MC145740

DUAL TONE MULTIPLE FREQUENCY LINE INTERFACE

DualToneMultipleFrequencyLineInterface TheMC145740isasilicongateHCMOSLSIdesignedforgeneralpurposeDualToneMultipleFrequency(DTMF)communications,andcontainsaDTMFsignalgeneratorandareceiverforall16standarddigits. Thegeneratorblockhasadifferentiallinedriver

MC145740

Dual Tone Multiple Frequency Line Interface; Theserial control interface permits a CPU to exercise the following built-in features:\n\n •Single Power Supply:3.6 to 5.5 V\n •DTMF Generator and Receiver for All 16 Standard Digits\n •0 dBm Line Driver Into 600 ohm Load\n •AGC Amplifier\n •Programmable Transmit Attenuator\n •Serial Control Interface\n •Power Down Mode, Less Than 1 micro Amp\n;

Overview The MC145740 has been discontinued. Suggested replacement: none.The MC145740 is a silicon gate HCMOS LSI designed for general purpose Dual Tone Multiple Frequency (DTMF) communications, and contains a DTMF signal generator and a receiver for all 16 standard digits. The generator block has a differential line driver which drives a 600 ohm load with 0 dBm level. The transmit signal level is adjusted in 1 dB steps by the programmable attenuator. The receiver block has an Auto Gain Control (AGC) amplifier to demodulate 50 dB (typ) dynamic range of DTMF signals to thehexadecimal codes. The device also includes a serial control interface that permits a CPU to exercise several built-in features.