Isolated phase shifted DC to DC converter with frequency synthesizer to reconstruct primary clock

A phase shifted dual active bridge DC to DC converter, comprising:

• a first bridge circuit configured to convert an input signal to provide a primary voltage signal to a primary winding of a transformer according to a primary side switching control signal;
• a primary side control circuit configured to provide the primary side switching control signal according to a primary side clock signal;
• a second bridge circuit configured to convert a secondary voltage signal from a secondary winding of the transformer to provide an output voltage signal according to a secondary side switching control signal;
• a secondary side control circuit operative in a first mode to provide the secondary side switching control signal to regulate the output voltage signal by controlling a phase shift angle between switching transitions of the secondary side switching control signal and switching transitions of a secondary side clock signal, the secondary side control circuit operative in a second mode to discontinue the secondary side switching control signal, and to synchronize the secondary side clock signal to transitions in the secondary voltage signal while the secondary side switching control signal is discontinued.

A method for operating a phase shifted dual active bridge DC to DC converter, the method comprising:

• operating secondary switches of a dual active bridge DC to DC converter to convert a transformer secondary voltage signal to regulate a converter output voltage signal by controlling a phase shift angle between switching transitions of secondary side switching control signals and switching transitions of a secondary side clock signal;
• discontinuing the secondary side switching control signals after an integer number N cycles of the secondary side clock signal, N being greater than 1;
• synchronizing the secondary side clock signal to transitions in the transformer secondary voltage signal while the secondary side switching control signals are discontinued;
• and
• resuming the secondary side switching control signals after synchronizing the secondary side clock signal to the transitions in the transformer secondary voltage signal.