Semiconductor Gate Drive Timing Using Dual Sawtooth Wave Control
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Solution Overview
Problem
Existing semiconductor drive devices face challenges in reducing turn-on and turn-off losses in semiconductor devices like IGBTs due to the need for complex delay circuits to achieve time differences in control signals.
Innovation Solution
A semiconductor drive device utilizing two sawtooth waves with different bias values and phases to generate output signals that simultaneously turn on and turn off gates of an IGBT at specific times, eliminating the need for delay circuits and achieving time differences without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If delay circuits are used to achieve time differences in control signals, then gate turn-on and turn-off timing can be controlled, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the delay circuit from the system by using a natural time difference between two separate sawtooth wave generation circuits. Each sawtooth wave circuit independently generates its control signal without requiring artificial delay elements, thereby removing the source of complexity while maintaining timing control.
Solution Approach 2:
The two sawtooth wave generation circuits inherently produce time-shifted control signals through their own operating characteristics. The circuits self-generate the necessary time differences based on their respective RC time constants, eliminating the need for external delay circuits to impose timing relationships.
2Loss of energy
If delay circuits are used to control gate timing, then turn-on and turn-off losses can be reduced, but the number of components increases
Solution Approach 1:
The delay circuit component is completely removed from the system architecture. Instead of using artificial delay elements, the patent relies on the inherent time differences between two independently operating sawtooth wave generation circuits, thereby reducing component quantity while maintaining energy loss reduction benefits.
Solution Approach 2:
The two sawtooth wave generation circuits serve dual purposes: they generate control signals for gate timing while simultaneously providing the necessary time differences for optimizing turn-on and turn-off losses. This multi-functionality eliminates the need for separate delay circuit components.
3Manufacturing precision
If complex delay circuits are implemented, then signal timing can be adjusted, but ease of manufacture decreases
Solution Approach 1:
The complex delay circuit is extracted and replaced with simpler sawtooth wave generation circuits that naturally produce time-shifted signals. This simplification makes the circuit easier to manufacture while maintaining the ability to adjust signal timing through standard RC component selection.
Solution Approach 2:
The patent achieves signal timing adjustment by changing the RC time constant parameters of the two sawtooth wave generation circuits rather than using complex delay circuitry. This parameter-based approach simplifies manufacturing while maintaining timing control flexibility.
Data Source
AI summary
According to one embodiment, a semiconductor drive device includes a circuit section. The circuit section is configured to output a first output signal and a second output signal based on a first sawtooth wave and a second sawtooth wave different from the first sawtooth wave. The first output signal is configured to change from a first potential to a second potential at a first time. The first output signal is configured to change from the second potential to the first potential at a second time. The second output signal is configured to change from a third potential to a fourth potential at the first time. The second output signal is configured to change from the fourth potential to the third potential at a third time. The third time is after the first time and before the second time.