MT88L89

® MT88L89 3V Integrated DTMF Transceiver Advance Information with Adaptive Micro Interface Features Central office quality DTMF transmitter/ receiver Low voltage operation (2.7-3.6V) Adjustable guard time Automatic tone burst mode Call progress tone detection to -30dBm ISSUE 1 May 1995 Adaptive micro interface enables compatibility with existing MT8880/MT8888 designs DTMF transmitter/receiver power down via register control Applications Credit card systems Paging systems Repeater systems/mobile radio Interconnect dialers Personal computers Description The MT88L89 is a monolithic DTMF transceiver with call progress filter. It is fabricated in CMOS technology offering low power consumption and high reliability. TONE IN+ INGS OSC1 OSC2 + - m o .c U 4 t e e h S a t a .D w w w ∑ D/A Converters Row and Column Counters Transmit Data Register Status Register Data Bus Buffer Tone Burst Gating Cct. Dial Tone Filter Control Logic Interrupt Logic High Group Filter Low Group Filter Control Logic Digital Algorithm and Code Converter Control Register A Oscillator Circuit Bias Circuit Control Register B I/O Control Steering Logic Receive Data Register VSS ESt St/GT Ordering Information MT88L89AE 20 Pin Plastic DIP MT88L89AC 20 Pin Ceramic DIP MT88L89AS 20 Pin SOIC MT88L89AN 24 Pin SSOP MT88L89AP 28 Pin PLCC -40°C to +85°C The receiver section is based upon the industry standard MT8870 DTMF receiver while the transmitter utilizes a switched capacitor D...