for assistance or to order, call (800) 531-5782 power trends, inc. 27715 diehl road, warrenville, il 60555 (800) 531-5782 fax: (630) 393-6902 http://www.powertrends.com 3 amp positive step-down integrated switching regulator 78st300 series standard application c1 = optional 1f ceramic c2 = required 100f electrolytic pin-out information pin no. function 1v i n 2 gnd 3v out ordering information 78st3 c output voltage xx y 05 = 5.0 volts package suffix v = vertical mount h = horizontal mount ? high efficiency > 80% ? wide input range ? self-contained inductor ? short-circuit protection ? over-temperature protection ? fast transient response the 78st300 is a series of wide input voltage, 3 terminal integrated switching regulators (isrs). employ- ing a ceramic substrate, these isrs have a maximum output current of 3a. the output voltage is laser trimmed for high accuracy. the 78st300 series regulators have internal short-circuit and over- temperature protection and may be used in a wide variety of applications. specifications characteristics 78st300 series (t a = 25c unless noted) symbols conditions min typ max units output current i o over v in range 0.1* 3.0 a input voltage range v in i o = 0.1 to 3.0a 8 20 v output voltage tolerance d v o over v in range 1.0 2.0 %vo t a = 0c to +60c line regulation reg line over v in range 0.4 0.8 %v o load regulation reg load 0.1 i o 3.0a 0.2 0.4 %v o ripple/noise v n v in = v in min , i o = 3.0a 1 %vo transient response t tr 50% load change 100 sec (with 100f output cap) v o over/undershoot 5.0 %v o efficiency h v in = 9v, i o = 3.0a 80 % switching frequency ? o over v in and i o ranges 0.95 1.0 1.05 mhz absolute maximum t a -40 +70 c operating temperature range recommended operating t a free air convection, (40-60lfm) -40 +70** c temperature range over v in and i o ranges thermal resistance q ja free air convection, (40-60lfm) 35 c/w storage temperature t s -40 +125 c mechanical shock per mil-std-883d, method 2002.3 500 gs mechanical vibration per mil-std-883d, method 2007.2, 10gs 20-2000 hz, soldered in a pc board weight 11 grams * isr will operate down to no load with reduced specifications. ** see thermal derating chart. note: the 78 st300 series requires a 100f electrolytic or tantalum output capacitor for proper operation in all applications. 78st300 c2 + vout gnd gnd vin c1 1 2 3 (for dimensions and pc board layout see package style 600.) revised 6/30/98
for assistance or to order, call (800) 531-5782 power trends, inc. 27715 diehl road, warrenville, il 60555 (800) 531-5782 fax: (630) 393-6902 http://www.powertrends.com characteristic data note 1: all data listed in the above graphs, except for derating data, has been developed from actual products tested at 25c. this dat a is considered typical data for the isr. note 2: thermal derating graphs are developed in free air convection cooling of 40-60 lfm. (see thermal application n ote) 78ST305_ 5.0 vdc (see note 1) efficiency vs output current ripple vs output current power dissipation vs output current efficiency (%) ripple (mv) pd (watts) iout (a) iout (a) iout (a) 78st300 series vin vin vin 40 50 60 70 80 90 100 0.00.51.01.52.02.53.0 7.5v 9.0v 12.0v 15.0v 20.0v 0 5 10 15 20 25 30 35 40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 7.5v 9.0v 12.0v 15.0v 20.0v 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 7.5v 9.0v 12.0v 15.0v 20.0v thermal derating (t a ) (see note 2) iout (a) vin (volts) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 8 101214161820 85c 70c 60c 50c
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