Patent ID: 6272026
Filing Date: 2001-08-07
Classification: H02M

Abstract:
A pseudo push-pull DC:DC converter comprising:a transformer with a gapped core having wound thereon at least first and second transformer primary windings, said windings switchably coupleable between a source of voltage Vin and a reference potential, said transformer further comprising at least one transformer secondary transformer winding coupled to an output voltage Vout node;a control circuit outputting a single-phase drive signal having a drive signal duty cycle approximating but less than about 50%;a first switch, having a input coupled to an output of said control circuit, coupled to the first primary winding to conduct current therethrough responsive to said drive signal from said control circuit;a passively controlled second switch coupled to the second primary winding to control current flow therethrough;wherein when said control circuit turns said first switch on, current flows through said first primary winding, electromagnetic energy is delivered to a load coupled to said Vout node, and electromagnetic energy is also stored within said gapped core of said transformer; andwhen said control circuit turns-off said first switch, said second switch biases on and conducts current through said second primary winding, and at least a fraction of stored said electromagnetic energy is delivered to said load.