CMX868 CMX867 1999/5/EC DE8681 P3100SC 1812J2500334KXB 1206J2500103KXT - Datasheet Archive

 

COMMUNICATION SEMICONDUCTORS Application Note Reference Telephone Line interface For The CMX868 V.22bis Low Power Modem CMX867

 

CML Microcircuits COMMUNICATION SEMICONDUCTORS Application Note Reference Telephone Line interface For The CMX868 CMX868 V.22bis Low Power Modem CMX867 CMX867 V.22 Low Power Modem AN/Telecom/868/4 August, 2003 Introduction The CMX868 CMX868 and CMX867 CMX867 modem ICs are connected to a telephone line with a special interface circuit that is often referred to as a DAA (Data Access Arrangement). One of the main functions of the DAA is to provide a safety isolation barrier between the phone line and the low voltage circuits that users can touch. There are many considerations involved in the design of a suitable DAA. First, both data and control information must be transferred successfully across the isolation barrier. Second, the electrical characteristics that the DAA presents to the phone line are subject to various regulatory requirements. Lastly, there are certain environmental stresses, such as lightning and common mode noise, that a good DAA must be relatively immune to. Recent changes to the regulatory requirements in Europe have allowed designers to reduce the cost of their DAA design without compromising performance. Here we describe two DAA circuits for the CMX868 CMX868 and CMX867 CMX867. The first circuit complies with the former European standard CTR 21. Since CTR 21 is no longer mandatory for CE marking, a simplified DAA for use in Europe is also shown. This second DAA circuit can also be used in the USA, Japan, and many other countries worldwide. Appendix 1 describes how, with a few additional components, Caller ID services may be handled. CML Consumer Microcircuits Ltd 1/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 Regulatory Requirements In each country where a modem is to be approved for use, there are mandatory regulatory requirements that must be met. These requirements can be broken into three categories: safety, electromagnetic compatibility (EMC), and telecom. Safety Requirements In Europe, the applicable safety standard is EN 60950. Since EN 60950 is based on an international reference standard, it has many similarities to the USA standard UL 60950 and the safety standards of other countries. With attention to a few details, it is possible to design a DAA that meets the safety requirements of all countries worldwide EMC Requirements Most countries have regulatory requirements that place limits on the radio frequency emissions that a product can generate. In Europe, the applicable standard is EN 55022, while in the USA it is FCC Part 15. In Europe, the immunity standard EN 55024 also places requirements on a product's immunity to electromagnetic disturbances. Only a few other countries have similar immunity requirements. Since the EMC performance of a product is related to the overall system design, it is sometimes necessary to provide additional filtering on the phone line connection to the DAA. This filtering has not been included in the circuits shown here because in many cases no filtering is needed. Readers should be aware, however, that in certain systems some additional filtering might need to be added. Telecom Requirements Prior to 1998 in Europe, each member country in the European Union (EU) had individual telecom regulatory requirements for connection to a phone line. In 1998, these individual requirements were replaced with a single harmonized standard called CTR 21 that applied to all EU member countries. Compliance with CTR 21 was mandatory for CE marking. On 8th April 2000, a new directive, Directive 1999/5/EC 1999/5/EC, commonly known by its short name Radio and Telecommunication Terminal Equipment (RTTE), established a new regulatory framework for telecom