DTMF Generator
PBD 3534 is a monolithic integrated DTMF generator intended for use in a telephone set. Interal voltage reference and DC regulation make a direct connection of the circuit to the subscriber line possible. 8-bit or dual 4-bit interface capability enables PBD 3534 to be used as a computer to a telephone line interface. PBD 3534 fulfils the CEPT specification.