LM555C Harris Corporation, LM555C Datasheet - Page 3

• Manufacturer Part Number: LM555C
• Description: Timers for Timing Delays and Oscillator Application
• Manufacturer: Harris Corporation

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DataSheet
4
U
Electrical Specifications
NOTES:
Schematic Diagram
NOTE: Resistance values are in ohms.
Typical Applications
Reset Timer (Monostable Operation)
Figure 1 shows the CA555 connected as a reset timer. In this
mode of operation capacitor C
a transistor on the integrated circuit. Upon closing the “start”
switch, or applying a negative trigger pulse to terminal 2, the
integral timer flip-flop is “set” and releases the short circuit
across C
Output Rise Time
Output Fall Time
THRESHOLD
DISCHARGE
2. When the output is in a high state, the DC supply current is typically 1mA less than the low state value.
3. The threshold current will determine the sum of the values of R
CONTROL
VOLTAGE
.com
TRIGGER
RESET
R
V+
1
8
6
5
2
4
7
1
V-
+ R
T
2
PARAMETER
which drives the output voltage “high” (relay ener-
= 20M .
4.7K
Q
1
D
COMPARATOR
THRESHOLD
1
830
RESET
Q
Q
Q
6
3
2
DISCHARGE
Q
Q
10K
5
4
4.7K
D
Q
T
2
Q
8
T
7
is initially held discharged by
A
CA555, CA555C, LM555, LM555C, NE555
= 25
SYMBOL
t
t
R
F
o
C, V+ = 5V to 15V Unless Otherwise Specified (Continued)
100
Q
TEST CONDITIONS
9
COMPARATOR
TRIGGER
1K
Q
DataSheet4U.com
Q
11
100K
10
Q
12
Q
1
8-5
13
and R
5K
5K
5K
gized). The action allows the voltage across the capacitor to
increase exponentially with the constant t = R
voltage across the capacitor equals 2/3 V+, the comparator
resets the flip-flop which in turn discharges the capacitor rap-
idly and drives the output to its low state.
2
to be used in Figure 4 (astable operation); the maximum total
MIN
-
-
CA555, LM555
Q
14
4.7K
TYP
Q
100
100
15
FLIP-FLOP
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7K
MAX
D
3
-
-
Q
Q
16
6.8K
17
CA555C, LM555C, NE555
MIN
-
-
Q
18
TYP
100
100
3.9K
4.7K
D
220
OUTPUT
Q
4
19
1
MAX
C
-
-
Q
Q
T
20
21
. When the
OUTPUT
UNITS
ns
ns
3