同(tong)相比例運(yun)算放大(da)器(qi)，在反(fan)(fan)饋電(dian)(dian)(dian)(dian)阻上并一(yi)個(ge)電(dian)(dian)(dian)(dian)容的(de)(de)作用是什么(me)？(1)反(fan)(fan)饋電(dian)(dian)(dian)(dian)阻并電(dian)(dian)(dian)(dian)容形成一(yi)個(ge)高(gao)通濾波(bo)器(qi),局部(bu)高(gao)頻率(lv)放大(da)特別厲害(hai)。(2)防止自激。在運(yun)算放大(da)器(qi)輸(shu)入(ru)(ru)端上拉(la)電(dian)(dian)(dian)(dian)容，下(xia)拉(la)電(dian)(dian)(dian)(dian)阻能(neng)起到(dao)什么(me)作用？是為了獲得(de)正反(fan)(fan)饋和負(fu)反(fan)(fan)饋的(de)(de)問題，這要看具體(ti)連接。比如我把現在輸(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)壓(ya)信號(hao)，輸(shu)出(chu)電(dian)(dian)(dian)(dian)壓(ya)信號(hao)，再在輸(shu)出(chu)端取出(chu)一(yi)根線連到(dao)輸(shu)入(ru)(ru)段(duan)，那么(me)由(you)于上面的(de)(de)那個(ge)電(dian)(dian)(dian)(dian)阻，部(bu)分(fen)輸(shu)出(chu)信號(hao)通過(guo)該電(dian)(dian)(dian)(dian)阻后獲得(de)一(yi)個(ge)電(dian)(dian)(dian)(dian)壓(ya)值(zhi)，對(dui)輸(shu)入(ru)(ru)的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)進行分(fen)流(liu)(liu)，使得(de)輸(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)壓(ya)變小，這就是一(yi)個(ge)負(fu)反(fan)(fan)饋。因為信號(hao)源輸(shu)出(chu)的(de)(de)信號(hao)總(zong)是不變的(de)(de)，通過(guo)負(fu)反(fan)(fan)饋可以(yi)對(dui)輸(shu)出(chu)的(de)(de)信號(hao)進行矯正。高(gao)阻運(yun)放特點是差模輸(shu)入(ru)(ru)阻抗非(fei)常(chang)高(gao),輸(shu)入(ru)(ru)偏(pian)置(zhi)電(dian)(dian)(dian)(dian)流(liu)(liu)非(fei)常(chang)小,一(yi)般rid>（109~1012）W,IIB為幾皮(pi)安到(dao)幾十皮(pi)安。安徽LMV358低功耗(hao)雙通道運(yun)放/比較器(qi)資料

零漂(piao)移(yi)運算放(fang)大(da)(da)器采用(yong)臺積電(dian)(dian)(dian)(dian)先進(jin)的(de)(de)(de)CMOS工藝及全新(xin)的(de)(de)(de)斬波電(dian)(dian)(dian)(dian)路結構設(she)計，可(ke)提供極低(di)的(de)(de)(de)輸入(ru)失(shi)調電(dian)(dian)(dian)(dian)壓(ya)，同時(shi)隨時(shi)間推(tui)(tui)移(yi)和溫度變化輸入(ru)失(shi)調電(dian)(dian)(dian)(dian)壓(ya)接近于零的(de)(de)(de)漂(piao)移(yi)，并且內(nei)置(zhi)抗RF干擾功能。這些(xie)高(gao)(gao)精度、低(di)靜態電(dian)(dian)(dian)(dian)流(liu)微型放(fang)大(da)(da)器可(ke)提供高(gao)(gao)阻(zu)抗輸入(ru)（共模(mo)范圍超出(chu)電(dian)(dian)(dian)(dian)源(yuan)軌電(dian)(dian)(dian)(dian)壓(ya)100mV）和軌至軌輸出(chu)（擺幅低(di)于電(dian)(dian)(dian)(dian)源(yuan)軌電(dian)(dian)(dian)(dian)壓(ya)50mV以內(nei)）。可(ke)以使用(yong)低(di)至1.8V(±0.9V)和高(gao)(gao)達5.5V(±2.75V)的(de)(de)(de)單電(dian)(dian)(dian)(dian)源(yuan)或雙(shuang)電(dian)(dian)(dian)(dian)源(yuan)。GS655X系列(lie)高(gao)(gao)精度、零漂(piao)移(yi)運放(fang)可(ke)工作電(dian)(dian)(dian)(dian)壓(ya)1.8V至5.5V的(de)(de)(de)單電(dian)(dian)(dian)(dian)源(yuan)驅(qu)動。上海SGM324低(di)功耗四通道運放(fang)/比較器更(geng)低(di)的(de)(de)(de)失(shi)調電(dian)(dian)(dian)(dian)壓(ya)溫漂(piao)、更(geng)大(da)(da)帶(dai)寬、更(geng)小功耗、更(geng)高(gao)(gao)電(dian)(dian)(dian)(dian)壓(ya)方向不斷(duan)(duan)創新(xin)，產品不斷(duan)(duan)推(tui)(tui)陳(chen)出(chu)新(xin)，滿足客戶設(she)計需求。

