ICs for Timer
1
AN6783S
IC for long interval timer
s
Overview
The AN6783S is an IC designed for a long interval
timer. It is oscillated by using the external resistor and
capacitor, and the oscillation frequency divided by a 15-
stage F.F. is provided as the output.
It is frequency divider type, so that a long interval
timer can be constructed by using a capacitor with small
capacitance.
s
Features
Oscillation frequency dispersion of IC itself is small (
5
%)
Oscillation frequency can be checked by 1/2 f
OSC
moni-
tor terminal
Wide operating supply voltage range (3.2 V to 18 V)
Small consumption current (3 mA typ.)
s
Applications
Timer
s
Block Diagram
SOP008-P-0225A
Unit : mm
1
2
3
4
8
7
6
5
0.40.25
0.60.3
1.27
5.00.3
0.10.1
0.3
4.20.3
6.50.3
0.15
0.65
1.50.2
To each
block
F.F.
15
F.F.
2
F.F.
1
OSC
Voltage
stabilizer
Input
circuit
Input
circuit
1
2
3
4
8
V
S
Stop
Reset
GND
CR
Out
V
CC
Mon.
7
6
5
2
AN6783S
ICs for Timer
s
Absolute Maximum Ratings
Parameter
Symbol
Rating
Unit
Supply voltage
V
CC
20
V
Supply current
I
CC
7
mA
Power dissipation
P
D
140
mW
Operating ambient temperature
*
T
opr
-
35 to
+
85
C
Storage temperature
*
T
stg
-
55 to
+
125
C
Stop terminal voltage
V
STOP
0 to 18
V
Reset terminal voltage
V
RESET
0 to 18
V
CR terminal voltage
V
CR
0 to 3
V
Out terminal current
I
OUT
-
15 to
+
15
mA
s
Recommended Operating Range
Parameter
Symbol
Range
Unit
Supply voltage
V
CC
3.2 to 18.0
V
Pin No.
Symbol
Description
1
V
S
Reference voltage
2
Stop
Oscillation stop input
3
Reset
Reset input
4
GND
Grounding
5
CR
C and R connection
6
Out
Output
7
V
CC
Supply voltage
8
Mon.
Monitor pin
s
Pin Descriptions
Note) 1. Do not apply external currents or voltages to any pins not specifically mentioned.
For circuit currents, '
+
' denotes current flowing into the IC, and '
-
' denotes current flowing out of the IC.
2. *: Except for the operating ambient temperature and storage temperature, all ratings are for T
a
=
25
C.
s
Electrical Characteristics at T
a
=
25
C
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Quiescent supply current
I
CC
V
CC
=
5 V
2.0
4.0
5.0
mA
Internal reference voltage
V
S
V
CC
=
5 V, I
S
=
-
3 mA
2.40
2.55
2.70
V
High-level input current
I
IH
V
CC
=
18 V, V
IH
=
18 V
10
A
Low-level input current
I
IL
V
CC
=
18 V, V
IL
=
0 V
-
100
A
High-level out terminal voltage
V
OH
V
CC
=
18 V, I
OH
=
-
10 mA
14.0
16.0
18.0
V
Low-level out terminal voltage
V
OL
V
CC
=
3.2 V, I
OL
=
-
10 mA
0.4
V
3
ICs for Timer
AN6783S
s
Electrical Characteristics at T
a
=
25
C (continued)
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
High-level Mon. terminal voltage
V
MH
V
CC
=
18 V
17.8
18.0
V
Low-level Mon. terminal voltage
V
ML
V
CC
=
3.2 V
0.4
V
Oscillation frequency precision
f
OSC
V
CC
=
5 V, R
T
=
1 k
,
9.0
9.5
10.0
kHz
C
T
=
0.1
F
Oscillation frequency fluctuation with
f
V
V
CC
=
5 V,
-
5.0
5.0
%
supply voltage
3.2 V to 18.0 V
High-level input voltage
V
IH
V
CC
=
5 V
2.0
V
Low-level input voltage
V
IL
V
CC
=
5 V
0.8
V
Design reference data
Note) The characteristic values below are theoretical values for designing and not guaranteed.
