開關電源(yuan)模塊(kuai)阻(zu)(zu)(zu)(zu)抗(kang)(kang)是指內部電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感組成的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)對(dui)(dui)交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)起到阻(zu)(zu)(zu)(zu)礙(ai)作(zuo)用(yong)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)的(de)阻(zu)(zu)(zu)(zu)抗(kang)(kang)就是其本身(shen)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感兩者(zhe)對(dui)(dui)交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)阻(zu)(zu)(zu)(zu)礙(ai)叫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中對(dui)(dui)交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)礙(ai)叫容(rong)抗(kang)(kang)，交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)頻率(lv)越(yue)大(da)(da)，容(rong)抗(kang)(kang)越(yue)小，有隔(ge)直通(tong)(tong)交(jiao)(jiao)(jiao)的(de)作(zuo)用(yong)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中對(dui)(dui)交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)礙(ai)叫感抗(kang)(kang)，交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)頻率(lv)越(yue)大(da)(da)，感抗(kang)(kang)就越(yue)大(da)(da)，有對(dui)(dui)交(jiao)(jiao)(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)通(tong)(tong)直隔(ge)交(jiao)(jiao)(jiao)的(de)作(zuo)用(yong)，可進(jin)行濾(lv)波。
　　電源模塊內阻較大會不(bu)利于負載(zai)穩壓電路(lu)(lu)工(gong)作(zuo)，嚴重的(de)負載(zai)電流(liu)任何變化(hua)都會導致模塊輸出(chu)的(de)起伏(fu)，起伏(fu)對測試的(de)影響(xiang)和脈(mo)沖(chong)與噪聲(sheng)對測試結果(guo)的(de)影響(xiang)一樣(yang)。當線電壓或(huo)負載(zai)電流(liu)變化(hua)時(shi)，直流(liu)電源模塊的(de)輸出(chu)電壓會有所起伏(fu)。穩壓程度由穩壓電路(lu)(lu)的(de)參數(shu)，濾(lv)波電容(rong)容(rong)量(liang)和能量(liang)釋放的(de)速率所決定，穩定大小是空載(zai)或(huo)滿載(zai)時(shi)輸出(chu)電壓的(de)百分比或(huo)變化(hua)值。
　　瞬(shun)態響(xiang)應或(huo)恢(hui)(hui)復(fu)(fu)時(shi)間(jian)(jian)一(yi)般在(zai)負(fu)(fu)載變化(hua)10%時(shi)，常(chang)(chang)用輸(shu)出(chu)(chu)偏離峰值電壓的(de)毫(hao)伏數標定(ding)輸(shu)出(chu)(chu)偏離量(liang)，用輸(shu)出(chu)(chu)恢(hui)(hui)復(fu)(fu)到正常(chang)(chang)值所用毫(hao)伏數標出(chu)(chu)恢(hui)(hui)復(fu)(fu)時(shi)間(jian)(jian)。電源模塊瞬(shun)態響(xiang)應和恢(hui)(hui)復(fu)(fu)時(shi)間(jian)(jian)的(de)大小表明(ming)輸(shu)出(chu)(chu)負(fu)(fu)載在(zai)突(tu)然(ran)變化(hua)時(shi)，穩(wen)壓電路恢(hui)(hui)復(fu)(fu)正常(chang)(chang)電壓能力的(de)大小，一(yi)般是用當負(fu)(fu)載突(tu)然(ran)發生變化(hua)時(shi)輸(shu)出(chu)(chu)的(de)偏離值或(huo)是輸(shu)出(chu)(chu)恢(hui)(hui)復(fu)(fu)到原(yuan)來值所用的(de)時(shi)間(jian)(jian)來標定(ding)。

　　阻(zu)抗(kang)匹配(pei)可以(yi)調整(zheng)負載功率和(he)抑制信(xin)號反射，信(xin)號源或傳輸線跟(gen)負載間(jian)達到合適(shi)搭配(pei)叫做阻(zu)抗(kang)匹配(pei)。對于(yu)一個純電(dian)阻(zu)電(dian)路(lu)(lu)或低頻電(dian)路(lu)(lu)，電(dian)容電(dian)感的電(dian)抗(kang)值(zhi)基本可以(yi)忽略，電(dian)路(lu)(lu)阻(zu)抗(kang)主要來源電(dian)阻(zu)。

　　在高(gao)頻(pin)(pin)(pin)領域中，當信(xin)(xin)(xin)號波長和(he)傳輸(shu)線長處于(yu)相同量級時(shi)，反射信(xin)(xin)(xin)號易(yi)與原信(xin)(xin)(xin)號混疊，而阻抗匹配(pei)可以有效減(jian)少(shao)消除高(gao)頻(pin)(pin)(pin)信(xin)(xin)(xin)號反射。PCB走線阻抗主要來自寄(ji)生(sheng)電容(rong)、電感、電阻，因素有材料介電常數、線寬(kuan)、線厚(hou)和(he)焊盤的(de)厚(hou)度等。高(gao)頻(pin)(pin)(pin)領域中信(xin)(xin)(xin)號頻(pin)(pin)(pin)率對(dui)PCB走線的(de)阻抗值影(ying)響很大，當數字(zi)信(xin)(xin)(xin)號邊沿時(shi)間小(xiao)于(yu)1ns或模擬信(xin)(xin)(xin)號頻(pin)(pin)(pin)率超過300M就要考慮阻抗問題。
　　目前阻(zu)抗(kang)匹配的(de)方法主要有改變阻(zu)抗(kang)力或調整傳輸線兩種。改變阻(zu)抗(kang)力是(shi)指通過電容、電感與(yu)負載(zai)(zai)的(de)串聯并聯調整負載(zai)(zai)阻(zu)抗(kang)值，達到源和負載(zai)(zai)阻(zu)抗(kang)匹配。調整傳輸線是(shi)加長源和負載(zai)(zai)間(jian)的(de)距離，配合電容電感把(ba)阻(zu)抗(kang)力調為零。
　　開關電源(yuan)(yuan)目標阻抗是(shi)電源(yuan)(yuan)系統的瞬態阻抗，和一定寬度(du)的頻段(duan)有關，在(zai)相(xiang)同條件下，電源(yuan)(yuan)系統的頻率越(yue)(yue)大，其阻抗越(yue)(yue)大。