Transcription of Snubber Capacitors - Application Guide
1 RC .. F .. DPP . / WPP .. DPP 630V . WPP 1000V . , . / DPFF DPPS.. DPPM DPMF .. EMI .. RC --- . RMS .. dV/dt I rms = 2 f C Vrms 10 6. RMS f = Hz; C = F. 15 V = Vrms rms . dV/dt . CDE C VPP C V PP. I RMS = I peak =. tT . Vpp = - V. dV/dt 100000V/ s DPP . t = s 2000V/ s . V = V rms DPFF DPPS .. 3000V/ s DPMF DPPM .. 1000V/ s .. --- .. --- RC . K . V. I pk = 0. RS . Vo = ; Rs = 50 200V/ s . Cs = 15 . dV/dt . dV. =. V0 rms . dt pk RS C S.. RMS . DPP .. K .. 1. Y5V 50 122F 1 = ( C S VO2 )(2 f S ). 2. 0 50% f S = . CS =. 1. V fS. O. 2.. 50kHz . 2 . 160 Vdc 5A .. R # 160/5 = 32 .. 1. CS = = 780 pF. (160) (50 10 3 ). 2.. AC . Vo . R . I.. Vo = I = .. R .. 100pF . 1/ 2 C S V O2 .. 2 .. 1 .. 2 fs 1 .. 4 1/ 2 C S V O2 fs .. 1 . fO =. 2 LC.. Ci . Pr = C s V o2 f s.
2 Cs = .. Vo = fs = . 1. Lj =. C i (2 f i ) 2 . fi = 1 . Ci = /3 . Li = 1/ 2 C S VO2 > 1/ 2 Li I 2. I = . L I i2. CS > . V O2.. 2 .. R C S < t ON /10 C S < t ON /10R. R = Li / C i .. LC . 8 10 Ci .. Li I 2 t 2. < C S < ON. Vo 10R.. ( 10 6 )(5) 2 2 10 6. < C <.. S. (160) 2 (10)(54). 192 < Cs < 3700 pF. 44 MHz . 200pF . 22 MHz 10% 220 pF . 50kHz . 160 Vdc 5A Pr = (220 10 12 )(160) 2 (50 10 3 ) = . fi = 44 MHz . Ci = 200/3 = 67 pF 5 . fs = 50 kHz 1W . t ON = (50 10 3 ) = 2 s 780pF 220pF . Vo = 160 Vdc . I=5A 54 32 .. Li =. 1. = H . (67 10 12. )(2 44 10 6 ) 2.. R = / 67(10 3 ) = 54 .. RC RCD . IGBT.