放(fang)大(da)電路有兩個基(ji)本(ben)類型：同相放(fang)大(da)器(qi)(qi)和(he)反相放(fang)大(da)器(qi)(qi)。他(ta)們的(de)(de)交流(liu)耦合版本(ben)如圖三所示(shi)。對于(yu)交流(liu)電路，反向的(de)(de)意思是相角被(bei)(bei)移動(dong)180度。這(zhe)種電路采用(yong)了耦合電容――Cin。Cin被(bei)(bei)用(yong)來阻止(zhi)電路產生(sheng)(sheng)直流(liu)放(fang)大(da)，這(zhe)樣(yang)電路就只會對交流(liu)產生(sheng)(sheng)放(fang)大(da)作用(yong)。如果(guo)在(zai)(zai)(zai)直流(liu)電路中，Cin被(bei)(bei)省略，那么就必須對直流(liu)放(fang)大(da)進行計算(suan)。在(zai)(zai)(zai)高頻電路中，不要違反運(yun)(yun)放(fang)的(de)(de)帶(dai)寬限制，這(zhe)是非常(chang)(chang)重要的(de)(de)。實際應用(yong)中，一(yi)(yi)級放(fang)大(da)電路的(de)(de)增(zeng)益(yi)通常(chang)(chang)是100倍(bei)(40dB)，再(zai)高的(de)(de)放(fang)大(da)倍(bei)數(shu)(shu)將(jiang)引起電路的(de)(de)振蕩(dang)，除(chu)非在(zai)(zai)(zai)布板(ban)的(de)(de)時候就非常(chang)(chang)注意。如果(guo)要得到一(yi)(yi)個放(fang)大(da)倍(bei)數(shu)(shu)比較的(de)(de)大(da)放(fang)大(da)器(qi)(qi)，用(yong)兩個等(deng)增(zeng)益(yi)的(de)(de)運(yun)(yun)放(fang)或者(zhe)多個等(deng)增(zeng)益(yi)運(yun)(yun)放(fang)比用(yong)一(yi)(yi)個運(yun)(yun)放(fang)的(de)(de)效果(guo)要好的(de)(de)多。

