73M2901CE-EVM User Manual Datasheet by Maxim Integrated

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fiTERIDIAN _ SEMICONDUCTOR CORP.
Simplifying System Integration
TM
73M2901CE
Demo Board User Manual
March 17, 2010
Rev. 1.5
UM_2901CE_026
73M2901CE Demo Board User Manual UM_2901CE_026
2 Rev. 1.5
© 2010 Teridian Semiconductor Corporation. All rights reserved.
Teridian Semiconductor Corporation is a registered trademark of Teridian Semiconductor Corporation.
Simplifying System Integration is a trademark of Teridian Semiconductor Corporation.
All other trademarks are the property of their respective owners.
Teridian Semiconductor Corporation makes no warranty for the use of its products, other than expressly
contained in the Company’s warranty detailed in the Teridian Semiconductor Corporation standard Terms
and Conditions. The company assumes no responsibility for any errors which may appear in this
document, reserves the right to change devices or specifications detailed herein at any time without
notice and does not make any commitment to update the information contained herein. Accordingly, the
reader is cautioned to verify that this document is current by comparing it to the latest version on
http://www.teridian.com or by checking with your sales representative.
Teridian Semiconductor Corp., 6440 Oak Canyon, Suite 100, Irvine, CA 92618
TEL (714) 508-8800, FAX (714) 508-8877, http://www.teridian.com
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 3
Table of Contents
1 Introduction ................................................................................................................................... 5
1.1 Getting Started......................................................................................................................... 5
1.2 Recommended Operating Conditions and Absolute Maximum Ratings ..................................... 6
1.3 Basic Connections ................................................................................................................... 6
2 Design Considerations .................................................................................................................. 7
3 73M2901CE EVM-600 Demo Board ............................................................................................... 8
3.1 Using the 73M2901CE EVM-600 Demo Board ......................................................................... 8
3.2 73M2901CE EVM-600 Hardware Design ................................................................................. 9
3.2.1 73M 2901CE EVM-600 Schematic Diagrams ............................................................. 9
3.2.2 73M2901CE EVM-600 Demo Board Pin Description ................................................ 12
3.2.3 73M2901CE-EVM-600 Demo Board Bill of Materials ................................................ 14
3.2.4 73M2901CE-EVM-600 Demo Board PCB Layout ..................................................... 15
4 73M2901CE EVM-WW Demo Board............................................................................................. 17
4.1 Using the 73M2901CE0-EVM-WW Demo Board .................................................................... 17
4.2 73M2901CE EVM-WW Hardware Design ............................................................................... 19
4.2.1 73M 2901CE EVM-WW Schematic Diagrams .......................................................... 19
4.2.2 73M2901CE EVM-WW Demo Board Pin Description................................................ 22
4.2.3 73M2901CE EVM-WW Demo Board Bill of Materials ............................................... 24
4.2.4 Recommended Components Used in the Demo Boards ........................................... 25
4.2.5 73M2901CE EVM-WW Demo Board PCB Layout .................................................... 28
5 DC Loop Circuit Schematic ......................................................................................................... 29
6 Related Documentation ............................................................................................................... 29
7 Contact Information ..................................................................................................................... 29
Revision History .................................................................................................................................. 30
73M2901CE Demo Board User Manual UM_2901CE_026
4 Rev. 1.5
Figures
Figure 1: T73M2901CE Demo Board Basic Connections ......................................................................... 6
Figure 2: 73M2901CE EVM-600 Demo Board Schematic ....................................................................... 10
Figure 3: 73M2901CE EVM-600 Motherboard Schematic ...................................................................... 11
Figure 4: 73M2901CE EVM-600 Demo Board Pin Connections ............................................................. 12
Figure 5: 73M2901CE EVM-600 Demo Board: Bottom Layer ................................................................. 15
Figure 6: 73M2901CE EVM-600 Demo Board: Top Layer ...................................................................... 15
Figure 7: 73M2901CE EVM-600 Demo Board: Top Silk Screen ............................................................. 16
Figure 8: 73M2901CE Worldwide Demo Board: Daughter Board Schematic .......................................... 20
Figure 9: 73M2901CE Worldwide Demo Board: Motherboard Schematic ............................................... 21
Figure 10: 73M2901CE Worldwide Daughter Board Pin Connections ..................................................... 22
Figure 11: 73M2901CE Worldwide Demo Board: Bottom ....................................................................... 28
Figure 12: 73M2901CE Worldwide Demo Board: Top Layer and Silk Screen ......................................... 28
Figure 13: Simple DC Loop Simulator .................................................................................................... 29
Tables
Table 1: Recommended Operating Conditions ......................................................................................... 6
Table 2: Absolute Maximum Ratings ........................................................................................................ 6
Table 3: Termination Impedance Network Values .................................................................................... 8
Table 4: 73M2901CE EVM-600 Demo Board Description: Digital Interface ............................................ 12
Table 5: 73M2901CE EVM-600 Demo Board: Telephone Network Interface .......................................... 12
Table 6: 73M2901CE EVM-600 Demo Board: DB-25 RS-232 Level Serial Interface ............................... 13
Table 7: 73M2901CE EVM-600 Demo Board Bill of Materials ................................................................ 14
Table 8: S-register Settings for Worldwide Modem Design ..................................................................... 17
Table 9: Termination Impedance Network Values .................................................................................. 17
Table 10: Worldwide Country AC Impedance Requirements .................................................................. 18
Table 11: 73M2901CE Worldwide Demo Board: Digital Interface ........................................................... 22
Table 12: 73M2901CE Worldwide Demo Board: Telephone Network Interface ....................................... 23
Table 13: 73M2901CE Worldwide Demo Board: DB-25 RS-232 Level Serial Interface ........................... 23
Table 14: 73M2901CE Worldwide Demo Board Bill of Materials ............................................................. 24
Table 15: Transformers and Suppliers Tested and Used with the 73M2901CE ....................................... 25
Table 16: EMI Inductors for the Tip/Ring Signal Path ............................................................................. 25
Table 17: Recommended PTC Fuses for CPE Applications ................................................................... 26
Table 18: Recommended TVS Over Voltage Protectors ......................................................................... 27
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 5
1 Introduction
The Teridian Semiconductor Corporation 73M2901CE Demo Board is a platform for evaluating the
73M2901CE single-chip modem ICs. It incorporates the 73M2901CE integrated circuit, and it has been
designed to operate with a PC using the serial COM1 or COM2 RS-232 level ports and standard
communications software packages such as HyperTerminal.
This document describes the two available demo board configurations, the 73M2901CE-EVM-600 and
the 73M2901CE-EVM-WW.
The 73M2901CE EVM-600 is a board fitted with 600 resistive termination and is suitable for use in USA
and Japan. This board has been designed to comply with U.S. Part 68, USA, and AS/ACIF S002:2001.
