555 Timer IC

555 Timer IC 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.

Important Features of the 555 Timer

• It works from a wide range of power supplies ranging from +5V to +18V.
• Sourcing or sinking load current is 200mA.
• The external components must be selected correctly, so that the timing intervals can be completed in several minutes along with the frequencies beyond several hundred kHz.
• The o/p of a 555 timer IC can drive TTL due to its high current o/p.
• It takes a temperature stability of 50 ppm/oC change in temperature (ppm means parts per million)
• The timers duty cycle is adjustable.
• The max power dissipation per package is 600 milliwatts & its reset and trigger i/ps has logic compatibility.