Back-to-Back Diode Clamping Structure for Overvoltage Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices such as IGBTs, MOSFETs, and BJTs are vulnerable to overvoltages during operation, which can cause damage without adequate protective measures, particularly in applications like induction cookers where mains power supply instabilities lead to overvoltages.
Innovation Solution
A semiconductor device with a clamping structure comprising a pn junction diode and a Schottky junction diode serially connected back to back between contacts, where the breakdown voltage of the pn junction diode is greater than 100 V and the Schottky junction diode is greater than 10 V, providing overvoltage protection by electrical breakdown before destructive overvoltages occur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single diode is used for overvoltage protection, then the structure is simple, but the breakdown voltage cannot be precisely tailored for different protection levels
Solution Approach 1:
The clamping structure is segmented into two separate diodes (first diode and second diode) connected in series, each with different breakdown voltage ratings. This segmentation allows each diode to be optimized for specific voltage protection levels, providing tailored overvoltage protection while maintaining a relatively simple overall structure.
2Reliability
If higher breakdown voltage diodes are used, then better high-voltage protection is achieved, but the diodes may not clamp lower overvoltages effectively
Solution Approach 1:
Each diode in the series connection is selected with specific breakdown voltage characteristics suited for different protection levels. The first diode handles higher voltage breakdown while the second diode provides clamping for lower overvoltages, creating localized protection zones within the clamping structure that address different overvoltage threats.
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 high-voltage transistors from overvoltages by ensuring electrical breakdown occurs within the diodes before reaching the transistor, thus preventing damage, and allows for reduced wiring effort and tailored breakdown voltage for effective protection.
Implementation Method 1
A breakdown voltage of the pn junction diode is greater than 100 V and a breakdown voltage of the Schottky junction diode is greater than 10 V, providing overvoltage protection by electrical breakdown before destructive overvoltages occur
Data Source
AI summary
Semiconductor device is provided with a semiconductor body that includes a clamping structure including a first pn junction diode and a second pn junction diode serially connected back to back between a first contact and a second contact. A breakdown voltage of the first pn junction diode is greater than 100 V, and a breakdown voltage of the second pn junction diode is greater than 10 V.