HEMT ESD Protection Circuit Using Intermediary Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High electron mobility transistors (HEMTs) are vulnerable to damage from electrostatic discharge (ESD) events due to the ESD current they conduct, which existing technologies fail to adequately protect against.
Innovation Solution
An ESD protection circuit comprising a resistance element and transistors is integrated into the electronic device, where the resistance element is coupled between the control electrode and the gate of the HEMT, and additional transistors are connected in series to form a discharge path that activates only during ESD events, preventing damage by clamping the voltage and routing the ESD current safely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If HEMTs are used to achieve high output voltage capability, then the device can satisfy requirements for high-power applications, but the HEMTs become vulnerable to ESD damage
Solution Approach 1:
The patent introduces an intermediary ESD protection circuit between the HEMT and the external environment. This circuit includes a first protection transistor connected to the HEMT gate and a second protection transistor connected to the HEMT drain, which act as mediators to divert ESD currents away from the HEMT channels while allowing normal operation signals to pass through unchanged.
Solution Approach 2:
The protection circuit is designed to activate preemptively upon detecting ESD events before the ESD current can damage the HEMT. The protection transistors are biased to turn on rapidly when ESD voltage exceeds a threshold, creating a low-impedance path for ESD current to flow through the protection circuit rather than through the HEMT channels.
2Reliability
If an ESD protection circuit is added to protect HEMTs, then ESD damage is prevented, but the device complexity increases
Solution Approach 1:
The protection circuit is merged with the existing HEMT structure by integrating the protection transistors into the same device layer. The first protection transistor shares the HEMT gate connection, and the second protection transistor shares the HEMT drain connection, combining protection functionality with the existing power transistor structure rather than adding completely separate external protection components.
Solution Approach 2:
The protection transistors are designed to serve multiple functions: they act as protection elements during ESD events, serve as biasing elements during normal operation, and provide voltage reference functions. This multi-functionality reduces the need for additional dedicated protection components and simplifies the overall circuit design.
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 protects HEMTs from ESD damage by activating a discharge path during ESD events, preventing voltage surge and reducing the risk of transistor damage, while maintaining low leakage current in normal operating conditions.
Implementation Method 1
The resistance element is coupled between the control electrode and the gate of the first transistor
Implementation Method 2
In response to an ESD event occurring at the control electrode and the second electrode is coupled to ground, the second transistor and the third transistor are turned on
Implementation Method 3
High electron mobility transistors (HEMTs) are widely used in high-power semiconductor devices as they possess the favorable advantage of a high output voltage
Data Source
AI summary
An electronic device including a first transistor, a second transistor, a third transistor, and a resistance element is provided. The first transistor includes a first gate and is coupled between a first electrode and a second electrode. The second transistor includes a second gate, a third electrode, and a fourth electrode. The second gate is coupled to the second electrode. The third electrode is coupled to a control electrode. The third transistor includes a third gate, a fifth electrode, and a sixth electrode. The third gate is coupled to the control electrode. The fifth electrode is coupled to the fourth electrode. The sixth electrode is coupled to the second electrode. The resistance element is coupled between the third electrode and the first gate.