Patent attributes
A self-oscillating DCM is disclosed comprising two inductors that charge and discharge 180 degrees out of phase such that the charging inductor is conducting an upward ramping current and the discharging inductor is conducting a downward ramping current. A load receives the upward and downward ramping currents, which combine to create a constant current. The current source that powers the DCM is current limited so as to output a maximum direct current of IIN. A relatively small capacitor is connected across the input terminals of the DCM and allows the inductors to ramp up to a peak current of 2*IIN. Since the current source only supplies the ramping current to one of the inductors at a time up to 2*IIN, and the average current conducted by each inductor is IIN, the current supplied by the current source is a constant IIN. However, since the inductors simultaneously supply two oppositely ramping currents to the load, the load current is a constant current equal to 2*IIN. So the DCM doubles the supply current and halves the average input voltage.
