Lm555

LM555
Timer
General Description

Features

The LM555 is a highly stable device for generating accurate
time delays or oscillation. Additional terminals are provided
for triggering or resetting if desired. In the time delay mode of
operation, the time is precisely controlled by one external
resistor and capacitor. For astable operation as an oscillator,
the free running frequency andduty cycle are accurately
controlled with two external resistors and one capacitor. The
circuit may be triggered and reset on falling waveforms, and
the output circuit can source or sink up to 200mA or drive
TTL circuits.

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Direct replacement for SE555/NE555
Timing from microseconds through hours
Operates in both astable and monostable modes
Adjustable duty cycleOutput can source or sink 200 mA
Output and supply TTL compatible
Temperature stability better than 0.005% per ˚C
Normally on and normally off output
Available in 8-pin MSOP package

Applications
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Precision timing
Pulse generation
Sequential timing
Time delay generation
Pulse width modulation
Pulse position modulation
Linear ramp generator

Schematic Diagram00785101

© 2006 National Semiconductor Corporation

DS007851

www.national.com

LM555 Timer

July 2006

LM555

Connection Diagram
Dual-In-Line, Small Outline
and Molded Mini Small Outline Packages

00785103

Top View

Ordering Information
Package

8-Pin MDIP

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Package Marking

Media Transport

LM555CM

LM555CM

Rails

LM555CM

2.5kUnits Tape and Reel

LM555CMM

Z55

1k Units Tape and Reel

LM555CMMX

8-Pin MSOP

Part Number
LM555CMX

8-Pin SOIC

Z55

3.5k Units Tape and Reel

LM555CN

LM555CN

Rails

2

NSC Drawing
M08A
MUA08A
N08E

Soldering Information
Dual-In-Line Package

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/Distributors for availability and specifications.
Supply Voltage

Soldering (10 Seconds)

+18V

(SOIC and MSOP)
Vapor Phase (60 Seconds)

LM555CM, LM555CN

613 mW

215˚C

Infrared (15 Seconds)

1180 mW

LM555CMM

220˚C

See AN-450 “Surface Mounting Methods and Their Effect
on Product Reliability” for other methods of soldering
surface mount devices.

Operating TemperatureRanges
Storage Temperature Range

260˚C

Small Outline Packages

Power Dissipation (Note 3)

LM555C

LM555

Absolute Maximum Ratings (Note 2)

0˚C to +70˚C
−65˚C to +150˚C

Electrical Characteristics (Notes 1, 2)
(TA = 25˚C, VCC = +5V to +15V, unless othewise specified)
Parameter

Conditions

Limits

Units

LM555C
Min
Supply Voltage
Supply Current

Typ

4.5Max
16

V

6
15

mA

VCC = 5V, RL = ∞
VCC = 15V, RL = ∞
(Low State) (Note 4)

3
10

1

%

RA = 1k to 100kΩ,

50

ppm/˚C

Timing Error, Monostable
Initial Accuracy
Drift with Temperature

C = 0.1µF, (Note 5)
Accuracy over Temperature

1.5

%

Drift with Supply

0.1

%/V

2.25

%

150

ppm/˚C

3.0

%

Timing Error, Astable
Initial AccuracyDrift with Temperature

RA, RB = 1k to 100kΩ,
C = 0.1µF, (Note 5)

Accuracy over Temperature
Drift with Supply

0.30

%/V

Threshold Voltage

0.667

x VCC

VCC = 15V

5

V

VCC = 5V

1.67

Trigger Voltage
Trigger Current

0.5

Reset Voltage

0.4

Control Voltage Level

µA

Pin 7 Leakage Output High

V
mA

0.25

µA

10
3.33

11
4

V

1

9
2.61
0.4

0.1

(Note 6)
VCC = 15V
VCC = 5V

0.5
0.1

Reset Current
Threshold Current

V
0.9

100

nA

Pin 7 Sat (Note 7)
Output Low

VCC = 15V, I7 = 15mA

180

Output Low

VCC = 4.5V, I7 = 4.5mA

80

3

mV
200

mV

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LM555

Electrical Characteristics (Notes 1, 2)

(Continued)
(TA = 25˚C, VCC = +5V to +15V, unless othewise...