approvals. The RTTE directive repealed CTR 21 and declared that henceforth, there would be no mandatory telecom requirements for devices that connect to public network phone lines. Under the RTTE directive, the only mandatory requirements for CE marking of a typical modem are those for safety and EMC. Otherwise, products are presumed to comply with the Directive when they meet the requirements within the usage conditions for which they are intended. While many EU countries now maintain certain recommended requirements for interfacing to their phone lines, compliance with these requirements is not mandatory for CE marking. To deal with the uncertainty regarding telecom compliance, some manufacturers have continued to design for compliance with CTR 21. This is perfectly acceptable, but it is no longer mandatory. Today, if a manufacturer chooses to depart from national recommendations and/or CTR 21 for the design of a European DAA, a certain amount of technical judgment must be used. Not all of the requirements in the national recommendations and CTR 21 are absolutely necessary for proper operation of a modem. CML Consumer Microcircuits Ltd 2/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 On the other hand, compromises in certain areas will likely cause interoperability problems or performance problems in some EU countries. It is believed that both of the DAA circuits presented here will function well throughout Europe. In the USA, the telecom requirements are called out in FCC Part 68. Maintenance of the technical requirements in FCC Part 68 is in the process of being turned over to an industry advisory group, but compliance with the requirements themselves remains mandatory. Most other countries also have mandatory telecom requirements for connection to standard phone lines. In some cases, one or both of the DAA designs presented here can be used in certain other countries. CTR 21 Compliant DAA Figure 1 shows a CTR 21 compliant DAA for the CMX868 CMX868 or CMX867 CMX867. This is a very simple and robust DAA that should work well in any EU country. The values of R4, R6, R8, R14, C10 and C25 have been optimized for use with the Midcom 82107 transformer. R7, R9 and C23 provide bias for the differential op-amp derived from the differential transmit outputs. This network gives more than the required 7dB external trans-hybrid loss required by the CMX868 CMX868 and CMX867 CMX867. R8, R14 and C25 form complex load impedance matching for the line. C25 provides some compensation for the transmit rolloff in the transformer and R4, R6 provide sufficient gain to compensate for the loss across the interface. C7 provides a low pass response in the input op-amp of the CMX868 CMX868 or CMX867 CMX867. The ring detect threshold is determined by C12, R13, D3 and the response of U3 to approximately 20 VRMS. C6 provides decoupling to VBIAS and should be placed as close to this pin as possible. The UK and Japan require detection of a line reversal regardless of Tip Ring polarity to provide an indication of Caller Identity delivery. To provide this detection U3 must be replaced with a bi-directional opto isolator and D2 removed. C26 can be added to increase the return loss by at least 1.5dB at 4kHz although the return loss is acceptable without it. This capacitor should be rated at more than 250V to meet safety regulations. Simplified DAA for USA and Europe Figure 2 shows a simplified DAA that can be used in Europe, the USA, and several other countries as well. The following changes have been made from the CTR 21 DAA: 1) The 60 mA current limiter function required by CTR 21 has been eliminated to reduce cost (D4, D5, C11, U4, U5, R10 and R11 in the CTR 21 schematic). This requires changing to a different transformer that can handle larger loop currents (Midcom 82111). The value of R6 and R8 have has been changed to match the new transformer. C10, C25 and R14 have been eliminated. The value of R7 is changed and C24 added to correct the bias conditions. 