TERIDIAN 73M2901CE

73M2901CE
V.22bis Single Chip Modem
Simplifying System Integration™
DATA SHEET
DS_2901CE_031
April 2009
DESCRIPTION
FEATURES
The 73M2901CE low speed modem integrates a
data pump, controller, and analog front end in a
3.3 V device with a powerful "AT" command host
interface. The modem reduces external
component count/cost by incorporating many
features like parallel phone detect, Line-In-Use
and Ring detection in software without requiring
additional components.
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The device is a "one chip fits all” solution for
applications including set-top boxes, point-of-sale
terminals, automatic teller machines, utility
meters, vending machines and smart card
readers.
Another distinctive feature of this device is pin
compatibility with Teridian’s flagship embedded
hard modems, the 73M2901CL, and the
73M1903 soft modem AFE. This offers
customers a cost effective method to design for
both hard or soft modem solutions in the same
system as a risk-free cost reduction path.
Complete support, modem reference designs
and error correction software are part of the
solution offered by Teridian. Our in-house
application engineering team is here to help
meet your international certification needs.
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Rev. 3.3
True one chip solution for embedded systems
As low as 9.5 mA operating with standby and
power down mode available
Power supply operation from 3.6 V to 2.7 V
Data modes and speeds:
V.22bis – 2400bps
V.22/Bell212 – 1200 bps
V.21/Bell103 – 300 bps
V.23 – 1200/75 bps (with PAVI turnaround)
Bell202 – 1200 bps
Bell202/V23 1200 bps FDX 4-wire operation
V.22/Bell 212A/V.22bis synchronous modes
International Call Progress support:
FCC part 68, CTR21, JATE, etc.
DTMF generation and detection
Worldwide Caller ID capability
U.S. Type I and II support
EIA 777A compliant
SIA-2000 compliant
SMS messaging support
On chip hybrid driver
Blacklisting capability
Line-In-Use and Parallel Pick-Up (911) detection
with voltage or low cost energy detection method
Incoming ring energy detection through CID
path; no optocoupler circuitry required
Manufacturing Self Test capability
Backward compatible with 73M2901CL
Packaging: 32 lead QFN, 32-pin TQFP
© 2009 Teridian Semiconductor Corporation
1
73M2901CE Data Sheet
DS_2901CE_031
Table of Contents
1
Hardware Description ......................................................................................................................... 4
Power Supply............................................................................................................................. 4
1.1
Low Power Mode ....................................................................................................................... 4
1.2
Analog Line / Hybrid Interface ................................................................................................... 4
1.3
Interrupt pins .............................................................................................................................. 4
1.4
Crystal Oscillator ....................................................................................................................... 5
1.5
1.5.1 Specifying a Crystal ......................................................................................................... 5
Reset ......................................................................................................................................... 5
1.6
Asynchronous and Synchronous Serial Data Interface ............................................................. 5
1.7
2
Pinout ................................................................................................................................................... 6
3
Pin Descriptions .................................................................................................................................. 7
Power Pins................................................................................................................................. 7
3.1
Analog Interface Pins ................................................................................................................ 7
3.2
Digital Interface Pins.................................................................................................................. 7
3.3
External Interrupt Pins ............................................................................................................... 8
3.4
Oscillator Pins ............................................................................................................................ 8
3.5
4
Electrical Specifications..................................................................................................................... 9
Absolute Maximum Ratings ....................................................................................................... 9
4.1
Recommended Operating Conditions ....................................................................................... 9
4.2
4.3
Receiver..................................................................................................................................... 9
Transmitter............................................................................................................................... 10
4.4
Maximum Transmit Level ........................................................................................................ 10
4.5
DC Characteristics, Vcc = 3.3 V .............................................................................................. 11
4.6
4.6.1 DC Supply Current, VDD = 2.7 V (Battery EOL) ........................................................... 11
4.6.2 DC Supply Current ,VDD = 3.0 V .................................................................................. 11
4.6.3 DC Supply Current VDD = 3.3 V ................................................................................... 12
4.6.4 DC Supply Current VDD = 3.6 V ................................................................................... 12
5
Firmware Description ....................................................................................................................... 13
Firmware Overview .................................................................................................................. 13
5.1
Firmware Features .................................................................................................................. 13
5.2
6
Design Considerations ..................................................................................................................... 14
Layout Considerations ............................................................................................................. 14
6.1
