This application note describes the operation of a Trisil™ crowbar type protection diode. The diode is designed to limit voltage and divert surge current, making it suitable for protecting electronic components.
The document describes the Trisil, a semiconductor device developed by STMicroelectronics for transient operation in parallel protection. It functions as a crowbar type protection diode, utilizing a thyristor structure with two conducting states to limit voltage and divert surge currents. This design addresses limitations found in standard avalanche junction diodes like the Transil series, particularly regarding the permanent voltage drop across the terminals during operation.
| Leakage current in standby | about 10 nA |
|---|---|
| Maximum junction temperature (standby) | 150 °C |
| Maximum junction temperature (transient) | about 350-400 °C |
The Trisil limits the voltage and diverts the surge current.
The Trisil provides absolute voltage limitation independently of the surge current level, whereas a Transil's limitation depends on the current level.
Destruction of the Trisil results in a short-circuit, providing absolute protection for the downstream equipment.