dated : 07/12/2002 ? semtech electronics ltd. ( subsidiary of sino-tech internatio nal holdings limited, a company listed on the hong kong stock exchange, stock code: 724 ) st 78l20 3-terminal positive voltage regulator 20v ? suitable for ttl, dtl, htl, c-mos, power supply ? internal short-circuit current limiting ? internal thermal overload protection ? maximum output current of 150ma (tj=25 o c) ? available in the plastic to-92 package to-92 plastic package weight approx. 0.19g absolute maximum ratings (t a = 25 o c) symbol rating unit input voltage v in 40 v power dissipation p tot 800 mw operating temperature t opr -30~75 c storage temperature range t s -55~150 c
dated : 07/12/2002 ? semtech electronics ltd. ( subsidiary of sino-tech internatio nal holdings limited, a company listed on the hong kong stock exchange, stock code: 724 ) st 78l20 electrical characteristics (unless otherwise specified, v in =29v, i out =40ma, c in =0.33 f, c out =0.1 f, t j =25 c) symbol test condition min. typ. max. unit output voltage v out 19.2 20 20.8 v input regulation reg. line 23.5v v in 35v - 33 330 mv 24v v in 35v - 28 285 load regulation reg. load 1.0ma i out 100ma - 33 180 mv 1.0ma i out 40ma - 17 90 output voltage v out 23.5v v in 35v 19.0 - 21 v 1.0ma i out 40ma v out v in =29v, 19.0 - 21 v 1.0ma i out 70ma quiescent current i b - 3.3 6.5 ma quiescent current with line i b 24v v in 35v - - 1.5 ma change with load 1.0ma i out 40ma - - 0.1 output noise voltage v no ta = 2 5 c, 10hz f 100khz - 170 - v ripple rejection rr f=120hz, 25v v in 35v,t j =25 c 31 37 - db dropout voltage ? v in -v out ? t j =25 c - 1.7 - v average temperature coefficient of output voltage tc vo i out =5ma - -1.7 - mv/ c
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