MC145574AAER2 Freescale Semiconductor, MC145574AAER2 Datasheet - Page 146

• Manufacturer Part Number: MC145574AAER2
• Manufacturer: Freescale Semiconductor

Specifications of MC145574AAER2

• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / Rohs Status: Compliant

Freescale Semiconductor, Inc.
Half Duplex — A transmission system that permits communication in one direction at a time. CB ratios, with “push–to–talk”
switches, and voice–activated speakerphones, are half duplex.
Handset — A rigid assembly providing both telephone transmitter and receiver in a form convenient for holding simultaneously
to mouth and ear.
Hookswitch — A switch that connects the telephone circuit to the subscriber loop. The name derives from old telephones where
the switch was activated by lifting the receiver off and onto a hook on the side of the phone.
Idle Channel Noise (ICN) — The total signal energy measured at the output of a device or channel under test when the input
of the device or channel is grounded (often a wide–band noise measurement using a C–message weighting filter to band–limit
the output noise).
Intermodulation — The modulation of the components of a complex wave by each other (in a nonlinear system).
Intermodulation Distortion — An analog line impairment when two frequencies interact to create an erroneous frequency, in
turn distorting the data signal representation.
IRED — Infrared. Used as a wireless link for remote control or to transfer data.
ISDN — Integrated Services Digital Network; a communication network intended to carry digitized voice and data multiplexed
onto the public network.
Jitter — A type of analog communication line distortion caused by abrupt, spurious signal variation from a reference timing posi-
tion, and capable of causing data transmission errors, particularly at high speeds. (The variation can be in amplitude, time, frequen-
cy, or phase.)
Key System — A miniature PABX that accepts 4 to 10 lines and can direct them to as many as 30 telsets.
–law — A companding law accepted as the North American standard for PCM based systems.
LAN — Local Area Network; a data–only communication network between data terminals using a standard interface to the net-
work.
Line — The portion of a circuit external to an apparatus that consists of the conductors connecting the apparatus to the exchange
or connecting two exchanges.
Line Length Compensation — Also referred to as loop length compensation, it involves changing the gain of the transmit and
receive paths, within a telephone, to compensate for different signal levels at the end of different line lengths. A short line (close
to the CO) will attenuate signals less, and therefore less gain is needed. Compensation circuits generally use the loop current
as an indication of the line length.
Longitudinal Balance — The common–mode rejection of a telephone circuit.
Loop — The loop formed by the two subscriber wires (Tip and Ring) connected to the telephone at one end, and the central
office (or PBX) at the other end. Generally it is a floating system, not referred to ground, or ac power.
Loopback — Directing signals back toward the source at some point along a communication path.
Loop Current — The dc current that flows through the subscriber loop. It is typically provided by the central office or PBX, and
ranges from 20 to 120 mA.
LT — Line Termination (Line Card).
MCU — MicroComputer Unit (also MicroController Unit).
MPU — MicroProcessor Unit.
Mu–Law — A companding/encoding law commonly used in U.S. (same as –law).
MUX — Multiplex or multiplexer.
Modem — MOdulator–DEModulator; a unit that modulates and demodulates digital information from a terminal or computer
port to an analog carrier signal for passage over an analog line.
Multiframing — When multiframing is enabled, 20 S/T frames are grouped together to provide maintenance subchannels be-
tween the TE and the NT. In the TE to NT direction, there is one subchannel called the Q channel. In the NT to TE direction,
there are five subchannels called SC1 through SC5. Messages for the Q, SC1, and SC2 subchannels have been defined in
CCITT I.430 and ANSI T1.605. Usage of the multiframing subchannels is not mandatory.
Multiplex — To simultaneously transmit two or more messages on a single channel.
NT1 — Network Termination 1 (OSI Layer 1 Only).
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MC145574
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