ESD Protection Circuit with Dynamic Resistance Control
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Solution Overview
Problem
Existing ESD protection devices often turn off prematurely, leading to residual voltage surges at component terminals due to rapid discharge of resistive-capacitive circuits, which can damage integrated circuits, especially during low-intensity or end-of-pulse electrostatic discharges.
Innovation Solution
An electronic device with a resistive-capacitive circuit and a control circuit that slows down the discharge by increasing the resistive value, allowing the protection circuit to remain triggered longer, using a control transistor in the resistive path and a configuration with NMOS transistors, capacitors, and resistors to manage the discharge effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the protection circuit is triggered by a resistive-capacitive circuit, then the protection device can respond quickly to ESD events, but the rapid discharge of the resistive-capacitive circuit causes the protection device to turn off prematurely, resulting in residual voltage surges
Solution Approach 1:
The patent applies the Dynamics principle by making the resistive value of the resistive-capacitive circuit dynamically adjustable. A control circuit modifies the resistive value based on the discharge state: initially providing a low resistive value for rapid discharge and quick protection circuit turn-on, then switching to a high resistive value to slow down the discharge and maintain the protection circuit in the triggered state longer, preventing premature turn-off and residual voltage surges.
2Speed
If the resistive value of the resistive-capacitive circuit is low, then the discharge is fast and the protection circuit triggers quickly, but the protection circuit turns off too early when current decreases
Solution Approach 1:
The patent applies the Periodic action principle by implementing a two-stage discharge process. The control circuit first enables rapid discharge (first period) to quickly trigger the protection circuit, then switches to a slow discharge mode (second period) to maintain the triggered state. This periodic transition between fast and slow discharge phases ensures both quick response and prolonged protection.
3Productivity
If the protection device turns off when current intensity decreases, then the device stops conducting, but this creates a residual voltage surge at the component terminals that can damage the protected component
Solution Approach 1:
The patent applies the Continuity of useful action principle by ensuring the protection circuit remains in the triggered state throughout the entire ESD event, including when the current intensity decreases. The control circuit achieves this by slowing down the discharge of the resistive-capacitive circuit after initial triggering, maintaining the gate voltage above the threshold level. This continuous action prevents the protection device from turning off prematurely and blocking residual current, thereby eliminating residual voltage surges at the component terminals.
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 reduces the risk and level of residual voltage surges below acceptable thresholds, ensuring prolonged protection against electrostatic discharges by maintaining the protection circuit in a triggered state during the entire discharge event.
Implementation Method 1
the control circuit is configured to slow down a discharge from the resistive-capacitive circuit when the protection circuit is in its triggered state
Implementation Method 2
a first resistive-capacitive circuit for triggering said protection circuit in the presence of a current pulse between the first and second device terminals
Implementation Method 3
the second circuit may include a control transistor inserted into the resistive path of the resistive-capacitive circuit and configured to be in its turned off state when the protection circuit is in its triggered state so as to increase the resistive value of the resistive-capacitive circuit
Implementation Method 4
a first transistor having a first electrode coupled to said second resistor, a second electrode coupled to said second device terminal, and a control electrode coupled to the common node between the capacitor and the control transistor
Data Source
AI summary
An electronic device includes first and second terminals with an electronic circuit coupled there between. The electronic circuit includes a protection circuit and a resistive-capacitive circuit. The resistive-capacitive circuit triggers the protection circuit to protect against electrostatic discharges in the presence of a current pulse between the first and second terminals. A control circuit is configured to slow down a discharge from the resistive-capacitive circuit when the protection circuit is triggered.