NE556
SA556 - SE556
General-purpose dual bipolar timers
Features
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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
D
SO14
(Plastic micropackage)
N
DIP14
(Plastic package)
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.
Pin connections
(top view)
Discharge
Threshold
1
2
14
13
12
11
10
9
8
VCC
Discharge
Threshold
Control Voltage
Reset
Output
Trigger
Control Voltage 3
Reset
Output
Trigger
GND
4
5
6
7
January 2009
Rev 2
1/16
16
STMICROELECTRONICS [ STMICROELECTRONICS ]
