73M2901CE-IMR/F Maxim Integrated Products, 73M2901CE-IMR/F Datasheet - Page 15

• Manufacturer Part Number: 73M2901CE-IMR/F
• Description: IC MODEM 3.3V V.22BIS 32-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 73M2901CE-IMR/F

• Data Format: V.21, V.22, V.23, Bell 103, Bell 212A
• Baud Rates: 300 ~ 9.6k
• Interface: Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS_2901CE_031
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.
6.2
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
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
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: R3 and R6 in Figure 3 and R15=0.242 x R13 in Figure 4.
Rev. 3.4
73M2901CE Design Compatibility
Telephone Line Interface
Section 7 Reference Designs
represent the basic components and
73M2901CE Data Sheet
15