1 www.semtech.com protection products - railclamp ? ? ? ? ? RCLAMP0554S railclamp ? ? ? ? ? low capacitance tvs diode array description features circuit diagram schematic and pin configuration revision 10/21/2009 a railclamp ? is a low capacitance tvs array designed to protect high speed data interfaces. this series has been specifically designed to protect sensitive compo- nents which are connected to data and transmission lines from overvoltage caused by electrostatic dis- charge (esd) , electrical fast transients (eft) , and lightning. the unique design incorporates eight surge rated, low capacitance steering diodes and a tvs diode in a single package. during transient conditions, the steering diodes direct the transient to either the positive side of the power supply line or to ground. the internal tvs diode prevents over-voltage on the power line, protecting any downstream components. the rclamp ? 0554s is in a 6-lead sot-23 package. the leads are finished with lead-free matte tin. each device will protect up to four high-speed lines. they may be used to meet the esd immunity requirements of iec 61000-4-2, level 4 (15kv air, 8kv contact discharge). the combination of small size, low capaci- tance, and high surge capability makes them ideal for use in applications such as 10/100 ethernet, usb 2.0, and video interfaces. applications mechanical characteristics ? usb 2.0 power and data line protection ? video graphics cards ? monitors and flat panel displays ? digital video interface (dvi) ? notebook computers ? ieee 1394 firewire ports ? esd protection for high-speed data lines to iec 61000-4-2 (esd) 15kv (air), 8kv (contact) iec 61000-4-4 (eft) 40a (5/50ns) iec 61000-4-5 (lightning) 25a (8/20 s) ? array of surge rated diodes with internal tvs diode ? small package saves board space ? protects four i/o lines and voltage bus ? low capacitance: 5pf (vr=0v) ? low clamping voltage ? low operating voltage: 5.0v ? solid-state silicon-avalanche technology ? jedec sot-23 6l package ? pb-free, halogen free, rohs/weee compliant ? molding compound flammability rating: ul 94v-0 ? marking : marking code + date code ? packaging : tape and reel sot-23 6l (top view) 5 13 4 6 2
2 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S absolute maximum rating electrical characteristics (t=25 o c) r e t e m a r a pl o b m y ss n o i t i d n o cm u m i n i ml a c i p y tm u m i x a ms t i n u e g a t l o v f f o - d n a t s e s r e v e rv m w r 5v e g a t l o v n w o d k a e r b e s r e v e rv r b i t a m 1 =6 v t n e r r u c e g a k a e l e s r e v e ri r v m w r c 5 2 = t , v 5 =5 . 0a e g a t l o v g n i p m a l cv c i p p s 0 2 / 8 = p t , a 1 = d n g o t o / i y n a 8 . 9v e g a t l o v g n i p m a l cv c i p p s 0 2 / 8 = p t , a 0 1 = d n g o t o / i y n a 2 1v e g a t l o v g n i p m a l cv c i p p s 0 2 / 8 = p t , a 5 2 = d n g o t o / i y n a 5 1v e c n a t i c a p a c n o i t c n u jc j d n g o t o / i y n a v r z h m 1 = f , v 0 = 5f p o / i o t o / i v r z h m 1 = f , v 0 = 3f p g n i t a rl o b m y se u l a vs t i n u ) s 0 2 / 8 = p t ( r e w o p e s l u p k a e pp k p 5 7 3s t t a w ) s 0 2 / 8 = p t ( t n e r r u c e s l u p k a e pi p p 5 2a ) r i a ( 2 - 4 - 0 0 0 1 6 c e i r e p d s e ) t c a t n o c ( 2 - 4 - 0 0 0 1 6 c e i r e p d s e d s e v0 3 - / + 5 2 - / + v k e r u t a r e p m e t g n i t a r e p ot j 5 2 1 + o t 5 5 -c e r u t a r e p m e t e g a r o t st g t s 0 5 1 + o t 5 5 -c
3 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S typical characteristics non-repetitive peak pulse power vs. pulse time power derating curve 0 10 20 30 40 50 60 70 80 90 100 110 0 25 50 75 100 125 150 ambient temperature - t a ( o c) % of rated power or i pp clamping voltage vs. peak pulse current 0 10 20 30 40 50 60 70 80 90 100 110 0 5 10 15 20 25 30 time (s) percent of i pp e -t td = i pp /2 waveform parameters: tr = 8s td = 20s pulse waveform forward voltage vs. forward current normalized capacitance vs. reverse voltage 0 2 4 6 8 10 12 14 0 5 10 15 20 25 30 peak pulse current - i pp (a) clamping voltage -v c (v) waveform parameters: tr = 8s td = 20s 0 0.2 0.4 0.6 0.8 1 1.2 00.511.522.533.544.55 reverse voltage (v r ) - v cj(v r ) / cj(v r =0v) f = 1 mhz 0.1 1 10 0.1 1 10 100 pulse duration - tp ( s) peak pulse power - p pp (kw) 0 1 2 3 4 5 6 7 8 9 10 0 5 10 15 20 25 30 peak pulse current - ipp (a) forward voltage - vf (v) waveform parameters: tr = 8s td = 20s
