
53
Features
Compatible with:
British Telecom (BT) SIN227 & SIN242
U.K.’s Cable Communications Association
(CCA) specification TW/P&E/312
Bellcore GR-30-CORE (formerly known as
TR-NWT-000030) & SR-TSV-002476
Bellcore ‘CPE Alerting Signal’ (CAS) and BT
‘Idle State Tone Alert Signal’ detection
Ring and line reversal detection
1200 baud Bell 202 and CCITT v.23 Frequency
Shift Keying (FSK) demodulation
3 or 5V
±
10% supply voltage
High input sensitivity (-40dBV Tone and FSK
Detection)
Selectable 3-wire FSK data interface
(microcontroller or MT88E43B initiated)
Low power CMOS with powerdown mode
Input gain adjustable amplifier
Carrier detect status output
Uses 3.58 MHz crystal
Applications
BT Calling Line Identity Presentation (CLIP),
CCA CLIP, and Bellcore Calling Identity
Delivery (CID) systems
Feature phones, including Analog Display
Services Interface (ADSI) phones
Phone set adjunct boxes
FAX and answering machines
Database query and Computer Telephony
Integration (CTI) systems
Description
The MT88E43B Calling Number Identification
Circuit 2 is a low power CMOS integrated circuit
intended for receiving physical layer signals
transmitted according to BT (British Telecom)
SIN227
&
SIN242,
the
Communications Association) TW/P&E/312 and
Bellcore
GR-30-CORE
specifications. The MT88E43B is suitable for
applications using a fixed voltage power source
between 3 and 5V
±
10%.
U.K.’s
CCA
(Cable
&
SR-TSV-002476
The MT88E43B contains a FSK demodulator and a
CAS/Tone Alert Signal detector. The 1200 baud FSK
demodulator is compatible with both Bell 202 and
CCITT v.23 formats. To facilitate FSK data extraction,
a dual mode 3-wire serial data interface is provided.
In one mode data transfer is initiated by the device.
In the second mode, the microcontroller initiates the
8-bit data word extraction from the device. The
MT88E43B also offers line reversal detection
capability for BT’s CLIP, ring burst detection for the
U.K.’s CCA’s CLIP, and ring detection for Bellcore’s
CID.
Figure 1- Functional Block Diagram
+
-
Anti-alias
Filter
FSK Bandpass
Filter
FSK
Demodulator
Data Timing
Recovery
Carrier
Detector
Alert Signal High
Tone Filter
Alert Signal Low
Tone Filter
Tone
Detection
Algorithm
Bias
Generator
Oscillator
Guard
Time
StD
St/GT
ESt
TRIGout
TRIGRC
TRIGin
DATA
DR
DCLK
MODE
FSKen
CD
CAP
PWDN
OSCin OSCout
IN+
IN-
GS
VRef
INT
VDD
VSS
cct.
To internal cct.
Interrupt
Generator
DS5157
ISSUE 1
April 1999
Ordering Information
MT88E43BE
24 Pin Plastic DIP
(0.6 inch package only)
MT88E43BS
24 Pin SOIC
-40
°
C to +85
°
C
MT88E43B
Extended Voltage Calling Number
Identification Circuit 2
Preliminary Information
CMOS