73M1903C Datasheet, PDF (1/46 Pages) Teridian Semiconductor Corporation – Modem Analog Front End

DESCRIPTION
The TERIDIAN 73M1903C 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 16.0kHz by programming the pre-
scaler NCO and the PLL NCO.
The TERIDIAN 73M1903C 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.
This interface can be configured as a single
master/slave mode or as a daisy chain mode that
allows the user to connect up to eight 73M1903C
devices to a single host for multi Analog Front
End applications, such as, central server
modems.
Costs saving features of the device include an
input reference frequency circuit, which accepts a
range of crystals from 4.9-27MHz. It also accepts
external reference clock values between 1MHz-
40MHz generated by the host processor. In most
applications, this eliminates the need for a
dedicated crystal oscillator and reduces the bill of
materials (BOM).
The 73M1903C also supports two analog loop
back and one digital loop back test modes.
73M1903C
Modem Analog Front End
DATA SHEET
Features
JANUARY 2008
• Two pairs of software selectable transmit
differential outputs for worldwide impedance
driver implementations.
• Up to 56kbps (V.92) performance
• Programmable sample rates (7.2-16.0kHz)
• Reference clock range of 1-40MHz
• Crystal frequency range of 4.9-27MHz
• Master or slave mode operation and daisy
chain configurable synchronous serial Host
interface
• Low power modes
• 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 pin QFN
Applications
• Central site server modems
• 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
• Digital Answering Machines
• RF Modems
TXAP1
TXAN1
TXAP2
TXAN2
RXAP
RXAN
(HYBRID)
Transmit
Drivers/
Filters
Analog
Sigma
Delta
VBG
Ref.
Receiver
MUX/
Filters
DAC
Control
Registers
Serial
Port
GPIO
HOOK
DAA
controls
Clock
Control
Logic
SCLK
SDIN
SDOUT
FS
FSD
Crystal
Page: 1 of 46
© 2005-2008 TERIDIAN Semiconductor Corporation
Rev 4.3