LM555CMMX National Semiconductor, LM555CMMX Datasheet - Page 9

• Manufacturer Part Number: LM555CMMX
• Manufacturer: National Semiconductor
• Type: Standardr

Specifications of LM555CMMX

• # Internal Timers: Single
• Power Dissipation: 613mW
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5/9/12/15V
• Operating Supply Voltage (max): 16V
• Package Type: MSOP
• High Level Output Current: -200mA
• Low Level Output Current: 200mA
• Pin Count: 8
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

Applications Information
V
TIME = 0.2 ms/DIV. Bottom Trace: Output Voltage 2V/Div.
R
C = 0.01µF
PULSE POSITION MODULATOR
This application uses the timer connected for astable opera-
tion, as in Figure 10, with a modulating signal again applied
to the control voltage terminal. The pulse position varies with
the modulating signal, since the threshold voltage and hence
the time delay is varied. Figure 11 shows the waveforms
generated for a triangle wave modulation signal.
CC
A
= 9.1kΩ
= 5V
FIGURE 10. Pulse Position Modulator
FIGURE 9. Pulse Width Modulator
Top Trace: Modulation 1V/Div.
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V
TIME = 0.1 ms/DIV.
R
R
C = 0.01µF
LINEAR RAMP
When the pullup resistor, R
replaced by a constant current source, a linear ramp is
generated. Figure 12 shows a circuit configuration that will
perform this function.
Figure 13 shows waveforms generated by the linear ramp.
The time interval is given by:
CC
A
B
= 3.9kΩ
= 3kΩ
= 5V
FIGURE 11. Pulse Position Modulator
Top Trace: Modulation Input 1V/Div.
Bottom Trace: Output 2V/Div.
FIGURE 12.
V
BE
. 0.6V
A
, in the monostable circuit is
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