MC34063A升壓電路圖
(2011/11/2 20:40:00)
MC33063A參數(shù)
| Iout (Max) (A) |
0.75 |
0.75 |
| Iq (Typ) (mA) |
|
4 |
| Switching Frequency (Max) (kHz) |
100 |
100 |
| Vin (Min) (V) |
3 |
3 |
| Vin (Max) (V) |
40 |
40 |
| Vout (Min) (V) |
1.25 |
1.55 |
| Vout (Max) (V) |
40 |
40 |
| Duty Cycle (Max) (%) |
|
90 |
| Switch Current Limit (Typ) (A) |
1.5 |
1.5 |
| Operating Temperature Range (C) |
-40 to 85 |
0 to 70 |
| Pin/Package |
8PDIP, 8SOIC, 8SON |
8PDIP, 8SOIC, 8SON |
| Approx. Price (US$) |
0.23 | 1ku |
0.21 | 1ku |
| Topology |
Inverting Buck/Boost |
Buck, Inverting Buck/Boost |
| Regulated Outputs (#) |
1 |
1 |
MC34063升壓電路設(shè)計(jì)及工作原理
MC34063組成的降壓電路原理如圖8,當(dāng)芯片內(nèi)開(kāi)關(guān)管(T1)導(dǎo)通時(shí),電源經(jīng)取樣電阻Rsc、電感L1、MC34063的1腳和2腳接地,此時(shí)電感L1開(kāi)始存儲(chǔ)能量,而由C0對(duì)負(fù)載提供能量。當(dāng)T1斷開(kāi)時(shí),電源和電感同時(shí)給負(fù)載和電容Co提供能量。電感在釋放能量期間,由于其兩端的電動(dòng)勢(shì)極性與電源極性相同,相當(dāng)于兩個(gè)電源串聯(lián),因而負(fù)載上得到的電壓高于電源電壓。開(kāi)關(guān)管導(dǎo)通與關(guān)斷的頻率稱為芯片的工作頻率。只要此頻率相對(duì)負(fù)載的時(shí)間常數(shù)足夠高,負(fù)載上便可獲得連續(xù)的直流電壓。
MC34063A在線電源計(jì)算器-Online Power calculation
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