The field of disclosure generally relates to a system and method for starting up a DC-to-DC power converter and, more particularly, to a system and method for starting up a high input voltage, high density, isolated DC-to-DC power converter with secondary side control, in which a primary microcontroller disposed within a primary circuit of the converter initiates a start-up sequence, and in which a secondary microcontroller disposed within a secondary circuit of the converter assumes control of the converter upon completion of the start-up sequence.
DC-to-DC power converters are used throughout the electronics industry and are designed to convert an input direct current (DC) voltage to a higher or lower output DC voltage. Such converters may be manufactured on a single printed circuit board (PCB), and board space may be allocated on the PCB to a plurality of converter components. For example, many DC-to-DC power converters implemented on a PCB include a bias voltage generator configured to provide a bias voltage to a microcontroller mounted on the PCB, such as, for example, to power on the microcontroller.
As the electronics and computing industries continue to mature, DC-to-DC power converters capable of handling high input voltages are increasingly in demand, such as, for example, in applications including renewable energy, telecommunications, automotive, and the like. The trend has been to reduce the physical footprint associated with such converters (thus, the term “high density” has come into use). Typically, however, high voltage isolated DC-to-DC power converters may include secondary side control (e.g. PMBus, I2C communication, etc.), which may require the addition of a secondary side microcontroller. To power the secondary side microcontroller, one or more on-board isolated bias supplies (e.g., one or more off-line flyback circuits) may be added to the PCB supporting the converter. However, these bias supplies typically operate at relatively higher voltages and lower frequencies, resulting in substantially larger bias supply form factors.
For example, many typical high voltage flyback bias supplies include, among other components, a high voltage transformer that has a larger form factor (e.g., by comparison to a lower voltage transformer). The larger form factor associated with such bias supplies may, in turn, consume more space than desired on a PCB supporting the DC-to-DC converter. The addition of such bias supplies (e.g., bias supplies having relatively larger form factors) may thus be undesirable, as described above, where board space on the PCB is at a premium, and where it is desirable to package the DC-to-DC converter as compactly as possible.