NE555 Timer

The NE555 is a popular timer IC used for generating precise time delays and oscillations. It operates in astable, monostable, and bistable modes, making it ideal for pulse generation, timing, and waveform shaping. Operating from 4.5V to 15V, it delivers strong output drive and timing accuracy. Its simplicity, low cost, and versatility have made it a staple in electronics projects and circuits.

Applications

Monostable timer (One-Shot Pulse): used for timed delays
Astable oscillator: generates square waves for blinking LEDs or clock signals
PWM generator: controls motor speed or LED brightness
Tone generator: simple audio-frequency tone for buzzers or alarms
Timer circuits: kitchen timers, countdowns, or automatic shutoff
Electronic dice roller: random number display with LEDs.

Specifications/Features

Supply Voltage Range	4.5V to 15V
Operating Modes	Astable, Monostable, Bistable
Typical Output Current	200 mA max (sink or source)
Timing Accuracy	±1% (typical with stable components)
Frequency Range	Up to several hundred kHz
Trigger Voltage	1/3 of VCC
Threshold Voltage	2/3 of VCC
Power Consumption	Low in standby, moderate when switching
Operating Temperature	0°C to +70°C

📄 NE555 datasheet (2238 kB)

Connections

Pin	Name	Description
1	GND	Ground (0 V)
2	Trigger	`Output` goes high and the interval begins when this input drops below 33% of VCC
3	Output	This output is driven by the IC to either VCC or GND
4	Reset	An interval can be interrupted if this input is set to GND
5	Control	Access to the internal voltage divider (typically 66% of VCC)
6	Threshold	The interval ends when the voltage at `Threshold` exceeds the voltage at `Control`
7	Discharge	Open-collector output can discharge a capacitor between intervals
8	VCC	Supply voltage; between 3V and 15V

Further information

Last edited by Christian Grieger on 2025-05-10

←

[top]
Applications
Specifications/Features
Connections
Further information