SA555 Fairchild Semiconductor, SA555 Datasheet - Page 9

• Manufacturer Part Number: SA555
• Description: Timers & Support Products
• Manufacturer: Fairchild Semiconductor
• Type: Standardr

Specifications of SA555

• Number Of Internal Timers: 1
• Supply Voltage (max): 16 V
• Supply Voltage (min): 4.5 V
• Maximum Power Dissipation: 600 mW
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: Through Hole
• Package / Case: PDIP-8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6. Linear Ramp
6. Linear Ramp
When the pull-up resistor RA in the monostable circuit shown in Figure 1 is replaced with constant current source, the V
increases linearly, generating a linear ramp. Figure 13 shows the linear ramp generating circuit and Figure 14 illustrates the
generated linear ramp waveforms.
In Figure 13, current source is created by PNP transistor Q1 and resistor R1, R2, and R
For example, if Vcc=15V, R
V
Ic=(15-10.7)/20k=0.215mA
6. Linear Ramp
6. Linear Ramp
Figure 11. Circuit for Pulse Position Modulation
Figure 11. Circuit for Pulse Position Modulation
Figure 11. Circuit for Pulse Position Modulation
Figure 11. Circuit for Pulse Position Modulation
E
=0.7V+10V=10.7V
Output
Output
Output
Output
Output
V
Figure 13. Circuit for Linear Ramp
Figure 13. Circuit for Linear Ramp
Figure 13. Circuit for Linear Ramp
Figure 13. Circuit for Linear Ramp
E
=
I
C
V
3
2
2
3
BE
=
TRIG
OUT
OUT
TRIG
V
-------------------------- -
RESET
RESET
+
Here, V
4
CC
--------------------- - V
R 1
4
R
GND
R 2
E
–
+
1
GND
V
R 2
1
E
E is
Vcc
THRES
DISCH
8
CONT
E
CC
=20k , R1=5kW, R2=10k , and V
THRES
Vcc
DISCH
CONT
8
7
6
5
12
Modulation
Modulation
Modulation
Modulation
6
7
5
13
C C C C
C2
R R R R
R R R R
A A A A
B B B B
+Vcc
+Vcc
+Vcc
+Vcc
R
C1
E
Q1
+Vcc
R2
R1
Figure 12. Waveforms of pulse position modulation
Figure 12. Waveforms of pulse position modulation
Figure 12. Waveforms of pulse position modulation
Figure 12. Waveforms of pulse position modulation
BE
Figure 14. Waveforms of Linear Ramp
Figure 14. Waveforms of Linear Ramp
Figure 14. Waveforms of Linear Ramp
Figure 14. Waveforms of Linear Ramp
=0.7V,
E
.
LM555/NE555/SA555
C1
9 9 9 9