MT8885

MT8885 ® Integrated DTMF Transceiver with Power Down & Adaptive Micro Interface Advance Information Features External power down pin Central office quality DTMF transmitter/ receiver Low power consumption High speed adaptive micro interface Adjustable guard time Automatic tone burst mode Call progress tone detection to -30dBm DTMF transmitter/receiver power down via register control ISSUE 1 May 1995 Ordering Information MT8885AE MT8885AN MT8885AP -40°C to 24 Pin Plastic DIP 24 Pin SSOP 28 Pin PLCC +85°C Applications Credit card systems Paging systems Repeater systems/mobile radio Interconnect dialers Personal computers 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 MT8885 utilizes an adaptive micro interface, which allows the device to be connected to a number of popular microcontrollers with minimal external logic. The MT8885 provides enhanced power down features. The transmitter and receiver may independently be powered down via register control. A full chip power down pin provides simple power and control capability. Description The MT8885 is a monolithic DTMF transceiver with call progress filte...