1 www.semtech.com protection products stf202-22 and stf202-30 usb upstream port filter and tvs for emi filtering and esd protection description features schematic and pin configuration revision 08/11/04 the stf202 is a combination emi filter and line termi- nation device with integrated tvs diodes for use on upstream usb ports. it is constructed using a propri- etary technology that allows passive components and tvs diodes to be integrated in the same package. each device will provide termination , filtering , and esd protection for one upstream usb port. the stf202 is an easily implemented solution for meeting the require- ments of revision 1.1 of the universal serial bus specification. usb line termination is achieved with series 22 ? or 30 ? resistors on both the d+ and d- usb lines. these resistors preserve signal integrity by matching the cable impedance to that of the differential driver. the 1.5k ? pull-up resistor completes the termination circuit on each line. this resistor is required by the usb specifi- cation to identify the equipment as either a full-speed (connected to d+ line) or low-speed (connected to d- line) device. the 47pf capacitors are used to bypass high frequency energy to ground and for edge rate control of the usb signals. finally, the stf202 con- tains tvs diodes for esd protection of both (d+ and d-) data lines and the voltage bus (v bus ). the tvs diodes provide effective suppression of esd voltages in excess of 15kv (air discharge) and 8kv (contact discharge) per iec 61000-4-2, level 4. the small size and integrated feature of the stf202 minimizes required board space and increases system reliability. the stf202 is suitable for use in usb hubs, computers, peripherals, and portable devices. applications mechanical characteristics ? usb hubs ? portable electronics ? cellular handsets ? modems ? peripherals ? servers, desktop, notebook, and handheld computers ? bidirectional emi/rfi filtering and line termination with integrated esd protection ? esd protection for usb power (v bus ) and data lines (d+ and d-) to iec 61000-4-2 (esd) 15kv (air), 8kv (contact) iec 61000-4-4 (eft) 40a (5/50ns) ? filtering and termination for two usb data lines ? different series resistors for impedance matching ? low tvs operating voltage (5.25v) ? low leakage current ? low capacitance ? solid-state technology ? eiaj sot23 6l package ? molding compound flammability rating: ul 94v-0 ? marking : marking code ? packaging : tape and reel per eia 481 s0t23-6l (top view) circuit diagram .
2 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 absolute maximum rating electrical characteristics g n i t a rl o b m y se u l a vs t i n u r e w o p e t a t s - y d a e t sp k p 0 0 1w m 2 - 4 - 0 0 0 1 6 c e i r e p e g r a h c s i d r i a d s e 2 - 4 - 0 0 0 1 6 c e i r e p e g r a h c s i d t c a t n o c d s e v d s e 6 1 0 1 v k e r u t a r e p m e t g n i r e d l o s d a e lt l ) . c e s 0 1 ( 0 6 2c 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 0 4 -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 x x - 2 0 2 f t s 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 r s v tv m w r 5 2 . 5v e g a t l o v n w o d k a e r b e s r e v e r s v tv 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 r s v ti r v m w r c 5 2 = t , v 5 2 . 5 = v n e e w t e b s u b d n a n i p d n u o r g 5a t n e r r u c e g a k a e l e s r e v e r s v ti r v m w r c 5 2 = t , v 3 . 3 = a t a d y n a n e e w t e b . d n u o r g d n a n i p ) - d , + d ( 1a e c n a t i c a p a c n o i t c n u j s v tc j d n a s n i p o / i n e e w t e b e c i v e d h c a e , d n u o r g v r z h m 1 = f , v 0 = 0 1f p ) 2 2 - 2 0 2 f t s ( e c n a t s i s e r s e i r e sr s e n i l h c a e0 22 24 2 ? ) 0 3 - 2 0 2 f t s ( e c n a t s i s e r s e i r e sr s e n i l h c a e7 20 33 3 ? e c n a t s i s e r p u l l u pr p u e n i l h c a e5 3 . 15 . 15 6 . 1k ? r o t i c a p a cce n i l h c a e7 4f p e c n a t i c a p a c l a t o tc t o t r o t u p n i n e e w t e b d n a d n u o r g d n a t u p t u o v s u b d e d n u o r g v r z h m 1 = f , v 0 = 0 6f p
3 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 typical characteristics esd clamping (8kv contact) esd clamping (15kv air) typical insertion loss 0.030mhz 2.0ghz 0 db -10 db -20 db analog crosstalk (d+ to d-) 0.030 mh z 1 gh z 0 db -20 db -60 db
