Gate-Off Pull-Down Circuit for Signal Pad ESD Protection
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Solution Overview
Problem
Semiconductor elements are vulnerable to damage from electrostatic discharge (ESD) currents introduced through pads, despite the presence of ESD protection circuits, as these currents can bypass the protection circuits and flow through semiconductor elements.
Innovation Solution
A gate-off circuit is connected to the gates of semiconductor elements, redirecting ESD-induced currents to an ESD protection circuit, preventing damage by blocking current paths through the semiconductor elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an ESD protection circuit is provided to protect semiconductor elements from electrostatic discharge, then the reliability of the semiconductor device is improved, but the semiconductor element may still be damaged by current introduced from sources other than ESD
Solution Approach 1:
The gate-off circuit is configured to preemptively connect the gate and source of the semiconductor element when high voltage is detected at the pad, before harmful current can flow through the semiconductor element. This preliminary action prevents the harmful effect by establishing a safe current path in advance.
Solution Approach 2:
The gate-off circuit acts as an intermediary mechanism between the pad and the semiconductor element. It monitors the voltage at the pad and intervenes by connecting the gate and source when necessary, thereby mediating the harmful current flow and directing it away from the semiconductor element through the clamping circuit.
2Object-affected harmful factors
If a gate-off circuit is added to connect gate and source during ESD events, then the protection against harmful current is improved, but the device complexity increases
Solution Approach 1:
The gate-off circuit merges the protection function with the existing semiconductor element structure by utilizing the gate-source connection of the element itself. This combining approach provides comprehensive protection without requiring entirely separate protection circuits, thereby reducing overall complexity.
Solution Approach 2:
The gate-off circuit is designed to handle multiple types of harmful current sources (both ESD and non-ESD) through a single unified mechanism. This multi-functional design protects against various harmful factors without requiring separate protection circuits for each type of threat, simplifying the overall device structure.
Data Source
Figure 1
Figure 2A~2B
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AI summary
A semiconductor device (200) is provided. The semiconductor device (200) includes: a first power pad (201); a second power pad (202); a signal pad (203); a clamping circuit (230) connected between the first power pad (201) and the second power pad (202); a driving circuit (210) connected to the signal pad (203) and including a pull-up circuit and a pull-down circuit; and a first gate-off circuit (220) connected to the pull-down circuit. The first gate-off circuit (220) is configured to connect a gate of at least one pull-down element (PD) included in the pull-down circuit and a source of the at least one pull-down element (PD) to each other during an electrostatic discharge, ESD, event in which a high voltage is applied to the signal pad (203), and control a current generated by the high voltage to flow to the clamping circuit (230).