There is disclosed herein integrated circuitry comprising a clock path for carrying a clock signal from a clock source to a circuit block, the circuit block being operable based on the clock signal. Clock buffer circuitry is provided along the clock path for buffering the clock signal. A tuneable inductance is connected to the clock path. A capacitor is connected to the clock path so as to form an AC coupling capacitor connected in series along the path, and is implemented between metal layers of the integrated circuitry.