2) The return loss performance has been relaxed to allow use of the new transformer. While this circuit does not meet the CTR 21 return loss requirement, there should be no measurable difference in the performance of the modem. 3) For compliance with the overvoltage test in the USA's UL 60950 safety requirements, fuse F1 has been added. This fuse is only required for the USA and Canada but is critical and must not be substituted for a different part. If desired, it can be omitted for use in other countries. CML Consumer Microcircuits Ltd 3/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 The 60 mA current limiter in CTR 21 was included at the request of France, since some of their older equipment was designed with the expectation that all terminal devices would contain the limiter function. This current limiter was not needed for any other EU country. When CTR 21 became non-mandatory in April 2000, France appealed to the European Commission to retain the requirement for a current limiter for a period of 30 months (until October 2002) to give France time to remove their remaining old equipment that still required the current limiter. The request was denied, but the Commission did rule that until October 2002, terminal equipment sold in France that did not have a current limiter should be provided with a warning that it should not be used on phone lines that still need current limiting. Thus, the current limiter function is only useful today in France, and it should no longer be useful even in France after October 2002. For this reason, many manufacturers are now phasing out the limiter function in their new designs. The only other requirement in CTR 21 that the simplified DAA does not quite meet is return loss. Return loss is an indirect measurement of the AC impedance that the DAA presents to the phone line. Return loss has very little effect on the performance of the modem speeds supported by the CMX868 CMX868 or CMX867 CMX867, so there should be no measurable difference in modem performance with the simplified DAA. Operation at Lower Voltages The component values in the circuits shown here are based on a design where VDD = 5.0 volts. The CMX868 CMX868 and CMX867 CMX867 can be operated at lower supply voltages, but several component values must be scaled appropriately. Following are two tables that show the component values that must change. CTR 21 Compliant DAA VDD 5.0 volts 3.3 volts 3.0 volts R6 57.6 k 86.6 k 93.5 k R7 220 k 180 k 180 k R12 620 ohm 270 ohm 220 ohm D1 4.3 V 3.0 V 3.0 V Simplified DAA VDD 5.0 volts 3.3 volts 3.0 volts R6 64.9 k 97.6 k 107 k R9 180 k 160 k 160 k C24 47 pF 39 pF 39 pF R12 620 ohm 270 ohm 220 ohm D1 4.3 V 3.0 V 3.0 V It is important to note that certain modem parameters, such as the maximum available transmit level and the maximum allowable receive level are reduced when the operating voltage is less than 5 volts. Care should be taken to compare the signal level requirements for the intended application to the signal levels achievable at reduced supply voltages. CML Consumer Microcircuits Ltd 4/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 DAA Layout Guidelines The following guidelines will be helpful in assuring that the circuit board layout allows the DAA to provide the desired safety isolation and modem performance: 1) The dotted line on the schematic shows the safety isolation barrier. All components inside the dotted line should be grouped reasonably close together. Only T1, U3, and U6 should bridge the isolation barrier. The isolation barrier should maintain a keep-out area at least 2.5 mm wide. 2) All traces inside the isolation barrier should be 0.5 mm wide with 0.5 mm separations. 3) D1 and C8 should be located close to T1. 