MT88E46 Datasheet, PDF (1/23 Pages) Zarlink Semiconductor Inc – Bellcore Compliant Calling Number Identification Circuit

MT88E46
Bellcore Compliant Calling Number
Identification Circuit
Advance Information
Features
• Compatible with Bellcore GR-30-CORE,
SR-TSV-002476; TIA/EIA-716 and TIA/EIA-777
• Pin compatible with MT88E45
• Differential input amplifiers with adjustable
gains for Tip/Ring and 4-wire side connections
• TIA (Telecommunications Industry Association)
MEI (Multiple Extension Interworking)
compatible architecture: CAS (CPE Alerting
Signal) detection is selectable between Tip/
Ring and 4-wire side
• 4-wire side CAS detection is Bellcore talkoff
and talkdown compliant when near end speech
is attenuated 8dB or better, and is close to
talkoff compliant even without near end speech
attenuation
• Tip/Ring side CAS detection typically meets
talkdown condition 1 (the average case)
• 1200 baud Bell 202 and CCITT V.23 FSK
demodulation
• Selectable 3-wire FSK data interface (serial bit
stream or 1 byte buffer) with facility to monitor
stop bit for framing error check
• FSK carrier detect status output
• 3 to 5V ± 10% supply voltage
• Uses 3.579545MHz crystal
• Low power CMOS with power down mode
Applications
• Bellcore compliant CIDCW (Calling Identity
Delivery on Call Waiting) and CWD (Call
Waiting Deluxe) telephones
DS5350
ISSUE 1
Ordering Information
March 2000
MT88E46AS
20 Pin SOIC
-40 to +85 °C
• CIDCW and CWD telephone adjunct boxes
• Computer Telephony Integrated (CTI) systems
Description
The MT88E46 is a CMOS integrated circuit suitable
for receiving the FSK and CAS signals in North
American (Bellcore) CIDCW, CWD and CID (Calling
Identity Delivery) services. It provides an optimal
solution for the CIDCW (also known as Type 2) and
CWD (Type 2.5) telephone set applications by
providing separate input op-amps for Tip/Ring and 4-
wire side (receive pair of the telephone hybrid or
speech IC) connections. The Tip/Ring connection is
compatible with TIA’s MEI scheme and can be used
for FSK demodulation and ‘on hook mode’ CAS
detection. The 4-wire side connection is for ‘off hook
mode’ CAS detection. The CAS detection modes - on
hook and off hook - use different algorithms which
are optimized for the CPE states. In ‘off hook mode’
the CAS detector is Bellcore compliant when near
end speech is attenuated 8dB or better. ‘On hook
mode’ is optimized for talkdown only and typically
meets talkdown condition 1 (the average case)
without speech attenuation at Tip/Ring such as in the
on hook state MEI CPE.
GS1
IN1+
IN1-
IN2+
IN2-
GS2
V_REF
GS1en
+
-
PWDN ^GS1en
Anti-Alias
Filter
+
-
PWDN
MODE PWDN GS1en
Bias
Generator
FSKen CASen
PWDN
Control Bit
Decode
Oscillator
FSK
Bandpass
FSK
Demod
FSKen
CASen
Carrier
Detector
2130Hz
Bandpass
2750Hz
Bandpass
Tone
Detection
Algorithm
CASen
On/Off Hook mode
OSC1 OSC2
CB0 CB1 CB2
Figure 1 - Functional Block Diagram
MODE
Data Timing
Recovery
DATA
DCLK
DR
DET
CD
DR/DET
Vdd
Vss
Patent pending
1