73M2901CE Design Compatibility ........................................................................................... 14
6.2
Telephone Line Interface ......................................................................................................... 14
6.3
7
Reference Designs ............................................................................................................................ 15
Low Cost Design Using DSP Ring and Status Monitoring ...................................................... 15
7.1
Reference Design Using Traditional Hardware Line Monitoring ............................................. 16
7.2
8
Modem Performance Characteristics ............................................................................................. 18
BER vs. SNR ........................................................................................................................... 18
8.1
BER vs. Receive Level ............................................................................................................ 18
8.2
9
Package Mechanical Drawing .......................................................................................................... 19
32-pin QFN .............................................................................................................................. 19
9.1
32-pin TQFP ............................................................................................................................ 20
9.2
10 Ordering Information ........................................................................................................................ 21
11 Related Documentation .................................................................................................................... 21
12 Contact Information .......................................................................................................................... 21
Revision History ........................................................................................................................................ 22
2
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
Figures
Figure 1: 32-pin QFN Pinout ..................................................................................................................... 6
Figure 2: 32-pin TQFP Pinout ..................................................................................................................... 6
Figure 3: Low Cost Design Using DSP Ring and Status Monitoring .......................................................... 15
Figure 4: Modem and Hybrid Circuitry – Traditional Line Monitoring ......................................................... 16
Figure 5: Traditional DAA Circuit Showing Hardware Detection Circuitry .................................................. 17
Figure 6: BER vs SNR ............................................................................................................................ 18
Figure 7: BER vs Receive Level ................................................................................................................. 18
Figure 8: 32-pin QFN Drawing .................................................................................................................... 19
Figure 9: 32 Pin TQFP Drawing .................................................................................................................. 20
Tables
Table 1: 73M2901CE QFN and TQFP Pinout............................................................................................... 6
Table 2: 73M2901CE Order Numbers and Packaging Marks .................................................................... 21
Rev. 3.3
3
73M2901CE Data Sheet
DS_2901CE_031
1 Hardware Description
The 73M2901CE is designed to operate from a +3.6 to +2.7 volt supply with low power consumption
(~30 mW @ 3.0 volts). The modem supports automatic standby idle mode. The modem will also accept
a request to power down from the DTE via hardware control. No additional major components are
required to complete the modem core logic. The modem provides direct firmware LED support via the
port pins (pins 3, 4, 5, 6, 31, and 32).
The 73M2901 CE includes the following hardware features:
•
Fully self-contained. “AT” Command interpreter and data pump.
•
User pins available.
•
Synchronous serial data I/O available.
•
Asynchronous serial port.
•
On-chip hybrid and line driver.
•
Autobaud capability from 300 bps to 9600 bps.
•
Reduced external hardware support required with energy incoming ring detection.
1.1
Power Supply
Power is supplied to the 73M2901CE by the VPD and VPA pins. The 73M2901CE is designed for a
single +3.6 to +2.7 volt supply and for low power consumption (~30mW @ 3.0 volts). Ground is supplied
to the 73M2901CE by the VND and VNA pins.
The 73M2901CE has been designed with separated analog and digital supplies to insure the best
performance of the part by using separately filtered power supplies. It is recommended that separate
locally bypassed traces be used to apply power to the analog supply VPA and the digital supply VPD.
1.2
Low Power Mode
The Teridian 73M2901CE supports a low power standby mode. If the low power standby option is
enabled, the 73M2901CE will go into a power saving mode when idle.
While in this mode, the oscillator will be running and clocks will be supplied to the UART, timers and
interrupt blocks, but no clocks will be supplied to the CPU. Instruction processing and activity on the
internal busses is halted. Normal operation is resumed when an interruption such as assertion of DTR or
RING occurs, a character is sent to the 73M2901CE TXD input, or a reset occurs.
1.3
Analog Line / Hybrid Interface
The 73M2901CE provides a differential analog output (TXAP and TXAN) and a single-ended analog input
(RXA) with internal A/D and D/A converters. A driver is provided for an internal hybrid function.
The internal hybrid driver is capable of driving an external load matching impedance and a line-coupling
transformer. The internal hybrid/line driver senses the load and adapts itself to its requirements.
The 73M2901CE provides firmware control for a hook relay driver (RELAY) as well as interrupt support
for a ring detect opto-coupler (RING).
1.4
Interrupt pins
The external interrupt sources, DTR and RING, come from dedicated input pins of the same name.
DTR informs the 73M2901CE that the host has requested the 73M2901CE to perform a specific function.
The function of DTR can be changed by “AT” commands (described in full in the 73M2901CE AT
Command User Guide).
4
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
RING is used to inform the 73M2901CE that the external DAA circuitry or ring energy detector has
detected a ring signal. It will go active when each “RING” message is sent on RXD.
In addition, sending any character on the TXD line also generates an internal interrupt.
