Gate Driving Circuit for Insulated Gate Power Semiconductors
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Solution Overview
Problem
The existing gate driving circuits for insulated gate-type power semiconductor elements suffer from increased steady-state loss due to voltage drops across the Nch MOSFET, which worsens when the same positive-side power supply is connected to the drain and gate electrodes, leading to inefficiencies and potential breakdowns.
Innovation Solution
A gate driving circuit design that includes an Nch MOSFET and a Pch MOSFET, along with a control circuit and power supply unit, where the Nch MOSFET is turned on with a positive voltage applied to its gate and drain, and the Pch MOSFET is turned off with a negative voltage applied to its gate and drain, utilizing a power supply unit that applies a positive voltage to the control circuit's positive-side electrode with an absolute value larger than the drain voltage of the Nch MOSFET, minimizing the potential difference between the drain and source electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same positive-side power supply is connected to the drain electrode and the gate electrode of the Nch MOSFET, then the circuit structure is simplified, but a voltage dropped by the gate threshold voltage is applied between the gate electrode and source electrode of the insulated gate-type power semiconductor element, worsening the steady-state loss
Solution Approach 1:
The power supply system is segmented into two separate power supplies: a first power supply connected to the drain electrode of the Nch MOSFET and a second power supply connected to the gate electrode of the Nch MOSFET. This segmentation allows independent voltage control, enabling the gate voltage to be maintained at a level that minimizes steady-state loss while the drain voltage is independently managed, thereby resolving the contradiction between circuit simplicity and energy efficiency.
Solution Approach 2:
The invention changes the voltage parameters by applying different voltage levels from separate power supplies to the drain and gate electrodes. Specifically, the second power supply applies a voltage to the gate electrode that is optimized to reduce the voltage drop across the insulated gate-type power semiconductor element, while the first power supply manages the drain voltage independently. This parameter change eliminates the gate threshold voltage drop issue while maintaining reasonable circuit complexity.
2Loss of energy
If the absolute value of the positive voltage applied to the positive-side electrode of the control circuit is made larger than the absolute value of the positive voltage applied to the drain electrode of the Nch MOSFET, then the steady-state loss is reduced, but the power supply design becomes more complex
Solution Approach 1:
The power supply is segmented into multiple independent power supplies, each responsible for specific voltage applications. The second power supply is dedicated to applying the optimized positive voltage to the gate electrode of the Nch MOSFET, while the first power supply handles the drain electrode voltage. This segmentation enables precise voltage control to minimize steady-state loss while distributing the design complexity across multiple standardized power supply modules.
Solution Approach 2:
The invention creates equipotential conditions by carefully controlling the voltage levels from separate power supplies. The second power supply applies a voltage to the gate electrode that ensures the potential difference across the insulated gate-type power semiconductor element is minimized during steady-state operation. This equipotential approach reduces energy loss while the modular power supply design manages the complexity through standardized voltage regulation techniques.
Data Source
AI summary
A gate driving circuit for an insulated gate-type power semiconductor element includes an Nch MOSFET which turns on the insulated gate-type power semiconductor element, a Pch MOSFET which turns off the insulated gate-type power semiconductor element, a control circuit which turns on the Nch MOSFET by applying a positive voltage to the gate electrode of the Nch MOSFET, and which turns on the Pch MOSFET by applying a negative voltage to the gate electrode of the Pch MOSFET, and a power supply which applies a negative voltage to the drain electrode of the Pch MOSFET and to a negative-side electrode of the control circuit, which applies a positive voltage to the drain electrode of the Nch MOSFET, and which applies to a positive-side electrode of the control circuit a positive voltage whose absolute value is larger than absolute value of the positive voltage applied to the drain electrode of the Nch MOSFET.