MT8888C

MT8888C Integrated DTMF Transceiver with Intel Micro Interface Data Sheet Features Central office quality DTMF transmitter/receiver Low power consumption High speed Intel micro interface Adjustable guard time Automatic tone burst mode Call progress tone detection to -30dBm Ordering Information MT8888CE MT8888CS MT8888CN MT8888CP 20 20 24 28 Pin Plastic DIP Pin SOIC Pin SSOP Pin Plastic LCC February 2004 Applications Credit card systems Paging systems Repeater systems/mobile radio Interconnect dialers Personal computers -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/A converter for low distortion, high accuracy DTMF signalling. Internal counters provide a burst mode such that tone bursts can be transmitted with precise timing. A call progress filter can be selected allowing a microprocessor to analyze call progress tones. The MT8888C utilizes an Intel micro interface, which allows the device to be connected to a number of popular microcontrollers with minimal external logic. Description The MT8888C is a monolithic DTMF transceiver with call progress filter. It is fabricated in CMOS technology offering low power consumption and high reliability. TONE ∑ D/A Converters Row and Column Counters Transmit Data Register Status Register Data Bus Buffer D0 D1 D2 D3 Tone Burst Gating Cct. IN+ INGS OSC1 OSC2 Oscillator Circuit Bias Circuit VDD VRef VSS + Dia...