4 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S insertion loss s21 - any i/o to gnd applications information 1 2 3 4 5 start . 030 mhz 3 stop 000 . 000 000 mhz ch1 s21 log 6 db / ref 0 db 1: -1.0964 db 800 mhz 2: -1.2545 db 900 mhz 3: -6.7229 db 1.8 ghz 4: -16.4457 db 2.5 ghz 0 db -6 db -12 db -18 db -24 db -30 db -36 db 1 ghz 100 mhz 3 ghz 10 mhz 1 mhz -42 db -48 db insertion loss s21 - i/o to i/o 1 2 3 4 5 start . 030 mhz 3 stop 000 . 000 000 mhz ch1 s21 log 6 db / ref 0 db 1: -0.47220 db 800 mhz 2: -0.5278 db 900 mhz 3: -2.6811 db 1.8 ghz 4: -9.2328 db 2.5 ghz 0 db -6 db -12 db -18 db -24 db -30 db -36 db 1 ghz 100 mhz 3 ghz 10 mhz 1 mhz -42 db -48 db esd clamping - between any i/o and gnd (-8kv contact per iec 61000-4-2) note: data is taken with a 10x attenuator esd clamping - between any i/o and gnd (+8kv contact per iec 61000-4-2) note: data is taken with a 10x attenuator
5 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S device connection options for protection of four high-speed data lines the RCLAMP0554S is designed to protect four data lines from transient over-voltages by clamping them to a fixed reference. when the voltage on the protected line exceeds the reference voltage (plus diode v f ) the steering diodes are forward biased, conducting the transient current away from the sensitive circuitry. data lines are connected at pins 1, 3, 4 and 6. the negative reference (ref1) is connected at pin 2. this pin should be connected directly to a ground plane on the board for best results. the path length is kept as short as possible to minimize parasitic inductance. the positive reference (ref2) is connected at pin 5. the options for connecting the positive reference are as follows: 1. to protect data lines and the power line, connect pin 5 directly to the positive supply rail (v cc ). in this configuration the data lines are referenced to the supply voltage. the internal tvs diode prevents over-voltage on the supply rail. 2. the RCLAMP0554S can be isolated from the power supply by adding a series resistor between pin 5 and v cc . a value of 100k is recommended. the internal tvs and steering diodes remain biased, providing the advantage of lower capacitance. 3. in applications where no positive supply reference is available, or complete supply isolation is desired, the internal tvs may be used as the reference. in this case, pin 5 is not connected. the steering diodes will begin to conduct when the voltage on the protected line exceeds the working voltage of the tvs (plus one diode drop). esd protection with railclamps ? ? ? ? ? railclamps are optimized for esd protection using the rail-to-rail topology. along with good board layout, these devices virtually eliminate the disadvantages of using discrete components to implement this topology. consider the situation shown in figure 1 where dis- crete diodes or diode arrays are configured for rail-to- rail protection on a high speed line. during positive duration esd events, the top diode will be forward biased when the voltage on the protected line exceeds data line and power supply protection using vcc as reference data line protection with bias and power supply isolation resistor data line protection using internal tvs diode as reference applications information
6 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S pin descriptions the reference voltage plus the v f drop of the diode. for negative events, the bottom diode will be biased when the voltage exceeds the v f of the diode. at first approximation, the clamping voltage due to the charac- teristics of the protection diodes is given by: v c = v cc + v f (for positive duration pulses) v c = -v f (for negative duration pulses) however, for fast rise time transient events, the effects of parasitic inductance must also be consid- ered as shown in figure 2. therefore, the actual clamping voltage seen by the protected circuit will be: v c = v cc + v f + l p di esd /dt (for positive duration pulses) v c = -v f - l g di esd /dt (for negative duration pulses) esd current reaches a peak amplitude of 30a in 1ns for a level 4 esd contact discharge per iec 61000-4-2. therefore, the voltage overshoot due to 1nh of series inductance is: v = l p di esd /dt = 1x10 -9 (30 / 1x10 -9 ) = 30v example: consider a v cc = 5v, a typical v f of 30v (at 30a) for the steering diode and a series trace inductance of 10nh. the clamping voltage seen by the protected ic for a positive 8kv (30a) esd pulse will be: v c = 5v + 30v + (10nh x 30v/nh) = 335v this does not take into account that the esd current is directed into the supply rail, potentially damaging any components that are attached to that rail. also note that it is not uncommon for the v f of discrete diodes to exceed the damage threshold of the protected ic. this is due to the relatively small junction area of typical discrete components. it is also possible that the power dissipation capability of the discrete diode will be exceeded, thus destroying the device. the