1.5
Crystal Oscillator
The Teridian 73M2901CE single chip modem can use an external 11.0592 MHz reference clock or can
generate a clock using only a crystal and two capacitors. If an external clock is used, it should be applied
to the OSCIN pin.
1.5.1
Specifying a Crystal
The manufacturer of a crystal resonator verifies its frequency of oscillation in a test set-up, but to ensure
that the same frequency is obtained in the application, the circuit conditions must be the same.
The Teridian 73M2901CE modem requires a parallel mode (anti-resonant) crystal, the important
specifications of which are as follows:
Mode:
Frequency:
Frequency tolerance:
Temperature drift:
Load capacitance:
ESR:
Drive level:
Parallel (anti-resonant)
11.0592 MHz
±50 ppm at initial temperature
An additional ±50 ppm over full range
18 pF to 22 pF
75 Ω max
Less than 1mW
The peak voltage level of the oscillator should be checked to assure it will not violate the maximum
voltage levels allowed on the oscillator pins. A resistor in series with the crystal can be used, if
necessary, to reduce the oscillator’s peak voltage levels.
Crystals with low ESRs may oscillate at higher than specified voltage levels.
1.6
Reset
A reset is accomplished by holding the RESET pin high. To ensure a proper power-on reset, the reset
pin must be held high for a minimum of 3 µs. At power on, the voltage at VPD, VPA, and RESET must
come up at the same time for a proper reset.
The signals DCD, CTS and DSR will be held inactive for 25 ms, acknowledging the reset operation, within
a 250 ms time window after the reset-triggering event. The 73M2901CE is ready for operation after the
250 ms window and/or after the signals DCD, CTS and DSR become active.
1.7
Asynchronous and Synchronous Serial Data Interface
The serial data interface consists of the TXD and RXD data paths (LSB shifted in and out first) and the
TXCLK and RXCLK serial synchronous clock outputs associated with the data pins; CTS/RTS flow
control; DCD, DSR and DTR. In asynchronous mode, the data is passed at the bit rate (tolerance is +1%,
-2.5%).
Rev. 3.3
5
73M2901CE Data Sheet
DS_2901CE_031
2 Pinout
The 73M2901CE is available in a 32-pin QFN or 32-pin TQFP package. Table 1 lists the pins for both
packages.
Table 1: 73M2901CE QFN and TQFP Pinout
4
DSR
12
TXAP
20
VPD
28
DTR
5
CTS
13
VREF
21
NC
29
USR20
6
RTS
14
VBG
22
VND
30
RING
7
USR11
15
RXA
23
TXD
31
RELAY
8
USR10
16
VNA
24
TXCLK
32
RI
VND
1
24
TXCLK
VND
1
24
TXCLK
VPD
2
23
TXD
VPD
2
23
TXD
DCD
3
22
VND
DCD
3
22
VND
DSR
4
21
NC
DSR
4
21
NC
CTS
5
20
VPD
CTS
5
20
VPD
RTS
6
19
OSCIN
RTS
6
19
OSCIN
7
18
OSCOUT
USR11
7
18
OSCOUT
8
17
VND
USR10
8
17
VND
12
13
14
15
16
VREF
VBG
RXA
VNA
16
VNA
TXAP
15
RXA
11
14
VBG
TXAN
13
VREF
10
12
TXAP
VPA
11
TXAN
9
10
VPA
Figure 1: 32-pin QFN Pinout
TERIDIAN
73M2901CE
RESET
9
USR10
TERIDIAN
73M2901CE
RESET
USR11
6
VPD
RXCLK
25
27
RXD
OSCIN
26
19
RXCLK
TXAN
27
11
DTR
DCD
28
3
USR20
RXD
29
26
RING
OSCOUT
30
18
RELAY
VPA
31
10
RI
VPD
32
2
VPD
VPD
25
25
RXD
VND
26
17
RXCLK
RESET
27
9
DTR
VND
28
1
USR20
Name
29
Pin
RING
Name
30
Pin
RELAY
Name
31
Pin
RI
Name
32
Pin
Figure 2: 32-pin TQFP Pinout
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
3 Pin Descriptions
3.1
Power Pins
Pin Name
Pin Number
Type
VPA
10
I
Positive analog voltage (analog supply)
VNA
16
I
Negative analog voltage (analog ground)
VPD
2, 20, 25
I
Positive digital voltage (digital supply)
VND
1, 17, 22
I
Negative digital voltage (digital ground)
3.2
Description
Analog Interface Pins
Pin Name
Pin Number
Type
RXA
15
I
Receive analog input
TXAN
11
O
Transmit analog - output
TXAP
12
O
Transmit analog + output
VBG
14
O
Analog Band Gap voltage reference (0.1 µF to VNA). This pin
must not be connected to external circuitry other than the
decoupling capacitor.
