關于DC / DC轉換器的幾點思考

　　簡介

　　許多系統要求直流電源的主要來源被轉換為其他電壓。電池驅動電路明顯的候選人。在筆記本電腦6V或12V電池必須轉換為不同的潛力存儲器，磁盤驅動器，顯示和操作邏輯。在理論，交流線路供電系統不需要DC / DC轉換器因為隱含的電源變壓器可以裝備具有多個次級。在實踐中，經濟學，噪音要求，供應總線分配問題和其他限制往往使DC / DC轉換。一常見的例子是邏輯為主，5V供電系統利用±15v驅動模擬元件。

　　DC / DC轉換器的應用范圍是大，有許多變化。興趣是相應的轉換器相當高。增加單電源供電系統，剛度性能要求和電池操作增加了轉換器的使用。

　　Historically， effi ciency and size have received heavy emphasis. In fact， these parameters can be signifi cant， but often are of secondary importance. A possible reason behind the continued and overwhelming attention to size and effi ciency in converters proves surprising. Simply put， these parameters are （within limits） relatively easy to achieve！ Size and effi ciency advantages have their place， but other system-oriented problems also need treatment. Low quiescent current， wide ranges of allowable inputs， substantial reductions in wideband output noise and cost effectiveness are important issues. One very important converter class， the 5V to ±15V type， stresses size and effi ciency with little emphasis towards parameters such as output noise. This is particularly signifi cant because wideband output noise is a frequently encountered problem with this type of converter. In the best case， the output noise mandates careful board layout and grounding schemes. In the worst case， the noise precludes analog circuitry from achieving desired performance levels （for further discussion see Appendix A， “The 5V to ±15V Converter — A Special Case”）。 The 5V to ±15V DC/DC conversion requirement is ubiquitous， and presents a good starting point for a study of DC/DC converters.