Transistor Drive Circuit ESD Protection via Level Shifter Segmentation
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Solution Overview
Problem
High-voltage transistor drive chips have weak electrostatic discharge (ESD) capabilities, making them prone to damage and compromising the overall ESD performance of the chip, especially when static electricity is discharged between high-voltage and low-voltage power supply domains.
Innovation Solution
The drive circuit incorporates a current limiting module and a discharge module within the level shifter circuit to manage electrostatic discharge, increasing internal resistance and providing additional discharge paths, thereby preventing damage to the level shifter circuit and enhancing ESD capabilities by utilizing a high-voltage ESD device to discharge static electricity effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the withstand voltage of the device is increased, then the high-voltage power supply domain can operate at higher voltages, but the ESD capability of the device is decreased
Solution Approach 1:
The patent divides the ESD protection function into multiple segments: low-voltage ESD devices for the low-voltage power supply domain, high-voltage ESD devices for the high-voltage power supply domain, and intermediate ESD devices for discharge between domains. This segmentation allows each device to be optimized for its specific voltage range, resolving the contradiction between high withstand voltage and strong ESD capability.
Solution Approach 2:
The patent introduces intermediate ESD devices as mediators between the low-voltage and high-voltage power supply domains. These intermediate devices provide dedicated discharge paths for static electricity between domains, preventing damage to the level-shifter circuit while maintaining high voltage operation capability.
2Adaptability or versatility
If a level-shifter circuit is used to discharge static electricity between power supply domains, then voltage level conversion is achieved, but the ESD capability of the DMOS is weak and easy to damage
Solution Approach 1:
The patent applies beforehand cushioning by placing current limiting modules in series with the DMOS devices in the level-shifter circuit. These modules provide prior protection against excessive current during ESD events, preventing damage to the DMOS while maintaining the voltage level conversion function.
Solution Approach 2:
The patent introduces intermediate ESD devices as mediators that provide dedicated discharge paths between power supply domains. These intermediaries handle the ESD current separately from the level-shifter circuit, protecting the DMOS from damage while maintaining voltage level conversion capability.
3Adaptability or versatility
If independent ESD devices are used in each power supply domain, then domain-specific ESD protection is provided, but the entire chip ESD capability remains weak
Solution Approach 1:
The patent merges the ESD protection systems by introducing intermediate ESD devices that connect the low-voltage and high-voltage power supply domains. This creates a unified ESD protection network where static electricity can be discharged between domains through dedicated paths, significantly enhancing the overall chip ESD capability while maintaining domain-specific protection.
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 enhanced drive circuit achieves a strong anti-static electricity capability, improving stability and reliability by limiting current during discharge and utilizing multiple discharge paths to shunt electrostatic discharge effectively, thus protecting the circuit from damage.
Implementation Method 1
a current limiting module, where the level detection circuit is connected to the positive electrode of the high-voltage power supply and is separately connected to the current limiting module
Implementation Method 2
an electrostatic discharge apparatus, where the electrostatic discharge apparatus is separately disposed between electrodes of the high-voltage power supply, between electrodes of the low-voltage power supply, and between a positive electrode of the high-voltage power supply and a negative electrode of the low-voltage power supply
Data Source
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AI summary
This application discloses a drive circuit of a transistor, including: a high-voltage power supply and a low-voltage power supply; a circuit in a high-voltage power supply domain and a circuit in a low-voltage power supply domain, where the circuit in a high-voltage power supply domain is connected to the high-voltage power supply; an electrostatic discharge apparatus; a level shifter circuit, wherein the level shifter circuit includes a level detection circuit, a current limiting module, a discharge module, and a switch tube, the level detection circuit is connected to a positive electrode of the high-voltage power supply and is separately connected to the current limiting module, the discharge module, and the circuit in a high-voltage power supply domain, the current limiting module is further connected to a first end of the switch tube, the discharge module is further connected to a negative electrode of the high-voltage power supply, a control end of the switch tube is connected to the circuit in a low-voltage power supply domain and a second end of the switch tube is connected to a negative electrode of the low-voltage power supply, the current limiting module is configured to limit the discharged electricity when the drive circuit performs electrostatic discharge, and the discharge module is configured to form a discharge assisting path between the negative electrode of the high-voltage power supply and the first end of the switch tube to assist electrostatic discharge of the drive circuit.