VREF
13
O
Analog reference voltage (0.1 µF to VNA)
3.3
Description
Digital Interface Pins
Pin Name
Pin Number
Type
RESET
9
I
Reset
RXCLK
27
O
Receive data synchronous clock, valid on rising edge
TXCLK
24
O
Transmit data synchronous clock, valid on rising edge
TXD
23
I
Serial data input from DTE
RXD
26
O
Serial output to DTE
USR10
8
I/O
Programmable I/O port. This pin can optionally be used to
control an external switch for external Line In Use circuitry.
USR11
7
I/O
Programmable I/O port. This pin can optionally be used to
control an external switch for caller ID operation.
RTS
6
I
Request to send
CTS
5
O
Clear to send
DSR
4
O
Data set ready
DCD
3
O
Data carrier detect
RI
32
O
Ring indicator
RELAY
31
O
Relay driver output
USR20
29
I/O
Programmable I/O port
Rev. 3.3
Description
7
73M2901CE Data Sheet
3.4
DS_2901CE_031
External Interrupt Pins
Pin Name
Pin Number
Type
RING
30
I
External interrupt – Line interface ring detection circuitry input
DTR
28
I
External interrupt – DTE DTR signal input
3.5
Description
Oscillator Pins
Pin Name
Pin Number
Type
OSCIN
19
I
Crystal input for internal oscillator, also input for external source
OSCOUT
18
O
Crystal oscillator output
8
Description
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
4 Electrical Specifications
4.1
Absolute Maximum Ratings
Parameter
Rating
Supply Voltage
-0.5 V to +4.0 V
Pin Input Voltage (except OSCIN)
-0.5 V to + 6.0 V
Pin Input Voltage (OSCIN)
-0.5 V to VPD + 0.5 V
Storage Temperature
-55 ºC to 150 ºC
Absolute maximum ratings are stress ratings ONLY, functional operation of the device at these
or any other conditions above those indicated in the recommended operation sections of this
specification is not implied. Exposure to absolute maximum conditions for extended periods of
time may affect reliability.
4.2
Recommended Operating Conditions
Parameter
Rating
Supply Voltage
2.7 V to 3.6 V
Oscillator Frequency
11.0592 MHz +/- 50 ppm
Operating Temperature
-40 ºC to 85 ºC
4.3
Receiver
Parameter
Conditions
Min
Nominal
Max
Carrier Detect On
Tip and Ring
-43
dBm0 1
Carrier Detect Off
Tip and Ring
-48
dBm01
Carrier Detect Hysteresis
Tip and Ring
Receive Level
Tip and Ring
Idle Channel Noise
0.2 kHz to 4.0 kHz
Input Impedance
RXA
150
Receive Gain Boost
S110 bit 5=1, CID mode
18.8
19.3
19.8
dB
Max Input Level at RXA
VREF=1.25 V
0.587
0.622
0.658
Vpk
Total Harmonic Distortion
(THD)
1kHz 450 mVpk on RXA
THD=2nd and 3rd harmonic
-70
-50
dB
2
-43
-70
Units
dB
-9
dBm01
-65
dB
kΩ
1
dBm0 refers to the Teridian recommended line interface (8 dB loss from transmit pins to the line and 5 dB loss from
the line to the receiver pin). Results may vary depending on the selected DAA components. 0dBm=0.775 mVrms;
dBm=10log(Vrms2/(1mW)(600Ω))
Rev. 3.3
9
73M2901CE Data Sheet
4.4
DS_2901CE_031
Transmitter
Parameter
Conditions
Min
Nominal
Max
Units
ITU Guard tone power
550 Hz (relative to carrier)
-5
-3.5
-2
dB
1800 Hz (relative to carrier)
-8
-6.5
-5
dB
Calling Tone
1300 Hz
-11
-10
-9
dBm0 1
Answer Tone power
2225 Hz / 2100 Hz
-11
-10
-9
dBm01
DTMF Transmit power
High band tones
-12
-11.5
-11
dBm01
Low band tones
-13.7
-13.2
-12.7
dBm01
Gain adjust tolerance
By step
-0.3
0
0.3
dBm01
Total Harmonic Distortion
(THD)
1 kHz sine wave at output
(TXAP-TXAN)
1.5 Vpk (2.7 dBm) for
VREF=1.25 V
