US Patent 9432031 PLL-VCO based integrated circuit aging monitor

A PLL-VCO based integrated circuit aging monitor, including: a control circuit, a monitoring circuit, and an output circuit. The monitoring circuit includes a reference circuit, an aging generation circuit, and a comparison circuit. The reference circuit is a PLL circuit insensitive to a parameter error caused by the aging of circuit. The aging generation circuit is a VCO circuit sensitive to the parameter error. The control circuit is connected to the PLL circuit, the VCO circuit, the comparison circuit, and the output circuit. The output end of the PLL circuit is connected to a first input end of the comparison circuit, and the output end of the VCO circuit is connected to a second input end of the comparison circuit. The output end of the comparison circuit is connected to the input end of the output circuit. The input end of the PLL circuit inputs a reference clock signal.