Inductive relaxation oscillator with current-limiting

In this paper a resistive-inductive relaxation oscillator allowing a current limitation through the inductor and the other passive components is presented. The proposed topology is an astable multivibrator using one current-input to voltage-output comparator, one inductor and 3 resistances only. A prototype has been designed using ADA4891 opamps from Analog Devices. Under a 3.3 V single supply voltage, measurement results have shown a clock frequency variation from 1.8 kHz to 6 MHz for a set of inductance values between 100 nH to 10 mH. The measurement has confirmed the limitation of the currents passing through the inductor.