THD=2nd and 3rd harmonic
-50
dB
Intermod Distortion
At output (TXAP-TXAN)
1 kHz, 1.2 kHz sine waves
summed
2 Vpk for VREF=1.25 V
Each unwanted
frequency component
-33
dBm
Sum of unwanted
frequency components
in pass band
-20
dB
below
low tone
30
dB
Max
Units
Power supply rejection
ratio
4.5
-30 dBm signal at VPA
300 Hz to 30 kHz
measured TXAP to TXAN
Maximum Transmit Level
Parameter
Conditions
Min
Nominal
QAM
VREF=1.25 V
VPA=3.3 V
-9.6
dBm01
DPSK
VREF=1.25 V
VPA=3.3 V
-7.4
dBm01
FSK
VREF=1.25 V
VPA=3.3 V
-5.3
dBm01
DTMF (High Tone)
VREF=1.25 V
VPA=3.3 V
S13=$20,
S85=80
-8
-7
dBm01
DTMF (Low Tone)
VREF=1.25V
VPA=3.3V
S13=$20,
S85=80
-9.7
-8.7
dBm01
1
dBm0 refers to the Teridian recommended line interface (8 dB loss from transmit pins to the line and 5 dB loss from
the line to the receiver pin). Results may vary depending on the selected DAA components. 0dBm=0.775 mVrms;
dBm=10log(Vrms2/(1mW)(600Ω))
10
Rev. 3.3
DS_2901CE_031
4.6
73M2901CE Data Sheet
DC Characteristics, Vcc = 3.3 V
(Vdd stands for VPD and VPA)
Parameter
Symbol
Input low voltage (except OSCIN)
VIL
Input low voltage OSCIN
Conditions
Min
Nom
Max
Unit
-0.5
0.8
V
VIL
-0.5
0.2 Vdd
V
Input high voltage (except OSCIN)
VIH
0.7 Vdd
+5.5
V
Input high voltage OSCIN
VIH
0.7 Vdd
Vdd+0.5
V
Output low voltage (except OSCOUT)
VOL
IOL=4 mA
0.45
V
Output low voltage OSCOUT
VOLOSC
IOL=3 mA
0.7
V
Output high voltage (except OSCOUT) VOH
IOH=-4 mA
Vdd-0.45
V
Output high voltage OSCOUT
VOHOSC
IOH=-3 mA
Vdd-0.9
V
Input leakage current (except OSCIN)
IIH
Vss<Vin<Vdd
Input leakage current OSCIN
IIH
Vss<Vin<Vdd
1
1
µA
30
µA
Parameter
Conditions
Min
Nom
Max
Unit
VBG
Vdd=3.3 V
1.19
1.25
1.31
V
VREF
Vdd=3.3 V
1.19
1.25
1.31
V
TXAP to TXAN offset
Vdd=3.3 V, steady state
50
mV
Nom
Max
Unit
4.6.1
DC Supply Current, VDD = 2.7 V (Battery EOL)
Parameter
Symbol
Conditions
Maximum power supply,
normal operation
IDD1
30 pF/pin
9.5
10.5
mA
Maximum power supply,
Idle mode
IDD2
30 pF/pin
900
1500
µA
Maximum power supply,
Power Down mode
IDD3
30 pF/pin
10
µA
Nom
Max
Unit
4.6.2
Min
DC Supply Current ,VDD = 3.0 V
Parameter
Symbol
Conditions
Maximum power supply,
normal operation
IDD1
30 pF/pin
10.6
11.9
mA
Maximum power supply,
Idle mode
IDD2
30 pF/pin
1.1
1.7
mA
Maximum power supply,
Power Down mode
IDD3
30 pF/pin
10
µA
Rev. 3.3
Min
11
73M2901CE Data Sheet
4.6.3
DS_2901CE_031
DC Supply Current VDD = 3.3 V
Parameter
Symbol
Conditions
Maximum power supply,
normal operation
IDD1
Maximum power supply,
Idle mode
Maximum power supply,
Power Down mode
4.6.4
Min
Nom
Max
Unit
30 pF/pin
11.8
13.6
mA
IDD2
30 pF/pin
1.25
1.85
mA
IDD3
30 pF/pin
10
µA
Nom
Max
Unit
DC Supply Current VDD = 3.6 V
Parameter
Symbol
Conditions
Maximum power supply, normal
operation
IDD1
30 pF/pin
13.4
15.5
mA
Maximum power supply, Idle mode
IDD2
30 pF/pin
1.4
2.0
mA
Maximum power supply, Power
Down mode
IDD3
30 pF/pin
10
µA
12
Min
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
5 Firmware Description
An “AT” command interpreter provides command and configuration of the 73M2901CE. This provides the
user a uniform interface to control the modem in embedded applications. The signal processing is
performed to provide data to the DAC and process data from the A/D converter. A MAC hardware
coprocessor is provided for computation.
