daa with 2/4 wire hybrid XE0002B features small size - 1.25" x 1.0" x 0.5" fcc part 68 compliant ring detection 2 to 4 wire converter 1500 volt isolation 800 volt surge protection hookswitch control description the XE0002B data access arrangement provides a 'direct connect' telephone line interface. it complies with fcc part 68 hazardous voltage, surge and leakage current specifications. this component may be used as the direct connect telephone line interface for virtually any application in which voice or data is to be transmitted over the public switched telephone network. the XE0002B provides high voltage isolation, independent on/off hook control, ring detection circuitry and a 2 to 4 wire converter hybrid for use in modem applications. it operated from ? volt power supplies and occupies 1.25 square inches of board space. 1 20 2 3 4 17 5 6 7 14 8 13 9 12 10 11 v dd vcc ri rcvr xmit xmfr t1 oh gnd t2 tip ring n/c n/c n/c n/c pin configuration c a u t i o n pins 17 & 20 have 1500v isolation from the rest of the circuitry. this isolation should be preserved throughout the system xecom (top view) block diagram
typical connection diagram 2/xecom XE0002B pin name i/o description pin descriptions 1 vdd --- -5 volts. 2 vcc --- +5 volts 3 \ri o ring indicator, output, active lo, ttl. when low indicates the modem is receiving a ring signal. 4 rcvr o analog signal output from the 2-4 wire convertor. 5 xmit i analog signal input to the 2-4 wire convertor. 6 xmfr i analog input/output from the surge and protective network to the internal 2-4 wire convertor. must be tied to pin 7, t1, to use the internal 2-4 wire convertor. 7 t1 i analog signal input/output to the surge and protective network. 8 oh i off-hook controls the hookswitch relay within the XE0002B. a high on oh closes the internal relay and connects the equipment to the telephone line. 9 gnd --- ground. 10 t2 i analog signal input/output to the surge and protective network. 17 ring --- ring connection to the phone line (rj11 pin4) from the internal daa. 20 tip --- tip connection to the phone line (rj11 pin3) from the internal daa.
mechanical specifications connection diagram with external 2-4 wire converter XE0002B xecom\3 inches metric(mm) pin min max min max a 1.235 1.265 31.37 32.13 b 0.985 1.015 25.02 25.78 c 0.490 0.510 12.45 12.95 d 0.890 0.910 22.61 23.11 e 0.890 0.910 22.61 23.11 f 0.125 --- 3.18 --- g 0.040 0.060 1.02 1.52 h 0.165 0.185 4.19 4.70 j 0.090 0.110 2.29 2.79 k 0.020 0.025 0.51 0.64
4/xecom XE0002B 1200bps modem using sierra semiconductor sc11007/sc11014 typical connection diagram with silicon systems k-series family
XE0002B xecom\5 interface to exar xr2401/xr2402
power supply current vcc 6 10 ma v dd 4 6 ma transmission gain gain between transmit input and -0.5 0 +0.5 db telephone line at 1800 hz with 600 ohm termination telephone line at 1800 hz 540 600 660 ohms impedance coupler match output impedance of external 531 536 541 ohms input impedance circuitry when t1 driven directly to provide 600 ohm phone line impedance match transhybrid loss attenuation between the trans- 10 18 db mitter input and receiver output at 1khz with 600 ohm termination attenuation receive and transmit attenuation 0.8 3 db at 300 hz with 600 ohm termina- tion transmit input at 1800 hz 8 10 12 kohm impedance receive output at 1800 hz 10 100 ohm ring detect min. ac voltage between tip & 38 vrms sensitivity (on hook) ring type b ringer loop current switch on: (off hook) 2.0 3.0 volts control voltage off: (on hook) 0.5 0.8 volts loop current switch 1.0 2.0 ma control current d.c. electrical specification (vcc=+5v ?0%, vdd=-5v ?0%, ta=0 to 70 deg c) parameter conditions min typ max units fcc user instructions ringer equivalence 0.9b 6/xecom XE0002B
XE0002B xecom\7 typical characteristics
telephone line connection information when developing a product that is to be connected to the telephone line, it is necessary to use a circuit described as a data access arrangement (daa) which is approved by the appropriate governmental agency. in the us, for example, this agency is the federal communications commission (fcc), while in canada it is the department of communications (doc). these agencies test and approve the product to ensure that it meets their specifications, thereby protecting the telephone system from damage and protecting the user from high voltage transients (such as lightning strikes) which may come down the telephone l i n e . the XE0002B has been designed to meet all fcc part 68 requirements for hazardous voltage, surge protection and leakage current. if the system developed transmits data, or dtmf tones on the telephone line, the user must certify that the signals transmitted from the XE0002B meet basic fcc requirements for maximum transmission levels of out of band energy and billing delay. full details may be obtained from the fcc under part 68 of the fcc rules and regulations, or in title 47 of the code of federal regulations, however the basic requirements are as follows: 1. maximum transmit level for the normal permissive?(standard) telephone line, equipment which transmits data (such as a modem) must not exceed a transmission level of -9 dbm. 2. out of band energy data equipment must not transmit out of band?energy on the telephone line which exceeds the following limits: f r e q u e n c y r a n g e max. power 2 0 0 h z t o 3 9 9 0 h z -9 dbm 3 9 9 0 h z t o 4 0 0 5 h z -27 dbm 4 0 0 5 h z t o 1 6 k h z -16 dbm 8 k h z t o 9 4 k h z -47 dbm 8 6 k h z t o 2 7 0 k h z -46 dbm 2 7 0 k h z t o 6 m h z -6 dbm for modem applications, the out of band energy limit is normally ensured by the transmit filter in the modem circuitry. 3 . dtmf transmission level if the system is capable of dtmf dialing, the maximum dtmf transmission level must be less than 0 dbm averaged over a 3 second interval. 4. billing delay a delay of 2 seconds or greater is required after the time the XE0002B is taken ?ff hook?and before any data is transmitted. this is required to ensure that billing information may be exchanged between telephone company central offices without i n t e r f e r e n c e . the user of the XE0002B must certify to the fcc that the final system meets the requirements of part 68 which include the criteria above as well as the high voltage protection that is provided by the XE0002B. this is generally accomplished through an independent testing lab which will test the system and submits the proper paperwork to the fcc for approval. since the XE0002B already complies with fcc part 68 rules, this is a relatively simple process. jack rj11c ringer equivalence = 0.9b registration number dwe6tm - 72963 - wp - e copyright, xecom ?1991 while xecom, inc. has made every effort to ensure that the information presented here is accurate, xecom will not be liable for any damages arising from errors or omission of fact. xecom reserves the right to modify specifications and/or prices without notice. product mentioned herein are used for identification purposes only and may be trademarks and/or registered trademarks of their respective companies. x e c om incorporated 374 turquoise st r e e t , m i l pitas, ca 95035 ph:408 -945 -66 40 fax: 4 0 8 - 9 4 2 - 1 3 46 xecom 8/xecom XE0002B
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