sa555d-dt STMicroelectronics, sa555d-dt Datasheet - Page 11

• Manufacturer Part Number: sa555d-dt
• Description: General Purpose Single Bipolar Timers
• Manufacturer: STMicroelectronics

NE555 - SA555 - SE555
Figure 15. Typical schematics in astable operation
Figure 16
The charge time (output HIGH) is given by:
and the discharge time (output LOW) by:
Thus the total period T is given by:
The frequency of oscillation is then:
It can easily be found from
The duty cycle is given by:
t1 = 0.693 (R
t2 = 0.693 (R
T = t1 + t2 = 0.693 (R1 + 2R2) C1
shows the actual waveforms generated in this mode of operation.
V
0.01
CC
Output
1
2
) C
+ R
= 5 to 15V
μ
F
1
2
) C
Voltage
Control
1
Figure
3
5
17.
f =
1
1
-- -
T
D
4
=
NE555
=
-------------------------------------- -
(
R1
------------------------- -
R1
R2
+
+
1.44
2R2
2R2
8
)C1
2
6
7
Application information
R2
R1
C1
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