To provide maximum flexibility, the system host processor can access the internal RAM and Control
Register space in the modem. This will allow the OEM user to modify parameters such as filter response
and transmit levels through the AT command set using proprietary commands. The host processor can
also access the modem I/O port pins, providing extended I/O capability.
Refer to the 73M2901CE AT Command User Guide for a complete description of the software.
5.1
Firmware Overview
The modem always powers up in the idle (on hook) mode. “AT” commands are issued via the serial
interface from the host. All modem configuration commands are received in this manner. The data
modem firmware is contained in an internal ROM.
The firmware will automatically enter a power saving idle mode if the modem is on hook and there are no
incoming host commands. The modem automatically powers up upon receiving the next command. This
power up sequence occurs without delay to the host. This function, while saving power, is transparent to
the host processor and can be disabled by the host via an “AT” command. The host can also program
the modem to power down via an external pin (DTR) or via a firmware command.
5.2
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Firmware Features
“AT” command set
Supports data standards through V.22bis
Provides DAA control firmware (e.g. ring detect, hook control)
Multinational Call Progress support (FCC part 68, ITU CTR21, Japan JATE, etc.)
Caller ID capability
FSK demodulation (V.23, V.21, Bell 202 and Bell 103)
DTMF detection and decoding
Selectable number of rings and line reversal for CID data operation
On hook CID data operation
On hook Line-In-Use detection support (No line seizure will occur when a Line-In-Use condition is
detected)
Off hook Parallel Pick-Up detection support (Line seizure will be aborted as soon as a Parallel Pick-Up
condition is detected)
Off hook voltage change detection (requires external circuitry)
Receive energy change detection
Directly interfaces with standard V.24/EIA-232 bus drivers (3.3 V inverted level) serial interface using
the built in serial port and firmware control of port pins
Provides tone generation and detection including four imprecise and four precise call progress detect
filters with programmable frequency and detection threshold
Blacklisting capability
Long Space disconnect support
Inactivity timeout
Host access to program RAM provided
User programmable general purpose I/O
Rev. 3.3
13
73M2901CE Data Sheet
DS_2901CE_031
6 Design Considerations
The 73M2901CE single chip modem includes all the basic modem functions. Programmable configuration
options make this device highly adaptable to a wide variety of applications.
Unlike digital logic circuitry, modem designs must contend with precise frequency tolerances and verify
low-level analog signals to ensure acceptable performance. Using good analog circuit design practices
will generally result in a sound design. The crystal oscillator should be held to a 50 ppm tolerance. The
recommendations in this section should be taken into consideration when starting new designs.
6.1
Layout Considerations
Good analog/digital design rules must be used to control system noise in order to obtain high
performance in modem designs. The more digital circuitry present in the application, the more attention
to noise control is needed.
High speed, digital devices should be locally bypassed, and the telephone line interface and the modem
should be located next to each other near where the telephone line connection is accessed. It is
recommended that power supplies and ground traces be routed separately to the analog and digital portions
on the board. Digital signals should not be routed near low-level or high impedance analog traces.
The 73M2901CE should be considered a high performance analog device. A 3.3 µF electrolytic capacitor in
parallel with a 0.1 µF Ceramic capacitor should be placed between each VPD and VND pin and a 10 µF and
0.1 µF between VPA and VNA. A 0.1 µF ceramic capacitor should be placed between VREF and VNA as
well as between VBG and VNA. Use of ground planes and large traces on power is recommended.
6.2
73M2901CE Design Compatibility
The Teridian 73M2901CE is an enhanced version of the Teridian 73M2901CL and has a number of
additional features. These parts are highly compatible with the earlier 73M2901, however, users should
pay special attention when changing an existing 73M2901 design to use the 73M2901CE or 73M2901CL.
From a hardware standpoint, the key differences involve the User I/O pins USR10 and USR11, the
ASRCH pin and the HBDEN pin. An additional user I/O pin, USR20, replaces the ASRCH pin on the
73M2901CE. This pin may remain safely connected to TXD as long as the host software does not
reconfigure USR20 as an output (S104 bit0=0).
The 73M2901CE contains a high efficiency low power hybrid driver. Due to this enhancement, HBDEN is no
longer required. This pin is an internal no-connect and can safely remain connected to its previous VPD or
GND. The functions of USR10 and USR11 are related to Caller ID and Line In Use/Parallel Pickup support.
Software enhancements to the 73M2901CE are typically achieved by the addition of new AT commands.
The device can be considered a superset of the 73M2901CL and 73M2901C. When converting a design to
the 73M2901CE, it is recommended that the user check the commands and register settings for backward
compatibility to the earlier parts (refer to the 73M2901CE AT Command User Guide for complete details).