除(chu)了注意(yi)(yi)對(dui)運(yun)放(fang)PSRR或CMRR參數(shu)(shu)的(de)(de)選擇和(he)加強運(yun)放(fang)供(gong)電(dian)(dian)(dian)(dian)(dian)去耦(ou)（如(ru)采用(yong)RC去耦(ou)）外，在(zai)(zai)開關電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)供(gong)電(dian)(dian)(dian)(dian)(dian)設計中，還(huan)應(ying)注意(yi)(yi)如(ru)下(xia)一些方面：電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)中的(de)(de)噪(zao)(zao)聲(sheng)(sheng)可(ke)能(neng)通過(guo)基準源(yuan)(yuan)或PCB的(de)(de)漏(lou)電(dian)(dian)(dian)(dian)(dian)直接(jie)(jie)耦(ou)合(he)到放(fang)大器的(de)(de)輸(shu)入(ru)端(duan)。要注意(yi)(yi)對(dui)電(dian)(dian)(dian)(dian)(dian)壓(ya)基準源(yuan)(yuan)輸(shu)出(chu)的(de)(de)濾(lv)(lv)波(bo)，對(dui)于PCB漏(lou)電(dian)(dian)(dian)(dian)(dian)，可(ke)在(zai)(zai)信(xin)號(hao)(hao)(hao)輸(shu)入(ru)引線(xian)(xian)(xian)與(yu)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)走(zou)(zou)線(xian)(xian)(xian)間(jian)加地(di)線(xian)(xian)(xian)防護。噪(zao)(zao)聲(sheng)(sheng)可(ke)能(neng)通過(guo)PCB走(zou)(zou)線(xian)(xian)(xian)之(zhi)間(jian)的(de)(de)分布(bu)(bu)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)直接(jie)(jie)耦(ou)合(he)到放(fang)大器輸(shu)入(ru)端(duan)，造成干擾。在(zai)(zai)PCB布(bu)(bu)線(xian)(xian)(xian)時，要注意(yi)(yi)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)線(xian)(xian)(xian)與(yu)弱(ruo)信(xin)號(hao)(hao)(hao)線(xian)(xian)(xian)不(bu)要貼行走(zou)(zou)線(xian)(xian)(xian)，線(xian)(xian)(xian)凈距大于線(xian)(xian)(xian)寬的(de)(de)3倍(bei)（3W原則），并在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)線(xian)(xian)(xian)或數(shu)(shu)字信(xin)號(hao)(hao)(hao)線(xian)(xian)(xian)與(yu)模擬小(xiao)(xiao)信(xin)號(hao)(hao)(hao)線(xian)(xian)(xian)之(zhi)間(jian)加地(di)線(xian)(xian)(xian)隔離。接(jie)(jie)地(di)處理不(bu)當(dang)，噪(zao)(zao)聲(sheng)(sheng)通過(guo)公(gong)共(gong)阻(zu)抗(kang)影(ying)響(xiang)敏感(gan)電(dian)(dian)(dian)(dian)(dian)路部(bu)分。為了防止公(gong)共(gong)阻(zu)抗(kang)將(jiang)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)噪(zao)(zao)聲(sheng)(sheng)引入(ru)信(xin)號(hao)(hao)(hao)回路，要注意(yi)(yi)如(ru)下(xia)幾(ji)點(dian)：接(jie)(jie)地(di)上避(bi)(bi)免帶(dai)噪(zao)(zao)聲(sheng)(sheng)的(de)(de)大電(dian)(dian)(dian)(dian)(dian)流流過(guo)前(qian)級小(xiao)(xiao)信(xin)號(hao)(hao)(hao)地(di)；單點(dian)接(jie)(jie)地(di)，電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)、模擬、數(shu)(shu)字電(dian)(dian)(dian)(dian)(dian)路分開接(jie)(jie)地(di)；布(bu)(bu)板(ban)使用(yong)地(di)平(ping)面層，小(xiao)(xiao)化(hua)地(di)線(xian)(xian)(xian)阻(zu)抗(kang)；開關電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)輸(shu)出(chu)從(cong)一個濾(lv)(lv)波(bo)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)的(de)(de)地(di)端(duan)引出(chu)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)地(di)，避(bi)(bi)免從(cong)濾(lv)(lv)波(bo)電(dian)(dian)(dian)(dian)(dian)感(gan)前(qian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)的(de)(de)地(di)端(duan)引出(chu)。評價集成運(yun)放(fang)性(xing)能(neng)的(de)(de)優劣,應(ying)看其綜合(he)性(xing)能(neng)。

一(yi)(yi)(yi)般(ban)反相/同相放大(da)電(dian)路中都會有一(yi)(yi)(yi)個平(ping)衡(heng)電(dian)阻(zu)，這(zhe)個平(ping)衡(heng)電(dian)阻(zu)的(de)(de)作用(yong)是什么(me)呢？(1)為芯(xin)片(pian)內(nei)部的(de)(de)晶體管提供一(yi)(yi)(yi)個合適的(de)(de)靜(jing)態(tai)偏置(zhi)。芯(xin)片(pian)內(nei)部的(de)(de)電(dian)路通(tong)常(chang)都是直(zhi)接(jie)(jie)耦合的(de)(de)，它(ta)能(neng)夠(gou)自動調節靜(jing)態(tai)工作點，但是，如(ru)果某個輸入引腳被直(zhi)接(jie)(jie)接(jie)(jie)到了電(dian)源或者地，它(ta)的(de)(de)自動調節功(gong)(gong)能(neng)就不(bu)(bu)正(zheng)常(chang)了，因為芯(xin)片(pian)內(nei)部的(de)(de)晶體管無法抬高地線的(de)(de)電(dian)壓(ya)，也無法拉低電(dian)源的(de)(de)電(dian)壓(ya)，這(zhe)就導致芯(xin)片(pian)不(bu)(bu)能(neng)滿足虛短、虛斷的(de)(de)條件(jian)，電(dian)路需要(yao)另外分析。(2)消除靜(jing)態(tai)基極電(dian)流(liu)對輸出電(dian)壓(ya)的(de)(de)影響，大(da)小應與(yu)兩輸入端外界直(zhi)流(liu)通(tong)路的(de)(de)等效電(dian)阻(zu)值平(ping)衡(heng)，這(zhe)也是其得(de)名(ming)的(de)(de)原因。當(dang)一(yi)(yi)(yi)個系統中使用(yong)多(duo)個運放時,盡(jin)可能(neng)選用(yong)多(duo)運放集成電(dian)路。山東SGM3130低功(gong)(gong)耗四通(tong)道運放/比(bi)較器型(xing)號

