U4074B Datasheet, PDF (3/6 Pages) TEMIC Semiconductors – Tone Ringer Interface

15W
25W
U4074B
2 kV
10 mF
110W
0.22 mF
a
Tone ringing
Figure 1
b
Figure 2. Test circuit
93 7575 e
Outputs O₁, O₂ Pin 11, 12
The bridge push-pull outputs are used for direct
connection of a piezo electric sound transducer with a
typical value of 80 nF. The output stage transistors can
process up to 20 mA in both directions.
+ ǒ Ǔ ^{The output signal without load is 2}
R_i
V_(12,11 open
V_(12,11) load
–1
R_load
(V_B - V_DDā–ā3.5 V)
W where R_load = 400
Volume Adjustment A1, A0
Pin 5 (6), 6 (7)
The ringing volume is adjusted by means of a 2-bit D/A
converter. The maximum volume is achieved with the bit
combination A1 (MSB) = 1 and A0 (LSB) = 1. The
volume can be reduced by approximately 35 dB (A) if a
bit combination of A1 = 0, A0 = 0 is supplied. The volume
is programmed by supplying a ground potential to these
inputs.
Melody, Pin 7 (9)
The melody input inverts the activation phase of the
bridge push-pull output stage. The input is CMOS-
compatible and suitable for processing ringing
frequencies.
Supply Voltage V_DD, Pin 10 (12)
An external load, such as a microcomputer, can be
connected to V_DD. This value of V_DD is 3.5 V for a
maximum load current of 1.5 mA. V_DD is highly resistive
m ^{and can block up to 6 V in call and idle states. The typical}
value of the back-up capacitor is 47 F.
Frequency Detection 2f, Pin 4 (5)
Frequency detection takes place in the microcomputer.
For this purpose, the output 2f supplies a square wave
signal with double ringing frequency to the
microcomputer. The output signal is CMOS-compatible.
This terminal is highly resistive in idle and call states.
Comparator Threshold Adjustment
TH Pin 3 (4)
The on/ off threshold of the 2f comparator can be adjusted
( terminal against ground respectively V_DD ). To fulfill the
Bundespost specification this terminal should be open.
V_DC, Pin 8, 9
Decoupling diode for dc supply.
TELEFUNKEN Semiconductors
3 (6)
Rev. A1, 06-May-96
Preliminary Information