4 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 figure 1 - stf202 circuit diagram device connection the stf202 is designed to provide termination, emi filtering and esd protection for two usb i/o lines. the equivalent circuit diagram is shown in figure 1. the device is connected as follows: 1. 1. 1. 1. 1. full-speed devices: for full-speed devices the pull- up resistor is connected to the d+ line. pin 1 is connected to the voltage supply line (v bus ). the input of the d+ line is routed into pin 3 and out of pin 4. the input of the d- line is connected at pin 2 and the output at pin 5. pin 6 is connected to ground. 2. 2. 2. 2. 2. low-speed devices: for low speed devices the pull-up resistor is connected to the d- line. pins 1 is connected to the voltage supply line (v bus ). the input of the d- line is connected at pin 3 with the output taken at pin 4. the input of the d+ line is connected to pin 2 and the output is at pin 5. pin 6 is connected to ground. usb port design considerations the universal serial bus (usb) specification requires termination and filtering components for proper opera- tion. in addition, an open usb socket is vulnerable to hazardous esd discharges in excess of 15kv. these discharges can may occur on the data lines or the voltage bus. the stf202 is an easily implemented solution designed to meet the termination and emi filter requirements of the usb specification revision 1.1. it also provides esd protection to iec 61000-4-2, level 4. a simplified usb port is shown in figure 3. usb line termination is achieved with series resistors on both the d+ and d- lines. these resistors preserve signal integrity by matching the cable impedance to that of the differential driver. 15k ? pull-down resistors are used to identify a downstream port while an upstream port is identified with a 1.5k ? pull up resistor on either the d+ (full speed devices) or the d- (low speed de- vices) data line. capacitors are used to bypass high frequency energy to ground and for edge rate control of the usb signals. tvs diodes are added for esd protection of both (d+ and d-) data lines and the voltage bus (v bus ). a power distribution switch and voltage regulator provide the power management functions of the port. figure 2 - stf202 connection diagram (full speed devices) semtech provides a complete solution to simplify usb port design (figure 4). the stf201 and stf202 integrate all of the components necessary for line termination, bidirectional emi filtering, and esd protec- tion on downstream (stf201) or upstream (stf202) ports. the sc5826 is a dual port power switch that provides individual or ganged port switching, fault reporting, and inrush current limiting as required by the usb specification. the sc5205 uldo provides a stable voltage to the usb controller. board placement and layout guidelines. designing a usb hub to meet emi and esd immunity requirements requires a combination of optimum component placement, trace routing, and good circuit design practices. some general guidelines are given below: z avoid running d+ and d- signal line traces near high speed clock lines or similar signal lines. z avoid running critical signal lines near board edges. z locate the usb controller chip near the usb connectors. z place the stf202 near the usb connector to restrict transient coupling. z minimize the path length between the usb connec- tor and the stf202 1 2 34 5 6 . applications information
5 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 figure 3 - usb port components figure 4 - typical usb hub design applications information
6 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 outline drawing - sot23 6l land pattern - 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 .118 .010 - 6 a 0.20 1.60 3.00 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 h 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 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 this land pattern is for reference purposes only. consult your manufacturing group to ensure your company's manufacturing guidelines are met. notes: 1. dimensions inches y z dim g p x c millimeters .043 .141 .055 (.098) .037 .024 1.40 (2.50) 0.95 0.60 1.10 3.60 dimensions inches y z dim g p x c millimeters p (c) z y g x
7 ? 2004 semtech corp. www.semtech.com protection products protection products stf202-22 and stf202-30 marking codes ordering information r e b m u n t r a p g n i k r a m e d o c 2 2 - 2 0 2 f t s2 2 2 0 3 - 2 0 2 f t s0 3 2 r e b m u n t r a ph s i n i f d a e l r e p y t q l e e r e z i s l e e r c t . 2 2 - 2 0 2 f t sb p n s0 0 0 , 3h c n i 7 c t . 0 3 - 2 0 2 f t sb p n s0 0 0 , 3h c n i 7 t c t . 2 2 - 2 0 2 f t se e r f b p0 0 0 , 3h c n i 7 t c t . 0 3 - 2 0 2 f t se e r f b p0 0 0 , 3h c n i 7 h c n a r b n a w i a t 0 8 3 3 - 8 4 7 2 - 2 - 6 8 8 : l e t fx a0 9 3 3 - 8 4 7 2 - 2 - 6 8 8 : h b m g d n a l r e z t i w s h c e t m e s h c n a r b n a p a j 0 5 9 0 - 8 0 4 6 - 3 - 1 8 : l e t 1 5 9 0 - 8 0 4 6 - 3 - 1 8 : x a f h c n a r b a e r o k tl e7 7 3 4 - 7 2 5 - 2 - 2 8 : f6 7 3 4 - 7 2 5 - 2 - 2 8 : x a ) . k . u ( d e t i m i l h c e t m e s 0 0 6 - 7 2 5 - 4 9 7 1 - 4 4 : l e t 1 0 6 - 7 2 5 - 4 9 7 1 - 4 4 : x a f e c i f f o i a h g n a h s t0 3 8 0 - 1 9 3 6 - 1 2 - 6 8 : l e 1 3 8 0 - 1 9 3 6 - 1 2 - 6 8 : x a f l r a s e c n a r f h c e t m e s 0 0 - 2 2 - 8 2 - 9 6 1 ) 0 ( - 3 3 : l e t 8 9 - 2 1 - 8 2 - 9 6 1 ) 0 ( - 3 3 : x a f f o y r a i d i s b u s d e n w o - y l l o h w a s i g a l a n o i t a n r e t n i h c e t m e s . a . s . u e h t n i s r e t r a u q d a e h s t i s a h h c i h w , n o i t a r o p r o c h c e t m e s h b m g y n a m r e g h c e t m e s 3 2 1 - 0 4 1 - 1 6 1 8 ) 0 ( - 9 4 : l e t 4 2 1 - 0 4 1 - 1 6 1 8 ) 0 ( - 9 4 : x a f contact information for semtech international ag
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