4) The remaining circuitry between T1 and the CMX868 CMX868 or the CMX867 CMX867 should be grouped reasonably close to the IC body. 5) For good performance with low receive levels, it is helpful to use a 4-layer board with an internal ground plane under the CMX868 CMX868 or CMX867 CMX867. Any internal ground or power planes should not extend past the isolation barrier. Summary Two DAA designs have been presented for use with the CMX868 CMX868 or CMX867 CMX867 modem ICs. The first design complies with the former European regulatory requirement CTR 21. Although CTR 21 was withdrawn as a regulatory requirement in April 2000, some manufacturers continue to use it as a reference standard for their designs. The second DAA design is a simplified version that omits two features required by CTR 21. The simplified DAA does not provide the CTR 21 current limiter that is now only needed in France, and it does not quite meet the CTR 21 return loss requirement. The CTR 21 current limiter has not been needed in France since October 2002 and the reduction in return loss should not cause a measurable difference in modem performance. Thus, the simplified DAA offers a lower cost design that should still perform quite well and therefore comply with the current EC Directive. With the inclusion of a fuse in the simplified DAA, the circuit becomes suitable for use in the USA as well as Europe. This multi-country design may be attractive for certain applications. Further information To obtain information on parts used in these designs contact mailto:support@cmlmicro.com. A Demonstration Kit using the CMX868 CMX868 and the DAA circuits discussed is available from CML. The Gerber files and software used in the DE8681 DE8681 are available to download from the CML Website. These files could be used to form the basis of a fully featured modem design. Acknowledgments Randolph Telecom Inc. ­ Telecom design consultants Midcom Inc. ­ Telecommunications transformer specialists CML Consumer Microcircuits Ltd 5/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 NOTE: R11 11.5 SEE NOTE TRANSISTOR U5 WILL DISSIPATE 1.5 WATTS IN THE WORST-CASE FEEDING CONDITION SPECIFIED IN CTR 21. THE BOARD LAYOUT MUST INCLUDE A COPPER PAD FOR U5 WITH AN AREA OF AT LEAST ONE SQUARE CENTIMETER. A LARGER HEAT SINK PAD IS DESIRABLE. U5 U4 R10 33 K + U1 RDRVN 3 C11 10 uF 50 V /OFFHOOK VDD + D5 /OFFHOOK R12 620 C25 150 nF C4 1 XTALN X1 TXA 2 R14 330R C7 100 pF CMX868 CMX868 D4 33 V R9 120 K CMX867 CMX867 R4 9 RXAFB 10 T1 MIDCOM 82107 RXAN 11 RXA R2 100k 23 IRQ IRQN 22 REPLY DATA 20 SPI, USART or standard port SERIAL CLOCK 19 18 Port pin C6 0.33 uF COMMAND DATA C26 10 nF 250V See Text E1 SIDACTOR 310 V P3100SC P3100SC D3 18 V C23 0.1 uF RING D2 5 RD CSN R13 10 K 1/2 W 14 TXAN C12 0.33 uF 250 V R7 220 K 13 VBIAS U6 OPTOMOS RELAY D1 4.3 V R6 57.6 K 100 K VDD Host Micro ISOLATION BARRIER TIP XTAL/ CLOCK C2 - C10 2.2 uF R8 68R 15 VDD ISOLATION BARRIER R1 470 K VDD 6 RT R3 20 K C5 0.33 uF U3 FIGURE 1 CTR 21 COMPLIANT DAA (SET UP FOR VDD = 5.0 VOLTS) U1 VDD RDRVN 3 C4 U6 1 XTALN X1 TXA XTAL/ CLOCK C2 TIP C7 100 pF CMX868 CMX868 CMX867 CMX867 R6 64.9 K R9 120 K 9 RXAN 23 IRQN 22 20 19 13 C24 47 pF R7 180 K C6 0.33 uF C23 RING 14 COMMAND DATA RD D2 5 VDD CSN ISOLATION BARRIER 6 R1 470 K RT C5 0.33 uF VDD R3 20 K U3 FIGURE 2 SIMPLIFIED DAA FOR USA AND EUROPE (SET UP FOR VDD = 5.0 VOLTS) CML Consumer Microcircuits Ltd E1 SIDACTOR 310 V P3100SC P3100SC D3 18 V TXAN 18 Port pin 82111 C8 33nF VBIAS REPLY DATA SERIAL CLOCK R13 10 K 1/2 W T1 MIDCOM RXA IRQ C12 0.33 uF 250 V D1 4.3 V 100 K 11 R2 100 K SPI, USART or standard port 10 OPTOMOS RELAY F1 FUSE 1.25 A R4 RXAFB VDD Host Micro ISOLATION BARRIER R8 392 15 2 R12 620 6/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 TABLE 1 BILL OF MATERIALS Ref. Des. Vendor CTR 21 Design Component Description Simplified Design Component Description C2 Generic Ceramic cap, 22 pF, 25 V, X7R Ceramic cap, 22 