UTC TA31002A LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
1
TELEPHONE TONE RINGER
DESCRIPTION
The UTC TA31002A is a bipolar integrated circuit
designed for telephone bell replacement. It can also be
used as alarms or other alerting devices.
FEATURES
*Designed for telephone bell replacement.
*Low current drain for multiple extension of lines.
*Adjustable 2-frequency tone.
*Adjustable warbling rate.
*Built-in hysteresis prevents false triggering and
rotary dial 'CHIRPS'.
*Programmable for initiation current by simple
external resistor
DIP-8
PIN CONFIGURATIONS
1
2
3
4
8
7
6
5
Vcc
RSL
Low Freq.
Time Constant
Low Freq.
Time Costant
Output
High Freq.
Time Constant
High Freq.
Time Constant
GND
ABSOLUTE MAXIMUM RATINGS
(Ta=25
C )
PARAMETER
SYMBOL
VALUE
UNIT
Supply Voltage
Vcc
30
V
Power Dissipation
Pd
400
mW
Operating Temperature
Topr
-45 to 85
C
Storage Temperature
Tstg
-65 to 150
C
UTC TA31002A LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
2
BLOCK DIAGRAM
LOW
OSC
HIGH
OSC
AMP
POWER SUPPLY (WITH HYSTERESIS)
8
6
7
4
3
1
5
2
OUTPUT
R3
R2
C3
C2
Note:R2,R3,C2 and C3 are parts externally mounted
ELECTRICAL CHARACTERISTICS
(
Ta=25
C, all voltage referenced to GND unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Operating Supply Voltage
Vcc
29.0
V
Initiation Supply Voltage (note 1) Vsi
See Fig.2
17
19
21
V
Initiation Supply Current (note 1) Isi
6.8K-Pin 2 to GND
1.4
2.8
4.2
mA
Sustaining Voltage (note 2)
Vsus
See Fig.2
9.7
11.0
12.0
V
Sustaining Current (note 2)
Isus
No Load Vcc=Vsus,See Fig.2
0.7
1.4
2.5
mA
Output Voltage High
VOH
Vcc=21V, I8=-15mA
Pin6=6V, Pin7=GND
17.0
19.0
21.0
V
Output Voltage Low
VOL
Vcc=21V, I8=15mA
Pin6=GND, Pin7=6V
1.6
V
I
IN
(Pin 3)
I
IN
(Pin 7)
Pin3=6V, Pin4=GND
Pin7=6V, Pin6=GND
500
500
nA
nA
High Frequency 1
FH1
R3=191K, C3=6800pF
461
512
563
Hz
High Frequency 2
FH2
R3=191K, C3=6800pF
576
640
704
Hz
Low Frequency
FL
R2=165K, C2=0.47
F
9.0
10
11.0
Hz
*NOTE (See electrical characteristics sheet)
1. Initiation supply voltage (Vsi) is the supply voltage required to start the tone ringer oscillating.
2. Sustaining voltage (Vsus) is the supply voltage required to maintain oscillation.
UTC TA31002A LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
3
APPLICATION NOTE
The application circuit illustrates the use of the
UTCTA31002A device in typical telephone tone ringer
application.
The AC ringer signal voltage appears
across the TIP and RING inputs of the circuit and
is attenua-
ted by capacitor C1 and resistor R1.
C1 also provides isolation from DC voltage (48V)
on the exchanged line.
After full wave rectification by the bridge
diode, the wave form is filtered by capacitor C4 to
provide a DC supply for the tone ringer chip.
As this voltage exceeds the initiation voltage (Vsi),
oscillation starts.
With the components shown , the output frequency
chops between 512Hz (F
H1
) and 640 Hz(F
H2
)
at a 10 Hz(F
L
) rate.
The loudspeaker load is coupled through a 1300
to 8
transformer.
The output coupling capacitor C5 is required with
transformer coupled loads.
When driving a pizeo-ceramic transducer type load,
the coupling C5 and transformer (1300
:8
) are
not required.
However, a current limiting resistor is required.
The low frequency oscillator oscillates at a rate (F
L
)
controlled by an external resistor (R2) and capacitor
(C2).
The fequency can be determined using the relation
F
L
=1/1.289 R2* C2. The high frequency oscillates
at a FH1,F
H2
controlled by an external resistor (R3)
and capacitor (C3). The frequency can be determined
using the relation F
H1
=1/1.504 R3*C3 and F
H2
=
1/1.203 R3*C3.
Pin 2 of the UTC TA31002A allows connection of
external resistor RSL, which is used to program the
slope of the supply current vs. supply voltage
characteristics (see Fig.3), and hence the supply
current up to the initiation voltage (Vsi). This initiation
voltage remains constant independent of RSL.
The supply current drawn prior to triggering varies
inversely with RSL, decreasing for increasing value
of resistance. Thus, increasing the value of RSL, will
decrease the amount of AC ringing current required to
trigger the device. As such, longer sucribser loops are
possible since less voltage is dropped per unit length of
loop wire due to the lower current level. RSL can
also be used to compensated for smaller AC coupling
capacitors (C5 on Fig.4) (higher impedance) to the
line which can be used to alter the ringer
equivalence
number of a tone ringer circuit.
The graph in Fig.3 illustrates the variation of supply
current with supply voltage of the UTC
TA31002A.
Three curves are drawn to show the variation of
initiation current with RSL. Curve B ( RSL=6.8K)
shows the I-V characteristic for UTC TA31002A
tone ringer. Curve A is a plot with RSL<6.8K
and shows an increase in the current drawn up to the
initiation voltage Vsi. The I-V characteristic after
initiation remains unchanged. Curve C illustrates the
effect of increasing RSL above 6.8K
initiation current decreases but again current
alter triggering is unchanged.
UTC TA31002A LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
4
C:R
SL
=13K
B:R
SL
=6.8K
A:R
SL
=5K
34
30
26
22
18
14
10
6
2
34
30
26
22
18
14
10
6
2
Vcc(V),Supply voltage
34
30
26
22
18
14
10
6
2
34
30
26
22
18
14
10
6
2
Vcc(V),Supply voltage
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Icc(mA),Supply Current
0.5
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
Supply Current (mA)
Circuit Current-Supply Voltage
(No Load)
Supply Current Vs. Supply Voltage
(No Load)
Fig.2
Fig. 3
APPLICATION CIRCUIT
TIP
RING
C1
0.9
F
SP
2
1
3
4
8
7
6
5
R1
560
C4
22
F/35V
D1
29V
R2
165k+-1%
C2
0.47
F+-5%
5.6k - 1 M
R3
191k+-1%
C3
6.9nF+-5%
15k
1300:8
C5 0.22
F
10k
UTC
TA31002A
Fig.4
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