MC34011A

The MC34011A is a kind of electronic telephone circuit (ETC). It provides all the necessary elements of a tone dialing telephone in single IC. The functional blocks of the ETC include the DTMF dialer, speech network, tone ringer, and dc line interface circuit.

There are some features of MC34011A as follows: (1)DTMF generator uses low-cost ceramic resonator with accurate frequency synthesis technique; (2)tone ringer drives piezoelectric transducer and satisfies EIA RS-470 impedance signature requirements; (3)speech network provides two-four wire conversion with adjustable sidetone utilizing an eletret transmitter; (4)on-chip regulator insures stable operation over wide range of loop lengths; (5)I2L technology provides low 1.4 V operation and high static discharge immunity; (6)equalization provided to compensate for long/short line performance.

The following is about the maximum ratings of MC34011A (voltage reference to V-): (1)V+ terminal voltage (pin 34): +18 to -1.0 V; (2)VR terminal voltage (pin 29): +2.0 to -1.0 V; (3)RXO terminal voltage (pin 27): +2.0 to -1.0 V; (4)TRS terminal voltage (pin 37): +35 to -1.0 V; (5)TRO (with tone ringer inactive) terminal voltage (pin 29): +2.0 to -1.0 V; (6)R1-R4 terminal current (pins 1-4): ±100 mA; (7)C1-C4 terminal current (pins 5-8): ±100 mA; (8)operating ambient temperature range: -20 to +80; (9)storage temperature range: -65 to +150.