pF, 25 V, X7R C4 Generic Ceramic cap, 22 pF, 25 V, X7R Ceramic cap, 22 pF, 25 V, X7R C5,C6 Generic Ceramic cap, 0.33 uF, 25 V, X7R Ceramic cap, 0.33 uF, 25 V, X7R C7 Generic Ceramic cap, 100 pF, 25 V, X7R Ceramic cap, 100 pF, 25 V, X7R C8 Generic Not Required Ceramic cap, 0.033 uF, 25 V, X7R C10 Generic Aluminum cap, 2.2 uF, 16 V, non-polar Not Required C11 Generic Aluminum cap, 10 uF, 50 V Not Required C12 Syfer Tech 330 nF, 250 V, 1812J2500334KXB 1812J2500334KXB 330 nF, 250 V, 1812J2500334KXB 1812J2500334KXB C23 Generic Ceramic cap, 0.1 uF, 25 V, X7R Ceramic cap, 0.1 uF, 25 V, X7R C24 Generic Not Required Ceramic cap, 47 pF, 50 V, X7R C25 Generic Ceramic cap, 150 nF, 50 V, X7R Not Required C26 Syfer Tech 10 nF, 250 V, 10% 1206J2500103KXT 1206J2500103KXT Not Required X1 Generic 11.0592MHz or 12.288MHz crystal 11.0592MHz or 12.288MHz crystal D1 Central Semi Dual zener, 4.3 V, CMPZDA4V3 Dual zener, 4.3 V, CMPZDA4V3 D2 Generic Signal diode. See Note 1 Signal diode. See Note 1 D3 Central Semi Dual zener, 18 V, CMPZDA18V CMPZDA18V Dual zener, 18 V, CMPZDA18V CMPZDA18V D4 Motorola Surge diode, 600 W, P6SMB33CAT3 P6SMB33CAT3 Not Required D5 Central Semi Diode bridge, CBRHD-02 CBRHD-02 Not Required E1 Teccor Sidactor, 310 V, P3100SC P3100SC Sidactor, 310 V, P3100SC P3100SC R1 Generic 470 k, 5%, 0.1 W 470 k, 5%, 0.1 W R2 Generic 100 k, 5%, 0.1 W 100 k, 5%, 0.1 W R3 Generic 20 k, 5%, 0.1 W 20 k, 5%, 0.1 W R4 Generic 100 k, 1%, 0.1 W 100 k, 1%, 0.1 W R6 Generic 57.6 k, 1%, 0.1 W 64.9 k, 1%, 0.1 W R7 Generic 220k, 1%, 0.1 W 180 k, 1%, 0.1 W R8 Generic 68 ohm, 1%, 0.1 W 392 ohm, 1%, 0.1 W R9 Generic 120 k, 1%, 0.1 W 120k, 1%, 0.1 W R10 Generic 33 k, 5%, 0.1 W Not Required R11 Generic 11.5 ohm, 1%, 0.125 W Not Required R12 Generic 620 ohm, 5%, 0.1 W 620 ohm, 5%, 0.1 W R13 Generic 10 k, 5%, 0.5 W 10 k, 5%, 0.5 W R14 Generic 330 ohm, 1%, 0.1 W Not Required F1 Bussmann Not Required Fuse, Bussmann C515-1 C515-1.25. See Note 2 T1 Midcom Transformer, Midcom 82107 Transformer, Midcom 82111 U1 CML Modem, CMX868/CMX867 CMX868/CMX867 Modem, CMX868/CMX867 CMX868/CMX867 U3 NEC Opto-isolator, NEC PS2701-1 PS2701-1. See Note 1 Opto-isolator, NEC PS2701-1 PS2701-1.See Note 1 U4 Motorola NPN transistor, 65 V, BC846 BC846 Not Required U5 Zetex NPN Darlington, 120 V, FZT605 FZT605 Not Required U6 Clare Solid state relay, Clare LCA110S LCA110S Solid state relay, Clare LCA110S LCA110S Note 1. Where a line reversal must be detected, U3 is replaced by an NEC PS2705 PS2705 opto isolator and D2 should not be fitted. Line reversal detection is required on Caller ID systems in the UK and Japan. CML Consumer Microcircuits Ltd 7/13 Reference Telephone Line Interfaces AN/Telecom/868/4 August, 2003 Note 2. The Bussmann fuse is only required if the DAA is to be used in the US or Canada where it is required to meet the USA's UL60950 UL60950 safety requirements. It may be omitted or replaced with a lower cost alternative. CML Consumer Microcircuits Ltd 8/13 Reference Telephone Line Interfaces AN/Telecom/868/DAA/September2001 Appendix 1 Hardware Modifications for Type 1 and 2 Caller ID capability Included in Appendix 1 are modifications to the previous schematics allowing for the additional capability of automated calling party identification, Caller ID, Type 1 and 2. Figure 5 is the CTR 21 DAA with a Caller ID path added. Figure 6 is the simplified DAA with Caller ID added. Following is a description of the modifications: 1) The function that has been added is the provision of a high impedance on-hook AC transmission path that allows Caller ID signals to be passed to the modem chip for processing. 