features ? sc duplex single mode transceiver ? intermediate sonet oc12 sdh stm (i4.1) compliant ? single +5 v power supply ? multisourced 1 x 9 pin configuration ? aqueous washable plastic package ? interchangeable with led multisourced 1 x 9 transceivers ? unconditionally eyesafe laser iec 825/cdrh class 1 compliant applications ? sonet/sdh equipment interconnect ? atm description the HFCT-5208 transceiver is a high performance, cost effective module for serial optical data communications applications specified for a signal rate of 622 mbd. it is designed to provide a sonet/sdh compliant link for 622 mb/s intermediate reach links. this module is designed for single mode fiber and operates at a nominal wavelength of 1300 nm. it incorporates hewlett-packards high perfor- mance, reliable, long wavelength optical devices and proven circuit technology to give long life and consistent service. the transmitter section uses an advanced fabry perot laser with full iec 825 and cdrh class 1 eye safety. sc duplex single mode transceiver technical data HFCT-5208 the receiver section uses a movpe grown planar pin photo- detector for low dark current and excellent responsivity. a pseudo-ecl logic interface simplifies interface to external circuitry.
2 connection diagram pin descriptions: pin 1. receiver signal ground v cc : directly connect this pin to the receiver ground plane. pin 2. receiver data out rd+: terminate this high-speed, differential, pecl output with standard pecl techniques. pin 3. receiver data out bar rdC: terminate this high-speed, differential, pecl output with standard pecl techniques. pin 4. signal detect sd: normal optical input levels to the receiver result in a logic 1 output. low optical input levels to the receiver result in a fault condition indicated by a logic 0 output. this signal detect output can be used to drive a pecl input on an upstream circuit, such as signal detect input or loss of signal- bar. 1 2 3 4 5 6 7 8 9 top view receiver signal ground receiver data out receiver data out bar signal detect receiver power supply transmitter power supply transmitter data in bar transmitter data in transmitter signal ground n/c n/c pin 5. receiver power supply v cc : provide +5 v dc via the recommended transmitter power supply filter circuit. locate the power supply filter circuit as close as possible to the v cc pin. pin 6. transmitter power supply v cc : provide +5 v dc via the recommended transmitter power supply filter circuit. locate the power supply filter circuit as close as possible to the v cc pin. pin 7. transmitter data in bar tdC: terminate this high-speed, pecl output with standard pecl techniques. pin 8. transmitter data in td+: terminate this high-speed, pecl output with standard pecl techniques. pin 9. transmitter signal ground v cc : directly connect this pin to the transmitter ground plane. mounting studs the mounting studs are provided for mechanical attachment to the circuit board. they are embedded in the nonconductive plastic housing and are not tied to the transceiver internal circuit and should be soldered into plated- through holes on the printed circuit board.
