june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. tisp6ntp2a programmable protector tisp6ntp2a quad forward-conducting buffered p-gate thyristors device symbol independent overvoltage protection for two slics in short loop applications: C wide 0 to -90 v programming range C low 5 ma max. gate triggering current C high 150 ma min. (85 c) holding current C specified 1.2/50 & 0.5/700 limiting voltage C full -40 c to 85 c temperature range rated for common impulse waveforms how to order d package (top view) description the tisp6ntp2a has been designed for short loop systems such as: C will (wireless in the local loop) C fitl (fibre in the loop) C daml (digital added main line, pair gain) C soho (small office home office) C isdn-ta (integrated services digital network - terminal adaptors) typical tisp6ntp2a router application voltage impulse form current impulse shape i tsp a 10/1000 s 10/1000 s20 10/700 s 5/310 s25 1.2/50 s8/20 s75 2/10 s2/10 s85 terminal adaptor line lan pots 2 pots 1 slic 1 slic 2 tisp6 ntp2a transceiver processor transceiver mdrxam 1 2 3 45 6 7 8 k2 a a k4 g1,g2 k1 k3 g3,g4 sdrxai k1 k3 k4 k2 g3,g4 a a g1,g2 .............................................. ul recognized component *rohs directive 2002/95/ec jan 27 2003 including annex *rohs compliant device package carrier tisp6ntp2a d, small-outline tape and reel tisp6ntp2adr-s order as
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. description (continued) these systems often have the need to source two pots (plain old telephone service) lines, one for a telephone and the other for a facsimile machine. in a single surface mount package, the tisp6ntp2a protects the two pots line slics (subscriber line interface circuits ) against overvoltages caused by lightning, a.c. power contact and induction. the tisp6ntp2a has an array of four buffered p-gate forward conducting thyristors with twin commoned gates and a common anode connection. each thyristor cathode has a separate terminal connection. an antiparallel anode-cathode diode is connected across each thyristor. the buffer transistors reduce the gate supply current. in use, the cathodes of an tisp6ntp2a thyristor are connected to the four conductors of two pots lines (see applications inform ation). each gate is connected to the appropriate negative voltage battery feed of the slic driving that line pair. by having separate gates , each slic can be protected at a voltage level related to the negative supply voltage of that individual slic. the anode of the tisp6ntp2a is connected to the slic common. positive overvoltages are clipped to common by forward conduction of the tisp6ntp2a antiparallel diode. negative overvoltages a re initially clipped close to the slic negative supply by emitter follower action of the tisp6ntp2a buffer transistor. if sufficient clippin g current flows, the tisp6ntp2a thyristor will regenerate and switch into a low voltage on-state condition. as the overvoltage subsides, the high ho lding current of the tisp6ntp2a helps prevent d.c. latchup. rating symbol value unit repetitive peak off-state voltage, i g =0, -40 c t j 85 cv drm -100 v repetitive peak gate-cathode voltage, v ka =0, -40 c t j 85 cv gkrm -90 v non-repetitive peak on-state pulse current, -40 c t j 85 c, (see notes 1 and 2) i tsp a 10/1000 s (bellcore gr-1089-core, issue 1, november 1994, section 4) 20 0.2/310 s (i3124, open-circuit voltage wave shape 0.5/700 s) 5/310 s (itu-t k.20 & k.21, open-circuit voltage wave shape 10/700 s) 8/20 s (iec 61000-4-5:1995, open-circuit voltage wave shape 1.2/50 s) 25 25 75 2/10 s (bellcore gr-1089-core, issue 1, november 1994, section 4) 85 non-repetitive peak on-state current, 50/60 hz, -40 c t j 85 c, (see notes 1 and 2) i tsm a 100 ms 7 1s 5s 300 s 900 s 2.7 1.5 0.45 0.43 non-repetitive peak gate current, 1/2 s pulse, cathodes commoned (see note 1) i gsm 25 a operating free-air temperature range t a -40 to +85 c junction temperature t j -40 to +150 c storage temperature range t stg -65 to +150 c notes: 1. initially, the protector must be in thermal equilibrium with -40 c t j 85 c. the surge may be repeated after the device returns to its initial conditions. 2. these non-repetitive rated currents are peak values for either polarity. the rated current values may be applied to any catho de- anode terminal pair. additionally, all cathode-anode terminal pairs may have their rated current values applied simultaneously (in this case the anode terminal current will be four times the rated current value of an individual terminal pair). above 85 c, derate linearly to zero at 150 c lead temperature. absolute maximum ratings, t a = 25 c (unless otherwise noted) tisp6ntp2a programmable protector
