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This item is a lot of 2 pcs MC33218 circuits by MOTOROLA. They are Voice Switched Speakerphone with Microprocessor Interface devices made by Motorola and packaged in a DIP24 case. The Motorola MC33218 Voice Switched Speakerphone Circuit incorporates the necessary amplifiers, attenuators, level detectors, and control algorithm to form the heart of a high quality hands–free speakerphone system. Included are a microphone amplifier with mute, transmit and receive attenuators, a background monitoring system for both the transmit and receive paths, and level detectors for each path. An AGC system reduces the receive gain on long lines where loop current and power are in short supply. A dial tone detector prevents fading of dial tone. A Chip Disable pin permits conserving power when the circuit is not in use. Additionally, the MC33218 has a serial data port which permits microprocessor control of the receive volume level, microphone mute, attenuator range, and selection of transmit, receive, idle or normal modes. The data port can be operated at up to 1.0 MHz. The MC33218 can be operated from a power supply, or from the telephone line, requiring typically 4.6 mA. It can be used in conjunction with a variety of speech networks. Applications include not only speakerphones, but intercoms and other voice switched devices. * Supply Voltage Range: 2.7 to 6.5 V * Attenuator Range: 53 or 27 dB (Selectable) * 2 Point Sensing with Background Noise Monitor in Each Path * Microprocessor Port for Control of: * Volume Control (40 dB Range over 16 Levels) * Mute Microphone Amplifier Force to Receive, Transmit, or Idle Modes * Attenuator Range Selection (27 or 53 dB) * Chip Disable Pin Powers Down the Entire IC http://e- /files/timing_interconnect_access/doc/data_sheet/MC33218A.pdf (this posting is the responsibility of the poster) |
lottie.flowers@dfwind.com (Lottie Flowers) for more information. All emails will be forwarded to the poster's actual email address.