An oscillator/amplifier has a gain controlled amplifier that maintains a desired oscillation waveform amplitude for all possible oscillation frequencies of operation. A peak detector produces a direct current (DC) voltage proportional to the oscillation waveform, and a voltage reference generator provides a reference voltage that is compared against the DC voltage from the peak detector. When the DC voltage is less than the reference voltage the gain of the amplifier is increased, and when the DC voltage is equal to or greater than the reference voltage the gain of the amplifier is decreased. A programmable voltage reference generator may also be used to provide for selection of different oscillation waveform amplitudes. A digital control loop controls the oscillation waveform amplitude over the entire possible frequency range of operation. Various frequency determining elements, e.g., crystal, piezoelectric resonator, inductor-capacitor tuned circuit, resistor-capacitor network, etc., may be used in combination with the oscillator/amplifier.