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. recommended operating conditions min. typ. max. unit c g gate decoupling capacitor 100 220 nf r1, r2 series resistor for gr-1089-core first-level surge survival series resistor for itu-t recommendation k.20 series resistor for itu-t recommendation k.21 series resistor for iec 61000-4-5:1995, class 5, 1.2/50 or 10/700 40 12 20 4 ? electrical characteristics for any section, t a = 25 c (unless otherwise noted) parameter test conditions min. typ. max. unit i d off-state current v d =v drm , i g =0 t j =25 c-5 a t j =85 c-50 a v (bo) breakover voltage i t = -20 a, iec 61000-4-5:1995 combination impulse generator, v gg =-50v i t = -18 a, i3124 impulse generator, v gg =-50v -70 -70 v t (br) breakdown time i t = -18 a, i3124 impulse generator, v (br) <-50v 2 s v f forward voltage i f = 0.6 a, t w = 500 s, v gg =-50v i f =18a, t w = 500 s, v gg =-50v 3 5 v v frm peak forward recovery voltage i f = 20 a, iec 61000-4-5:1995 combination impulse generator, v gg =-50v i f = 18 a, i3124 impulse generator, v gg =-50v 15 15 v t fr forward recovery time i f = 18 a, i3124 impulse generator, v gg =-50v v f > 10 v v f > 5 v 2 4 s i h holding current i t = -1 a, di/dt = 1a/ms, v gg =-50v, t j =85 c -150 ma i gks gate reverse current v gg =v gkrm , v ak =0 t j =25 c-5 a t j =85 c-50 a i gat gate reverse current, on state i t =-0.6a, t w = 500 s, v gg =-50v -1 ma i gaf gate reverse current, forward conducting state i f = 0.6 a, t w = 500 s, v gg = -50 v -40 ma i gt gate trigger current i t =-5a, t p(g) 20 s, v gg =-50v 5 ma v gt gate trigger voltage i t =-5a, t p(g) 20 s, v gg =-50v 2.5 v c ak anode-cathode off- state capacitance f=1mhz, v d =1v, i g = 0, (see note 3) v d = -3 v 100 pf v d =-50v 60 pf note 3: these capacitance measurements employ a three terminal c apacitance bridge incorporating a guard circuit. the unmeasured device terminals are a.c. connected to the guard terminal of the bridge. thermal characteristics tisp6ntp2a programmable protector parameter test conditions min. typ. max. unit r ja junction to free air thermal resistance p tot =0.52w, t a = 85 c, 5 cm 2 , fr4 pcb 160 c/w
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. parameter measurement information tisp6ntp2a programmable protector figure 1. principal terminal and gate transfer characteristics pm6xaia -v i s v s v gg v d i h i t v t i tsm i tsp v (bo) i (bo) i d quadrant i forward conduction characteristic +v +i i f v f i fsm (= |i tsm |) i fsp (= |i tsp |) -i quadrant iii switching characteristic v gk(bo) principal terminal v-i characteristic i gt i gat i gaf i f +i k -i k i t -i g +i g gate transfer characteristic i k i g
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. operation of gated protectors tisp6ntp2a programmable protector applications information negative overvoltages (figure 2) are initially clipped close to the slic negative supply rail value (v bat ) by the conduction of the transistor base-emitter and the thyristor gate-cathode junctions. if sufficient current is available from the overvoltage, then the thyris tor will crowbar into a low voltage ground referenced on-state condition. as the overvoltage subsides, the high holding current of the crowbar thyris tor prevents d.c. latchup. the common gate of each thyristor pair is connected the appropriate slic battery feed voltage (v bat1 or v bat2 ). the negative protection voltage, v (bo) , will be the sum of the gate supply (v bat ) and the peak gate (terminal)-cathode voltage (v gt ). under a.c. overvoltage conditions v gt will be less than 2.5 v. the integrated transistor buffer in the tisp6ntp2a greatly reduces protectors source and sink current loading on the v bat supply. without the transistor, the thyristor gate current would charge the v bat supply. an electronic power supply is not usually designed to be charged like a battery. as a result, the electronic supply would switch off and the thyristor gate current would provide the slic supply current. normally the slic current would be less than the gate current, which would cause the supply voltage to increase and destroy the slic by a supply overvoltage. the integrated transistor buffer removes this problem. fast rising impulses will cause short term overshoots in gate-cathode voltage. the negative protection voltage under impulse co nditions will also be increased if there is a long connection between the gate decoupling capacitor and the gate terminal. during the initial rise of a fast impulse, the gate current (i g ) is the same as the cathode current (i k ). rates of 60 a/ s can cause inductive voltages of 0.6 v in 2.5 cm of printed wiring track. to minimize this inductive voltage increase of protection voltage, the length of the capacitor to gate te rminal tracking should be minimized. figure 2 and figure 3 show how the tisp6ntp2a limits overvoltages. the tisp6ntp2a thyristor sections limit negative overvoltage s and the diode sections limit positive overvoltages. figure 3. positive overvoltage condition figure 2. negative overvoltage condition c2 100 nf i g slic 2 tisp6ntp2a i k ai6xbn c1 100 nf slic 1 slic protector 0 v 0 v v bat2 v bat1 r1a r1b r2a r2b c2 100 nf i g slic 2 tisp6ntp2a ai6xbo c1 100 nf slic 1 slic protector 0 v 0 v v bat2 v bat1 i f r1a r1b r2a r2b
