使用反相穩(wěn)壓器的降壓/升壓直流到直流電壓轉(zhuǎn)換

　　使用反相穩(wěn)壓器的降壓/升壓直流到直流電壓轉(zhuǎn)換

　　降壓（降壓）開(kāi)關(guān)電壓轉(zhuǎn)換器（或穩(wěn)壓器）是受歡迎的電池供電產(chǎn)品，因?yàn)樗鼈兪怯行У碾妷汉拓?fù)載范圍廣泛，相對(duì)簡(jiǎn)單。然而，當(dāng)電池電壓低于所需的輸出下降，穩(wěn)壓器停止運(yùn)行。這可能是便攜式設(shè)計(jì)中的一個(gè)缺點(diǎn)，因?yàn)榻?jīng)常有一些未使用的能力，在電池中留下的電源“輟學(xué)”，否則可能已被用來(lái)延長(zhǎng)運(yùn)行時(shí)間。

　　針對(duì)未使用的電池容量的一個(gè)流行的解決方案是降壓/升壓（“降壓/升壓”）開(kāi)關(guān)穩(wěn)壓器或其他拓?fù)浣Y(jié)構(gòu)，如單端初級(jí)電感轉(zhuǎn)換器（SEPIC）。（見(jiàn)高新區(qū)第“SEPIC選項(xiàng)為電池電源管理”。）這類(lèi)電源自動(dòng)切換到升壓配置一旦電池輸出低于所需的電源輸出；但降壓/升壓設(shè)備比較昂貴，電路比較復(fù)雜，和電源需要更大的電路板空間。

　　However， there is a lesser-known option for a switching power supply which maximizes battery capacity in a portable product yet is simple and inexpensive： the switching inverting regulator. These are usually employed to convert a positive input voltage to a （lower） negative output， but can also be used to convert a varying positive input to a lower or higher negative output.

　　This article describes the function of a switching inverting regulator and its application and then leads on to describe a topology that uses the device to regulate a varying input voltage as an alternative to a conventional buck/boost regulator.

　　Anatomy of an inverting regulator

　　Figure 1 shows a simplified schematic of a switching inverting regulator. The regulator comprises a pulse width modulation （PWM） controller driving a metal oxide semiconductor field effect transistor （MOSFET） connected to an inductor. The inductor acts as an energy reservoir providing power when the storage MOSFET switches off.