2) The additional components are C9, R5 and U2. Capacitor C9 couples AC signals around the switchhook relay so they can pass through the transformer in the on-hook state. In this mode, there is approximately 30 dB loss to the CMX868 CMX868 or CMX867 CMX867 side of the transformer, compared to about 5 dB loss in the off-hook state. The analog switch U2 and resistor R5 are used to increase the receive gain in the on-hook state to help compensate for this loss. 3) The added receive gain is approximately 21 dB. It does not make up for the full 25 dB of additional loss because the Caller ID signals will generally be much stronger than a typical modem signal, which can be as low as ­43 dBm. The Caller ID signal is launched from the local central office at a typical level of about ­13 dBm, and suffers only a few dB of loss in the local loop. 4) The analog switch U2 is a Maxim MAX4501 MAX4501. Similar devices are made by Toshiba, Analog Devices, and ON Semiconductor. 5) The on-hook AC impedance in the voiceband is about 10 k ohms, established primarily by R13 in the ring detect circuit. This level of impedance is acceptable in almost all countries, including the USA and Europe. Australia requires 15 k minimum, and Singapore requires 20 k, so some component values will need changing to satisfy these countries. You can increase the on-hook AC impedance either by increasing the value of R13 or by adding a resistor in series with C9. Increasing the AC impedance, this way will reduce the signal that gets to the CMX868 CMX868 or CMX867 CMX867 side of the transformer, so the value of R5 would have to be changed to provide more gain boost. 6) Some of the ring detection current will travel through C9 and bypass the ring detector. In lab tests, the ring detect threshold increased by about 2 volts, but the ring detector was otherwise unaffected. 7) With the gain boosted so much in the on-hook state and some of the ringing current passing through C9, the op-amp output at RXAFB will be driven rail-to-rail when the ringing voltage is high. This should not cause any undesirable effects to the CMX868 CMX868 or CMX867 CMX867. 8) Figure 3 shows the off-hook receive response from tip/ring to the CMX868 CMX868 or CMX867 CMX867 side of the transformer. The loss at 1 kHz is about 5 dB. Figure 4 shows the on-hook receive response, where the loss at 1 kHz is about 30 dB. This plot does not include the roughly 21 dB gain that is switched in by U2. Note that in the on-hook mode there is some low frequency rolloff below 1 kHz, but since Caller ID signals are all above 1 kHz this should not present a problem. It should be noted that the plots shown are for the simplified DAA using the 82111 transformer. The CTR 21 DAA with the 82107 transformer has similar characteristics. CML Consumer Microcircuits Ltd 9/13 Reference Telephone Line Interfaces AN/Telecom/868/DAA/September2001 Appendix 1 9) In general, the voltage rating on C9 can probably be 50 volts. Due to the inductance of the transformer, there is a theoretical situation where lightning surges in the off-hook state could cause the voltage to reach 350 volts briefly, but it is not likely to ever reach this level. For caution, a 250-volt rating on C9 (similar to C12) could be used instead. Most capacitors with this rating can handle surges of 350 volts. 10) The UK and Japan require detection of a line reversal regardless of Tip Ring polarity to provide an indication of Caller ID delivery. To provide this detection U2 must be replaced with a bidirectional opto isolator and D2 removed. An NEC PS2705 PS2705 is a suitable replacement. Appendix 1 describes how a high impedance, on-hook AC transmission path can be added to the DAAs shown earlier on in this Application Note. This on-hook transmission path can be used to pass voice and Caller ID signals to the CMX868 CMX868 or CMX867 CMX867 modems. From that point, all Caller ID signal processing will have to be done by the modem chip and the microprocessor. The coupling method shown here has three advantages over other approaches that use capacitively coupled differential amplifiers. First, the overall cost is probably lower. Second, the