The 73M2901CE EVM-WW has selectable terminations, which makes it suitable for use in many different
countries worldwide. The board has been designed to comply with FCC Part 68, ETSI TS 203, JATE and
AS/ACIF S002:2001.
1.1 Getting Started
Figure 1 shows the basic connections of the Demo Board.
Use the supplied motherboard and 5 V power supply.
The motherboard includes a 3.3 V regulator to power the 73M2901CE Demo Board.
The motherboard also includes RS-232 level shifters and DCE connector to connect the demo board
to a PC or other terminal device.
Use a standard PC terminal emulation program to communicate with the 73M2901CE Demo Board.
See the 73M2901CE AT Command User Guide for a complete list of commands.
Type “AT” on the terminal at any speed from 1200 bps to 9.6 Kbps to verify communications with the
modem are working correctly. The 73M2901CE modem will return “OK” if communication is properly
established.
Connect the RJ-11 connector to a telephone network emulator or private branch exchange (BPX).
The demo board, although meeting all the required telecom standards, is not a certified device.
Therefore the 73M2901CE Demo Board should not be connected to the outside telephone network.
It is not possible to connect two 73M2901CE demo boards back-to-back to test their operation. A DC
loop current is needed to activate the network-side circuitry. A simple current-mirror current-source circuit
can be used to provide the required DC loop current. A simple circuit is shown in Figure 13. This circuit
supplies two independent sources, one for each modem. The loop current provided is approximately 20
mA to each modem. This circuit does not provide network impairments, call progress signals, or
attenuation, which are also typically used for modem testing.
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73M2901CE Demo Board User Manual UM_2901CE_026
6 Rev. 1.5
1.2 Recommended Operating Conditions and Absolute Maximum Ratings
Table 1: Recommended Operating Conditions
Parameter Conditions Rating
Supply Voltage VDD At the demo board power pins 2.7 to 3.6 VDC
Supply Voltage VPC At the mother board power connector 4.75 to 5.5 VDC
Ambient Operating Temperature Without condensation or icing -40 °C to +85 °C
Input Voltage for Digital Inputs 0 V to VDD + 0.3 V
Table 2: Absolute Maximum Ratings
Parameter Rating
Supply Voltage VDD -0.5 to 4.0 VDC
Supply Voltage VPC -0.5 to 6.0 VDC
Input Voltage for Digital Inputs -0.3 to (VDD+0.5) VDC
Storage Temperature -60 to 150 °C
Pin Voltage -0.3 to 5.5 V VDC
ESD Tolerance Other pins +/- 2kV
Operation outside these rating limits may cause permanent damage to the device.
1.3 Basic Connections
Figure 1: T73M2901CE Demo Board Basic Connections
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 7
2 Design Considerations
Keep OSCIN and OSCOUT signals as short as possible and locate the crystal near the pins. Use an
11.0592 MHz parallel mode crystal only. Do not use ground planes under the oscillator circuit since this
will increase the parasitic capacitance on the pins. The values of C2 and C3 depend on the load
capacitance rating of the crystal that is used, not the 73M2901CE. This load capacitance will typically be
between 15 pF and 27 pF, but usually 18 or 22 pF. Parallel resonant crystals are tuned with a specific
capacitive load and will be within their specifications when this load is used. This rating is the
capacitance measured between the crystal pins including all parasitic capacitances. It is not the values of
the capacitors used. The selection of these capacitors can vary with the layout of the PCB, so do not
assume the values used with the 73M2901CE demo board are correct for all designs.
System noise is the most likely cause of poor Caller ID and low-level receive performance. The lowest
amplitude signals that the modem will need to receive are on the order of 5 mV rms. The Caller ID
receive levels are also very low due to the requirement to have a high (60 kΩ) AC input impedance while
on hook. Having a 20 dB gain boost during Caller ID reception compensates for this, but if there is
excessive noise, it will also be amplified. Keeping the analog and digital grounds separate helps control
the amount of noise that gets to the receiver input. Dramatic improvements in low-level performance can
be gained by proper layout.
Keep the VCC trace as short as possible. Make the power trace a minimum of 0.5 mm thick. The analog
and digital power and ground should be kept separate for best low receive level performance. Route the
power to the digital pins and bypass capacitors on one net and the analog power and VBG bypass pins
on another net with inductors separating the two. If power planes are used, separate the power and
ground planes so there are separate analog and digital planes for the 73M2901CE.
Keep 0.1 µF and 3.3 µF bypass capacitors close to VPD power pins of the device and take other end to
the digital ground.
Keep 0.1 µF and 10 µF bypass capacitors close to VPA power pin of the device and directly connect the
other end to analog ground.
Keep all analog signaling away from any high-speed digital circuitry and traces that may be on the board.
Observe the separation of the network and modem side circuitry. Maintain at least ¼ inch (6 mm)
separation between the two. Do not run power planes under the network side circuitry and maintain the
same spacing for the planes from the network. Use only UL, CSA, or TUV approved components that
cross the isolation barrier or for network protection to assure compliant performance for the DAA.
The transformer used for coupling will have an influence on the values of the components in the DAA
circuitry. The winding resistance, inductances and other characteristics of the transformer affect the
values of the impedance matching components. Make sure you have the transformer manufacturer’s
recommended circuit values when using other transformers. The values can be determined through
simulations, but may still require some adjustment to optimize the design.
73M2901CE Demo Board User Manual UM_2901CE_026
8 Rev. 1.5
3 73M2901CE EVM-600 Demo Board
During the past several years, there have been significant changes to the way telecommunications device
certification is handled. Previously you were required to take your new product to an authorized
certification laboratory to have certification testing performed. The United States has fundamentally
changed their approval procedures for telephone equipment. They have introduced the concept of SDoC
(Self-Declaration of Conformity), implying that formal approval of a TCB (Telecommunication Certification
Body) is not further necessary. The definition of the technical requirements has been delegated to
industry. There is a choice of conformity testing but, in general, the manufacturer or his authorized
representative must maintain technical documentation that includes a declaration of conformity and
shows how compliance is achieved. It is still a requirement to meet all the same technical requirements
for electrical compatibility with the network (TIA/EIA/IS-968 (Part 68) ), electrical safely (UL-60950 power
cross) and EMI (Part 15 radiated emissions). Unless you are equipped to perform the tests to verify the
operation of your product, it is still prudent to use a third party testing laboratory to assure compliance
with applicable regulations. The ACTA (Administrative Council for Terminal Attachments) is the body that
now administers the telecom terminal equipment. The FCC is no longer involved in any aspect of the
process. The ACTA is a privatized organization and administers all aspects of the telecom equipment.
See http://www.part68.org for information on the ACTA.
