maximum ratings and thermal characteristics t a = 25 o c unless otherwise noted. parameter symbol smaj530 smaj550 unit device marking code hd sb steady state power dissipation (3) p m(av) 1.0 w peak pulse power dissipation (1)(2)(5) (fig. 1) p ppm minimum 300 w stand-off voltage v wm 477 495 v typical thermal resistance junction-to-lead r jl 27 ?/w typical thermal resistance junction-to-ambient r ja 75 c/w operating junction and storage temperature range t j , t stg 55 to +150 c electrical characteristics t a = 25 o c unless otherwise noted. minimum breakdown voltage at 100 av (br) 530 550 v max. clamping voltage at 400ma, 10/1000 s - waveform vc 760 v maximum dc reverse leakage current at v wm i d 1.0 a typical temperature coefficient of v (br) 650 mv c typical capacitance (4) at 0v c j 90 pf at 200v 7.5 notes: (1) non repetitive current pulse per fig.3 and derated above 25 o c per fig. 2 (4) measured at 1mh z (2) mounted on 5.0mm 2 copper pads to each terminal (5) peak pulse power waveform is 10/1000 s. (3) lead temperature at 75 o c = t l 0.157 (3.99) 0.177 (4.50) 0.006 (0.152) 0.012 (0.305) 0.030 (0.76) 0.060 (1.52) 0.008 (0.203) max. 0.194 (4.93) 0.208 (5.28) 0.100 (2.54) 0.110 (2.79) 0.078 (1.98) 0.090 (2.29) 0.049 (1.25) 0.065 (1.65) cathode band do-214ac (sma) dimensions in inches and (millimeters) 0.060 min (1.52 min) 0.050 min (1.27 min) 0.220 ref (5.58) 0.094 max (2.38 max) features plastic package has underwriters laboratory flammability classification 94v-0 protects power ic controllers such as topswitch glass passivated junction high temperature soldering guaranteed: 250 c/10 seconds at terminals excellent clamping capability available in unidirectional only mounting pad layout steady state power 1w peak pulse power 300w reverse voltage 530,550v mechanical data case: jedec do-214ac molded plastic body over passivated chip terminals: solder plated, solderable per mil-std-750, method 2026 polarity: the band denotes the cathode, which is positive with respect to the anode under normal tvs operation mounting position: any weight: 0.002 oz., 0.064 g packaging codes ?options (antistatic): 51 1k per bulk box, 20k/carton 61 1.8k per 7" plastic reel (12mm tape), 36k/carton 5a 7.5k per 13" plastic reel (12mm tape), 75k/carton smaj530 and smaj550 vishay semiconductors formerly general semiconductor surface mount t rans z orb transient voltage suppressors document number 88391 www.vishay.com 03-mar-03 1
application notes ? respect thermal resistance (pcb layout) as the temperature coefficient also contributes to the clamping voltage. ? select minimum breakdown voltage, so you get acceptable power dissipation and pcb tie point temperature. devices with higher breakdown voltage will have a shorter conduction time and will dissipate less power. ? clamping voltage is influenced by internal resistance design approximation is 7v per 100ma slope. ? keep temperature of tvs lower than topswitch ? as a recommendation. ? maximum current is determined by the maximum t j and can be higher than 300ma. contact supplier for different clamping voltage / current arrangements. ? minimum breakdown voltage can be customized for other applications. contact supplier. ? topswitch ? is a registered trademark of power integrations, inc. 0 25 50 75 100 0 75 25 50 100 125 150 175 peak pulse power (p pp ) or current (i pp ) derating in percentage, % t a ambient temperature ( c) fig. 2 pulse derating curve p ppm peak pulse power (kw) fig. 1 peak pulse power rating curve 0.1 1 10 100 0.1 s 1.0 s10 s td pulse width (sec.) 100 s 1.0ms 10ms non-repetitive pulse waveform shown in fig. 3 t a = 25 c 0 50 100 150 i ppm peak pulse current, % i rsm fig. 3 pulse waveform t j = 25 c pulse width (td) is defined as the point where the peak current decays to 50% of i ppm tr = 10 sec. peak value i ppm half value ipp i ppm 2 td 10/1000 sec. waveform as defined by r.e.a. 0 1.0 2.0 3.0 4.0 t time (ms) ratings and characteristic curves (t a = 25 c unless otherwise noted) smaj530 and smaj550 vishay semiconductors formerly general semiconductor www.vishay.com document number 88391 2 03-mar-03
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