U4074B
Tone Ringer Interface
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.
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.
Features
D
Suitable for specifications FTZ 1TR2 and ETR 2
D
Rectifier bridge
D
Z-diode
D
Amplitude detection
D
Supply voltage for microcomputer 3.5 @
D
DC operation possible
D
Bridge push-pull output stage
22
m
F
V
B
2(3)
TH
47
m
F
130 k
W
2f 4(5)
D
CMOS-compatible microcomputer interface
D
2-bit log. volume adjustment
D
High-voltage bipolar technology, 30 V
v
1.5 mA
Benefits
D
m
C controlled melody and volume
D
Low number of external components
3(4) VDD 10 (12)
On/Off
a 0.8
m
F
(1)1 a
Control
VRef
+V
B
12(14)
O2
2.2 k
W
Ringing signal
b
(16)14
b
Decoder and
DA converter
2f
+V B
PIEZO
Transducer
O1
11(13)
93 7793 e
(15)13 GND 5(6)
A1
Volume
6(7) (9)7 Mel
A0
VDC 8(10)
9(11)
Figure 1. Block diagram and application circuit ( pin connections for SO16 in brackets )
TELEFUNKEN Semiconductors
Rev. A1, 06-May-96
1 (6)
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
