9.4 Multiple Harmonic Oscillator.ppt; 9.4 Multiple Harmonic Oscillator; 9.4 Multiple Harmonic Oscillator
The NAND gate, as an inverter device, can be used to construct various pulse waveform generation circuits. The basic working principle of the circuit is to utilize the charging and discharging of the capacitor. When the input voltage reaches the threshold voltage Uth of the NAND gate, the output state of the gate changes. Therefore, the parameters of the pulse waveform output by the circuit directly depend on the values of the resistive and capacitive elements in the circuit. 9.4.1 Asymmetric Multiple Harmonic Oscillator
As shown in Figure 9.4.1, the NAND gate U1C is used for waveform shaping. The output waveform of the asymmetric multiple harmonic oscillator is asymmetrical. When composed with a TTL NAND gate, the output pulse width t01=RC, t02=1.2RC, t=2.2RC Figure 9.4.1 Asymmetric Multiple Harmonic Oscillator Adjusting the values of R and C can change the oscillation frequency of the output signal. Usually, the output frequency is roughly adjusted by changing C and finely adjusted by changing the potentiometer R. In actual digital circuits, many digital components need to be connected to a DC power source in order to function properly, although this is not directly shown in the schematic. To be more realistic, in the "Real" simulation of digital circuits in Multisim, digital components in the circuit need to be connected to an indicative power source (Digital Ground) which serves as the reference point for the power source. The digital ground terminal is only used for circuits containing digital components and usually should not be connected to any other devices. It is simply placed in the circuit as an indication. It should be connected to O; for completion.
