選擇正確的電壓轉(zhuǎn)換器不僅僅是為了達(dá)到峰值效率

　　選擇正確的電壓轉(zhuǎn)換器不僅僅是為了達(dá)到峰值效率。

　　開關(guān)直流/直流電壓變換器很受歡迎，因?yàn)樗鼈兲峁┝擞行У墓β兽D(zhuǎn)換，可以超過90%。這是一個(gè)優(yōu)勢，當(dāng)輸入功率是溢價(jià)，當(dāng)很難得到熱量（工程師共同設(shè)計(jì)的緊湊型便攜式產(chǎn)品的挑戰(zhàn)）。

　　關(guān)鍵的功率器件廠商提供的規(guī)格表出現(xiàn)幾乎相同的產(chǎn)品，一個(gè)工程師只挑選開關(guān)變換器具有最高的從候選名單，符合他們產(chǎn)品的一般要求的峰值效率很誘人。然而，這將是一個(gè)錯(cuò)誤，因?yàn)轱@然相同的轉(zhuǎn)換器可以提供顯著不同的性能。

　　本文認(rèn)為功率損耗和相關(guān)熱升高的主要影響是效率上的幾個(gè)百分點(diǎn)的差別。文章接著討論了如何根據(jù)負(fù)載模式，一個(gè)峰值效率較低，但平坦的效率曲線的轉(zhuǎn)換器，很可能是一個(gè)特定的應(yīng)用程序的更好的選擇。

　　Beware of the power loss

　　Efficient voltage converters are topical in electronics design circles because of the pressure on designers to minimize power consumption. For the designer of a battery-powered device， the challenge is obvious： maximizing battery life while providing good functionality. Less obvious， but still a major concern， is the requirement for designers of mains-powered equipment to meet various national and international regulations that mandate minimum supply efficiency.

　　The good news is that， due to increasingly clever design and the high performance of the switching and magnetic components of modern converters （see the TechZone article “The Inductor’s Role in Completing a Power Module-Based Solution”）， it is not difficult to locate a converter that offers a peak efficiency of 85 to 95 percent. That is a considerable improvement over the linear regulators of yesteryear that could only deliver perhaps 60 percent of the input power to their output terminals （although contemporary low-dropout （LDO） products perform much better – see the TechZone article “Understanding the Advantages and Disadvantages of Linear Regulators”）。