The 73M2901CE Demo Board is designed to meet all the applicable certification regulations defined in
those regulations. The 73M2901CE EVM-600 Demo Board design is intended for use in countries that
use a 600 Ω resistive termination. Although designed to meet the ACTA defined specifications, the
73M2901CE EVM-600 demo board is not a certified device, and it is therefore not intended for use on the
PSTN network. It should only be used in a laboratory environment with network simulation equipment.
The network input protection is now standard worldwide, so finding components that that meet UL-60950
Power Cross requirements are not too difficult. Input current limiting and over-voltage protection are both
universally required or advised. Self-resetting PPTC fuses are now available that not only protect the
product but eliminate the need to replace parts if they are tripped. These protection devices tend to be
some of the more expensive components in the design, but to scrimp on these in the initial design can
cause problems latter when fixing the problem is more expensive.
3.1 Using the 73M2901CE EVM-600 Demo Board
The schematic in Figure 2 shows the design for the 73M2901CE EVM-600 Demo Board. The design
uses a “wet transformer” that uses the transformer as the DC load on the line. The advantage to using
this topology is that the BOM cost can be lower compared to a “dry transformer” which passes the DC
current through an external circuit that simulates an inductor. A dry transformer can be made much
smaller, so if small size is important, a dry transformer is preferred.
Table 3 shows the termination impedances for 600 Ω resistive as well as ETSI TS 203 and Australian
complex impedances. With these three terminations, worldwide terminations impedance requirements
can be met. Other demo boards are available to support these other terminations. The 73M2901CE
EVM-600 Demo Board uses a wet transformer design that has a 600 Ω resistive termination.
Table 3: Termination Impedance Network Values
Termination
Terminator Component Values
600 Ohm 600Ω
ETSI TS 203 complex 750Ω || 150nF + 270Ω
Australia 820Ω || 120nF + 220Ω
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 9
3.2 73M2901CE EVM-600 Hardware Design
This section includes schematic drawings, PCB layouts and bill of materials for the 73M2901CE 600
Demo Board.
3.2.1 73M 2901CE EVM-600 Schematic Diagrams
Figure 2 and Figure 3 provide the schematics for the 73M2901CE EVM-600 Demo Board and
Motherboard.
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73M2901CE Demo Board User Manual UM_2901CE_026
10 Rev. 1.4
Figure 2: 73M2901CE EVM-600 Demo Board Schematic
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.4 11
Figure 3: 73M2901CE EVM-600 Motherboard Schematic
1
2
3
4
J1
RJ-11
C2+
1
GND
2
C2-
3
V-
4
T1OUT
5
T2OUT
6
T3OUT
7
R1IN
8
R2IN
9
T4OUT
10
R3IN
11
T5OUT
12
EN
13
SHDN
14 MBAUD 15
R1OUTB 16
T5IN 17
R3OUT 18
T4IN 19
R2OUT 20
R1OUT 21
T3IN 22
T2IN 23
T1IN 24
C1- 25
VCC 26
V+ 27
C1+ 28
U1
MAX3237E
IN
1OUT 3
GND 2
U2 LM3940-3.3
DTRB
DCD
TXDB
1
TP1
RING2
DTR
1 TP2
TIP2
1
TP3
RING
1
TP4
TIP
1 TP5
RI
1 TP6
DSR
RIB
1 TP7
DCD
1 TP8
CTS
1TP9
TXD
1TP10
RXD
1TP11
RTS
1TP12
DTR
1
TP13
V+
1TP14
GND
DCDB
1
TP15
GND
RTSB
DSRB
CTSB
R10
0 Ohms
RXDB
R9
NC VCC
VCC
O1
I3
S2
J2
POWER CONNECTOR
1
2
3
4
5
6
7
8
9
10
J11
CON-10
1
2
3
4
J7
CON-4
5VDC IN
D1
DTR D2
RTS D3
RXD D4
TXD D5
CTS D6
DCD D7
DSR D8
RI
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1
J3
RS-232 DB25
C1
0.1uF
C2
0.1uF
C3
0.1uF
C4
0.1uF
C5
0.1uF
C7
10UF
+C6
10uF
VCC
R1
330
R3
330
R4
330
R5
330 R6
330
R7
330
R8
330 R2
330
C8
0.1uF C9
0.1uF
VCC
VCC
RTS
TXD
R XD
CTS
DSR
RI
73H2901CE USA 9“” DEHD BOARD RXD DTR TXD RI 000 DSR CTS RTS vcca; RING \np . . 1 o o o o t 0’ I“ \—i Kl) \O H \m \U W: DJ IE I—I IU DJ ‘0
73M2901CE Demo Board User Manual UM_2901CE_026
12 Rev. 1.4
Figure 4: 73M2901CE EVM-600 Demo Board Pin Connections
3.2.2 73M2901CE EVM-600 Demo Board Pin Description
Table 4: 73M2901CE EVM-600 Demo Board Description: Digital Interface
Name
Pin #
Description
VCC J1-1 3.3V power source for the demo board.
RTS J1-2 Request To Send Low true input. Used for RTS/CTS flow control and V.23
transmission control. Controlled by the Kn command.
CTS J1-3 Clear To Send Low true output. Used for RTS/CTS flow control and to
indicate carrier is being sent in V.23 mode. Controlled by the Kn command.
DSR J1-4 Data Set Ready Low true output. Indicates the modem is present and
ready for use.
DCD J1-5 Data Carrier Detect Low true output. Indicates a carrier is being received.
Controlled by the Cn command.
RI J1-6 RI
TXD
ng Low true output. Indicates a valid ring signal is being received. Goes
low for the duration the “ring” result code is being sent on RXD.
J1-7 Transmit Digital Input. Pin used as the digital data input for commands and
data transmission.
DTR J1-8 Data Terminal Ready Low true Input. Pin used by the terminal to control
certain actions of the modem, such as return to command mode, terminate
call, V.23 turnaround, reset, and power down.
RXD J1-9 Receive Digital Output. Pin used as the digital data output for echoing
commands and for data reception.
GND J1-10 Demo board ground.
Table 5: 73M2901CE EVM-600 Demo Board: Telephone Network Interface
Name
Pin #
Description
TIP 2 J2-1 No Connection
TIP J2-2 Polarity independent connection to the telephone network.
RING J2-3 Polarity independent connection to the telephone network.
RING2 J2-4 No Connection
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UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 13
Table 6: 73M2901CE EVM-600 Demo Board: DB-25 RS-232 Level Serial Interface
Name
DB-25pin
Description
TXD 2
Transmit Digital Inverted Input. Pin used as the digital data input for
commands and data transmission.
RXD 3 Receive Digital Inverted Output. Pin used as the digital data output for
echoing commands and for data reception.
RTS 4 Request To Send High true input. Used for RTS/CTS flow control and
V.23 transmission control. Controlled by the Kn command.
CTS 5 Clear To Send High true output. Used for RTS/CTS flow control and to
indicate carrier is being sent in V.23 mode. Controlled by the Kn
command.