6.3
Telephone Line Interface
Transmit levels at the line are dependent on the interface used between the pins and the line. The internal
hybrid line drivers eliminate the need for additional active circuitry to drive the line-coupling transformer.
The analog outputs TXAP and TXAN can be connected directly to the transformer (with the required
impedance matching series resistor or network). Depending upon transformer design (specifically dry
transformers), operation may be affected by the limited amount of DC current generated by the analog
outputs (DC offset). For this reason, Teridian recommends using a coupling capacitor with those
transformers to insure maximum performance.
The line interface circuits shown in Section 7 Reference Designs represent the basic components and
values for interfacing the Teridian 73M2901CE analog pins to the telephone line. The values of these
components have been calculated to minimize the transmission and reception path hybrid losses and are
linked by the following equation: R15=0.242 x R13.
14
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
7 Reference Designs
7.1
Low Cost Design Using DSP Ring and Status Monitoring
11.0592 MHz
C3
VCC3_3D
C2
VCC3_3D
33pF
Y1
C11
0.1uF
27pF
+ C12
3.3uF
C13
C14
3.3uF
0.1uF
+
TXD
24
23
22
21
20
19
18
17
73M2901CE
25
26
27
28
29
30
31
32
DTRB
VPD
RXD
RXCLK
DTR
USR20
RING
RELAY
RI
VNA
RXA
VBG
VREF
TXAP
TXAN
VPA
RESET
16
15
14
13
12
11
10
9
R13
21K
DCDB
DSRB
C4
56nF
R2
2.7K
HY BRID2
VCC3_3A
1
2
3
4
5
6
7
8
RIB
R15
5.1K
VND
VPD
DCD
DSR
CTS
RTS
USR11
USR10
RXD
HY BRID1
TXCLK
TXD
VND
N/C
VPD
OSCIN
OSCOUT
VND
U1
R17
475
C7
C8
0.1uF
0.1uF
+ C9
10uF
C10
VCC3_3D
R20
27K
0.1uF
CTSB
RTSB
DETECT
R18 100
LIUCHK
R16 100
HOOKB
C1 10uF
+
VCC3_3D
C5
0.1uF
3.3uF
1
1
-
F1
BR1
CBRHD-04
3
4
1
VCC3_3D
+
E1
TISP4350T3BJR
Bourns
Thy ristor
2
1
4
L1
NLC322522T-4R7M
4
HY BRID2
T1
Sumida
MIT4115
2
3
2
HY BRID1
R1
10K
C6
+
3
2
U2
TLP627
R9
C19
63K
0.22uF
250V
L2
NLC322522T-4R7M
MF-R015/600
Bourns
PTC f use
J2
4
3
2
1
RJ-11
HOOKB
ISOLATION BARRIER
Figure 3: Low Cost Design Using DSP Ring and Status Monitoring
Rev. 3.3
15
73M2901CE Data Sheet
7.2
DS_2901CE_031
Reference Design Using Traditional Hardware Line Monitoring
11.0592 MHz
C3
VCC3_3D
C2
VCC3_3D
33pF
Y1
C11
0.1uF
+ C12
3.3uF
27pF
C13
C14
3.3uF
0.1uF
+
TXD
DTRB
RIB
DCDB
DSRB
24
23
22
21
20
19
18
17
VPD
RXD
RXCLK
DTR
USR20
RING
RELAY
RI
VNA
RXA
VBG
VREF
TXAP
TXAN
VPA
RESET
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
RXD
25
26
27
28
29
30
31
32
R15
5.1K
VND
VPD
DCD
DSR
CTS
RTS
USR11
USR10
73M2901CE
HY BRID1
TXCLK
TXD
VND
N/C
VPD
OSCIN
OSCOUT
VND
U1
R17
475
R13
21K
C4
56nF
R2
2.7K
HY BRID2
VCC3_3A
C7
C8
0.1uF
0.1uF
+ C9
10uF
C10
VCC3_3D
R20
27K
0.1uF
CTSB
RTSB
R18 100
R16 100
LIUCHK
HOOKB
C1 10uF
+
VCC3_3D
DETECT
C5
3.3uF
+
C6
R1
10K
0.1uF
Figure 4: Modem and Hybrid Circuitry – Traditional Line Monitoring
16
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
R4
13K
R5
13K
R6
27K
2
R3
33K
PPU Circuit
3
Q3
CMPT6429
C
15V
0.5W
1
D2
CMR1F-04M
D3
R19
20K
D7
A
C
A
C
C
HY BRID2
R21
100 OHMS
C16
1uF
R10
62K
A
4
R12
20K
A
D1
2
2
HY BRID1
R7
1K
1
CMPT6429
+ C15
10uF
R14
62K
Q2
3
3
1
T1
Sumida
MIT4114
3
2
Q1
2N5087
1
CMR1F-04M
12V
DETECT
4
1
D8
RING detection
R11
9.1K
C17
S1A
D6
D5
A
C
U2
TLP627
A
C
22V
22V
3
2
0.47UF
250V
L1
NLC322522T-4R7M
4
R8
51K
4
1
VCC3_3D
F1
4
1
LIUCHK
VCC3_3D
-
2
U5
Z602
+
1
E1
P3100EA70
TECCOR
SIDACTOR
3
CID coupling
3
2
U3
TLP627
L2
NLC322522T-4R7M
3
2
U4
TLP627
C18
0.15uF
250V
R9
TR250-145
RAY CHEM
POLY SWITCH
J2
4
3
2
1
C19
CON4
HOOKB
9.1K
RING/CID detection
0.47uF
250V
Figure 5: Traditional DAA Circuit Showing Hardware Detection Circuitry
Rev. 3.3
17
73M2901CE Data Sheet
DS_2901CE_031
8 Modem Performance Characteristics
The curves presented in this data sheet define modem IC performance under a variety of line conditions
typical of those encountered over the Public Switched Telephone Network.
