This is one of the timer ic types.
Part Number : NE555, SA555, NA555
Function : PRECISION TIMER
Package : SO-8 Pin
Manufacturers : Diodes Incorporated.
These devices are precision timing circuits capable of producing accurate time delays or oscillation. In the time delay or monostable mode of operation, the timed interval is controlled by a single external resistor and capacitor network. In the astable mode of operation, the frequency and duty cycle can be controlled independently with two external resistors and a single external capacitor.
The threshold and trigger levels normally are two-thirds and one-third, respectively, of VCC. These levels can be altered by use of the control-voltage terminal. When the trigger input falls below the trigger level, the flip-flop is set, and the output goes high. If the trigger input is above the trigger level and the threshold input is above the threshold level, the flip-flop is reset and the output is low.
NE555 block diagram
1. Timing from microseconds to hours
2. Astable or monostable operation
3. Adjustable duty cycle
4. TTL compatible output can source or sink up to 200mA
5. “Green” Molding Compound (No Br, Sb)
6. Lead Free Finish/ RoHS Compliant (Note 1)
Other data sheets within the file : 555, NA555, NA555S-13, NE555S-13