Texas Instruments Incorporated
ISOLATED DC-DC POWER CONVERTER WITH LOW RADIATED EMISSIONS

Abstract:

DC-DC power converter architecture is disclosed. In an example, an integrated circuit includes an H-bridge switching circuit operatively coupled with a transformer. The switching circuit is compensated to account for parasitic differences between the high-side (power) and low-side (ground). For instance, PMOS transistors connected to the high-side are sized larger to substantially match on-resistance of NMOS transistors connected to the low-side (e.g., such that the on-resistances are all within a tolerance of one another, or within a tolerance of a target on-resistance value), and the NMOS transistors include additional gate-drain capacitance to substantially match gate-drain capacitance of the larger PMOS transistors (e.g., such that the gate-drain capacitances are all within a tolerance of one another, or within a tolerance of a target gate-drain capacitance value). In addition, the transformer is configured with physical symmetry, such that the inductive and capacitive mid-points of the transformer are substantially co-located.