Patent ID: 9217769
Filing Date: 2015-12-22
Classification: G01R,H03K

Abstract:
1. A test circuit for a ring oscillator comprising a plurality of inverting stages, the test circuit comprising: a power supply, the power supply configured to provide a voltage to the plurality of inverting stages of the ring oscillator at a power output of the power supply; a power sensing resistor located between the power output of the power supply and direct current (DC) bias inputs of the plurality of inverting stages of the ring oscillator, wherein an input terminal of the power sensing resistor is connected to the power supply, and an output terminal of the power sensing resistor is connected to the DC bias inputs of the plurality of inverting states of the ring oscillator; and a signal processing circuit that is configured to: a decoupling capacitor located between the input terminal of the power sensing resistor and a ground connection of the power supply; and a DC blocking capacitor located between the output terminal of the power sensing resistor and the signal processing circuit, wherein the one of the voltage across and the current through the power sensing resistor is provided to the signal processing circuit from the output terminal of the power sensing resistor via the DC blocking capacitor.