EPE Association: EPE 2003 - Topic 13b: Reliability

EPE 2003 - Topic 13b: Reliability
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 13: SYSTEMS ENGINEERING > EPE 2003 - Topic 13b: Reliability

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   Using a distributed architecture to tolerate interdependencies in the electricity infrastructure
By J. Van de Vyver; G. Deconinck; R. Belmans [View]
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Abstract: The growing use of the communication infrastructure to control the production, transport and distribution of electricity enables faults to propagate through dierent interdependent infrastructures. This propagation of faults compromises dependability. A software module that implements an emergent algorithm is developed to enable the electricity infrastructure to tolerate interdependencies.

   MOSFET screening for reliable operation of DC-DC converters
By A. Singh Johar; K. Shenai [View]
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Abstract: One of the major causes for field failure of DC-DC converters is the failure of power MOSFETs. To cope with the fast advancement of the semiconductor technology and customers’ expectations toward performance, service, delivery, quality, and reliability, it is necessary to identify defect lots earlier in the production lines. For technologically advanced applications like power supplies for servers, it is essential that only the best semiconductor devices are used to prevent failures and as a result cut down on redundancy costs. Choosing power devices for converter applications has been largely based on selecting the optimum voltage and current ratings and the lowest on resistance of the devices. Blocking state leakage current limit of MOSFETs has never been a criterion with designers. In this paper we show that screening MOSFETs for leakage current can have a significant impact on the reliability of devices and hence on the DC-DC converter itself. The time between failures is a very useful measurement to analyze reliability models for timedependent systems. In many cases, the failure-generation process is assumed to be stationary, even though the process changes its statistics as time elapses. This paper analyses the reasons for failure of power MOSFETs in the useful life period of the device and based on a Weibull analysis estimates the reliability of the devices and the probability of failures. Weibull probability distribution efficiently maps the failures and it has been shown that it is identical to the smallest extreme value distributions. Engineers at Pratt and Whitney have long advocated that the Weibull method of failure estimation works very well even with extremely small samples, even 2 or 3 failures. These methods of analysis can be applied to MOSFET failures in DC-DC converters as well.

EPE 2003 - Topic 13b: Reliability
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 13: SYSTEMS ENGINEERING > EPE 2003 - Topic 13b: Reliability
	[return to parent folder]

	Using a distributed architecture to tolerate interdependencies in the electricity infrastructure By J. Van de Vyver; G. Deconinck; R. Belmans	[View] [Download]
Abstract: The growing use of the communication infrastructure to control the production, transport and distribution of electricity enables faults to propagate through dierent interdependent infrastructures. This propagation of faults compromises dependability. A software module that implements an emergent algorithm is developed to enable the electricity infrastructure to tolerate interdependencies.

	MOSFET screening for reliable operation of DC-DC converters By A. Singh Johar; K. Shenai	[View] [Download]
Abstract: One of the major causes for field failure of DC-DC converters is the failure of power MOSFETs. To cope with the fast advancement of the semiconductor technology and customers’ expectations toward performance, service, delivery, quality, and reliability, it is necessary to identify defect lots earlier in the production lines. For technologically advanced applications like power supplies for servers, it is essential that only the best semiconductor devices are used to prevent failures and as a result cut down on redundancy costs. Choosing power devices for converter applications has been largely based on selecting the optimum voltage and current ratings and the lowest on resistance of the devices. Blocking state leakage current limit of MOSFETs has never been a criterion with designers. In this paper we show that screening MOSFETs for leakage current can have a significant impact on the reliability of devices and hence on the DC-DC converter itself. The time between failures is a very useful measurement to analyze reliability models for timedependent systems. In many cases, the failure-generation process is assumed to be stationary, even though the process changes its statistics as time elapses. This paper analyses the reasons for failure of power MOSFETs in the useful life period of the device and based on a Weibull analysis estimates the reliability of the devices and the probability of failures. Weibull probability distribution efficiently maps the failures and it has been shown that it is identical to the smallest extreme value distributions. Engineers at Pratt and Whitney have long advocated that the Weibull method of failure estimation works very well even with extremely small samples, even 2 or 3 failures. These methods of analysis can be applied to MOSFET failures in DC-DC converters as well.