is enabled through a driver only after the load current i 1 n of the corresponding phase transitions from a positive current to zero current and the corresponding pwm signal is at its middle level the zero level e g zero volts and high level e g five volts of the tri level pwm signals 410 420 instruct the drivers 120 122 to operate in ccm when the pwm 1 signal 410 is at zero level the lower fet 130 is turned on when the pwm signal is at a high level the upper fet 131 is turned on fets 132 133 operate in an analogous fashion based upon the level of pwm 1 signal 420 other techniques for activating dcm and ccm may be used known conventional alternatives are not illustrated for the sake of brevity embodiments of the invention may also be used in coupled inductor voltage regulators that do not operate in dcm i e that only operate in ccm under a light load condition the interleaved signals waveforms of i 11 510 and i 12 520 may be undesirable because they create a more complex inductor current waveform i e the signal waveforms of i 11 i 12 hence implementation of diode emulation control circuitry and detection of zero current crossings may become more difficult also the magnitude of the ripple on vout may be undesirably increased therefore when a light load condition occurs such as at time t 1 222 the psc signal waveform 210 transitions to a high state the psc signal waveform 210 is provided to a generator and phase shift controller 114 upon the psc signal waveform 210 transitioning to a high voltage level representative of a light load condition the vr 100 enters a.