weitron http://www.weitron.com.tw 1/7 19-apr-07 slvu2.8 ultralow capacitance tvs diodes array for esd protection applications: * ethernet 10/100/1000 base t * wan/lan equipment * desktop,services,notebooks & handhelds * laser diode protection * * one device protects one unidirectional line. * low capacitance. * low leakage current. * low operating and clamping voltages. * transient protection for high speed data lines.to features: lea d( p b)- f r ee p b 400 w peak pulse power per line (tp=8/20 us) * iec61000-4-2(esd) 15kv(air), 8kv(contact) * iec61000-4-4(eft) 40a(5/50ns) * iec61000-4-5(lightning) 24a(8/20s) 1 2 3 sot-23 transient voltage suppressors 400 watts 2.8 volts absolute maximum ratings parameter value units symbol peak pulse power(tp = 8/20 s) - see fig.1 p pk 400 w peak pulse current(tp = 8/20 s) i pp 24 a storage temperature range t stg -55 to 150 c operating junction temperature range t j -55 to 150 c eqivalent circuit diagram:
weitron http://www.weitron.com.tw 2/7 19-apr-07 slvu2.8 electrical characteristics parameter symbol min typ max units parameter symbol min typ max units reverse stand-o? voltage pin 3 to 1 or pin 2 to 1 v rwm 2.8 v punch-through voltage i pt = 2a, pin 3 to 1 v pt 3.0 - - - - - - - - - - - v snap-back voltage i sb = 50ma, pin 3 to 1 v sb 2.8 v reverse leakage current v rwm = 2.8v, t = 25c pin 3 to 1 or pin 2 to 1 i r 1 a clamping voltage i pp =2a, t p =8/20s, pin 3 to 1 i pp =5a, t p =8/20s, pin 3 to 1 i pp =24a, t p =8/20s, pin 3 to 1 i pp =5a, t p =8/20s, pin 2 to 1 i pp =24a, t p =8/20s, pin 2 to 1 v c 3.9 7 12.5 8.5 15 v junction capacitance v r =0v, f =1mhz, pin 3 to 1 and 2 (pin 1 and 2 tied together) v r =0v, f =1mhz, pin 2 to 1 (pin 3 n.c.) c j 70 3.5 100 5 pf steering diode characteristics =10a, pin 3 to 2 reverse breakdown voltage v brr i 40 - - - - - v t v rwm = 2.8v, t =25c, pin 3 to 2 reverse leakage current i brr 1 - a forward voltage i f =1a, pin 2 to 3 v f 2 v
weitron http://www.weitron.com.tw 3/7 19-apr-07 slvu2.8 typical characteristics fig.3 pulse waveform fig.4 power derating curve fig.1 peak pulse power vs pulse time electrical parameter s y mbol parameter i pp peak pu l s e current v c clamp i ng vo l t age @ i pp v r w m reverse sta n d-off voltag e i r reverse l e a k a g e c u rrent @ v rwm v sb snap-b a ck voltage @ i sb i sb snap-b a ck current v pt punc h - t h r ou gh voltage i pt punc h - t h r ou gh c u rrent v brr reverse bre a kd o w n volta g e @ i brr i brr reverse bre a kd o w n curr e nt fig.2 slvu2.8 iv characteristic curve
weitron http://www.weitron.com.tw 4/7 19-apr-07 slvu2.8 fig.7 reverse voltage vs capacitance fig.8 insertion loss s21 fig.5 clamping voltage vs peak pulse current fig.6 forward voltage vs forward current
weitron http://www.weitron.com.tw 5/7 19-apr-07 slvu2.8 application note unidirectional common-mode protection (fig.9) the slvu2.8 provides one line of unidirectional protection in a common-mode con?guration as depicted in ?gure 9. circuit connectivity is as follows: line 1 is connected to pin 3 pins 1 and 2 are connected to ground bidirectional common-mode protection (fig.10) two slvu2.8 devices provide one line of bidirectional protection in a common-mode con?guration as depicted in ?g.10 circuit connectivity is as follows: * line 1 is connected to pin1 of device 1 & pin 2 of device 2 * pin 2 of device 1 and pin 1 of device 2 are connected to ground * pin 3 of both devices is not connected bidirectional differential-mode protection (fig.11) circuit connectivity is as follows: * line 1 is connected to pin1 of device 1 & pin 2 of device 2 * line 2 is connected to pin 2 of device 1 & pin 1 of device 2 fig.9 fig.10 fig.11 the slvu2.8 is ideal for providing protection for electronic equipment that is susceptible to damage caused by electrostatic discharge (esd), electrical fast transients (eft) and tertiary lightning effects. this product is offered in a unidirectional configuration and provides both commonmode or differential-mode protection. circuit board layout protection circuit board layout is critical for electromagnetic compatibility (emc) protection. the following guidelines are recommended: * the protection device should be placed near the input terminals or connectors, the device will divert the transient current immediately before it can be coupled into the nearby traces. * the path length between the tvs device and the protected line should be minimized. * all conductive loops including power and ground loops should be minimized. * the transient current return path to ground should be kept as short as possible to reduce parasitic inductance. * ground planes should be used whenever possible. for multilayer pcbs, use ground vias. two slvu2.8 devices provide up to two lines of bidrectional protection in a di?erenitalmode con?guration as depicted in ?g.11
weitron http://www.weitron.com.tw 6/7 19-apr-07 slvu2.8 t y pical applications fig12. 10/100 ethernet protection circuit slvu2.8 slvu2.8 fig13. 10/100 ethernet ?enhanced? lightning protection circuit slvu2.8 slvu2.8
weitron http://www.weitron.com.tw 7/7 19-apr-07 slvu2.8 a b d e g m l h j t o p v i e w a b c d e g h j k l m 0 . 3 5 1 . 1 9 2 . 1 0 0 . 8 5 0 . 4 6 1 . 7 0 2 . 7 0 0 . 0 1 0 . 8 9 0 . 3 0 0 . 0 7 6 0 . 5 1 1 . 4 0 3 . 0 0 1 . 0 5 1 . 0 0 2 . 1 0 3 . 1 0 0 . 1 3 1 . 1 0 0 . 6 1 0 . 2 5 k c sot-23 outline dimensions dim min max unit:mm
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