1
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MIKA2411
TONE RINGER
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DATA SHEET
M
ARCH
2003
N
O
. 00001
R
EV
1-03
CONTENTS
Page
GENERAL DESCRIPTION
1
FEATURES
1
PIN DESCRIPTIONS
&
SCHEMATIC
DIAGRAM
2
ABSOLUTE MAXIMUM RATINGS
2
ELECTRICAL CHARACTERISTICS
2
CIRCUIT OPERATION
3
CONTENTS
Page
APPLICATION INFORMATION
3
MEASUREMENT CIRCUITS
4
APPLICATION EXAMPLE
4
PHYSICAL DIMENSIONS AND MARKING
DIAGRAMS
5
ORDERING INFORMATION
6
DIP-8
5
GENERAL DESCRIPTION
The MIKA2411 is a bipolar integrated circuit designed
for telephone bell replacement.
It can also be used as alarms or other alerting
devices --
telephones, multi-function telephones,
telephone answering machines, facsimiles, equipment
involving telephones.
FEATURES
Low current drain
Adjustable 2 tone frequency
Hysteresis circuit prevent false triggering and
rotary dial Chirps
Small size DIP8 plastic package
Adjustable for reduced supply initiation current
REPLACEMENT
of
KA2411
MIKA2411
TONE RINGER
2
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TONE RINGER
MIKA2411
Design by Vladimir F.Lityaghin / E-mail: lityaghin@mail.ru / Tel: +7(095)532-64-54
DIP-8
MIKA2411
PIN DESCRIPTIONS
&
SCHEMATIC DIAGRAM
Note 1
: Supply initiation voltage is the value of DC supply voltage required to start the tone ringer
oscillating.
Note 2
: Sustaining voltage is the value of DC supply voltage required to maintain the oscillation.
Note 3
: Oscillator frequency is determined by the following equations:
f
L
=1/(1.359 x R1 x C1) (Hz)
f
HI
=1/(1.518 x R2 x C2) (Hz)
f
H2
=1.214 x f
HI
(Hz)
ELECTRICAL CHARACTERISTICS
(V
CC
=24V, T
A
=25C, unless otherwise noted)
HIGH
FREQUENCY
OSCILLATOR
OUTPUT
AMPLIFIER
LOW
FREQUENCY
OSCILLATOR
HYSTERESIS
REGULATOR
O
O
O
O
O
O
O
O
PIN
No. PIN NAME
NAME
FUNCTION
1 V
CC
Power supply pin
This is the power supply pin for
the IC. It is connected to the (+)
pin of the diode bridge.
2 RSL
RSL pin
This is used to change the
operation initiation current when
connected to the GND pin.
3 LFI
4 LFO
Low-frequency time
constant connector pin
This is connected to the time
constant that determines the
oscillation frequency on the
warble.
5 GND
GND pin
This pin has the lowest potential
on the IC. It is connected to the ()
pin of the diode bridge.
6 HFO
7 HFI
High-frequency time
constant connector pin
This is connected to the time
constant that determines the
oscillation frequency on the tone
side (the audible frequency side).
8 OUT
Output pin
This is used to connect a
piezoelectric buzzer, or to
connect a dynamic speaker
through a transformer.
Note
: Voltage values are with respect to the anode terminal unless otherwise noted
ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
RATING
UNIT
V
CC
DC
supply
voltage
29
V
P
d
Power
dissipation
450
mW
T
A
Operating
ambient
temperature
range
-
25
+
75
C
T
STG
Storage
temperature
range
-
65
+
150
C
SYMBOL
PARAMETER
TEST
CONDITIONS
MIN
TYP
MAX
UNIT
V
CC
Operating
Voltage
29
.
0
V
Supply
Initiation
V
SI
Voltage
(
Note
1
)
17
.
0
19
.
0
21
.
0
V
I
SI
Current
V
CC
=
V
SI
,
No
load
1
.
4
2
.
5
4
.
2
mA
Sustaining
V
SUS
Voltage
(
Note
2
)
9
.
7
10
.
5
12
.
0
V
I
SUS
Current
V
CC
=
V
SUS
,
No
load
0
.
2
0
.
9
2
.
5
mA
Oscillator
f
L
Frequency
Low
(
Note
3
)
R1
=
165k
,
C1
=
0
.
47F
9
.
0
10
.
0
11
.
0
Hz
f
H1
Frequency
High
(
Note
3
)
R2
=
191k
,
C2
=
6800pF
461
.