DSR 6 Data Set Ready High true output. Indicates the modem is present and
ready for use.
DCD 8 Data Carrier Detect High true output. Indicates a carrier is being
received. Controlled by the Cn command.
DTR 20 Data Terminal Ready High true Input. Pin used by the terminal to
control certain actions of the modem, such as return to command mode,
terminate call, V.23 turnaround, reset, and power down.
RI 22 RI
ng High true output. Indicates a valid ring signal is being received.
Goes low for the duration thering” result code is being sent on RXD.
73M2901CE Demo Board User Manual UM_2901CE_026
14 Rev. 1.5
3.2.3 73M2901CE-EVM-600 Demo Board Bill of Materials
Table 7: 73M2901CE EVM-600 Demo Board Bill of Materials
Quant
Reference
Part
PCB Footprint
DigiKey #
Manufacturer #
Manufacturer
1 BR1 HD04 miniDIP HD04DITR-ND HD04 Diodes, Inc.
2 C1,C9 10µF 0805 PCC2182CT-ND Panasonic
1 C2 27pF 0805 PCC270ACVCT-ND Panasonic
1
C3
33pF
0805
PCC330ACVCT-ND
Panasonic
1 C4 47nF 0805 PCC1808CT-ND Panasonic
3 C5,C12,C13 3.3µF 0805 PCC1841CT-ND
6 C6,C7,C8,
C10,C11,C14
0.1µF 0805 PCC1762CT-ND Panasonic
1 C19 0.22µF 1812
CR1812X7R224ZWT
UTC
1 E1 Bidirectional
Thyristor
SMB TISP4350T3BJR,
TB03100M Bourns,
Diodes, Inc
1 F1 MF-R015/600 200mil T.H. Bourns,
Raychem
1
J1
HEADER 10
100 mil, 10 position
1 J2 HEADER 4 100 mil, 4 position
4 L1,L2,L3,L4 NLC322522T-4R7M 1206 TDK
1 R1 10K 0805 311-10KHCT-ND Phicomp
1 R2 20K 311-20KHCT-ND Phicomp
1 R3 5.1K 0805 311-5.1KHCT-ND Phicomp
1 R4 470 0805 Phicomp
1 R6 21K 0805 311-21KHCT-ND Phicomp
1 R9 63K 0805 311-63KHCT-ND Phicomp
1 R16 100 0805 311-100HCT-ND Phicomp
1 T1 MIT4115 MIT4115 Sumida
1 U1
2901CE_MLF/TQFP32
0805 Teridian
Semi.
1 U2 TLP627 0805 TLP627TP1CT-ND Toshiba
1 Y1 11.0592 MHz 200 mil T.H. CTX409-ND
.2, ”7 a fi Q
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 15
3.2.4 73M2901CE-EVM-600 Demo Board PCB Layout
Figure 5: 73M2901CE EVM-600 Demo Board: Bottom Layer
Figure 6: 73M2901CE EVM-600 Demo Board: Top Layer
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73M2901CE Demo Board User Manual UM_2901CE_026
16 Rev. 1.5
Figure 7: 73M2901CE EVM-600 Demo Board: Top Silk Screen
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 17
4 73M2901CE EVM-WW Demo Board
It is possible to design a modem that can be used in virtually any country without the need to fit different
hardware for different countries’ standards. One of the more significant differences between countries is
the line impedance match that is required. This termination can be a concern since poorly matched
impedances will affect the network by increasing the reflections and crosstalk. Therefore, there are
different terminations required in different countries to match the equipment impedance to the local
network’s characteristics. Worldwide countries use three basic network models (see Table 8 and Table
9). In the U.S and North America, a 600 Ω resistive termination is used. Many other counties also use
this termination. In most of Europe, the primary termination is a complex AC impedance commonly called
“ETSI TS 203. This is also used in other countries outside of Europe. The third network model is for
Australia and New Zealand. There are other concerns such as transmit levels, ring frequencies and
levels, call progress tone frequencies and cadence, and network protection. The first four of these are all
programmable through the 73M2901CE S-registers. The last can be taken care of by designing for the
most stringent specifications. Keep in mind that the overall cost of components will tend to be higher
since components with higher ratings will cost more. If Australia and New Zealand are on your list of
target countries, then design your protection for them.
Australia and New Zealand have higher isolation voltage requirements than other countries (3750VDC)
and require that the transformer be encapsulated. Any other devices that cross the isolation barrier, such
as opto-couplers, must also meet this requirement. They also have somewhat larger creepage and
clearance requirements to match their isolation requirements. The network input protection is now
standard, so finding components that that meet worldwide requirements are not too difficult. Input current
limiting and over-voltage protection are both universally required or advised. It is possible to pass PTT
testing in some cases without current limiting, but you put the integrity and survivability of your product at
jeopardy by not using it. Self-resetting PPTC fuses are now available that not only protect the product but
eliminate the need to replace parts if they are tripped.
4.1 Using the 73M2901CE0-EVM-WW Demo Board
The schematic in Figure 8 shows how to change the termination using the USR pins of the 73M2901CE to
control the AC termination network. The user pins control the analog switches that determine the
termination impedance. The user pins may have some other defined purposes if certain S register
settings are used.
Table 8: S-register Settings for Worldwide Modem Design
Termination Initialization String
WW DAA 600Ω ATS102-3S104-1S95-128S110-64S101+1S101-2S103-1
WW DAA CTR21 ATS102-3S104-1S95-128S110-64S101-1S101+2S103-1
WW DAA Australia ATS102-3S104-1S95-128S110-64S101-1S101-2S103+1
An example of this is the USR11 pin. If the continuous Caller ID mode is selected by setting the MSB of
S95, the USR11 pin will toggle during the Caller ID time. If you are using S95 in this mode, you should
set the modem termination just before going off hook to assure that you are configured with the correct
termination. Table 8 shows the initialization strings needed for the 73M2901CE Worldwide Demo Board.
If you choose to rearrange the USR controls in your design, the string settings will of course need to be
changed.
Table 9: Termination Impedance Network Values
Termination
Component Values
600 Ohm 600Ω
ETSI TS 203 750Ω || 150nF + 270Ω
Australia
820Ω || 120nF + 220Ω
73M2901CE Demo Board User Manual UM_2901CE_026
18 Rev. 1.5
Table 10: Worldwide Country AC Impedance Requirements
Country AC Impedance Country AC Impedance Country AC Impedance
Argentina 600 Hong Kong 600 Oman 600
Australia
Aust.
Hungary
600
Pakistan
600
Austria Aust. Iceland ETSI TS 203 Peru 600
Bahrain ETSI TS 203 India Aust. Philippines 600
Belgium ETSI TS 203 Indonesia 600 Poland 600
Brazil 600 Ireland ETSI TS 203 Portugal ETSI TS 203
Bulgaria Aust. Israel ETSI TS 203 Romania 600
Canada 600 Italy ETSI TS 203 Russia 600
Chile 600 Japan 600 Saudi
A bi
600
China 600 Jordan 600 Singapore 600
Columbia 600 Kazakhstan 600 Slovakia Aust.
