If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage, V
+
Thermal Resistance (θ
JA
) (Note 2)
SO, 8-Pin Small
Outline
MSOP, 8-Pin
Mini Small
Outline
MDIP, 8-Pin
Molded Dip
8-Bump micro
SMD
Maximum
Allowable Power
Dissipation
@
25˚C
MDIP-8
SO-8
MSOP-8
8 Bump micro
SMD
1126 mW
740 mW
555 mW
568 mW
169˚C/W
15V
−0.3V to V
S
+ 0.3V
15V
100 mA
−65˚C to +150˚C
260˚C
215˚C
220˚C
Input Voltages, V
TRIG
, V
RES
, V
CTRL
,
V
THRESH
Output Voltages, V
O
, V
DIS
Output Current I
O
, I
DIS
Storage Temperature Range
Soldering Information
MDIP Soldering (10 seconds)
SOIC, MSOP Vapor Phase (60 sec)
SOIC, MSOP Infrared (15 sec)
225˚C/W
111˚C/W
220˚C/W
Note:
See AN-450 “Surface Mounting Methods and Their Effect on Product
Reliability” for other methods of soldering surface mount devices.
Operating Ratings
(Notes 2, 3)
Termperature
Range
−40˚C to +85˚C
Electrical Characteristics
(Notes 1, 2)
Test Circuit, T = 25˚C, all switches open, RESET to V
S
unless otherwise noted
Symbol
I
S
Parameter
Supply Current
V
S
= 1.5V
V
S
= 5V
V
S
= 12V
V
S
= 1.5V
V
S
= 5V
V
S
= 12V
0.8
2.9
7.4
Conditions
Min
Typ
50
100
150
1.0
3.3
8.0
75
150
0.2
0.3
1.0
1.0
4.4
10.5
0.4
3.7
0.4
0.4
1.25
4.7
11.3
0.5
4.0
10
0.7
0.75
10
10
1.0
0.9
1.0
1.0
1.1
1.1
1.1
0.3
100
1.25
1.20
1.25
1.0
1.1
0.6
4.3
Max
150
250
400
1.2
3.8
8.6
150
300
0.4
0.6
2.0
Units
(Limits)
µA
V
CTRL
Control Voltage
V
V
DIS
V
OL
Discharge Saturation Voltage V
S
= 1.5V, I
DIS
= 1 mA
V
S
= 5V, I
DIS
= 10 mA
Output Voltage (Low)
V
S
= 1.5V, I
O
= 1 mA
V
S
= 5V, I
O
= 8 mA
V
S
= 12V, I
O
= 50 mA
V
S
= 1.5V, I
O
= −0.25 mA
V
S
= 5V, I
O
= −2 mA
V
S
= 12V, I
O
= −10 mA
V
S
= 1.5V
V
S
= 12V
V
S
= 5V
V
S
= 1.5V (Note 4)
V
S
= 12V
V
S
= 5V
V
S
= 5V
V
S
= 12V
SW 2, 4 Closed
V
S
= 1.5V
V
S
= 5V
V
S
= 12V
V
S
= 5V
±
1V
mV
V
V
OH
Output Voltage
(High)
Trigger Voltage
Trigger Current
Reset Voltage
Reset Current
Threshold Current
Discharge Leakage
Timing Accuracy
V
V
TRIG
I
TRIG
V
RES
I
RES
I
THRESH
I
DIS
t
V
pA
V
pA
pA
nA
ms
∆t/∆V
S
Timing Shift with Supply
%/V
3
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LMC555
Electrical Characteristics
(Notes 1, 2)
Test Circuit, T = 25˚C, all switches open, RESET to V
S
unless otherwise noted (Continued)
Symbol
∆t/∆T
f
A
f
MAX
t
R
, t
F
t
PD
Parameter
Timing Shift with
Temperature
Astable Frequency
Maximum Frequency
Output Rise and
Fall Times
Trigger Propagation Delay
Conditions
V
S
= 5V
−40˚C
≤
T
≤
+85˚C
SW 1, 3 Closed, V
S
= 12V
Max. Freq. Test Circuit, V
S
= 5V
Max. Freq. Test Circuit
V
S
= 5V, C
L
= 10 pF
V
S
= 5V, Measure Delay
from Trigger to Output
4.0
Min
Typ
75
4.8
3.0
15
5.6
Max
Units
(Limits)
ppm/˚C
kHz
MHz
ns
100
ns
Note 1:
All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which
guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit
is given, however, the typical value is a good indication of device performance.
Note 3:
See AN-450 for other methods of soldering surface mount devices, and also AN-1112 for micro SMD considerations.
Note 4:
If the RESET pin is to be used at temperatures of −20˚C and below V
S
is required to be 2.0V or greater.
Note 5:
For device pinout please refer to table 1
Test Circuit
(Note 5)
Maximum Frequency Test Circuit
(Note 5)
00866902
00866903
TABLE 1. Package Pinout Names vs. Pin Function
Pin Function
GND
Trigger
Output
Reset
Control Voltage
Threshold
Discharge
V
+
1
2
3
4
5
6
7
8
Package Pin numbers
8-Pin SO, MSOP, and MDIP
8-Bump micro SMD
A3
B3
C3
C2
C1
B1
A1
A2
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4
LMC555
Application Information
MONOSTABLE OPERATION
In this mode of operation, the timer functions as a one-shot
(Figure
1).
The external capacitor is initially held discharged
by internal circuitry. Upon application of a negative trigger
pulse of less than 1/3 V
S
to the Trigger terminal, the flip-flop
is set which both releases the short circuit across the capaci-
tor and drives the output high.
negative pulse to the reset terminal. The output will then
remain in the low state until a trigger pulse is again applied.
When the reset function is not use, it is recommended that it
be connected to V
+
to avoid any possibility of false triggering.
Figure 3
is a nomograph for easy determination of RC values
for various time delays.
Note:
In monstable operation, the trigger should be driven high before the
end of timing cycle.
00866904
00866911
FIGURE 1. Monostable (One-Shot)
The voltage across the capacitor then increases exponen-
tially for a period of t
H
= 1.1 R
A
C, which is also the time that
the output stays high, at the end of which time the voltage
equals 2/3 V
S
. The comparator then resets the flip-flop which
in turn discharges the capacitor and drives the output to its
low state.
Figure 2
shows the waveforms generated in this
mode of operation. Since the charge and the threshold level
of the comparator are both directly proportional to supply
voltage, the timing internal is independent of supply.
FIGURE 3. Time Delay
ASTABLE OPERATION
If the circuit is connected as shown in
Figure 4
(Trigger and
Threshold terminals connected together) it will trigger itself
and free run as a multivibrator. The external capacitor
charges through R
A
+ R
B
and discharges through R
B
. Thus
the duty cycle may be precisely set by the ratio of these two
