An integrated circuit includes processing circuitry that includes a plurality of critical path circuits. These critical path circuits include variable delay circuits which add an additional delay in to a path delay through each of the critical path circuits so as to adjust the path delay to match a target path delay. Variable delay circuit includes a tank capacitor which is charged or discharged to generate a control voltage. This control voltage serves to control a power supply voltage fed to an inverter chain. Variation in the power supply voltage of the inverter chain adjust the propagation speed of a processing signal through the inverter chain and accordingly adjusts the additional delay imposed by the variable delay circuit.