73M1903
Modem Analog Front End
DATA SHEET
SEPTEMBER 2006
DESCRIPTION
The TERIDIAN 73M1903 Analog Front End
(AFE) IC includes fully differential hybrid driver
outputs, which connect to the telephone line
interface through a transformer-based DAA. The
receive pins are also fully differential for
maximum flexibility and performance. This
arrangement allows for the design of a high
performance hybrid circuit to improve signal to
noise performance under low receive level
conditions, and compatibility with any standard
transformer intended for PSTN communications
applications.
The device incorporates a programmable
sample rate circuit to support soft modem and
DSP based implementations of all speeds up to
V.92 (56kbps). The sampling rates supported
are from 7.2kHz to 14.4kHz by programming
pre-scaler NCO and PLL NCO.
The TERIDIAN 73M1903 device incorporates a
digital host interface that is compatible with the
serial ports found on most commercially
available DSPs and processors and exchanges
both payload and control information with the
host.
Cost saving features of the device include an
input reference frequency circuit, which accepts
a range of crystals from 9-27MHz. It also
accepts external reference clock values between
9-40MHz generated by the host processor. In
most applications, this eliminates the need for a
dedicated crystal oscillator and reduces the bill
of material (BOM).
The 73M1903 also supports two analog loop
back and one digital loop back test modes.
The 73M1903 in 32-TQFP package is footprint
compatible with 73M2901CL embedded modem
and allows for the same circuit design to
accommodate soft modem, V.22bis hard
modem, and high speed (V.32bis/V.34/V.92)
applications through population of an external
data pump device.
FEATURES
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Up to 56kbps (V.92) performance
Programmable sample rates (7.2 - 14.4kHz)
Reference clock range of 9-40MHz
Crystal frequency range of 9-27MHz
Host synchronous serial interface operation
Pin compatible with 73M2901CL/CE
modems
Low power modes
On board line interface drivers
Fully differential receiver and transmitter
Drivers for transformer interface
3.0V – 3.6V operation
5V tolerant I/O
Industrial temperature range (-40 to +85°C)
JATE compliant transmit spectrum
Package options: 32-TQFP and 32-QFN
APPLICATIONS
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Set Top Boxes
Personal Video Recorders (PVR)
Multifunction Peripherals (MFP)
Fax Machines
Internet Appliances
Game Consoles
Point of Sale Terminals
Automatic Teller Machines
Speaker Phones
RF Modems
VBG
(HYBRID)
TXAP
TXAN
Transmit
Drivers/
Filters
Receive
Mux/
Filters
DAA
Controls
Analog
Sigma
Delta
Ref.
SCLK
SDIN
RXAP
RXAN
DAC
Control
Registers
Serial
Port
SDOUT
FSB
GPIO
HOOK
Clocks
Control
Logic
Crystal
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©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