The data show the changing amount within T
a
=
-
35
C to +85
C when the values at T
a
=
25
C is taken as the reference.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Oscillation frequency-
f
r
V
CC
=
5 V, R
T
=
1 k
,
-
5.0
5.0
%
temperature dependency
C
T
=
0.1
F
Pin No.
Equivalent circuit
Description
I/O
DC
voltage
1
V
S
:
O
2.55 V
Stabilized power supply output terminal.
Reference voltage source for oscillation
circuit.
2
Stop :
I
Oscillation stop input terminal. Only the
oscillation circuit stops when this termi-
nal becomes low-level.
(F.F. is not cleared)
When not used, the terminal should be
open or connected to V
CC
.
s
Terminal Equivalent Circuits
V
CC
V
S
Stop
4
AN6783S
ICs for Timer
Pin No.
Equivalent circuit
Description
I/O
DC
voltage
3
Reset :
I
Reset input terminal.
F.F. is reset when the terminal becomes
low-level and is set in the initial state.
When not used, the terminal should be
open or connected to V
CC
.
The reset is applied by rising V
CC
from a
voltage below 0.8 V (power-on reset
function).
4
GND :
0 V
Grounding terminal.
5
CR :
0.7 V to 1.8 V
C and R connection terminal.
The oscillation period is determined by
an external resistor and capacitor.
When applying a pulse to this terminal
from the outside, the voltage should be
within the range of 0 V to 3 V.
6
Out :
O
High-level
Output terminal.
V
CC
-
1.4 V
A frequency which is 1/32768 of the
oscillation frequency is outputted.
Low-lebel
Use with an output current within
10
<
0.4 V
mA.
7
V
CC
:
Supply voltage terminal.
8
Mon. :
O
High-level
Oscillation frequency monitor terminal.
V
CC
The output is given from the first stage
of F.F. and a frequency which is 1/2 of
Low-level
the oscillation frequency f
OSC
is output-
<
0.4 V
ted. If not used, the terminal should be
open. This terminal is provided for con-
necting probe such as oscilloscope. Use
it with an output current under 100
A.
s
Terminal Equivalent Circuits (continued)
V
CC
V
S
Reset
CR
V
S
V
CC
Out
V
CC
Mon.
RA
=
10 k
to 40 k
5
ICs for Timer
AN6783S
s
Usage Notes
Pay attention to the following matters in order to prevent the destruction during the use and to increase the reliability ;
1. In the application circuit example, the calculated value by the theoretical equation for timer interval calculation and
the characteristics curve vary depending on the precision of the time interval capacitor used in the actual set. Take
such matter of the above into consideration.
Also, the proportional constant
depends on the kinds and characteristics of the time interval resistor and time
interval capacitor.
Make a final confirmation with the finished products.
In the case when a high precision is required, adjust the value by using a variable resistor as the time interval
resistor.
2. Use a time interval resistor in the range of 1 k
to 1 M
, and a time interval capacitor in the range of 0.1
F to
100
F which is polyester or tantalum electrolytic capacitor with a small tan
value.
3. Connect a capacitor (1
F to 10
F) to the V
S
terminal in order to protect the IC from an external noise and stabilize
its operation.
4. If turning on power again after an extremely short-time power supply off state during the normal operation, be
careful that there may be a case that the automatic reset (power-on reset) fails due to a residual potential of the
external capacitance.
5. Take measures against noise in order to avoid the malfunction caused by the external noise. Pay attention to the
noise from an external source especially at setting a long interval time.
6. When connecting a plunger or relay to the output circuit, connect a diode to the both ends of coil in order to
protect the IC from the counter-electromotive force generted after the circuit is turned off .
7. Do not short circuit the V
S
terminal with V
CC
terminal in order to avoid malfunction.
s
Main Characteristics
f
OSC
R
t
t
T
R
t
Oscillation frequency
f
OSC
(Hz)
10
-
2
10
1
10
-
1
10
3
10
2
10
1
Time decision resistance R
t
(k
)
10
4
10
3
10
2
C
t
=
0.1
F
C
t
=
1
F
C
t
=
10
F
C
t
=
100
F
Timer interval
t
T
(s)
1
10
3
10
2
10
10
3
10
2
10
1
Time decision resistance R
t
(k
)
10
6
10
5
10
4
C
t
=
0.1
F
C
t
=
1
F
C
t
=
10
F
C
t
=
100
F
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