提高電源可靠性的最佳實踐

　　雖然乍看之下電源供應器可能不像微處理器或DSP那樣富有魅力，但它們是電子系統必不可少的一部分，因為任何電源故障都會使系統癱瘓。它的性能差會危及給定產品的質量。因此，無論是直接供應失敗和性能不佳的系統設計人員的關注。換言之，在任何系統中電源的可靠性是絕對關鍵的。

　　選擇或建立可靠的電源需要全面了解影響產品可靠性的因素和應力。本文將探討可靠性的含義和可靠性與失效率之間的關鍵差異，提出在一張白紙上崔“供電可靠性的考慮。”1它還將討論如何制造像崔是通過設計，提高可靠性和元件的選擇、制造工藝。幾個例子將演示如何供應商是在AC / DC和DC / DC轉換器模塊由公司制造和指定這些做法。

　　Reliability and failure

　　Before investigating the process involved in boosting the reliability of a power supply， it is important to first understand its definition and the difference between reliability and the failure rate. Per CUI’s white paper， reliability is the probability that the supply， operating under specified conditions， works properly for a given period of time. Failure rate is the percentage of units that fail in a given unit of time. As shown in Figure 1， it follows a “bathtub” curve and has been classified into three key phases by engineers， which include infant mortality， useful life， and wear-out. While infant mortality is the result of poor workmanship and inferior quality components， the second phase， which is useful life， keeps failure rate low and constant to keep the supply in proper operation for a longer time. In the wear-out phase， which is third and final， the supply fails when its components reach the end of their operating life.