LMC555 Datasheet, PDF (7/12 Pages) National Semiconductor (TI) – CMOS Timer

Application Info (Continued)
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.
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FIGURE 10. Pulse Position Modulator
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V_CC = 5V
TIME = 0.1 ms/Div.
R_A = 3.9 kΩ
R_B = 3 kΩ
C = 0.01µF
Top Trace: Modulation Input 1V/Div.
Bottom Trace: Output Voltage 2V/Div.
FIGURE 11. Pulse Position Modulator Waveforms
50% DUTY CYCLE OSCILLATOR
The frequency of oscillation is
f = 1/(1.4 R_CC)
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FIGURE 12. 50% Duty Cycle Oscillator
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