Low Clamping Voltage ESD Protection Circuit for Transient Sensitive Applications
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ESD protection circuits in integrated circuits often inadvertently trigger during normal operation, degrading performance due to their design requirements, which include lowering signal speed and rise time to avoid false triggering, leading to suboptimal performance and increased risk of damage from electrostatic discharge events.
Innovation Solution
A low clamping voltage ESD protection circuit with a common trigger circuit and multiple voltage clamps, including a series diode string and RC detector, allows for adjustable clamping voltages and prevents inadvertent triggering by ensuring the ESD protection circuitry is only activated during ESD events, maintaining optimal performance during normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ESD protection circuits are used to protect against electrostatic discharge, then ESD protection is provided, but the circuit performance degrades due to inadvertent triggering during normal operation
Solution Approach 1:
The ESD protection circuit dynamically adjusts its clamping voltage based on the detected ESD event characteristics. The circuit transitions from a high-clamping-voltage state during normal operation to a low-clamping-voltage state during ESD events, allowing optimal performance during normal operation while providing robust protection during ESD strikes
Solution Approach 2:
The invention changes the clamping voltage parameter from a fixed conventional value to a variable value that adapts to different operational conditions. The common trigger circuit detects ESD events and modifies the clamping voltage parameter in real-time, enabling the circuit to maintain high performance during normal operation while providing low-clamping-voltage protection during ESD events
2Reliability
If signal speed and rise time are lowered to avoid inadvertent triggering of ESD protection, then false triggering is prevented, but operational speed and accuracy degrade
Solution Approach 1:
The circuit dynamically switches between two operational modes: a normal mode with high signal speed and a protection mode with low clamping voltage. The common trigger circuit enables this dynamic transition, allowing signals to operate at full speed during normal conditions while providing protection when ESD events are detected
Solution Approach 2:
The common trigger circuit acts as an intermediary that monitors signal characteristics and activates the low-clamping-voltage protection only when genuine ESD events are detected. This intermediary mechanism prevents false triggering without requiring degradation of normal signal performance
3Reliability
If multiple separate ESD protection circuits are used for different pins, then comprehensive ESD protection is provided, but device complexity increases
Solution Approach 1:
The invention merges multiple ESD protection circuits into a single unified structure with a common trigger circuit. This common trigger circuit simultaneously controls multiple voltage clamps, providing comprehensive ESD protection across multiple pins while reducing overall device complexity compared to separate independent protection circuits
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 solution effectively provides robust ESD protection without degrading the performance of the integrated circuit's functional circuitry, ensuring that ESD events are managed without affecting the circuit's operational speed and accuracy.
Implementation Method 1
a resistor-capacitor (RC) detector circuit 112
Implementation Method 2
a resistor-capacitor (RC) detector circuit 112
Implementation Method 3
A string of diodes couples the signal terminal to the positive supply rail
Implementation Method 4
These ESD structures provide low resistance paths that direct current from an input, output or power pin to a ground or positive power rail during an ESD event
Data Source
AI summary
An example apparatus includes: a signal terminal for inputting a signal or for outputting a signal; functional circuitry coupled to the signal terminal; a positive supply rail for supplying a positive voltage; a ground supply rail for supplying a ground voltage; a first electrostatic discharge protection circuit coupled between the positive supply rail and the ground supply rail; a second electrostatic discharge protection circuit coupled between the signal terminal and the ground supply rail; an enable circuit coupled to the signal terminal and to the positive supply rail; and a common trigger circuit having a trigger output signal coupled to the first electrostatic discharge protection circuit and to the second electrostatic discharge protection circuit. Additional apparatus and methods are disclosed.