xecom (1) XE0204 XE0204 july 2000 2-wire/4-wire telephone line interface description the XE0204 provides a common telephone interface for networks integrating two and four-wire telephone connections. the XE0204 supplies two and four wire leased line connections, and complies with fcc part 68 rules for 2-wire connections to the public switched network. the XE0204 supports voice, data and fax transfer at speeds to 14,400 bits per second, v.32bis data transfer over two wires and v.33 data transfer over four wires. the XE0204 is a complete daa in a compact package. it includes the telephone line transformers, loop current holding circuit, ring detection, switch hook, two-to-four wire convertor and four-wire switch. the small size of the XE0204, just 1.5 square inches, allows the XE0204 to be used in most any application requiring connection to the telephone network. features * small size 0 1.5 x 1.08 0.42 * fcc part 68 compliant * integral ring detection * integrated switch hook * switchable between two-wire and four-wire lines * integral two-to-four wire convertor * integrated telephone line transformers * 1500 volt isolation barrier between the telephone line and host equipment * supports both dial-up and leased line applications * supports 14,400 bps data transfer; v.32bis (2-wire), v.33 (4-wire) * operates on a single +5 volt supply * standard operating temperature range 0c to 70c optional operating range, -40c to 85c available XE0204 block diagram 2 to 4 wire convertor xmit rcvr telephone line transformer loop current holding circuit tx tip tx ring hook switch oh ring detect /ri rx tip rx ring 4 wire switch telephone line transformer /4wire
xecom (2) XE0204 a b denotes pin 1 c d g j h e f k inches millemeters dim min max min max a 1.480 1.520 37.59 38.61 b 1.060 1.100 26.92 27.94 c 0.420 0.430 10.67 10.92 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 0.290 0.310 7.37 7.87 j 0.090 0.110 2.29 2.79 k 0.020 0.025 0.51 0.64 XE0204 mechanical specifications XE0204 pin configuration XE0204 (top view) vcc 1 20 txtip /ri 3 rcvr 4 17 txring xmit 5 oh 7 14 rxtip /4wire 8 n/c 9 gnd 10 11 rxring
xecom (3) XE0204 XE0204 pin configuration pin name description 1 vcc vcc supplies +5 volts power to the XE0204 3 /ri ring indicate, output, active low, ttl. /ri indicates the XE0204 is receiving a ring signal. /ri remains low for the duration of each ring. 4 rcvr rcvr acts as the analog output for signals recevied from the telephone line by the XE0204. in two wire mode the received signal is placed on rcvr by the 2-to-4 wire convertor. in four wire mode the received signal comes directly from the receive phone line pair. 5 xmit xmit provides the analog input to the XE0204 for signals to be transmitted onto the telephone line. in two wire mode the signal is passed to the 2-to-4 wire convertor. in four wire mode the signal goes directly the transmit phone line pair. 7 oh hookswitch relay control. a high on oh closes the internal relay and connects the equipment to the telephone line. oh must be forced high to maintain a 2 wire or 4 wire leased line. 8 /4wire /4wire is an active low input to the XE0204 which selects four wire operation. if pin 8 is open or driven high, two wire mode is selected. 9 n/c no connection 10 gnd gnd provides the ground reference connection to the XE0204. 11 rxring rxring provides the ring connection to the receive pair of the four wire phone line. rxring is not used for two wire connections. rxring has 1500 volts isolation from the rest of the circuitry. this isolation must be preserved throughout the system. 14 rxtip rxtip provides the tip connection to the receive pair of the four wire phone line. rxtip is not used for two wire connections. txtip has 1500 volts isolation from the rest of the circuitry. this isolation must be preserved throughout the system. 17 txring txring provides the ring connection to two wire lines as well as to the transmit pair of four wire phone lines. txring has 1500 volts isolation from the rest of the circuitry. this isolation must be preserved throughout the system. 20 txtip txtip provides the tip connection to two wire lines as well as to the transmit pair of four wire phone lines. txtip has 1500 volts isolation from the rest of the circuitry. this isolation must be preserved throughout the system.
