SA555

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community NA555, NE555, SA555, SE555 SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014 xx555 Precision Timers 1 Features 1 Timing From Microseconds to Hours Astable or Monostable Operation Adjustable Duty Cycle TTL-Compatible Output Can Sink or Source Up to 200 mA On Products Compliant to MIL-PRF-38535, All Parameters Are Tested Unless Otherwise Noted. On All Other Products, Production Processing Does Not Necessarily Include Testing of All Parameters. 2 Applications Fingerprint Biometrics Iris Biometrics RFID Reader 3 Description These devices are precision timing circuits capable of producing accurate time delays or oscillation. In the time-delay or mono-stable mode of operation, the timed interval is controlled by a single external resistor and capacitor network. In the a-stable 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 twothirds 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 flipflop is reset and the output is low. The reset (RESET) input can override all other inputs and c...