To receive the best efficiency possible at light loads, the user can select the auto PFM/PWM mode which transitions seamlessly between pulse frequency modulation and forced PWM modes. The device enters PFM at the discontinuous conduction mode (DCM) boundary where the inductor current goes to zero and the switching frequency scales down linearly with load current. Alternately, forced PWM mode enables the device to remain in continuous conduction mode (CCM) through a negative inductor current. This has some efficiency impact at light load but the user can easily predict the operating frequency and set filters as needed. The user can choose between these modes using the MODE/S-CONF pin discussed previously.