xecom (4) XE0204 power supply current 4-wire operation 10 16 ma transmit insertion loss 2-wire line, 1000 hz, 600 ohm line -0.5 0 0.5 db receive insertion loss 2-wire line, 1000 hz, 600 ohm line -0.5 0 0.5 db 4-wire line, 1000 hz, 600 ohm line 0.8 3.0 db telephone line impedance at 1800 hz, (2 and 4 wire lines) 540 600 660 ohms coupler match input output impedance driving rcvr in four- 531 536 541 ohms impedance wire mode transmit input impedance at 1800 hz 8 10 12 kohms receive output impedance 2 wire mode, 1800 hz 10 100 ohms transhybrid loss 2-wire mode, 1 khz, 600 ohm line 15 21 db ring detect sensitivity type b ringer 38 150 vrms ring indicate output ring voltage present on tip and ring 0.2 0.5 volts hook switch control voltage on: (off-hook) 4.0 volts off: (on-hook) 0.8 volts hook switch control current off-hook 0.5 ma /4wire switch 2-wire 4.0 volts 4-wire 0.8 volts loop current, tx pair off-hook 0 100 ma loop current, rx pair 4-wire line 0 ma parameter conditions min typ max units XE0204 electrical specifications (vcc= +5v + 10%, ta = 0c to 70c) XE0204 absolute maximum ratings supply voltage - vcc +6.5 volts storage temperature -25 o c to +85 o c operating temperature range 0 o c to +70 o c maximum lead temperature 260 o c (soldering 2 seconds per wave)
xecom (5) XE0204 XE0204 typical connection diagram for a 2-wire, dial-up line modem analog front end rj11 4 3 /ring receive transmit ohrly +5 volts 10 ohms, 1/2 w 470 pfd 2600 volts 470 pfd 2600 volts ferritebead ferritebead teccor p3100sb 10 ohms, 1/2 w XE0204 vcc txtip /ri rcvr txring xmit oh rxtip /4wire gnd rxring XE0204 typical connection diagram for a 2-wire, leased line modem analog front end rj11 4 3 /ring receive transmit ohrly +5 volts 10 ohms, 1/2 w 470 pfd 2600 volts 470 pfd 2600 volts ferritebead ferritebead teccor p3100sb 10 ohms, 1/2 w XE0204 vcc txtip /ri rcvr txring xmit oh rxtip /4wire gnd rxring
xecom (6) XE0204 XE0204 typical connection diagram for a 4-wire, leased line modem analog front end rj11 4 3 /ring receive transmit ohrly +5 volts 10 ohms, 1/2 w ferritebead ferritebead teccor p3100sb 10 ohms, 1/2 w XE0204 vcc txtip /ri rcvr txring xmit oh rxtip /4wire gnd rxring rj11 4 3 470 pfd 2600 volts 10 ohms, 1/2 w 10 ohms, 1/2 w teccor p3100sb ferritebead ferritebead recommended parts refer ence designation recommended part number ferrite beads tdk acb2012l-120-x high voltage capacitors panasonic eckdrs471, 470 pfd, 2600 volts rj11 telephone jack stewart ss6446nf
xecom (7) XE0204 when developing a product 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 line. the XE0204 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 meet basic fcc requirements for maximum transmission levels, out of band energy and billing delay. full details may be obtained fro m 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: frequency range max. power 200hz to 3990hz -9 dbm 3990hz to 4005hz -27 dbm 4005hz to 16khz -16 dbm 8khz to 94khz -47 dbm 86khz to 270khz -46 dbm 270khz to 6mhz -6 dbm 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 XE0204 is taken off hook and before any information is transmi tted. this is required to ensure that billing information may be exchanged between telephone company central offices without interference. the user of the XE0204 must certify to the fcc that the final system meets the requirements of part 68 which include the criter ia above as well as the high voltage protection provided by the XE0204. this is generally accomplished through an independent testing lab which tesst the system and submits the proper paperwork to the fcc for approval. since the x0204 already complies with fcc part 68 rules, this is a relatively simple proces s. XE0204 fcc instructions
xecom (8) XE0204 copyright, xecom ? 2000 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 trade- marks and/or registered trademarks of their respective companies. xecom incorporated 374 turquoise street, milpitas, ca 95035 ph:408-945-6640 fax:408-942-1346 email: info@xecom.com terms of sale devices sold by xecom are covered by the warranty provisions appearing in its terms of sale only. xecom makes no warranty, express, statutory, implied, or by description regarding the information set forth herein, or regarding the freedom of the described devices from patent infringement. xecom makes no warranty of merchantability or fitness for any purposes. xecom reserves the right to discontinue production and change specifications and prices at any time and without notice. this product is intended for use in normal commercial applications. applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment, are specifically not recommended without additional processing and authorization by xecom for such application. xecom assumes no responsibility for the use of any circuitry other than circuitry embodied in a xecom product. no other circuits, patents, or licenses are implied. life support policy xecom's products are not authorized for use as critical components in life support devices or systems. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions pro- vided in the labeling, can be reasonably expected to result in significant injury to the user. a critical component is any component of a life support device or system whose failure to perform can be rea- sonably expected to cause failure of the life support device or system, or to affect its safety or effectiveness.
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