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. operation of gated protectors (continued) tisp6ntp2a programmable protector applications information positive overvoltages (figure 3) are clipped to ground by forward conduction of the diode section in the tisp6ntp2a. fast risin g impulses will cause short term overshoots in forward voltage (v frm ). central office application to bellcore gr-1089-core issue 1 the most stressful impulse for first-level surge testing (section 4.5.7) is the 1000 v, 10/1000 impulse. to limit the circuit c urrent to the tisp6ntp2a rating of 20 a requires the total circuit resistance to be 1000/20 = 50 ? . subtracting the generator fictive source impedance of 10 ? gives 40 ? as the required series resistor value for the tisp6ntp2a (r1a, r1b, r2a and r2b). the various first level impulse current levels are shown in table 1. the maximum 1.2/50 and 2/10 current levels of 56 a are below the tisp6ntp2a ratings of 60 a and 85 a. in table 1, the designation 2x20 means that each conductor has a simultaneous peak current of 20 a and 2x20 = 40 a flows in the anode (g round) connection. central office application to itu-t recommendation k.20 the test level of 1000 v 10/700 delivers a peak short-circuit current level of 25 a, which is equal to the tisp6ntp2a rated val ue. a series resistor (r1a, r1b, r2a and r2b) is required to ensure coordinated operation with the primary protector at the 4000 v test leve l. the resistor value will be set by the sparkover voltage of the primary protector. a sparkover voltage of 300 v will give a 300/25 = 12 ? series resistor. local subscribers line equipment to itu-t recommendation k.21 the test level of 1500 v 10/700 delivers a peak short-circuit current level of 37.5 a. to limit the circuit current to the tisp 6ntp2a rating of 25 a requires the total circuit resistance to be 1500/25 = 60 ? . subtracting the generator fictive source impedance of 40 ? gives 20 ? as the required series resistor value for the tisp6ntp2a. even at the 1500 v test level, this resistor develops 25x20 = 500 v, which s hould ensure the coordination with the primary protector sparkover. ta ble 1 . first-level surge currents wa veshape open-circuit voltage v short-c ircuit current a generator resistance ? wires tested to t a l s e r i e s resistance ? i t a 2/10 2500 500 5 both 22.5 2x56 1.2/50 8/20 2500 500 2 + 3/wire single 45 56 both 28.5 2x53 10/1000 1000 100 10 single 50 20 both 25 2x20
june 1998 - revised july 2008 specifications are subject to change without notice. customers should verify actual device performance in their specific applications. indoor pots lines to itu-t recommendation k.21. k.22 and iec 61000-4-5: 1995 tisp6ntp2a programmable protector internal pots lines from will and isdn-ta equipment are in a relatively unexposed environment. if these lines are galvanically isolated (floating), the return path for any induced surges can only be through equipment capacitance or insulation breakdown. the most stressful condition would be when the pots lines are not galvanically isolated. such a case is when an isdn-ta has a c ommon connection between the incoming isdn line and the internal pots lines. the isdn line is likely to be ground referenced and may have primary protection at the subscriber connection. if the primary protection operates, it provides a direct return to ground. itu-t recommendation k.22 for a floating 4-conductor t/s bus uses a 1 kv 1.2/50 or 2/10 impulse, capacitively coupled via 8 nf to the bus conductors. very little circulating current is likely to flow during k.22 testing. if the t/s bus has a ground return, then the testing changes to itu-t recommendation k.21. the required series resistor values for k.21 and the tisp6ntp2a have been calculated earlier. in iec 61000-4-5: 1995 the highest specified test level is class 5. for unshielded symmetrically operated lines, class 5 testin g uses a 4000 v combination wave (1.2/50, 8/20) generator to apply a simultaneous impulse to all conductors. for the four conductors of the two pots lines, the currents are equalized by the use of specified 160 ? feed resistors. as the generator fictive source impedance is 2 ? , the peak current in each conductor is 4000/(2x4 + 160) = 24 a. this is less than the 60 a tisp6ntp2a rating. if the lines are long and exit the building, testing is done with a 10/700 generator. in this case the feed resistors are 100 ? and the fictive impedance is 15 ? . the peak current in each conductor will be 4000/(15x4 + 100) = 25 a. this value is the same as the tisp6ntp2a rating. as the equipment connected to the pots line may have uncoordinated protection, it is desirable to provided the ring-tip pair cu rrent sharing to the tisp6ntp2a by series resistors (r1a, r1b, r2a and r2b). a value of 4 ? should be sufficient to ensure sharing. applications information tisp is a trademark of bourns, ltd., a bourns company, and is registered in u.s. patent and trademark office. bourns is a registered trademark of bourns, inc. in the u.s. and other countries.
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