Croatia ETSI TS 203 Kuwait 600 Slovenia ETSI TS 203
CTR/TBR 21 ETSI TS 203 Latvia ETSI TS 203 S. Africa ETSI TS 203
Cyprus ETSI TS 203 Lebanon ETSI TS 203 S. Korea 600
Czech Rep. ETSI TS 203 Luxembourg ETSI TS 203 Spain ETSI TS 203
Denmark ETSI TS 203 Macao 600 Sweden ETSI TS 203
Ecuador 600 Malaysia 600 Switzerland ETSI TS 203
Egypt 600 Malta ETSI TS 203 Syria 600
El Salvador 600 Mexico 600 Taiwan 600
Finland ETSI TS 203 Morocco ETSI TS 203 Thailand 600
France ETSI TS 203 Netherlands ETSI TS 203 UAE 600
Germany Aust. New Zealand Aust. UK ETSI TS 203
Greece ETSI TS 203 Nigeria ETSI TS 203 USA 600
Guam 600 Norway ETSI TS 203 Yemen 600
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 19
4.2 73M2901CE EVM-WW Hardware Design
This section includes schematic drawings, PCB layouts and bill of materials for the 73M2901CE-WW Demo Board.
4.2.1 73M 2901CE EVM-WW Schematic Diagrams
Figure 8 and Figure 9 illustrate the schematics for the 73M2901CE EVM-WW Demo Board and
Motherboard.
73M2901CE Demo Board User Manual UM_2901CE_026
20 Rev. 1.5
Figure 8: 73M2901CE Worldwide Demo Board: Daughter Board Schematic
L3
NLV32T-4R7J-PF
L4
NLV32T-4R7J-PF
C29
220pF, 3kV
R20
20K
C26
82nF
VCC3_3A
Q1
MMBTA06 B
EC
R17
100
-EMIT4033 is required for Austalia only;
the non-encapsulated MIT4033 can be
used for designs not requiring Austalian
operation.
VCC3_3D Q2
MMBTA06 B
EC
T1
EMIT4033L
Sumida
3A 2A
4A 1A
2C
4C
7C
9C
Q3
BCP-56
1
23 4
U2A 74LVC4066D
12
13
AUST
U2B 74LVC4066D
11 10
12
-This version supports only:
---Ring-E
---PPU-E
---LIU-E
D1
RS1G
CTR-21
US600
CTR-21
AUST
US600
U2C 74LVC4066D
SOIC14
43
5
-To use the programmable termination:
For all: S102-3, S104-1, S95-128, S110-64
600 Ohm termination: S101+1, S101-2, S103-1
CTR-21 termination: S101-1, S101+2, S103-1
Australian termination: S101-1, S101-2, S103+1
VCC3_3D
-All resistors 0603 footprint except R25 which is
1206
D2
MMSZ5248BT
2 1
VCC3_3
-Keep Vref and Vbg traces away from digital
traces, especially clocks. Keep traces short and
connect Vref and Vbg caps to analog ground.
-Keep analog and digital power and
ground separate up to J1 connector.
Note: A termination MUST be programmed
or no termination will be activated.
18V
C27
.047uF
D3
BZT52C2V4-7-F
2
1
C18
0.22uF
250V
C19
0.22uF
250V
R28
47K
RING/CID detection
R8
30K
R9
30K
HOOK
RING/CIDdetection
C20 150nF
TXA N
R27 420
R26 820
C25 120nF
F1
MF-R015/600
Bourns
PTC fuse
E1
TISP4350T3BJR
Bourns
Thy ristor
R15
5.1K
R25
18
1/4W
+
C21
3.3uF, 25V
R12
62K
R23
33K
+C22
3.3uF, 25V
L2
NLV32T-4R7J-PF
L1
NLV32T-4R7J-PF
U4
TLP627
12
4
3
-+
BR1
HD04
4
1
3
2
J2
RJ-11
1
2
3
4
VCC3_3D
R XA
VBG
C3
33pF
C11
0.1uF
VCC3_3A
DTRB
J1
1
2
3
4
5
6
7
8
9
10
DCDB C4
0.002uF(NC)
C7
0.1uF
OSCIN
R2
2K(NC)
+C12
3.3uF
RESET
C8
0.1uF
C24
3.3uF
C14
0.1uF
DSRB
DCDB
RXDB R13
21K
Y1
11.0592 MHz
TXA P
C10
0.1uF
TXD B
R16
100
OSCOUT
VCC3_3D
VCC3_3
RIB
+C1
10uF
C2
27pF
CTSB
VBG
VREF
U1A 2901CE_QFN/TQFP32
USR20
29
RING
30
RELAY
31
RI
32
DTR
28 RXCLK
27 R XD
26
VND
1
VPD
2
DCD
3
DSR
4
CTS
5
RTS
6
USR11
7
USR10
8
RESET 9
VPA 10
TXA N 11
TXA P 12
VREF 13
VBG 14
R XA 15
VNA 16
VND 17
OSCOUT 18
OSCIN 19
VPD 20
N/C 21
TXD 23
TXCLK 24
VPD
25
VND 22
TXA N
TXA P
VCC3_3D
RESET VCC3_3A
DTRB
RXDB
+
C5
3.3uF
RELAY B
AUST
DSRB
DCDB
RIB
+
C13
3.3uF
Note:
Mount J1 and J2 on the BACK of the board
CTR-21
RTSB
CTSB
C6
0.1uF
VCC3_3D
US600
R1
10K
OSCOUT
OSCIN
VCC3_3D
TXDB
+C9
10uF
RTSB
VREF
U1B 2901CE_QFN/TQFP32
USR20
61
RING
62
RELAY
63
RI
64
DTR
60 RXCLK
59 R XD
58
VND
33
VPD
34
DCD
35
DSR
36
CTS
37
RTS
38
USR11
39
USR10
40
RESET 41
VPA 42
TXA N 43
TXA P 44
VREF 45
VBG 46
R XA 47
VNA 48
VND 49
OSCOUT 50
OSCIN 51
VPD 52
N/C 53
TXD 55
TXCLK 56
VPD
57
VND 54
RELAY B
VCC3_3D
R XA
R24 750
C15
220pF, 250V
VCC3_3D C28
220pF, 3kV
UG_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 21
Figure 9: 73M2901CE Worldwide Demo Board: Motherboard Schematic
C5
0.1uF
D2
DSR
D1
RI
D4
CTS
D3
DCD
R2
330
R3
330
R6
330
R8
330
R1
330
D6
R XD
R4
330
R5
330
R7
330
D8
DTR
D7
RTS
D5
TXD
C7
0.1uF
VCC
C8
10uF
TP1
RI
1
TP2
DSR
1
TP3
DCD
1
TP4
CTS
1
TP6
R XD
