Description
The NE556, SA556 and SE556 dual monolithic timing circuits are highly stable controllers capable of producing accurate time delays or oscillation. 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 the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuits 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
NE556 Pinout Configuration
| Pin Number |
Pin Name |
Description |
| 1,13 |
Discharge |
Open collector output which discharges a capacitor between intervals (in phase with output). 7 I It toggles the output from high to low when voltage reaches 2/3 of the supply voltage |
| 2,12 |
Threshold |
Compares the voltage applied to the terminal with a reference voltage of 2/3 Vcc. The 6 I amplitude of voltage applied to this terminal is responsible for the set state of the flip-flop |
| 3,11 |
Control Voltage |
Controls the threshold and trigger levels. It determines the pulse width of the output 5 Voltage I waveform. An external voltage applied to this pin can also be used to modulate the output waveform |
| 4,10 |
Reset |
Negative pulse applied to this pin to disable or reset the timer. When not used for reset 4 I purposes, it should be connected to VCC to avoid false triggering |
| 5,9 |
Out |
This pin is normally connected to load as it is the only pin with output driven waveform |
| 6,8 |
Trigger |
Responsible for transition of the flip-flop from set to reset. The output of the timer depends 2 I on the amplitude of the external trigger pulse applied to this pin |
| 7 |
Ground |
Ground Reference Voltage 0V |
| 14 |
Vcc |
Supply Voltage (Typical = 5V, Maximum = 18V) |
Features and Specifications
- Two precision Timers in one single package
- Typical operating voltage is +5V, can withstand a maximum of +18V.
- The source/sink current of the output pin is 220mA
- Minimum Threshold voltage is 2.4 @ Vcc=5V
- Operating Temperature is 70 degree Celsius.
- Available in 14-pin SO package
| Physical |
| Case/Package |
SOIC |
| Mount |
Surface Mount, Through Hole |
| Number of Pins |
14 |
| Technical |
| Current Rating |
20 A |
| Frequency |
500 kHz |
| High Level Output Current |
-200 mA |
| Low Level Output Current |
200 mA |
| Max Operating Temperature |
70 °C |
| Max Supply Voltage |
16 V |
| Min Operating Temperature |
0 °C |
| Min Supply Voltage |
4.5 V |
| Nominal Supply Current |
20 mA |
| Number of Channels |
2 |
| Number of Timers/Counters |
2 |
| Operating Supply Current |
20 mA |
| Output Current |
200 mA |
| Quiescent Current |
30 mA |
Reviews
There are no reviews yet.