具體而言，斬(zhan)波穩定型運算(suan)放(fang)大器(qi)（零(ling)漂移放(fang)大器(qi)）非常適用于(yu)要求失調電壓以及零(ling)漂移的應用。安徽LMV358低功耗雙通道運放(fang)/比較器(qi)資料

GS4558由兩個(ge)高(gao)(gao)(gao)性能運(yun)算放大(da)器(qi)(qi)組(zu)成。該(gai)集成電(dian)(dian)(dian)路(lu)具有(you)高(gao)(gao)(gao)增益、低(di)等效輸入(ru)(ru)噪聲電(dian)(dian)(dian)壓(ya)、高(gao)(gao)(gao)輸入(ru)(ru)電(dian)(dian)(dian)阻、良好的(de)通道分離、寬(kuan)工作電(dian)(dian)(dian)壓(ya)范圍和(he)內部頻(pin)率(lv)補(bu)償等特點。可在(zai)(zai)±18V的(de)比(bi)較(jiao)大(da)供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)下(xia)工作，也可單(dan)路(lu)供(gong)電(dian)(dian)(dian)36V。GS4580是(shi)一(yi)款單(dan)片雙(shuang)低(di)噪聲運(yun)算放大(da)器(qi)(qi)。它是(shi)專門為(wei)音頻(pin)系統設計的(de)，以改善音調(diao)控制;它也可用(yong)于前置(zhi)放大(da)器(qi)(qi)，工業測(ce)量工具和(he)應用(yong)，在(zai)(zai)增益和(he)相(xiang)位匹配通道是(shi)強制性的(de)。該(gai)集成電(dian)(dian)(dian)路(lu)具有(you)內部頻(pin)率(lv)補(bu)償、低(di)噪聲、低(di)失調(diao)、高(gao)(gao)(gao)增益、高(gao)(gao)(gao)分辨(bian)率(lv)等特點帶寬(kuan)。GS4580可在(zai)(zai)±18V的(de)雙(shuang)電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)壓(ya)或36V的(de)單(dan)電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)壓(ya)下(xia)工作。安徽(hui)LMV358低(di)功耗雙(shuang)通道運(yun)放/比(bi)較(jiao)器(qi)(qi)資料

互勤(qin)(深圳(zhen))科(ke)技(ji)有限公司(si)位(wei)于(yu)光明街道東周(zhou)社區高新(xin)路研祥科(ke)技(ji)工業園二棟研發大樓1007。公司(si)業務(wu)分為(wei)電(dian)源芯(xin)片，MOS管，MCU方案，必易芯(xin)片等，目(mu)前(qian)不斷(duan)進行創(chuang)新(xin)和服(fu)(fu)務(wu)改進，為(wei)客(ke)戶提供良好的(de)產品(pin)(pin)和服(fu)(fu)務(wu)。公司(si)將不斷(duan)增強企(qi)業重點競爭(zheng)力，努力學習(xi)行業知識，遵守行業規范(fan)，植根于(yu)電(dian)子元(yuan)器件行業的(de)發展。互勤(qin)科(ke)技(ji)憑借創(chuang)新(xin)的(de)產品(pin)(pin)、專業的(de)服(fu)(fu)務(wu)、眾多的(de)成(cheng)功案例積累起來的(de)聲譽(yu)和口(kou)碑(bei)，讓(rang)企(qi)業發展再(zai)上新(xin)高。

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