Description
The TCM1520A is a monolithic ring-detection integrated circuit designed for use in isolated or nonisolated telephone applications.
Features
- efficient high-voltage (40 V to 150 V) operation with a typical current drain of 1 mA. Phone Line AC Ring Signal
TCM1520A
Electronic Telephone or Accessory
TTL /NMOS/CMOS Microprocessor
During standby, the input impedance is approximately 1 MΩ or greater, which prevents any interference with parallel off-hook telephones transmitting DTMF or voice frequencies. The device achieves this high input impedance with an on-chip series zener diode that does not conduct until the voltage across AC INPUT.
TCM1520A-etcTI.pdf