8.1
BER vs. SNR
This test represents the ability of the modem to operate over noisy lines with a minimum amount of data
transfer errors. Since some noise is generated in the best dial up lines, the modem must operate with the
lowest signal to noise ratio (SNR) possible.
Better modem performance is indicated by test curves that are closest to the BER axis. A narrow spread
between curves representing the four line parameters indicates minimal variation in performance while
operating over a range of typical operating conditions. A DPSK or QAM modem will exhibit better BER
performance test curves receiving in the low band (answer mode) than in the high band (originate mode).
8.2
BER vs. Receive Level
This test measures the dynamic range of the modem. Because signal levels vary widely over dial up
lines, the widest possible dynamic range is desirable. The SNR is held constant at the indicated values
as the receive level is lowered from a very high to a very low signal level. The width of the bowl of these
curves, taken at the BER break points is the measure of the dynamic range.
Figure 6: BER vs SNR
18
Figure 7: BER vs Receive Level
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
9 Package Mechanical Drawing
9.1
32-pin QFN
0.85 NOM./ 0.9MAX.
0.00 / 0.005
5
0.20 REF.
2.5
1
2.5
2
3
5
SEATING
PLANE
SIDE VIEW
TOP VIEW
0.35 / 0.45
3.0 / 3.75
CHAMFERED
0.30
0.18 / 0.3
1.5 / 1.875
1
2
3
3.0 / 3.75
0.25
1.5 / 1.875
0.5
0.2 MIN.
0.35 / 0.45
0.5
0.25
BOTTOM VIEW
Figure 8: 32-pin QFN Drawing
Rev. 3.3
19
73M2901CE Data Sheet
9.2
DS_2901CE_031
32-pin TQFP
Figure 9: 32 Pin TQFP Drawing
20
Rev. 3.3
DS_2901CE_031
73M2901CE Data Sheet
10 Ordering Information
Table 2 lists the order numbers and packaging marks used to identify 73M2901CE products.
Table 2: 73M2901CE Order Numbers and Packaging Marks
Part Description
Order Number
Packaging Mark
73M2901CE 32-Pin QFN Lead Free
73M2901CE-IM/F
M2901CEM
73M2901CE 32-Pin QFN Lead Free Tape & Reel
73M2901CE-IMR/F
M2901CEM
73M2901CE 32-Pin Thin Quad Flat Pack Lead Free
73M2901CE-IGV/F
73M2901CEIGV
73M2901CE 32-Pin Thin Quad Flat Pack Lead Free
Tape & Reel
73M2901CE-IGVR/F
73M2901CEIGV
11 Related Documentation
The following 73M2901CE documents are available from Teridian Semiconductor Corporation:
73M2901CE AT Command User Guide
73M2901CE Demo Board User Guide
12 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: [email protected]
For a complete list of worldwide sales offices, go to http://www.teridian.com.
Rev. 3.3
21
73M2901CE Data Sheet
DS_2901CE_031
Revision History
Revision
Date
Description
2.2.1
4/20/2004
First publication.
3.1
12/14/2007
Replaced 32QFN punched with SAWN package, removed leaded package
option, updated schematic and minor clean up.
3.2
1/21/2008
Changed dimension of bottom exposed pad on 32QFN mechanical package
figure.
3.3
4/3/2009
Formatted to new Teridian style.
Assigned new document number.
Minor corrections have been made to Section 5.3 and Section 6.3.
© 2009 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
22
Rev. 3.3