LM555 Precision Timer

The most produced integrated circuit in history, and still the first chip most people learn analogue timing with. Two resistors and a capacitor configure it either as a one-shot producing a single timed pulse, or as an oscillator producing a continuous square wave from under a hertz to hundreds of kilohertz. Used for timing, pulse generation, LED flashing, PWM and tone generation. Note it produces significant current spikes when switching, so decouple its supply well. Timing set entirely by two resistors and one capacitor; Works as either a one-shot timer or an oscillator; Frequency range from under 1 Hz to hundreds of kHz; Output drives up to 200 mA directly