Conclusion

AN3169

10/12

Doc ID 17194 Rev 1

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Conclusion

This application note has given experimental benchmarking analysis among different

alternating current switch offerings. The impacts of silicon process technologies and

sensitivity levels have been discussed. It has thus been shown that sensitivity and dV/dt

parameters are not relevant enough to evaluate the immunity rating of different devices. A

silicon process. It has been furthermore shown that the die area has also a big impact on

immunity. Indeed, a bigger die area will lead to a higher device capacitance. This will help to

absorb energy coming from the bursts, and thus reducing the dV/dt across the device. On

the other hand, when dV/dt immunity of Triacs is measured, the voltage rate is forced across

the device. So a bigger die area will lead to a higher capacitive current. So a bigger device,

with the same sensitivity level, will withstand a lower dV/dt level.

Planar technology seems to offer devices with the highest immunity. However, Z04 and T410

devices, respectively produced with a top and mesa technologies, offer the same minimum

level of immunity as the tested planar devices. ACST2 presents the highest immunity level

compared to other technologies or compared to other planar devices from other companies.

ACST2 can then be used without any snubber circuit with a high immunity to bursts and is

the solution for applications requiring a high immunity level.

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References

1.

J. Arnould, P. Merle, “Dispositifs de l'Electronique de Puissance”, Vol. 2, HERMES

edition, 1992, ISBN 2-86601-308-5.

2.

STMicroelectronics, “SCRs, Triacs and AC Switches Quality and Reliability”, SCRs,

Triacs and AC Switches databook, 4th Edition, 2001.

3.

B. Morillon, “Study of Aluminum Thermomigration in Silicon for the Industrial

Implementation of Isolation Walls in Bidirectioanl Power Devices”, Ph.D. Dissertation,

Institut National des Sciences Appliquées de Toulouse, Toulouse (France), July 2002.

4.

STMicroelectronics, “ACST2 series - AC Switch family”, datasheet, Rev.1, March 2007.

5.

L. Gonthier, “ACS and Triacs Comparison towards Fast Voltage Transients”, conf.

Power Conversion Intelligent Motion, PCIM 2000, Nuremberg, Germany, 2000, Proc.

CD-ROM.