rs-485 port protection evaluation board 2 11/11 ? fu1107 rs-485 evaluation board 2 bill of materials table 1 no. part number qty. description reference 1 tbu-ca065-300-wh 2 tbu? single bidirectional line 650 v 300 ma tbu? hsp 1, tbu? hsp 2 2 MOV-10D201K 2 single line 10 mm mov 200 v mov1, mov2 3 cdsot23-sm712 2 dual bidirectional line 7 v / 12 v tvs5 introduction tis evaluation board serves as an aid in evaluating circuit protection on rs-485 serial device port solutions using bourns? tbu? high-speed protector (hsp), mov and tvs products to meet the required industry standards on rs-485 port interfaces. te recommended bourns? tbu? hsp solution ofers enhanced performance features over competing technologies, which can help the design engineer to increase the surge & transient protection level on rs-485 ports and place the entire circuit protection solution into a smaller pcb area. bourns has developed a rs-485 evaluation board (measuring 50 mm x 25 mm x 1.2 mm) manufactured using fr4 pcb with nickel gold plating on top and bottom sides. how to connect the evaluation board for test set-up ? connect j1 and j2 to the exposed lines. ? connect j3 and j4 to the rs-485 ic device. * in addition to the two tbu? hsps, the default confguration of this board uses two movs (mov1, mov2) and a single tvs diode array (tvs5). te board allows diferent confgurations: ? 2 movs (mov1 and mov2) may be replaced by a) 2 single 2031 gdts (gdt1 and gdt2) or b) a dual 2030 gdt (gdt3, not yet released) ? 1 tvs diode array (tvs3) may be replaced with a) 2 smb tvs diodes (tvs1, tvs2) or b) 2 sot23 tvs diodes (tvs3, tvs4) or c) 2 sot23-5 thyristor devices (tisp1, tisp2) rs-485 evaluation board 2 top side layout* rs-485 evaluation board 2 schematic figure 2 figure 1 tbu? hsp 1 t vs5 tisp1 tisp2 t vs1 t vs2 t vs3 t vs4 gd t3 gd t1 mov1 line a unprotec ted 40 mils trac ep rote ct ed load a line b unprotec ted 40 mils trac ep rote ct ed load b j1 j 2 j3 j4 gd t2 mov2 tbu? hsp 2 3 2 1 3 2 1 3 3 2 1 12 21 21 21 2 1 1 1 2 2 1 2 1 2 ii i i i ii ii i ii nu nu 1 2 12
rs-485 port protection evaluation board 2 performance graphs 11/11 ? fu1107 esd +8 kv contact discharge (iec-61000-4-2) surge 1.2/50 5 kv 120 v rms 28 v rms figure 3 figure 4 figure 5 figure 6 ch 1: input voltage / surge / fault to tbu? hsp ch 4: tbu? hsp current 1 ch1 ch1 116 v ma 400 ns 31.60 % 1.00 a ch4 200 v ch1 ma x 329 v ch1 mi n -20.5 v tr ig? pr ev u ch4 ma x 1.98 a ch4 mi n -81.1 ma t t 4 the ohm unit following the current units shown for channel 4 (i. e. ao hm) indic ates that a 50 ohm termination w as used internal to the oscilloscope t ch 1: input voltage / surge / fault to tbu? hsp ch 4: tbu? hsp current 1 ch1 line 116 v ma 4.00 ms 20.20 % 200 ma ch4 100 v ch1 ma x 124.4 v run tr ig d ch4 ma x 365.4 ma ch4 mi n -322.4 ma t t 4 the ohm unit following the current units shown for channel 4 (i. e. ao hm) indic ates that a 50 ohm termination w as used internal to the oscilloscope t ch 1: input voltage / surge / fault to tbu? hsp ch 4: tbu? hsp current 4 1 ch1 line 116 v ma 4.00 ms 20.20 % 200 ma ch4 20.0 v ch1 ma x 28.3 v run tr ig d ch4 ma x 451.8 ma ch4 mi n -395.7 ma t t the ohm unit following the current units shown for channel 4 (i. e. ao hm) indic ates that a 50 ohm termination w as used internal to the oscilloscope t reference or more information on implementin advanced circuit protection technoloies for rs- ports please review the bourns rs- application note httpwww.bourns.comdatalobalpdfsbournsrs-ppnote.pdf tbu is a registered trademark of bourns, inc. in the u.s., taiwan and european community. bourns is a registered trademark of bourns, inc. in the u.s. and other countries. copyright? 2011 ? bourns, inc. ? 11/11 ? e/fu1107 www.bourns.com ch 1: input voltage / surge / fault to tbu? hsp ch 4: tbu? hsp current 1 ch1 ch1 -380 v ma 10.0 ns 20.40 % 5.00 a ch4 500 v ch1 ma x 545 v ch1 mi n -390 v tr ig? run ch4 ma x 11.3 ma ch4 mi n -2.55 a t t 4 the ohm unit following the current units shown for channel 4 (i. e. ao hm) indic ates that a 50 ohm termination w as used internal to the oscilloscope t
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