1
TP7
RTS
1
TP8
DTR
1
TP5
TXD
1
R9
NC
TP12
RING2
1
TP11
RING
1
TP10
TIP
1
TP9
TIP2
1
C9
0.1uF
+
C10
10uF, 10V
C1
0.1uF
TP15
VCC
1
TP13
GND
1
TP14
GND
1
C4
0.1uF
J2
RAPC712
1
2
3
C3
0.1uF
C2
0.1uF
NOTE: For 5V
operation, R10 is a
NC and R9 is 0 Ohm
U1
MAX3237
VCC
26
C1+
28
C1-
25
C2+
1
C2-
3
T1I N
24
T2I N
23
T3I N
22
T4I N
19
T5I N
17
R1OUTB
16
R1OUT
21
R2OUT
20
R3OUT
18
ENB
13
SHDNB
14
MBAUD
15
GND
2
T1OUT 5
T2OUT 6
T3OUT 7
T4OUT 10
T5OUT 12
R1IN 8
R2IN 9
R3IN 11
V+ 27
V- 4
+C6
10uF, 10V
U2
LM3940IMP-3.3
IN
1OUT 3
GND
2
GND 4
J3
DSUB-25
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
+5VDC
J5
HEADER 10 (Female)
1
2
3
4
5
6
7
8
9
10
RTS
DSR
CTS
DCD
RI
TXD
R XD
DTR
VCC
VCC
J4
HEADER 4 (Female)
1
2
3
4
R10
0
VCC
VCC
VCC
J6
RJ11 modular jack 6 pin
1
2
3
4
5
6
VCC
ONIH IL , I§ Q I§ Q§B E I Q B Q
73M2901CE Demo Board User Manual UM_2901CE_026
22 Rev. 1.5
Figure 10: 73M2901CE Worldwide Daughter Board Pin Connections
4.2.2 73M2901CE EVM-WW Demo Board Pin Description
Table 11: 73M2901CE Worldwide Demo Board: Digital Interface
Name
Pin #
Description
VCC J1-1 3.3 V power source for the demo board.
RTS J1-2 Request To Send Low true input. Used for RTS/CTS
flow control and V.23
transmission control. Controlled by the Kn command.
CTS J1-3 Clear To Send Low true output. Used for RTS/CTS flow control and to
indicate carrier is being sent in V.23 mode. Controlled by the Kn command.
DSR J1-4 Data Set ReadyLow true output. Indicates the modem is present and
ready for use.
DCD J1-5 Data Carrier Detect Low true output. Indicates a carrier is being received.
Controlled by the Cn command.
RI J1-6 RI
TXD
ng Low true output. Indicates a valid ring signal is being received. Goes
low for the duration the “ring” result code is being sent on RXD.
J1-7 Transmit Digital Input. Pin used as the digital data input for commands and
data transmission.
DTR J1-8 Data Terminal Ready Low true Input. Pin used by the terminal to control
certain actions of the modem, such as return to command mode, terminate
call, V.23 turnaround, reset, and power down.
RXD J1-9
Receive Digital Output. Pin used as the digital data output for echoing
commands and for data reception.
GND J1-10 Demo board ground.
RING TIP
GND
RXD
DTR
TXD
RI
DCD
DSR
CTS
RTS
VCC3_3
I Q B Q B I§ 9 I§ Q§B 29 D DI B
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 23
Table 12: 73M2901CE Worldwide Demo Board: Telephone Network Interface
Name
Pin #
Description
TIP 2
J2-1
No Connection
TIP J2-2 Polarity independent connection to the telephone network.
RING J2-3 Polarity independent connection to the telephone network.
RING2 J2-4 No Connection
Table 13: 73M2901CE Worldwide Demo Board: DB-25 RS-232 Level Serial Interface
Name DB-25pin Description
TXD 2 Transmit Digital Inverted Input. Pin used as the digital data input for
commands and data transmission.
RXD 3 Receive Digital Inverted Output. Pin used as the digital data output for
echoing commands and for data reception.
RTS 4 Request To Send High true input. Used for RTS/CTS flow control and
V.23 transmission control. Controlled by the Kn command.
CTS 5 Clear To Send High true output. Used for RTS/CTS flow control and to
indicate carrier is being sent in V.23 mode. Controlled by the Kn
command.
DSR 6 Data Set Ready High true output. Indicates the modem is present and
ready for use.
DCD 8 Data Carrier Detect High true output. Indicates a carrier is being
received. Controlled by the Cn command.
DTR 20
Data Terminal Ready High true Input. Pin used by the terminal to
control certain actions of the modem, such as return to command mode,
terminate call, V.23 turnaround, reset, and power down.
RI 22 RI
ng High true output. Indicates a valid ring signal is being received.
Goes low for the duration thering” result code is being sent on RXD.
73M2901CE Demo Board User Manual UM_2901CE_026
24 Rev. 1.5
4.2.3 73M2901CE EVM-WW Demo Board Bill of Materials
Table 14: 73M2901CE Worldwide Demo Board Bill of Materials
* Equivalent parts are available from Datatronics, Sumida, Umec, and Allied.
