MT88L85

MT88L85 ® 3V Integrated DTMF Transceiver with Power Down & Adaptive Micro Interface Advance Information Features External power down pin Low voltage operation (2.7V - 3.6V) Central office quality DTMF transmitter/ receiver Low power consumption Adjustable guard time High speed adaptive micro interface Automatic tone burst mode ISSUE 1 May 1995 Ordering Information MT88L85AE MT88L85AN MT88L85AP -40°C to 24 Pin Plastic DIP 24 Pin SSOP 28 Pin PLCC +85°C Call progress tone detection to -30dBm DTMF transmitter/receiver power down via register control Applications Credit card systems Paging systems Repeater systems/mobile radio Interconnect dialers Personal computers Description The MT88L85 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 PWDN ESt St/GT The receiver section is based upon the industry standard MT8870 DTMF receiver while the transmitter utilizes a switched capacitor D/A converter for low distor...