©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 KA555 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

KA555

Single Timer