TCM1705A

The TCM1705A is designed as monolithic integrated circuit which performs 2/4 wire conversion in an analog telephone set plus the functions of the receiving and transmitting amplifiers and sidetone operations. The device replaces the bulky hybrid coil and gain regulation components, allowing the replacement of the carbon grenule mocrophone with passive higher performance transducer.

TCM1705A has seven features. (1)Monolithic replacement for hybrid coil for the 2/4 wire conversion. (2)Low power requirement. (3)Automatic gain variation with DC line. (4)Externally adjustable transmitting and receiving gains. (5)Flat electrical response. (6)Externally adjustable sidetone. (7)Externally adjustable regulation function. Those are all the main features.

Some absolute maximum ratings TCM1705A have been concluded into several points as follow. (1)Its forward line current would be 120mA. (2)Its reverse line current would be -150mA. (3)Its line voltage (3ms pulse duration) would be 22V. (4)Its storage temperature range would be from -65°C to 150°C. (5)Its operating free-air temperature range would be from -25°C to 70°C. (6)Its continuous power dissipation at 25°C free-air temperature would be 1150mW. (7)Its thermal resistance junction ambient would be 102°C/W. It should be noted that stresses above those listed in absolute maximum ratings may cause permanent damage to device.

Also some electrical characteristics TCM1705A are concluded as follow. (1)Its DC line voltage would be typ 3.5V at IL=9mA and would be typ 4.0V and max 4.8V at IL=18mA and would be typ 5.6V and max 6.5V at IL=50mA. (2)Its shunt regulator would be min 3.3V and typ 4.0V and max 4.8V at IL=30mA. (3)Its series regulator would be min 1.7V and typ 1.9V and max 2.1V. (4)Its transmitting gain would be typ 47dB at IL=9mA and would be min 45.8dB and typ 47.3dB and max 48.8dB at IL=18mA. (5)Its transmitting noise would be typ -70dBVp. And so on. If you have any question or suggestion or want to know more information please contact us for TCM1705A details. Thank you!