Quant Reference Part DigiKey # Manufacturer P/N Manufacturer
1 BR1 HD04 HD04DICT-ND HD04-T Diodes, Inc.
2 C1,C9 10µF 587-1295-1-ND EMK212BJ106KG-T Taiyo
1 C2 27pF PCC270ACVCT-ND ECJ-1VC1H270J Panaso nic
1 C3 33pF PCC330ACVCT-ND ECJ-1VC1H330J Panaso nic
0 R2,C4 NC
4 C5,C12,C13,C24 3.3µF Cer. PCC2288CT-ND ECJ-2FB1A335K Panasonic
2 C21,C22 3.3µF, 25V 399-3140-1-ND C1206C335K3PACTU Kemet
6 C6,C7,C8,C10,C11,C14 0.1µF 445-1314-1-ND C1608X7R1H104K TDK
1 C15 220pf, 250V (min.) 445-2338-1-ND C3216COG2J221J TDK
2 C18,C19 0.22µF, 200V 490-3544-1-ND GRM43DR72E224KW01L Murata
1 C20 0.15µF (150nF) PCC1748CT-ND ECJ-1VB1A154K Panasonic
1 C25 0.12µF (120nF) PCC1906CT-ND ECJ-1VB1A124K Panasonic
1 C26 0.082µF (82nF) PCC2280CT-ND ECJ-1VB1E823K Panasonic
1 C27 0.047µF PCC1758CT-ND ECJ-1VB1C473K Panasonic
2 C28, C29 220pF, 3kV 445-2380-1-ND C4532COG3F221K TDK
1 D1 Rectifier, 1A, 400V RS1G-FDICT-ND RS1G-13-F Diodes, Inc.
2 D2 18V Zener Diode MMSZ5248BT1GOSCT-
ND MMSZ5248BT1G ON
1 D3 2.4V Zener Diode BZT52C2V4-FDICT-ND BZT52C2V4-7-F Diodes, Inc.
1 E1 Thyristor, 270V 250A P3100SBLRPCT-ND P3100SBLRP,
TISP4350T3BJR Teccor Elect.,
Bourns
1 F1 PPTC Fuse, 150mA,
600V TRF600-150-ND TRF600-150,
MF-R0150/600
Rachem,
Bourns
1 J1 HEADER 10 S1011E-36-ND PBC36SAAN Sullins
1 J2 HEADER 3 S1011E-36-ND PBC36SAAN Sullins
4 L1,L2,L3,L4 NLV32T-4R7J-PF 445-1521-1-ND NLV32T-4R7J-PF TDK
2 Q1,Q2 MMBTA06 MMBTA06LT1GOSCT-
ND MMBTA06LT1G ON
1 Q3 BCP-56 BCP56T1GOSCT-ND BCP56T1G ON
1 R1 10K P10.0KHCT-ND ERJ-3EKF1002V Panaso nic
2 R8,R9 30K P30KGCT-ND ERJ-3GEYJ623V Panaso nic
1 R12 62K P62KGCT-ND ERJ-3GEYJ303V Panaso nic
1 R13 21K P21.0KHCT-ND ERJ-3EKF2102V Panaso nic
1 R15 5.1K P5.1KGCT-ND ERJ-3GEYJ512V Panasonic
2 R16,R17 100 P100HCT-ND ERJ-3EKF1000V Panaso nic
1 R20 20K P20KGCT-ND ERJ-3GEYJ203V Panaso nic
1 R23 33K P33KGCT-ND ERJ-3GEYJ333V Panaso nic
1 R24 750 P750GCT-ND ERJ-3GEYJ751V Panasonic
1 R25 18 P18ECT-ND ERJ-8GEYJ180V Panaso nic
1 R26 820 P820GCT-ND ERJ-3GEYJ821V Panasonic
1 R27 422 P422HCT-ND ERJ-3EKF4220V Panasonic
1 R28 47K P47KGCT-ND ERJ-3GEYJ473V Panaso nic
1 T1 See Table 15* See Table 15*
1 U1 2901CE_QFN/TQFP32 Teridian
1 U2 74LVC4066D-T 74LVC4066D-T-ND NXP
1 U4 TLP627(F,T) TL627F-ND TLP627(F,T) or SD400 TOSHIBA
1 Y1 11.0592 MHz CTX409-ND ATS111 CTS
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 25
4.2.4 Recommended Components Used in the Demo Boards
Several components are required in all modem designs that significantly affect the total BOM cost. The
following parts and suppliers have proven to supply reliable and cost effective components.
Table 15: Transformers and Suppliers Tested and Used with the 73M2901CE
Manufacturer “Wet” Transformers (DC Current OK) “Dry Transformers (No DC Current)
Allied
AEE-208D1
AEE-207D1, AEP-322D1
Datatronics LM72019 PT79281
Etal None currently available P1200
Sumida MIT4115V MIT4033L, T50101
Wurth-Midcom 671-8001, 671-8005 671-8236-MU/-LF1
Umec None currently available UTB01542
The transformers listed in Table 15 are used in the 73M2901CE Demo Boards. The transformers listed
as “wet” are suitable in applications that pass the DC current through the transformer windings. These
transformers are physically larger than thedry“ types in order to prevent saturation with DC current, and
generally have lower return loss performance. These are used in the EVM-600 type designs. The “dry”
transformers require a separate DC holding circuit or gyrator (Q1-Q3 and associated circuitry in Figure 8)
to provide a DC load to the network. This circuit is also used for pulse dialing (when required), and must
present a high AC impedance to the line so that AC audio performance is not compromised. These
transformers are used on the 73M2901CE EVM-WW Demo Boards.
The Tip/Ring inductors on the demo board are 4.7uH and are used to control EMI that might be coupled
out to the line. Inductors that are intended for EMI control applications are sometimes rated for a
particular impedance at some frequency, e.g., 2 k at 100 MHz. Since the telephone connections also
carry DC current, these inductors must also work with the DC current that may be present. All inductors
in the Tip/Ring path must be rated to operate with a minimum of 200 mA so that performance is not overly
degraded at high frequencies by core saturation. Inductance also tends to go down with temperature, so
this must also be factored into the component selection. The actual EMI frequencies and levels that must
be controlled are not always the same since EMI generated in any part of the design can end up being
radiated from the telephone connection, so some characterization of the emissions is needed to
determine the best fit for the frequencies that are present. The parts we use have good characteristics for
the board when used alone, but may not work in every application that is encountered. Inductors can
have a wide range of impedance versus frequency depending on the materials that are used, so there
cannot be “one size fits all” solution for every application. Be sure the inductors are not located between
the Tip and Ring connection and the over voltage/over current protection in the design. You do not want
to have the surge current and voltage across these devices! Table 16 contains some inductors that
might be used in your application.
Table 16: EMI Inductors for the Tip/Ring Signal Path
Manufacturer
Part Number
Value, µH or Z @ Freq.
Rated Current
Allied MC20A-4R7M-RC 4.7 µH 220 mA
Laird (Steward) HZ0805C202R-00 2 k @ 100MHz 300 mA
TDK
NLV32T-4R7J-PF
4.7 µH
220 mA
There are high voltage capacitors connected to Tip and Ring to earth ground that also aid in limiting EMI
to the outside connections. These must have the same voltage ratings as the isolation required for the
design (i.e., normally the transformer isolation voltage rating). There is also a capacitor across the
Tip/Ring path that acts as a shunt to EMI energy coming from the DAA. The voltage rating of this part
only needs to be high enough to tolerate voltages up to the TVS clamp voltage (see the over voltage
protection section that follows).
73M2901CE Demo Board User Manual UM_2901CE_026
26 Rev. 1.5
If TVS devices are also provided on the Tip and Ring lines to earth ground, the voltage rating for the
Tip/Ring capacitors only needs to be able to withstand the maximum TVS clamping voltage. These and
the TVS devices must be removed during the isolation voltage certification tests to prevent triggering the
TVS devices or damaging the capacitors.
Over voltage and current protection are required for a reliable design that will survive the real-world
conditions that are encountered in the field. Nearly all certifying bodies have specifications for the severe
conditions that can occur due to lightning, static discharge, and even voltage cross to power mains. In
some cases these minimums are not adequate to survive some common fault conditions or ignore other
conditions that would seem to be less severe, but actually can present more stress to the design, so
many equipment providers will have even higher level or additional requirements not specified by the
certifying bodies.
