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
Page: 1 of 45
©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
73M1903
Modem Analog Front End
DATA SHEET
REVISION HISTORY
Revision Level
2.4
2.5
Revision Date
March 13, 2003
May 22, 2003
Revision Description
Generated Preliminary Datasheet Release
Inconsistent Pin-out tables corrected; Entered
limitation on effective divide > = 2.0; VBG=1.19V; Fs
range increased to 14.4kHz; Gain change in ALB
mode (Txd code must be reduced by 3dB);SCLK drive
strength increased by x5.
Make changes to reflect B01
Make changes to reflect B02
Make changes to delete test comments and pass
band ripple
Revised front sheet, added block diagram, IDD current
changed.
Add active low fonts, clean up register map, match
text to figures, general cleanup
Update footer revision on pages 1,2
Removed Pin 21 CLKOUT signal from package
drawing.
Update divider tables, RXG[1,0] setting, misc.
corrections
Create Final Data Sheet
Minor modification for format
Company Logo change and minor modification for
format
Correct QFN pin-out drawing
Correct QFN pin-out drawing
3.0
3.3
3.4
3.5
3.6
3.7
3.8
1.0
1.1
1.2
1.3
1.4
June 2003
August 2003
August 2003
September 2003
September 9, 2003
September 9,2003
October 10, 2003
April 16, 2004
December 13, 04
July 15, 2005
Sept. 14,2006
Sept. 14,2006
Page: 2 of 45
©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
73M1903
Modem Analog Front End
DATA SHEET
Table of Contents
DESCRIPTION.............................................................................................................................................. 1
FEATURES ................................................................................................................................................... 1
APPLICATIONS ............................................................................................................................................ 1
REVISION HISTORY .................................................................................................................................... 2
SIGNAL DESCRIPTION ............................................................................................................................... 5
SERIAL INTERFACE .................................................................................................................................... 6
MEMORY MAP ............................................................................................................................................. 9
GPIO ........................................................................................................................................................... 11
ANALOG I/O ............................................................................................................................................... 11
CLOCK GENERATION ............................................................................................................................... 13
Crystal Oscillator and Pre-scaler NCO
.............................................................................................. 13
MODEM RECEIVER ................................................................................................................................... 19
MODEM TRANSMITTER............................................................................................................................ 22
TEST MODES............................................................................................................................................. 26
POWER SAVING MODES.......................................................................................................................... 26
ELECTRICAL SPECIFICATIONS............................................................................................................... 27
ABSOLUTE MAXIMUM RATINGS.........................................................................................................
27
RECOMMENDED OPERATING CONDITIONS
..................................................................................... 27
DIGITAL SPECIFICATIONS ....................................................................................................................... 28
DC CHARACTERISTICS
........................................................................................................................ 28
AC TIMING..............................................................................................................................................
29
ANALOG SPECIFICATIONS ...................................................................................................................... 30
DC SPECIFICATIONS
............................................................................................................................ 30
AC SPECIFICATIONS
............................................................................................................................ 30
PERFORMANCE
.................................................................................................................................... 31
PACKAGE OPTIONS.................................................................................................................................. 34
MECHANICAL DRAWINGS........................................................................................................................ 35
MECHANICAL DRAWINGS cont................................................................................................................ 36
APPENDIX A............................................................................................................................................... 37
73M1903 DAA Resistor Calculation Guide..........................................................................................
37
APPENDIX B............................................................................................................................................... 40
Crystal Oscillator...................................................................................................................................
40
PLL
.......................................................................................................................................................... 41
Examples of NCO settings
................................................................................................................... 42
ORDERING INFORMATION....................................................................................................................... 45
Page: 3 of 45
©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
73M1903
Modem Analog Front End
DATA SHEET
List of Figures
Figure 1 -SCLK and
FS
with SckMode = 0................................................................................................
8
Figure 2 -Control frame position vs. SPOS
.............................................................................................. 8
Figure 3 -Serial Port Timing Diagram......................................................................................................
10
Figure 4 -Analog block diagram
.............................................................................................................. 12
Figure 5 -Clock Generation
...................................................................................................................... 18
Figure 6 -Overall Receiver Frequency Response
.................................................................................. 20
Figure 7 -Rx Path Passband Response
.................................................................................................. 20
Figure 8 -RXD Spectrum of 1kHz tone
.................................................................................................... 21
Figure 9 -RXD Spectrum of 0.5kHz, 1kHz, 2kHz, 3kHz and 3.5kHz tones of Equal Amplitudes........
21
Figure 10 -Frequency Response of TX Path for DC to 4kHz in band Signal.......................................
22
Figure 11 -Serial Port Data Timing
.......................................................................................................... 29
ge: 4 of 45
©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
73M1903
Modem Analog Front End
DATA SHEET
SIGNAL DESCRIPTION
The TERIDIAN 73M1903 modem AFE IC is available in a 32 pin TQFP or QFN package with same pin
out. The following table describes the function of each pin. There are two pairs of power supply pins,
VPA(analog) and VPD(digital). They should be separately decoupled from the supply source in order to
isolate digital noise from the analog circuits internal to the chip. Failure to adequately isolate and
decouple these supplies will compromise device performance.
PIN NAME
VND
VNA
VPD
VPA
VPPLL
VNPLL
RST
OSCIN
OSCOUT
GPIO(0-7)
VREF
RXAP
RXAN
TXAP
TXAN
SCLK
SDOUT
SDIN
FS
TYPE
SckMode
TYPE
GND
GND
PWR
PWR
PWR
PWR
I
I
O
I/O
O
I
I
O
O
O
O
I
O
I
I
PIN #
1,22
16
2,25
10
20
17
9
19
18
3, 4, 5, 6,
23, 24,30,31
13
15
14
12
11
8
32
29
7
27
28
DESCRIPTION
Negative Digital Ground
Negative Analog Ground
Positive Digital Supply
Positive Analog Supply
Positive PLL Supply, shared with VPD
Negative PLL Ground
Master reset. When this pin is a logic 0 all registers are reset to
their default states; Weak-pulled high- default
Crystal oscillator input. When providing an external clock
source, drive OSCIN.
Crystal oscillator circuit output pin.
Software definable digital input/output pins.
Reference voltage pin (Reflects Vref)
Receive analog positive input.
Receive analog negative input.
Transmit analog positive output
Transmit analog negative output
Serial interface clock. With SCLK continuous selected,
Frequency = 256*Fs ( =2.4576MHz for Fs=9.6kHz)
Serial data output (or input to the host).
Serial data input (or output from the host)
Frame synchronization. (Active Low)
Type of frame sync. Open, weak-pulled high = early (mode1);
tied low = late (mode0)
Controls the SCLK behavior after FS. Open, weak-pulled high
= SCLK Continuous; tied low = 32 clocks per R/W cycle.
Table 1: -32 TQFP and QFN Pin Description
Page: 5 of 45
©
2005 TERIDIAN Semiconductor Corporation
Rev 1.4
