Description
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.

Features
 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

Benefits
µC controlled melody and volume
 Low number of external components