©2002 Fairchild Semiconductor Corporation

www.fairchildsemi.com

www.fairchildsemi.com

www.fairchildsemi.com

www.fairchildsemi.com

Rev. 1.0.3

Features

Features

Features

Features

• High Current Drive Capability (200mA)

• Adjustable Duty Cycle

• Temperature Stability of 0.005%/

°C

• Timing From

µSec to Hours

• Turn off Time Less Than 2

µSec

Applications

Applications

Applications

Applications

• Precision Timing

• Pulse Generation

• Time Delay Generation

• Sequential Timing

Description

Description

Description

Description

The LM555/NE555/SA555 is a highly stable controller

capable of

producing

accurate timing pulses. With a

monostable operation, the time delay is controlled by one

external resistor and one capacitor. With an astable

operation, the frequency and duty cycle are accurately

controlled by two external resistors and one capacitor.

8-DIP

8-DIP

8-DIP

8-DIP

8-SOP

8-SOP

8-SOP

8-SOP

1

1

Internal Block Diagram

Internal Block Diagram

Internal Block Diagram

Internal Block Diagram

F/F

F/F

F/F

F/F

OutPut

OutPut

OutPut

OutPut

Stage

Stage

Stage

Stage

1

1

1

1

7

7

7

7

5

5

5

5

2

2

2

2

3

3

3

3

4

4

4

4

6

6

6

6

8

8

8

8

R

R

R

RR

R

R

RR

R

R

R

Comp.

Comp.

Comp.

Comp.

Comp.

Comp.

Comp.

Comp.

Discharging Tr.

Discharging Tr.

Discharging Tr.

Discharging Tr.

Vref

Vref

Vref

Vref

Vcc

Vcc

Vcc

Vcc

Discharge

Discharge

Discharge

Discharge

Threshold

Threshold

Threshold

Threshold

Control

Control

Control

Control

Voltage

Voltage

Voltage

Voltage

GND

GND

GND

GND

Trigger

Trigger

Trigger

Trigger

Output

Output

Output

Output

Reset

Reset

Reset

Reset

LM555/NE555/SA555

Single Timer