為應(yīng)用程序選擇正確的調(diào)節(jié)器

　　今天的系統(tǒng)板與各種電源調(diào)節(jié)器一起激增。在實際應(yīng)用中，有三種不同類型的電壓調(diào)節(jié)器：線性、開關(guān)和電荷泵。雖然射頻電路可能需要具有最小噪聲和rf發(fā)射的線性電源調(diào)節(jié)器，但處理器可能需要具有優(yōu)良調(diào)節(jié)特性的高效率、高密度開關(guān)DC-DC轉(zhuǎn)換器。和一個沒有調(diào)節(jié)電荷泵可能足以驅(qū)動一系列1車載LED。

　　更重要的是，線性穩(wěn)壓器只能產(chǎn)生低于電源電壓的電壓，而多功能開關(guān)穩(wěn)壓器可以升壓（降壓）、降壓（降壓）或反轉(zhuǎn)（改變輸入電源電壓的極性）。同樣，電荷泵執(zhí)行升壓，降壓和反向輸入電壓，但具有有限的輸出電流能力。

　　Linear choices

　　As a result of these characteristics， linear regulators are recommended when the voltage of the source powering the regulator is near the regulator’s output voltage and the circuit being powered does not care about the efficiency of the regulator， but requires very low noise specifications. In the last several years， however， these devices have been further improved in noise as well as in efficiency performance， while their input voltage handling capability has been enhanced and they now feature a wider operating temperature range. Among key suppliers pushing the performance envelope of linear regulators are Exar， Linear Technology， Maxim， Micrel， ON Semiconductor， and Texas Instruments.