CPC H02M 1/4233 (2013.01) [H02M 1/4241 (2013.01); H02M 3/33569 (2013.01); H02M 7/4815 (2021.05); H02M 3/01 (2021.05); H02M 7/02 (2013.01); H02M 7/04 (2013.01)] | 15 Claims |
1. An AC input AC/DC Switching Mode Power Supply (SMPS) comprising:
a first stage comprising a non-isolated AC/DC converter comprising a power factor correction (PFC) stage which receives an AC input voltage and provides a DC bus voltage; and a PFC controller;
a second stage comprising an isolated DC/DC converter comprising an LLC resonant DC/DC converter which receives the DC bus voltage and provides an output voltage; and an LLC controller;
the LLC resonant DC/DC converter comprising first and second half-bridge legs, which are operable in a half-bridge mode and in a full-bridge mode;
and
a control circuit configured to:
sense the AC input voltage,
provide a first control signal, comprising a voltage feedback control signal, to the PFC controller to regulate an output of the PFC to provide the DC bus voltage, dependent on the AC input voltage;
provide a second control signal, comprising one of a full-bridge mode signal and a half-bridge mode control signal, to the LLC controller to operate the LLC resonant DC/DC converter in the full-bridge mode or the half-bridge mode, dependent on the AC input voltage;
in a first operating mode, for a low line AC input at or below a threshold value, the PFC stage regulates the DC bus voltage to a first value and LLC resonant DC/DC converter operates in the full-bridge mode to provide a first output voltage;
and
in a second operating mode, for a high line AC input above the threshold value, the PFC stage regulates the DC bus voltage to a second value, which is twice the first value, and the LLC resonant DC/DC converter operates in the half-bridge mode to provide the first output voltage.
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