0
512
.
0
563
.
0
Hz
f
H2
Frequency
High
(
Note
3
)
R2
=
191k
,
C2
=
6800pF
576
.
0
640
.
0
703
.
0
Hz
Output
V
OH
High
Voltage
V
CC
=
21V
,
I
OH
=
15mA
17
.
7
19
.
0
21
.
5
V
V
OL
Low
Voltage
I
OL
=
15mA
1
.
6
V
3
_
MIKA2411
TONE RINGER
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TIP
RING
R1 560
C1
1F 250V
X
C2
22F
35V
x
C4
0.22F
29V
R
SL
V
CC
R2
165k 1%
C3
0.47F
5%
C5
0.068F
1%
R3
191k 1%
!
!
!
!
!
!
!
!
1
2
3
4
5
6
7
8
10k
150k
1300
8
SP
EA
K
E
R
VOLUME
+
!
!
APPLICATION INFORMATION
The application circuit illustrates the use of the
MIKA2411 device in typical telephone or extensive tone
ringer applications. The AC ringer signal voltage
appears across the TIP and RING inputs of the circuit
and is attenuated by capacitor C1 and resistor R1. C1
also provides isolation from DC voltages (48V) on the
exchange line.
After full wave rectification by the bridge diode, the
waveform is filtered by capacitor C2 to provide a DC
supply for the tone ringer chip. When this voltage
exceeds the initiation (V
SI
), oscillation starts.
With the components shown, the output frequency
chops between 512 Hz (f
H1
) and 640Hz (f
H2
) at a 10Hz
(f
L
) rate. The loudspeaker load is coupled through a
1300
to 8
transformer. The output coupling
capacitor C4 is required with transformer coupled
loads.
When driving a piezo-ceramic transducer type load,
the coupling C4 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 (C3). The frequency can be determined using
the relation f
L
= 1/(1.289 R2 x C3). The high frequency
oscillates at a f
H1
, f
H2
controlled by an external resistor
(R3) and capacitor (C5). The frequency can be
determined using the relation t
HI
= 1/(1.504 R3 x C5)
voltage remains constant independent of R
SL
.
Pin 2 of the MIKA2411 allows connection of an external
resistor R
SL
, which is used to program the slope of the
supply current vs supply voltage characteristics (see
Fig. 2) and hence the supply current up to the initial
voltage (V
SI
). This initial voltage remains constant
independent of R
SL
.
The supply current drawn prior to triggering varies
inversely with R
SL
, decreasing for an increasing value
of resistance. Thus, increasing the value of R
SL
, will
decrease the amount of AC ringing current required to
trigger the device. As such longer subscriber loops are
possible since less voltage is dropt per unit length of
loop wire due to the lower current level. R
SL
can also
be used to compensate for smaller AC coupling
capacitors (C4 on Fig. 3) (higher impedance) to the
line which is used to alter the ringer equivalence
number of a tone ringer circuit.
The graph in Fig. 2 illustrates the variation of supply
current with supply voltage of the MIKA2411. Three
curves are drawn to show the variation of initiation
current with R
SL
. Blue curve (b) (R
SL
= 6.8k
) shows
the V
CC
/I
CC
characteristic for the MIKA2411 tone ringer.
Red curve (a) is a plot with R
SL
< 6.8k
and shows an
increase in the current drawn up to the initiation
voltage V
SI
. After initiation, the V
CC
/I
CC
characteristic
remain unchanged. Green curve (c) illustrates the
effect of increasing R
SL
above 6.8k
initiation current
decreases but is unchanged again after triggering.
CIRCUIT OPERATION
With the MIKA2411, the RSL pin can be used to change
the initial supply current (I
SI
).
As shown in Figure 1, resistor R
SL
is connected from
the RSL pin (Pin 2) to the GND. The operation
initiation current consumption can be changed by
changing the value of the resistor R
SL
.
Figure 2 shows the supply voltage (V
CC
) -- supply
current (I
CC
) characteristics when the value of the
resistor R
SL
is changed.
Fig. 3
"
Fig. 1
Fig. 2 $
2
6
10
14
18
22
26
30
5.5
4.5
3.5
2.5
1.5
0.5
R
SL
= 5k
R
SL
= 6.8k
R
SL
= 13k
I
CC
(mA)
V
CC
(V)
!
!
a
b
c
%
%
%
%
%
%
%
%
%
%
%
%
%
%
R
SL
GND
V
CC
!
!
!
1
2
5
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