U4076B
Three-Tone Ringer for Telephone Sets
Description
The three-tone ringing integrated circuit U4076B, in
conjunction with a piezo transducer or loudspeaker
replaces the normal electromechanical telephone bell. It
is operated with the ringing current from the exchange.
There is also a possibility of operating the IC with the dc
supply voltage, being developed for large operating
range. The integrated circuit is overload protected.
Features
D
Three-tone ringing sequence with 800 Hz, 1067 Hz
and 1333 Hz
D
Clock oscillator with ceramic resonator or LC series
cct possible
D
Sequence frequency adjustable between 2.5 Hz and
25 Hz
D
Input protective diode
D
On-chip rectifier bridge
D
Protection circuit against ringing in a parallel circuit
D
D
D
D
D
Adjustable volume
Push-pull output stage
Piezo transducer or loudspeaker connection
Common input for frequency and call recognition
Reduced pulse duration for electromagnetic
transducers
Benefit
D
Suitable for German Post Office Specification,
FTZ 121671 Pfl. 3, edition dated 24.03.82
22
m
F
2.2 k
W
a
~
~
b
0.8
m
F
4
7
(5)
6
(7)
600 k
W
10 (11)
43 k
W
8
(9)
4.7 nF
9 (10)
(15) 13
Ground: output signal
Open: output signal
(8)
Supply
5
(6)
Level
monitoring
Tone sequence
oscillator
Divider
32:1
Tone signal
generator
11
Reset
a
(12)
100 k
W
log
12
(13)
96 ms
127 ms
Frequency
monitoring
Frequency
Three
state
Divider
32:1
Divider
14:1
Clock signal
generator
3 (3)
93 7792 e
Reset
b
2 (2)
455 kHz
Divider
128:1
Divider
2:1
RL
14
(16)
1
(1)
Figure 1. Block diagram and application circuit
Case:
DIP14 or SO16-L (Pin connections for SO 16-L case in bracket)
TELEFUNKEN Semiconductors
Rev. A1, 15-May-96
1 (6)
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