3 functional description receiver section design the receiver section contains an ingaas/inp photo detector and a preamplifier within the receptacle, coupled to a postamp/ decision circuit on a separate circuit board. the postamplifier is ac coupled to the preamplifier as illustrated in figure 1. the coupling capacitor is large enough to pass the sonet/sdh test pattern at 622 mbd without significant distor- tion or performance penalty. if a lower signal rate, or a code which has significantly more low frequency content is used, sensitivity, jitter and pulse distortion could be degraded. figure 1 also shows a filter net- work which limits the bandwidth of the preamp output signal. the filter is designed to bandlimit the preamp output noise and thus improve the receiver sensitivity. these components will also reduce the sensitivity of the receiver as the signal bit rate is increased above 622 mbd. noise immunity the receiver includes internal circuit components to filter power supply noise. under some conditions of emi and power supply noise, external power supply filtering may be necessary. if receiver sensitivity is found to be degraded by power supply noise, the filter network illus- trated in figure 2 may be used to improve performance. the values of the filter components are general recommendations and may be changed to suit a particular system environment. shielded inductors are recommended. terminating the outputs the pecl data outputs of the receiver may be terminated with the standard thevenin-equivalent 50 ohm to v cc -2 v termination. other standard pecl terminating techniques may be used. the two outputs of the receiver should be terminated with identical load circuits to avoid unnecessarily large ac current in v cc . if the outputs are loaded identically, the ac current is largely nulled. the sd output of the receiver is pecl logic and must be loaded if it is to be used. the signal detect circuit is much slower than the data path, so the ac noise generated by an asymmetrical load is negligible. power consumption may be reduced by using a higher than normal load impedance for the sd output. transmission line effects are not generally a problem as the switching rate is slow. the signal detect circuit the signal detect circuit works by sensing the peak level of the received signal and comparing this level to a reference. figure 1. receiver block diagram. transimpedance
preamplifier limiting
amplifier receiver
receptacle gnd filter pecl
output
buffer pecl
output
buffer data out data out sd signal detect
circuit
4 functional description transmitter section design the transmitter section uses a buried heterostructure fabry- perot laser as its optical source. the package of this laser is designed to allow repeatable coupling into single mode fiber. in addition, this package has been designed to be compliant with iec 825 eye safety require- ments under all fault conditions. the optical output is controlled by a custom ic which detects the laser output via the monitor photodiode. this ic provides both dc and ac current drive to the laser to ensure correct modulation, eye diagram and extinction ratio over temperature, supply voltage and life. pcb mounting the HFCT-5208 has two solderable mounting studs. these studs are not electrically connected. the transceiver is designed for common production processes. it may be wave soldered and aqueous washed providing the process plug is in place. each process plug can only be used once during processing, although with subsequent use, it can be used as a dust cover. figure 3. simplified transmitter schematic. pecl
input laser
modulator laser
bias
driver laser
bias
control data data laser photodiode
(rear facet
monitor) figure 2. p filter network for noise filtering. v cc filtered v cc to data link 100 nh 100 nf 10 ? 10 nf
5 transmitter section (ambient operating temperature t a = 0 c to +70 c, v cc = 4.75 v to 5.25 v) parameter symbol minimum maximum units notes output center wavelength l ce 1274 1356 nm - output spectral width (rms) dl - 2.5 nm - average optical output power p o -15 -8 dbm 1 extinction ratio e r 8.2 - db - power supply current i cc - 140 ma 2 output eye compliant with bellcore tr-nwt-000253 and itu recommendation g.957 operating environment parameter symbol minimum maximum units power supply voltage v cc +4.75 +5.25 v ambient operating temperature HFCT-5208a/c t op C40 +85 ?c ambient operating temperature HFCT-5208b/d t op 0 +70 c performance specifications absolute maximum ratings parameter symbol minimum maximum units storage temperature t s C40 +85 c operating temperature HFCT-5208a/c C C40 +85 ?c operating temperature HFCT-5208b/d C 0 +70 c lead soldering temperature/time C C +240/10 c/s output current (other outputs) i out 030ma input voltage C gnd v cc v power supply voltage C 0 6 v receiver section (ambient operating temperature t a = 0 c to +70 c, v cc = 4.75 v to 5.25 v) parameter symbol minimum typical maximum units notes receiver sensitivity - -28 - - dbm 3 maximum input power - -7 - - dbm - alarm on - -42 - -31 dbm - hysteresis - 0.5 - 4.0 db - power supply current i cc - 105 150 ma 4 data outputs pecl alarm output pecl notes: 1. output power is power coupled into a single mode fiber. 2. the power supply current varies with temperature. maximum current is specified at v cc = maximum at maximum temperature (not including terminations and end of life). 3. minimum sensitivity and saturation levels for a 2 23 -1 prbs with 72 ones and 72 zeros inserted. (itu-t recommendation g.958). 4. the current excludes the output load current. v
6 drawing dimensions all dimensions in millimeters min. max. ? ? ? 0.65
2.92
? ? ? 39.16
12.70
25.40
0.85
3.68
10.35
20.32
15.93
20.32 a
b
c
d
e
f
g
h
j
k dim. as shown in diagram a area
reserved
for
process
plug b c g j h d e f k (8 x 2.54 mm) pin 1 electric pins are nominally 0.46 mm/0.018 in. diameter.
mounting posts are nominally 1.27 mm/0.050 in. diameter.
