73M1903
Modem Analog Front End
Simplifying System Integration
TM
DATA SHEET
February 2009
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 (56 kbps). The sampling rates supported
are from 7.2 kHz to 14.4 kHz by programming
pre-scaler NCO and PLL NCO.
The 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 9-27 MHz. It also
accepts external reference clock values between
9-40 MHz 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.
VBG
(HYBRID)
TXAP
TXAN
FEATURES
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Up to 56 kbps (V.92) performance
Programmable sample rates (7.2 - 14.4 kHz)
Reference clock range of 9-40 MHz
Crystal frequency range of 9-27 MHz
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
3.0 V – 3.6 V operation
5 V tolerant I/O
Industrial temperature range (-40 to +85
°C)
JATE compliant transmit spectrum
Package options:
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32-pin QFN
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20-pin TSSOP
RoHS compliant (6/6) lead-free packages
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APPLICATIONS
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SCLK
SDIN
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
Transmit
Drivers/
Filters
Receive
Mux/
Filters
DAA
Controls
Analog
Sigma
Delta
Ref.
RXAP
RXAN
DAC
Control
Registers
Serial
Port
SDOUT
FSB
GPIO
HOOK
Clocks
Control
Logic
Crystal
Rev. 2.0
© 2009 Teridian Semiconductor Corporation
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TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
