MT88E46

• 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 speechis attenuated 8dB or better, and is close totalkoff 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 monitorstop 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

* Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.
** Under normal operating conditions voltage on any pin except supplies can be minimum Vss-1V to maximum Vdd+1V for an input current limited to less than 200A.

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. MT88E46 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 of MT88E46  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'of MT88E46  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.