LM555 Datasheet PDF | What is Timer IC?

What is LM555 Timer IC?

This is a popular integrated circuit chip used in a variety of electronic applications, primarily for timing and oscillator functions. It was first introduced by National Semiconductor (now part of Texas Instruments) in the 1970s.

Part Number: LM555

Function: Timer(Direct Replacement for SE555/NE555)

Package: SOIC, PDIP, VSSOP 8 Pin type

Manufacturer: Texas Instruments


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 a stable operation as an oscillator, the free running frequency and duty 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 200 mA or drive TTL circuits.


LM555 datasheet


Application Information ( LM555 Datasheet )

The LM555 timer can be used a various configurations, but the most commonly used configuration is in monostable mode. A typical application for the LM555 timer in monostable mode is to turn on an LED for a specific time duration. A pushbutton is used as the trigger to output a high pulse when trigger pin is pulsed low. This simple application can be modified to fit any application requirement.


1. Timing from Microseconds through Hours

2. Operates in Both Astable and Monostable Modes

3. Adjustable Duty Cycle

4. Output Can Source or Sink 200 mA

5. Output and Supply TTL Compatible



1. Timing and oscillator functions: Primarily used for timing and oscillator functions, such as generating clock signals, pulse-width modulation (PWM), and oscillation circuits.

2. Low power consumption: It is designed to operate with a low power consumption, making it suitable for use in battery-powered devices.

3. Wide operating voltage range: It has a wide operating voltage range of 4.5V to 16V, making it suitable for use in a variety of electronic devices.

4. Single timer integrated circuit chip that contains a voltage comparator, a flip-flop, and a discharge transistor.

5. It can provide either a digital output (0 or 1) or an analog output, depending on the application.

Overall, LM555 is a versatile and widely used integrated circuit chip that offers a low-cost, low-power solution for timing and oscillator applications.


• Precision Timing

• Pulse Generation

• Sequential Timing

• Time Delay Generation

• Pulse Width Modulation

• Pulse Position Modulation

• Linear Ramp Generator


More Informations

555 Time ic Wiki Info, ne555 timer ic info

LM555 Datasheet

LM555 pdf

Other data sheets are available within the file:

555CM, 555CN, LM555CM, LM555CM-NOPB

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