LMC555CM/HFPB National Semiconductor, LMC555CM/HFPB Datasheet - Page 7

• Manufacturer Part Number: LMC555CM/HFPB
• Manufacturer: National Semiconductor
• Type: Standardr

Specifications of LMC555CM/HFPB

• # Internal Timers: 1
• Power Dissipation: 740mW
• Propagation Delay Time: 100ns
• Operating Supply Voltage (typ): 1.5V
• Package Type: SOIC N
• High Level Output Current: -10mA
• Low Level Output Current: 50mA
• Pin Count: 8
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

Application Information
V
TIME = 0.2 ms/Div. Bottom Trace: Output Voltage 2 V/Div.
R
C = 0.01 µF
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
= 9.1 kΩ
= 5V
FIGURE 9. Pulse Width Modulator Waveforms
FIGURE 10. Pulse Position Modulator
Top Trace: Modulation 1 V/Div.
(Continued)
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V
TIME = 0.1 ms/Div.
R
R
C = 0.01 µF
50% DUTY CYCLE OSCILLATOR
The frequency of oscillation is
Bumps are numbered counter-clockwise
CC
A
B
= 3.9 kΩ
= 3 kΩ
FIGURE 11. Pulse Position Modulator Waveforms
= 5V
f = 1/(1.4 R
FIGURE 12. 50% Duty Cycle Oscillator
micro SMD Marking Orientation
C
C)
Bottom Trace: Output Voltage 2 V/Div.
Top Trace: Modulation Input 1 V/Div.
Top View
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