For example, the minimum isolation voltage required for the telecom transformers is 2 kV, but lightning
strikes near power and telephone lines often far exceed these levels. For these reasons, some
customers require 6kV or more isolation. Protection from the telephone network connection is usually
provided to prevent over voltage and over current conditions from causing the product to fail. The PTC
(Positive Temperature Coefficient) fuse (F1) and thyristor Transient Voltage Suppressor or TVS (E1)
provide this protection on our demo boards. The devices we chose are parts that meet the minimums
required for UL 60950 and EN-60950, which have the most stringent requirements of the commonly used
standards. The 73M2901 designs are fully functional after the surge and power cross testing has been
performed, even though this is not a requirement to pass, (the requirement for off hook is that it not catch
fire). The following tables show the recommended components to meet various certification
requirements. The PTC fuses listed are through-hole mounted, but surface mount is also available for
most types. There are also different initial “ON” resistance versions that primarily affect the cost; the
lower the initial resistance, the higher the cost.
There are also single fault telecom fuses that are designed to be used in these applications, but they
must be replaced if they are triggered. The cost of these is about the same or more compared to the PTC
types, so there is little advantage to using them in most cases.
Table 17: Recommended PTC Fuses for CPE Applications
The TVS is important because large voltages can damage the DAA if the DAA transistor switches voltage
ratings are exceeded. The TVS works in conjunction with the PTC fuse by going into a low impedance
state when the TVS are triggered, which then causes the fuse to go to a high impedance until the fault
condition is cleared. This prevents the TVS from having to dissipate large amounts of energy if there is a
persistent high voltage fault. The TVS will also be triggered for short duration surges, but this will usually
not trigger the fuse since it may take seconds for the fuse to go to the high impedance mode, depending
on the current through it. In any case, these components work as a “team” to protect the DAA circuitry.
Manufacturer Part Number Voltage/Current Rating Specification
Bourns MF-R015/600
MF-RX012/250
600V, 150mA
250V, 120mA
TIA-968-A, UL60950
ITU-T K.20/21/45
Thinking Electronic Ind. Co.
KRT6000015xxx
KRT2500012xxx
600V, 150mA
250V, 120mA
TIA-968-A, UL60950
ITU-T K.20/21/45
Tyco (Raychem) TRF600-150
TRF250-120x 600V, 150mA
250V, 120mA TIA-968-A, UL60950
ITU-T K.20/21/45
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 27
Table 18: Recommended TVS Over Voltage Protectors
Manufacturer
Part Number
Voltage/Current Rating
Specification
Bourns
TISP4395T3BJR
275V/100A (10/560µS)
TIA-968-A, UL60950
ITU-T K.20/21/45
Diodes, Inc TB3100H 275V/100A (10/560µS) TIA-968-A, UL60950
ITU-T K.20/21/45
Littlefuse (SIDACtor) P3100EB 275V/100A (10/560µS) TIA-968-A, UL60950
ITU-T K.20/21/45
Tyco SiBar TVB275NSC 275V/100A (10/560µS) TIA-968-A, UL60950
ITU-T K.20/21/45
It is not a requirement to function after the safety testing has been performed as long as there is not a
hazardous condition afterwards. If this is not a primary concern, it is possible to pass these tests with less
expensive protection solutions. This usually involves supplying a heavier gauge telephone cord and TVS
that replace the ones above. It also requires mounting in a fire enclosure to contain any resultant fire and
damage. This is a choice that the designer (and buyer) must make when deciding on the end product’s
requirements.
The recommendations listed should not be construed as the final word on components that can be used
with Teridian’s products. Other sources exist that we have not had experience with that could also be
used in applications with our modem and FXO devices. The customer is encouraged to investigate other
sources of parts that are not listed here.
73M2901CE Demo Board User Manual UM_2901CE_026
28 Rev. 1.5
4.2.5 73M2901CE EVM-WW Demo Board PCB Layout
Figure 11: 73M2901CE Worldwide Demo Board: Bottom
Figure 12: 73M2901CE Worldwide Demo Board: Top Layer and Silk Screen
_P’ h H N \l \\
UM_2901CE_026 73M2901CE Demo Board User Manual
Rev. 1.5 29
5 DC Loop Circuit Schematic
The following circuit can be used to connect two modems for back-to-back testing. Most modems require
DC loop current is present for the DAA to operate correctly. Generally they cannot be connected together
directly without some provision for providing this current. The following circuit can be used for this
purpose. This circuit also provides a termination impedance that is close to the 600 Ohms used in the
U.S.and many other countries.
+12V
+12V
Q3
2N2905
+
C2
22UF 50 V
1
2
3
4
J2
RJ-11
Q4
2N2905
R4
10 OHM
R5
690 OHM
R6
10 OHM
Q1
2N2905
R3
10 OHM
R2
690 OHM
R1
10 OHM
Q2
2N2905
1
2
3
4
J1
RJ-11
+
C1
22UF 50 V
Figure 13: Simple DC Loop Simulator
6 Related Documentation
The following 73M2901CE documents are available from Teridian Semiconductor Corporation:
73M2901CE Data Sheet
73M2901CE AT Command User Guide
7 Contact Information
For more information about Teridian Semiconductor products or to check the availability of the
73M2901CE, contact us at:
6440 Oak Canyon Road
Suite 100
Irvine, CA 92618-5201
Telephone: (714) 508-8800
FAX: (714) 508-8878
Email: modem.support@teridian.com
For a complete list of worldwide sales offices, go to http://www.teridian.com.
73M2901CE Demo Board User Manual UM_2901CE_026
30 Rev. 1.5
Revision History
Revision Date Description
1.0 11/12/2008 Created from a merge of the USA (version 1.2) and Worldwide (version 2.1)
DBUM documents. Modified to use new corporate format and assign a
Document Number. Section on the AT Command has been moved to its
own document (UM_2801CE_027).
1.1 2/19/2009 In Table 8, corrected the entries for WW DAA CTR21 and WW DAA
Australia.
1.2 8/7/2009 Replaced the Daughter Board schematic in Figure 8.
1.3 10/1/2009 Fixed the corrupted schematics in Figure 2 and Figure 8.
1.4 1/15/2010 Replaced the schematic in Figure 9 with a new schematic.
Removed Section 5 (the 73M2901CE/CL differences were moved to the
73M2901CE Data Sheet) and subsequent sections were renumbered.
1.5 3/17/2010 Updated the schematic in Figure 8.
Replaced the layouts in Figure 10, Figure 11 and Figure 12.
Updated the Bill of Materials in Table 14.
Updated the first part of Section 4.1.
Added Section 4.2.4, Recommended Components Used in the Demo Boards.

Products related to this Datasheet

BOARD DEMO 73M2901CE USA&JAPAN
BOARD DEMO 73M2901CE WORLDWIDE