The waveform to the right shows two cases; both cases assume the output voltages and currents are the same for simplification. The first case shows the switch currents and input capacitor current when two converters are connected to a common bus with no phase shift in the operating frequencies. As can be seen, the input capacitor will have to handle a huge ripple current. To hold the input more stable, the value of the input capacitor would need to be doubled. The second case shows the same converters running with a phase shift of 180 degrees in the oscillator frequency. This phase shift can reduce the ripple current allowing the use of fewer or smaller input capacitors.