U4074B

` Suitable for specifications FTZ 1TR2 and ETR 2
` Rectifier bridge
` Z-diode
` Amplitude detection
` Supply voltage for microcomputer 3.5 @ 1.5 mA
` DC operation possible
` Bridge push-pull output stage
` CMOS-compatible microcomputer interface
` 2-bit log. volume adjustment
` High-voltage bipolar technology, 30 V

The U4074B is a monolithic integrated circuit that contains all integral components of a ringing circuit for telephone sets used in conjunction with a microcomputer. The combination of a microcomputer and the U4074B permits flexible programming of the ringing sequence (melody), tone and volume control.

Ringing frequency detection takes place in the microcomputer. The U4074B is responsible for the interface to the line, driver stages for the piezoelectric sound transducer, volume adjustment, amplitude detection, voltage supply for the microcomputer and other auxiliary functions.