Cross-Domain ESD Discharge Circuit With Shared Multi-Supply Clamping
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Solution Overview
Problem
Computer devices are vulnerable to electrostatic discharge (ESD) events, which can damage integrated circuits due to the rapid application of voltages exceeding the circuit's design limits, and existing protection methods may not effectively manage ESD events across different power supplies with varying voltages.
Innovation Solution
An ESD protection circuit is designed with a first and second power supply connected through diodes to a common node, an inverter that receives input voltage from the node to produce an output voltage, and an ESD discharge device that provides a discharge path when an ESD event is detected, using NMOS transistors to manage both positive and negative ESD events by creating a low impedance path before damage occurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple voltage clamping circuits are used for each power supply, then ESD protection coverage is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple ESD protection functions into a single shared discharge device that serves multiple power supplies. Instead of implementing separate clamping circuits for each power supply, the invention uses one discharge device with multiple diode-connected transistors that can clamp ESD events on any of the power supplies (VDDA, VDD, VDDCORE) through a common discharge path, thereby reducing overall circuit complexity while maintaining comprehensive protection coverage.
Solution Approach 2:
The discharge device is designed with universal functionality to handle ESD events from multiple different power supplies simultaneously. The single discharge device can be activated by ESD events on any of the connected power supplies through the diode network, making it a multi-functional protection element that replaces what would traditionally require multiple separate protection circuits.
2Reliability
If a discharge path is provided for each power supply separately, then ESD protection effectiveness is improved, but ease of operation deteriorates
Solution Approach 1:
The patent merges multiple separate discharge paths into a single shared discharge path that serves all power supplies. The common discharge device and shared discharge path simplify the operational complexity while maintaining the ability to protect against ESD events on any individual power supply, making the circuit easier to operate without sacrificing protection effectiveness.
3Reliability
If voltage clamping circuits are implemented for each power supply, then ESD transient current discharge capability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The invention reduces manufacturing precision requirements by consolidating multiple ESD protection functions into a single discharge device structure. Instead of fabricating and precisely matching multiple separate clamping circuits, the shared discharge device with diode-connected transistors requires fewer precise manufacturing parameters, thereby reducing overall manufacturing precision requirements while maintaining adequate ESD transient current discharge capability for all power supplies.
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 ESD protection circuit effectively protects integrated circuits by providing a discharge path for both positive and negative ESD events, preventing damage across different power supply configurations and voltage levels, ensuring the integrity of the computing device.
Implementation Method 1
An ESD discharge device is provided that provides a discharge path for the first power supply and the second power supply if the output voltage from the inverter indicates an ESD event
Data Source
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AI summary
In one example, an electrostatic discharge (ESD) protection circuit includes a first power supply having a first supply voltage, wherein the first power supply is connected to a first node. The ESD protection circuit also includes a second power supply having a second supply voltage, wherein the second power supply is connected to the first node. The ESD protection circuit also includes an inverter that receives an input voltage from the first node and produces an output voltage. An ESD discharge device receives the output voltage and provides a discharge path for the first power supply and the second power supply if the output voltage indicates occurrence of an ESD event affecting the first power supply or the second power supply.