Posted on Sep 19, 2012

An exclusive-OR gate, IClD, turns a simple CMOS oscillator into an FSK generator. When the data input increases, IClD inverts, and negative feedback through R2 lowers the circuit`s output frequency. A low input results in positive feedback and a higher output frequency. Rl and C set the oscillator`s frequency range, and R2 determines the circuit`s frequency shift.

Click here to download the full size of the above Circuit.

To ensure frequency stability, make R3 much greater than Rl and use a high-quality feedback capacitor. The three gates constituting the oscillator itself need not be exclusive- OR types; use any CMOS inverter.

Leave Comment

characters left:

New Circuits



Popular Circuits

12 Vdc - 120 Vac Inverter
50 Watt power Amplifier with preamplifier and headphone output
how to make digital voltmeter
Up/Down Timer For A Power Antenna
Dual Power Amplifier Using TDA7293 MOSFET IC
Operation of an Pierce Oscillator
Buick LeSabre
Current source circuit diagram of the operational amplifier and Darlington transistors
High Fidelity Valve audio Amplifier 40W