Programmable Gate Driver Dead-Time Circuit for Noise-Stable Switching
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Solution Overview
Problem
Conventional gate driver ICs with programmable dead-time insertion are prone to noise injection, lack precision in dead-time setting, and experience instability due to temperature variations, especially when requiring narrow dead-times for applications like Class D audio amplifiers.
Innovation Solution
The dead-time is set internally within the integrated circuit using a window comparator circuit with an external dead-time setting terminal, allowing discrete dead-time selection and compensation for temperature and supply voltage variations, ensuring precise and stable dead-time insertion between the on times of high side and low side switches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an external resistor is used to set the dead-time in conventional gate driver integrated circuits, then the dead-time can be adjusted, but noise injection occurs from the dead-time setting terminal and precision is compromised
Solution Approach 1:
The patent extracts the dead-time setting function from external components and implements it internally within the integrated circuit. The dead-time generator circuit is fully integrated with preset dead-time values stored inside the IC, eliminating the need for external resistors and thereby removing the noise injection problem from the dead-time setting terminal while maintaining precise dead-time control.
Solution Approach 2:
The patent changes the parameter representation from continuous external resistor values to discrete preset dead-time values stored in internal memory or lookup tables. This allows precise selection of specific dead-time values (e.g., 50ns, 100ns, 150ns) without the noise and precision issues associated with external analog component setting.
2Measurement precision
If external and internal components independently determine dead-time, then flexibility is provided, but precise dead-time values cannot be achieved due to component variations
Solution Approach 1:
The patent merges the dead-time setting function and dead-time generation function into a single integrated circuit block. The dead-time generator receives a select signal that chooses from preset values stored internally, ensuring that both the setting and generation of dead-time are performed by coordinated internal circuits with matched temperature coefficients, thereby achieving precise and reliable dead-time values for shoot-through prevention.
3Adaptability or versatility
If conventional dead-time circuits use external components with different temperature coefficients, then programmability is achieved, but temperature stability deteriorates and thermal runaway may occur
Solution Approach 1:
The patent implements self-service by providing temperature compensation entirely within the integrated circuit. The dead-time generator includes internal temperature sensing and compensation circuits that automatically adjust the preset dead-time values to compensate for temperature drift, eliminating the need for external components with matched temperature coefficients and achieving both programmability and temperature stability.
Data Source
AI summary
A dead-time generator for incorporation in an integrated circuit wherein the integrated circuit includes a high side and low side gate driver and wherein the high side and low side gate driver drive output switches such that a dead-time is provided between on times of the output switches, the dead-time generator comprising a circuit internal to the integrated circuit having an external terminal at which a dead-time setting component is connected, and wherein the dead-time generator comprises a circuit for providing a discrete dead-time for a range of dead-time setting values at the dead-time setting terminal and wherein, for a plurality of ranges of dead-time setting values at the dead-time setting terminal, the dead-time generator generates an associated plurality of discrete dead-times.