IMPEDANCE MEASUREMENT CIRCUIT AND IMPEDANCE MEASUREMENT METHOD THEREOF

An impedance measurement circuit and an operating method thereof are provided. The impedance measurement circuit includes a current source, a voltage controlled oscillator (VCO), an operation circuit, and a first delay circuit. The current source, electrically connected to a power rail, is able to sink a current from the power rail according to the delayed clock signal. The VCO is configured to generate an oscillation signal according to a power voltage on the power rail. The operation circuit is electrically connected to the VCO and is configured to receive a sampling clock signal and the oscillation signal, sense the power voltage to generate a sampled signal, and accumulate the sampled signal to generate a measurement result. The first delay circuit, electrically connected to the current source and the operation circuit, is able to receive the sampling clock signal and transmit the delayed clock signal to the current source.