提高電源可靠性的最佳實踐

　　雖然乍看之下電源供應(yīng)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(tǒng)必不可少的一部分，因為任何電源故障都會使系統(tǒng)癱瘓。它的性能差會危及給定產(chǎn)品的質(zhì)量。因此，無論是直接供應(yīng)失敗和性能不佳的系統(tǒng)設(shè)計人員的關(guān)注。換言之，在任何系統(tǒng)中電源的可靠性是絕對關(guān)鍵的。

　　選擇或建立可靠的電源需要全面了解影響產(chǎn)品可靠性的因素和應(yīng)力。本文將探討可靠性的含義和可靠性與失效率之間的關(guān)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(shè)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(yīng)商是在AC / DC和DC / DC轉(zhuǎn)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.