railclamp is designed to overcome the inherent disadvantages of using discrete signal diodes for esd suppression. the railclamp?s integrated tvs diode figure 1 - ?rail- figure 1 - ?rail- figure 1 - ?rail- figure 1 - ?rail- figure 1 - ?rail- t t t t t o-rail? pr o-rail? pr o-rail? pr o-rail? pr o-rail? pr o o o o o t t t t t ection t ection t ection t ection t ection t opology opology opology opology opology (first approximation) (first approximation) (first approximation) (first approximation) (first approximation) figure 2 - the effects of parasitic inductance figure 2 - the effects of parasitic inductance figure 2 - the effects of parasitic inductance figure 2 - the effects of parasitic inductance figure 2 - the effects of parasitic inductance when using discrete components to implement when using discrete components to implement when using discrete components to implement when using discrete components to implement when using discrete components to implement rail- rail- rail- rail- rail- t t t t t o-rail pr o-rail pr o-rail pr o-rail pr o-rail pr o o o o o t t t t t ection ection ection ection ection figure 3 - rail- figure 3 - rail- figure 3 - rail- figure 3 - rail- figure 3 - rail- t t t t t o-rail pr o-rail pr o-rail pr o-rail pr o-rail pr o o o o o t t t t t ection using ection using ection using ection using ection using railclam railclam railclam railclam railclam p t p t p t p t p t v v v v v s arra s arra s arra s arra s arra ys ys ys ys ys applications information (continued)
7 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S applications information (continued) helps to mitigate the effects of parasitic inductance in the power supply connection. during an esd event, the current will be directed through the integrated tvs diode to ground. the maximum voltage seen by the protected ic due to this path will be the clamping voltage of the device. universal serial bus esd protection the RCLAMP0554S may also be used to protect the usb ports on monitors, computers, peripherals or portable systems. each device will protect up to two usb ports (figure 4). when the voltage on the data lines exceed the bus voltage (plus one diode drop), the internal rectifiers are forward biased conducting the transient current away from the protected controller chip. the tvs diode directs the surge to ground. the tvs diode also acts to suppress esd strikes directly on the voltage bus. thus, both power and data pins are protected with a single device. figure 4 - dual usb port protection RCLAMP0554S
8 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S outline drawing - so-8 land pattern -sot23 6l outline drawing -sot23 6l .110 bsc .037 bsc detail aaa c seating ccc c 2x n/2 tips 2x e/2 6 see detail a1 a a2 bxn a .008 12 n e .060 .114 .063 .122 .010 - 6 a 0.20 1.60 3.10 2.80 bsc 0.95 bsc .069 1.50 2.90 .020 0.25 1.75 0.50 - ei l (l1) c 01 0.25 plane gage h 2.80 .110 bbb c a-b d 0 .008 - .004 .012 .003 (.024) .018 - .035 .000 .035 - - .045 0.10 0.20 10 0 - 10 1.15 (0.60) 0.45 .024 .009 0.30 0.08 .057 .051 .006 0.00 .90 0.90 0.22 0.60 - 0.15 1.45 1.30 - - 1.90 bsc .075 bsc a e1 d e b c plane d datums and to be determined at datum plane controlling dimensions are in millimeters (angles in degrees). dimensions "e1" and "d" do not include mold flash, protrusions 3. or gate burrs. notes: 1. 2. -a- -b- -h- side view nom inches dimensions l1 aaa bbb ccc 01 n dim c e e1 l e1 e d a1 a2 b a min millimeters max min nom max dimensions inches y z dim g p x c millimeters p (c) z y g .043 .141 .055 (.098) .037 .024 1.40 (2.50) 0.95 0.60 1.10 3.60 x dimensions inches y z dim g p x c millimeters this land pattern is for reference purposes only. consult your manufacturing group to ensure your company's manufacturing guidelines are met. notes: 1.
9 ? 2009 semtech corp. www.semtech.com protection products RCLAMP0554S contact information semtech corporation protection products division 200 flynn road, camarillo, ca 93012 phone: (805)498-2111 fax (805)498-3804 marking codes ordering information tape and reel specification e p a t h t d i w ) x a m ( , bd1 de f k ) x a m ( p0 p2 p) x a m ( tw m m 8 m m 2 . 4 ) 5 6 1 . ( m m 1 . 0 + 5 . 1 m m 0 . 0 - m m 0 . 1 5 0 . 0 0 1 . 0 5 7 . 1 m m 5 0 . 0 5 . 3 m m m m 4 . 2 1 . 0 0 . 4 m m 1 . 0 0 . 4 m m 5 0 . 0 0 . 2 m m m m 4 . 0 m m 0 . 8 m m 3 . 0 + m m 1 . 0 - 0 a0 b0 k m m 5 0 . 0 - / + 3 2 . 3m m 5 0 . 0 - / + 7 1 . 3m m 5 0 . 0 - / + 7 3 . 1 yw = 2 - alphanumeric characters for date code user direction of feed pin 1 location r e b m u n t r a p d a e l h s i n i f r e p y t q l e e r e z i s l e e r t c t . s 4 5 5 0 p m a l c rn i t e t t a m0 0 0 , 3h c n i 7 v54 yw
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