Floating output voltage boost-buck regulator using a buck controller with low input and low output ripple

A circuit having a converter coupled to drive a floating load comprising:

• an input terminal for receiving an input voltage Vin;
• a first inductor having a first end for being coupled to ground;
• a first switch coupled to a second end of the first inductor for coupling the second end to the input voltage when the first switch is in an on-state to charge the first inductor;
• a rectifier coupled to the second end of the first inductor for electrically coupling the second end of the first inductor to a first terminal of the load when the first switch is in an off-state, wherein the converter generates a voltage VEE at the first terminal during steady state operation;
• a first capacitor coupled between the input voltage and the first terminal of the load, wherein a voltage across the first capacitor equals Vin-VEE, where VEE is a negative voltage with respect to ground at the first terminal of the load;
• a second inductor having a first end coupled to the second end of the first inductor at least during a time when the first switch is in its on-state, wherein the load is coupled between a second end of the second inductor and the first capacitor;
• and
• a controller coupled to receive a first feedback signal corresponding to an instantaneous current through the first inductor when the first switch is on, and the controller coupled to receive a second feedback signal corresponding to a load current or load voltage,
• wherein the controller controls at least the first switch to regulate a peak current through the first inductor to regulate the load current or load voltage.