1.5SMC27AT3

Introduction: TVS- Diodes (Transient Voltage Suppressors) are voltage protection devices designed to limit transient over-voltage, which occurs within an electronic circuit due to switching or lightning surges. The 1.5SMC27AT3 is a unidirectional device designed to protect equipment down stream from a direct strike to the electrical system. Its low capacitance design allows it to react fast enough to prevent any damage from high frequency surges.

Application field: The 1.5SMC27AT3 can be used in all applications which require low capacitance transient protection, such as high speed communications systems or automotive auxiliary DC-DC converters. It can also be used for protection of sensitive equipment such as medical sensors. The device is designed to operate efficiently in temperatures from -40°C to +125°C.

Working principle: The 1.5SMC27AT3 works by utilizing a Zener diode and a pair of MOSFETs. When the supply voltage exceeds the Zener voltage, the voltage across it builds up and the ESD protection elements are activated. The MOSFETs activate in an avalanche mode and the breakdown voltage of the diode is raised. This increases the current through the MOSFET and reduces the excess voltage to a safe level. The device is also protected against reverse polarity with a built-in back-bias feature.

Conclusion: The 1.5SMC27AT3 is designed to protect equipment from high voltage transients and is capable of operating efficiently in temperatures from -40°C to +125°C. It utilizes a Zener diode and a pair of MOSFETs to limit the bolt current to a safe level, and is back-biased to protect against reverse polarity.