STMicroelectronics NE555N
The NE555, SA555, and SE555 monolithic timing circuits are highly stable controllers capable of producing accurate time delays or oscillation. For a stable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output structure can source or sink up to 200 mA.FEATURES
● Low turn-off time● Maximum operating frequency greater than 500 kHz
● Timing from microseconds to hours
● Operates in both astable and monostable modes
● Output can source or sink up to 200 mA
● Adjustable duty cycle
● TTL compatible
● Temperature stability of 0.005% per °C
DESCRIPTION
In the time delay mode of operation, the time is precisely controlled by one external resistor and capacitor. N DIP8 (Plastic package) D SO8 (Plastic micropackage) Pin connections (top view) 1 2 3 4 1 - GND 2 - Trigger 3 - Output 4 - Reset 8 7 6 5 5 - Control voltage 6 - Threshold 7 - Discharge 8 - VCC January 2012 Doc ID 2182 Rev 6 1/20 20 Schematic diagrams 1 Schematic diagrams Figure 1. Block diagram VCC+ THRESHOLD CONTROL VOLTAGE TRIGGER RESET 5kΩ COMP R FLIP-FLOP 5kΩ Q COMP S INHIBIT/ RESET 5kΩ S Figure 2. Schematic diagram NE555 - SA555 - SE555 DISCHARGE OUT 2/20 Doc ID 2182 Rev 6 NE555 - SA555 - SE555 Absolute maximum ratings and operating conditions 2 Absolute maximum ratings and operating conditions Table 1.