without requiring complex real-time voltage generation during operation.
2Reliability
If negative voltage is generated at initial stage, then false turn-on issues are prevented, but circuit structure becomes more complex
Solution Approach 1:
The storage circuit acts as an intermediary energy storage element between the voltage supply circuit and the main switching device. It temporarily holds the negative voltage in the capacitor during the initial state, mediating the voltage transfer and enabling reliable turn-off control without requiring direct complex voltage generation at every switching moment.
Solution Approach 2:
The circuit utilizes parameter changes in the switching elements (transistors Q1, Q2) and diodes (D1, D2) to dynamically alter the voltage states. By controlling the conduction states of these elements, the circuit transforms the voltage parameters from positive to negative and back, achieving reliable initial control through parameter manipulation rather than complex circuit topology.
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 conversion circuit effectively outputs a negative voltage at the initial stage, preventing false turn-on issues and ensuring precise control of the main device by adjusting the voltage range through the voltage clamp circuit.
Implementation Method 1
The storage circuit is configured to storage the storage voltage according to the bias voltage and the low voltage
Implementation Method 2
adjusts the voltage range through the voltage clamp circuit
Data Source
AI summary
A conversion circuit includes a voltage supply circuit, a storage circuit, and a gate terminal. The storage circuit includes a first terminal and a source terminal. The voltage supply circuit is configured to provide a bias voltage according to a power supply voltage. The first terminal is configured to receive a low voltage. The source terminal is configured to output a source voltage according to a storage voltage and the low voltage, wherein the storage circuit is configured to storage the storage voltage according to the bias voltage and the low voltage. The gate terminal is configured to output a gate voltage, wherein during a first period, the gate terminal is coupled to the first terminal, and the gate-source voltage can form a negative voltage.