7 table 1. regulatory compliance C typical performance feature test method performance electrostatic discharge mil-std-883c class 1 (>1000 v) (esd) to the electrical pins method 3015.4 electrostatic discharge variation of iec 801-2 products of this design typically (esd) to the duplex sc withstand at least 25 kv without damage receptacle. when the duplex sc connector receptacle is contacted by a human body model probe. electromagnetic fcc class b typically provide 5 db margin to fcc interference (emi) cenelec en55022 class b when tested at a certified test class b (cispr 22b) range with the transceiver mounted to a vcci class 2 circuit card without a chassis enclosure at frequencies up to 1 ghz. margins above 1 ghz are dependent on customer board and chassis designs. immunity variation of iec 801-3 typically shows 2 db margin against sensitivity when swept with a 3 v/m field from 27 mhz to 16 ghz. eye safety iec 825 license pending. cdrh class 1 license pending. regulatory compliance the HFCT-5208 is intended to enable commercial system designers to develop equipment that complies with the various regulations governing certification of information technology equipment. see the regulatory compliance table 1 for details. additional information is available from your hewlett-packard sales representative. electrostatic discharge (esd) there are two design cases in which immunity to esd damage is important. the first case is during handling of the transceiver prior to mounting it on the circuit board. it is important to use normal esd handling precautions for esd sensitive devices. these precautions include using grounded wrist straps, work benches, and floor mats in esd controlled areas. the second case to consider is static discharges to the exterior of the equipment chassis containing the transceiver parts. to the extent that the duplex sc connector is exposed to the outside of the equipment chassis, it may be subject to whatever esd system level test criteria that the equipment is intended to meet. electromagnetic interference (emi) most equipment designs utilizing these high-speed transceivers from hewlett-packard will be required to meet the requirements of fcc in the united states, cenelec en55022 (cispr 22) in europe and vcci in japan. the HFCT-5208 has been characterized without a chassis enclosure to demonstrate the robustness of the parts integral shielding. performance of a system containing these transceivers within a well-designed chassis is expected to be better than the results of those tests with no chassis enclosure. immunity equipment utilizing these hfct- 5208 transceivers will be subject to radio-frequency electromagnetic fields in some environments. these transceivers, with their integral shields, have been characterized without the benefit of a normal equipment chassis enclosure and the results are reported below. performance of a system containing these transceivers within a well-designed chassis is expected to be better than the results of these tests without a chassis enclosure.
for technical assistance or the location of your nearest hewlett-packard sales office, distributor or representative call: americas/canada: 1-800-235-0312 or 408-654-8675 far east/australasia: call your local hp sales office. japan: (81 3) 3335-8152 europe: call your local hp sales office. data subject to change. copyright ? 1997 hewlett-packard co. obsolete: 5966-0625e printed in u.s.a. 5966-1890e (11/97) handling precautions 1. the HFCT-5208 can be damaged by current surges or overvoltage. power supply transient precautions should be taken. 2. normal handling precautions for electrostatic sensitive devices should be taken. ordering information HFCT-5208 x temperature range: a = C40 c to +85 c, black case b = 0 to +70 c, black case c = C40 c to +85 c, blue case d = 0 to +70 c, blue case model name: HFCT-5208 recommended part numbers: HFCT-5208c HFCT-5208d class i laser product: this product conforms to the applicable requirements of 21 cfr 1040 at the date of manufacture. date of manufacture: ___________________ hewlett-packard ltd., whitehouse rd., ipswich, england www.hp.com/go/fiber
|
