Hcu-hct-based-oscillator


Posted on Jan 27, 2013

When frequency stability is not of prime importance, a simple, yet reliable, digital clock oscillator can be made with the aid of relatively few components. High-speed CMOS (HCU/HCf) inverters or gates with an inverter function are eminently suitable to make such oscillators, thanks to their low power consumption, good output signal definition, and extensive frequency range. The circuit as shown uses two inverters in a 74HCf04 or 74HCU04.


Hcu-hct-based-oscillator
Click here to download the full size of the above Circuit.

The basic design equations are: ForHCU: J~l!T; T~2.2RC; Vee 6V; I,~13mA For HCT: f~liT; T~2.4 RC; Vee 5.5 V; !,~2.2 mA With R, and R calculated for a given frequency and value of C, both resistors can be realized as presets to enable precise setting of the output frequency and the duty factor. Do not forget, however, to fit small series resistors in series with the presets, in obse=ce of the minimum values for R and R, as given in the design equations. The values quoted for I, are only valid if the inputs of the remaining gates are grounded.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Precision calibration standard
    3In1-test-set
    Automatic lamp dimmer circuit
    Serial programmer circuit for AT89Sx MCUs
    bd5460 class d amplifier circuit
    9 volt headphone amplifier
    Video Clock and Message Generator
    Anti-theft car audio system circuit diagram



    Top