In one embodiment, a semiconductor processing tool includes a plasma chamber and an impedance matching circuit. The matching circuit includes a first electronically variable capacitor having a first variable capacitance, a second electronically variable capacitor having a second variable capacitance, and a control circuit. The control circuit is configured to determine a variable impedance of the plasma chamber, determine a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor, and generate a control signal to alter at least one of the first variable capacitance and the second variable capacitance to the first capacitance value and the second capacitance value, respectively. An elapsed time between determining the variable impedance of the plasma chamber to when RF power reflected back to the RF source decreases is less than about 150 μsec.