CA555, CA555C, LM555, LM555C, NE555
t
1
5V
10
CAPACITANCE (µF)
R
1
+ 2R
2
= 1kΩ
1
100kΩ
1MΩ
0.1
10MΩ
10kΩ
t
2
100
T
A
= 25
o
C, V+ = 5V
0
3.3V
0.01
1.7V
0.001
10
-1
1
10
10
2
10
3
10
4
10
5
0
Top Trace: Output voltage (2V/Div. and 0.5ms/Div.)
Bottom Trace: Capacitor voltage (1V/Div. and 0.5ms/Div.)
FIGURE 5. TYPICAL WAVEFORMS FOR REPEAT CYCLE TIMER
FREQUENCY (Hz)
FIGURE 6. FREE RUNNING FREQUENCY OF REPEAT CYCLE
TIMER WITH VARIATION IN CAPACITANCE AND
RESISTANCE
Typical Performance Curves
MINIMUM PULSE WIDTH (ns)
150
10
T
A
= -55
o
C
0
o
C
25
o
C
50
125
o
C
70
o
C
SUPPLY CURRENT (mA)
9
8
7
6
5
4
3
2
1
0
0.1
0.2
0.3
0.4
0
2.5
5
7.5
10
12.5
15
SUPPLY VOLTAGE (V)
MINIMUM TRIGGER (PULSE) VOLTAGE (x V+) (NOTE)
50
o
C
25
o
C
T
A
= 125
o
C
100
NOTE: Where x is the decimal multiplier of the supply voltage.
FIGURE 7. MINIMUM PULSE WIDTH vs MINIMUM TRIGGER
VOLTAGE
SUPPLY VOLTAGE - OUTPUT VOLTAGE (V)
2.0
OUTPUT VOLTAGE - LOW STATE (V)
T
A
= -55
o
C
1.6
25
o
C
FIGURE 8. SUPPLY CURRENT vs SUPPLY VOLTAGE
10.0
V+ = 5V
T
A
= -55
o
C
1.0
25
o
C
125
o
C
1.2
125
o
C
0.8
0.1
0.4
5V
≤
V+
≤
15V
0
1
10
SOURCE CURRENT (mA)
100
0.01
1
10
SINK CURRENT (mA)
100
FIGURE 9. OUTPUT VOLTAGE DROP (HIGH STATE) vs
SOURCE CURRENT
FIGURE 10. OUTPUT VOLTAGE LOW STATE vs SINK
CURRENT
8-7
HARRIS [ HARRIS CORPORATION ]
