
用 500mW Zener 作輸出OVP時,故障時,是100%開路還是短路?
各路英雄豪傑,在設計開關(guān)電源時通常最經(jīng)濟的方法是用什麼作輸出OVP,
,我通常用Zener diode 並聯(lián)在輸出端來用.這樣用不知大家有沒有更多的意見,還有通常出現(xiàn)問題,Zener 100%是開路還是短路?

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@powerint_emi
主要與電源在開路短路時的輸出能量有關(guān)系.如輸出能量很少,Zener就可以保持穩(wěn)定.
According my experiences, it shoould be short, but you can try and evaluate it.
Even if short, you still check your circuit can withstand the overload or not, else you need to improve your overcurrent protection, so that your circuit can reduce the output power during the output short.
Even if short, you still check your circuit can withstand the overload or not, else you need to improve your overcurrent protection, so that your circuit can reduce the output power during the output short.
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PI的Tinyswitch第三代產(chǎn)品具有初級側(cè)檢測輸出過壓并進行保護的功能,請參考附件的文件說明.1151028295.pdf
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@xiaoping.chu
Accordingmyexperiences,itshoouldbeshort,butyoucantryandevaluateit.Evenifshort,youstillcheckyourcircuitcanwithstandtheoverloadornot,elseyouneedtoimproveyourovercurrentprotection,sothatyourcircuitcanreducetheoutputpowerduringtheoutputshort.
建議是個好建議,但不是每一經(jīng)濟形的產(chǎn)品都會設計有專門的過流保護和過壓保護,在adapter and charger 這個行業(yè)中,成本是越來越低,所以一般人會選擇PWM的方案,直接用IC的OCP,OVP來做,所以OVP就用了最經(jīng)濟的 zener在輸出端,
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