三端穩壓(ya)(ya)管”通常是(shi)(shi)以(yi)78xx為代(dai)表的集成線(xian)性(xing)(xing)穩壓(ya)(ya)電(dian)(dian)路(lu),其(qi)根本原(yuan)理是(shi)(shi)“串(chuan)聯(lian)電(dian)(dian)路(lu)電(dian)(dian)阻分壓(ya)(ya)規律”。由于(yu)是(shi)(shi)線(xian)性(xing)(xing)穩壓(ya)(ya)電(dian)(dian)路(lu),其(qi)效(xiao)率(lv)是(shi)(shi)與壓(ya)(ya)差(cha)成反比的,壓(ya)(ya)差(cha)越(yue)高效(xiao)率(lv)越(yue)低(di)。在壓(ya)(ya)差(cha)較大、電(dian)(dian)流也較大時,三端線(xian)性(xing)(xing)穩壓(ya)(ya)芯片(pian)的發熱會非常嚴重。
解決(jue)這個問題可以從兩個角度考慮(lv):
加強散熱,比(bi)如安(an)裝散熱片、加大散熱片面(mian)積、使(shi)用風扇進行(xing)強制(zhi)風冷等等。
減小發(fa)熱,比如通(tong)過(guo)降低電(dian)源(yuan)電(dian)壓來降低壓差,或者使(shi)用Buck斬波電(dian)路(lu)來代(dai)替(ti)線性(xing)穩壓電(dian)路(lu)。