73k224bl ETC-unknow, 73k224bl Datasheet - Page 2
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73k224bl
Manufacturer Part Number
73k224bl
Description
Single-chip Modem Integrated Hybrid
Manufacturer
ETC-unknow
Datasheet
1.73K224BL.pdf
(33 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
73k224bl-IH
Manufacturer:
TERIDIAN
Quantity:
229
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DESCRIPTION
The 73K224BL is pin and software compatible with
the 73K222BL, allowing system upgrades with a
single component change.
The 73K224BL is designed to be a complete
V.22bis compatible modem on a chip. The
complete modem requires only the addition of the
phone line interface, a control microprocessor, and
RS-232 level converter for a typical system. Many
functions were included to simplify implementation
of typical modem designs. In addition to the basic
2400 bit/s QAM, 600/1200 bit/s DPSK and 300
bit/s FSK modulator/demodulator sections, the
device also includes synch/asynch converters,
scrambler/descrambler, call progress tone detect,
DTMF tone generator capabilities and handshake
pattern detectors. Test features such as analog
loop, digital loop, and remote digital loopback are
supported. Internal pattern generators are also
included for self-testing.
FUNCTIONAL DESCRIPTION
HYBRID AND RELAY DRIVER
To make designs more cost effective and space
efficient, the 73K224BL includes the 2-wire to 4-
wire hybrid with sufficient drive to interface directly
to the telecom coupling transformers. In addition,
an off hook relay driver with 30mA drive capability
is also included to allow use of commonly
available mechanical telecom relays.
QAM MODULATOR/DEMODULATOR
The 73K224BL encodes incoming data into quad-
bits represented by 16 possible signal points with
specific phase and amplitude levels. The base-
band signal is then filtered to reduce intersymbol
interference on the band limited telephone
network. The modulator transmits this encoded
data using either a 1200 Hz (originate mode) or
2400 Hz (answer mode) carrier. The demodulator,
although more complex, essentially reverses this
procedure while also recovering the data clock
from the incoming signal. Adaptive equalization
corrects
automatically
compensate for line characteristics.
for
changing
varying
(continued
filter
line
)
parameters
conditions
by
to
2
FEATURES
DPSK MODULATOR/DEMODULATOR
The 73K224BL modulates a serial bit stream into
di-bit pairs that are represented by four possible
phase shifts as prescribed by the Bell 212A/V.22
standards. The base-band signal is then filtered to
reduce intersymbol interference on the bandlimited
2-wire PSTN line. Transmission occurs on either a
1200 Hz (originate mode) or 2400 Hz carrier
(answer mode). Demodulation is the reverse of
the modulation process, with the incoming analog
signal
converted back to a serial bit stream. The
demodulator also recovers the clock which was
encoded into the analog signal during modulation.
Demodulation occurs using either a 1200 Hz
carrier (answer mode or ALB originate mode) or a
2400 Hz carrier (originate mode or ALB answer
mode). Adaptive equalization is also used in
DPSK modes for optimum operation with varying
line conditions.
FSK MODULATOR/DEMODULATOR
The
modulated analog output signal using two discrete
frequencies to represent the binary data. The Bell
103 standard frequencies of 1270 and 1070 Hz
Adaptive equalization for optimum perform-
ance over all lines
Programmable transmit attenuation (16 dB,
1 dB steps), selectable receive boost (+18
dB)
Call
unscrambled mark, S1, and signal quality
monitors
DTMF, answer and guard tone generators
Test modes available: ALB, DL, RDL, mark,
space, alternating bit, S1 pattern generation
and detection
CMOS
consumption (typically 100 mW @ 5 V) with
power-down mode (15 mW @ 5 V)
TTL and CMOS compatible inputs and
outputs
FSK
eventually
progress,
(continued)
modulator
technology
decoded
carrier,
produces
for
into
answer
low
a
di-bits
frequency
power
tone,
and