High Side Gate Driver Protection Device for Switching Reliability
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Solution Overview
Problem
High side gate drivers face breakdown issues due to the high voltage required to control normally-on switches, which can damage surrounding switching devices.
Innovation Solution
Incorporating a protection device with a resistance value 50 to 100 times that of the switching device, implemented as an additional normally-on switch with a smaller area, connected in series between the switching device and the gate of the high side normally-on switch to mitigate the high voltage applied to the switching device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high level voltage is applied to the gate of the high side normally-on switch to turn it on or off, then the switching function is achieved, but breakdown of surrounding switching devices occurs
Solution Approach 1:
A protection device is introduced as an intermediary element connected between the first switching device and the gate of the high side normally-on switch. This protection device absorbs the high level voltage that would otherwise damage the first switching device, allowing the gate to receive the necessary high voltage for switching while protecting the surrounding circuitry from breakdown.
2Reliability
If a protection device is added to prevent breakdown, then reliability of switching devices is improved, but device complexity increases
Solution Approach 1:
The protection device utilizes a normally-on switch with specifically adjusted resistance parameters. By controlling the resistance value to be within a predetermined range, the device provides effective voltage protection while maintaining compatibility with existing circuit parameters and avoiding significant increases in device complexity.
3Reliability
If the resistance value of the protection device is increased to reduce voltage applied to the switching device, then protection effectiveness is improved, but voltage division ratio changes
Solution Approach 1:
The resistance value of the protection device is precisely controlled to fall within a predetermined range. This optimized resistance value creates an appropriate voltage division ratio between the protection device and the first switching device, ensuring that sufficient voltage is dropped across the protection device to prevent breakdown, while maintaining proper voltage levels for the switching operation.
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
Prevents breakdown phenomena by applying the high voltage primarily to the protection device, ensuring the stability and longevity of the switching devices without increasing the chip area significantly.
Implementation Method 1
a protection device connected in series between the first switching device and a gate of the high side normally-on switch, the protection device configured to reduce a voltage that is applied to the first switching device
Data Source
AI summary
A high side gate driver, a switching chip, and a power device, which respectively include a protection device, are provided. The high side gate driver includes a first terminal configured to receive a first low level driving power supply that is provided to turn off the high side normally-on switch; a first switching device connected to the first terminal; and a protection device connected in series between the first switching device and a gate of the high side normally-on switch, the protection device configured to absorb a majority of a voltage applied to a gate of the high side normally-on switch. The power device includes the high side gate driver. In addition, the switching chip includes a high side normally-on switch, an additional normally-on switch, and a low side normally-on switch, which have a same structure.