®
CMOS
MT8841
Calling Number Identification Circuit
Features
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1200 baud BELL 202 and CCITT V.23
Frequency Shift Keying (FSK) demodulation
Compatible with Bellcore TR-NWT-000030 and
SR-TSV-002476
High input sensitivity: -36dBm
Simple serial 3-wire data interface eliminating
the need for a UART
Power down mode
Internal gain adjustable amplifier
Carrier detect status output
Uses 3.579545 MHz crystal or ceramic
resonator
Single 5V power supply
Low power CMOS technology
ISSUE 4
May 1995
Ordering Information
MT8841AE
16 Pin Plastic DIP
MT8841AS
16 Pin SOIC
MT8841AN
20 Pin SSOP
-40 °C to +85 °C
Description
The MT8841 Calling Number Identification Circuit
(CNIC) is a CMOS integrated circuit providing an
interface to various calling line information delivery
services that utilize 1200 baud BELL 202 or CCITT
V.23 FSK voiceband data transmission schemes.
The CNIC receives and demodulates the signal and
outputs data into a simple 3-wire serial interface.
Typically, the FSK modulated data containing
information on the calling line is sent before alerting
the called party or during the silent interval between
the first and second ring using either CCITT V.23
recommendations or Bell 202 specifications.
The CNIC accepts and demodulates both CCITT
V.23 and BELL 202 signals. Along with serial data
and clock, the CNIC provides a data ready signal to
indicate the reception of every 8-bit character sent
from the Central Office. The received data can be
processed externally by a microcontroller, stored in
memory, or displayed as is, depending on the
application.
Applications
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Calling Number Delivery (CND), Calling Name
Delivery (CNAM) and Calling Identity on Call
Waiting (CIDCW) features of Bellcore CLASS
SM
service
Feature phones
Phone set adjunct boxes
FAX machines
Telephone Answering machines
Database query systems
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GS
IN-
IN+
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+
Receive
Bandpass
Filter
FSK
Demodulator
Data and Timing
Recovery
DATA
DR
DCLK
CAP
V
Ref
Bias
Generator
Carrier
Detector
CD
Clock
Generator
to other
circuits
PWDN
SM
OSC1 OSC2
V
SS
V
DD
IC1
IC2
Figure 1 - Functional Block Diagram
CLASS
is a service mark of Bellcore
5-11
MITEL [ MITEL NETWORKS CORPORATION ]