coupling capacitor C9 does not bridge the isolation barrier, so it does not have to be the safety rated "Y2" type that Norway and Sweden require for capacitors that bridge the isolation barrier. Lastly, this circuit has better common mode rejection of 50/60 Hz AC noise than most implementations of capacitively coupled differential amplifiers. These last two advantages only apply to products that have the CMX868 CMX868 or CMX867 CMX867 power supply connected to earth ground, either directly via the power supply or indirectly via an RS-232 RS-232 or USB port. For fully floating applications, a capacitively coupled differential amplifier can be considered as a viable alternative. Fig. 3 Off-hook receive response CML Consumer Microcircuits Ltd Fig. 4 On-hook receive response (no gain added) 10/13 Reference Telephone Line Interfaces AN/Telecom/868/DAA/September2001 Appendix 1 R11 11.5 NOTE: SEE NOTE TRANSISTOR U5 WILL DISSIPATE 1.5 WATTS IN THE WORST-CASE FEEDING CONDITION SPECIFIED IN CTR 21. THE BOARD LAYOUT MUST INCLUDE A COPPER PAD FOR U5 WITH AN AREA OF AT LEAST ONE SQUARE CENTIMETER. A LARGER HEAT SINK PAD IS DESIRABLE. U5 R10 33 K U4 U1 + /OFFHOOK 3 RDRVN C11 10 uF 50 V VDD + D5 CMX868 CMX868 CMX867 CMX867 TXA C10 2.2 uF 150 nF R8 68 15 R14 - ISOLATION BARRIER TIP 330 C7 100 pF D4 33 V R9 120 K C12 0.33 uF 250 V R13 D1 4.3 V R6 57.6 K 100 K 10 RXAN U2 OPTOMOS RELAY R4 9 RXAFB 11 T1 MIDCOM 82107 1 COM NO VCC GND 6.04 K VDD R7 220 K 13 EN 5 VBIAS 10 K 1/2 W C9 U2 R5 RXA 2 0.1 uF E1 SIDACTOR 310 V P3100SC P3100SC C26 10 nF 250V See Text 4 D3 18 V 3 MAX4501 MAX4501 C6 0.33 uF TXAN /OFFHOOK R12 620 C25 RING C23 0.1 uF D2 14 5 RD VDD ISOLATION BARRIER R1 470 K RT VDD 6 R3 20 K FIGURE 5 CTR 21 COMPLIANT DAA INCLUDING ON - HOOK RECEIVE PATH FOR CALLER ID (SET UP FOR VDD = 5.0 VOLTS) C5 0.33 uF U3 U1 VDD RDRVN 3 R12 620 U6 ISOLATION BARRIER CMX868 CMX868 CMX867 CMX867 TXA R8 392 15 TIP C7 100 pF OPTOMOS RELAY R9 120 K RXAFB 9 R4 RXAN RXA VBIAS 10 R5 6.04 K 11 13 C24 47 pF R7 180 K C6 0.33 uF TXAN RD D1 4.3 V R6 64.9 K 100 K U2 1 COM NO VCC GND VDD C23 0.1 uF EN 5 2 C8 0.033uF T1 MIDCOM 82111 C9 0.1 uF 4 C12 0.33 uF 250 V R13 10 K 1/2 W MAX4501 MAX4501 RING D2 14 5 ISOLATION BARRIER 6 R1 470 K VDD U3 C5 0.33 uF FIGURE 6 SIMPLIFIED DAA FOR USA AND EUROPE INCLUDING ON - HOOK RECEIVE PATH FOR CALLER ID (SET UP FOR VDD = 5.0VOLTS) CML Consumer Microcircuits Ltd E1 SIDACTOR P3100SC P3100SC 310 V D3 18 V 3 VDD RT F1 FUSE 1.25 A 11/13 Reference Telephone Line Interfaces AN/Telecom/868/DAA/September2001 Appendix 1 TABLE 2 BILL OF MATERIALS FOR `Caller ID' OPTION The optional Caller ID requires three additional components. There are no other changes to the circuit or component values. Ref. Des. R5 C9 U2 Vendor Generic Generic Generic CTR 21 Design Component Description 6.04 k, 1%, 0.1 W Ceramic cap, 0.1 uF, 25 V, X7R MAX 4501 CUK-T. See Note 1 Simplified Design Component Description 6.04 k, 1%, 0.1 W Ceramic cap, 0.1 uF, 25 V, X7R MAX 4501 CUK-T. See Note 1 Note 1. Other analog switches can be used. Toshiba, Analog Devices, ON Semiconductor and others, make similar devices. Reference Telephone Line Interfaces AN/Telecom/868/DAA/September2001 Appendix 1 www.cmlmicro.com For FAQs see: http://www.cmlmicro.com/products/faqs/index.htm For a full data sheet listing see: For detailed application notes: Oval Park - Langford - Maldon Essex - CM9 6WG - England. Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 4800 Bethania Station Road Winston-Salem - NC 27105 - USA. Tel: +1 336 744 5050, 800 638 5577 Fax: +1 336 744 5054 Sales: sales@cmlmicro.com Technical Support: techsupport@cmlmicro.com Sales: us.sales@cmlmicro.com Technical Support: us.techsupport@cmlmicro.com 2, Kallang Pudding Road #09 - 05/06 Mactech Industrial Building Singapore 349307 Tel: +65 67450426 Fax: +65 67452917 Sales: sg.sales@cmlmicro.com Technical Support: sg.techsupport@cmlmicro.com