DC-DC converter circuit, corresponding method of operation and method of trimming a DC-DC converter circuit

A method of operating a DC-DC boost converter circuit, comprising:

• receiving an input voltage between first and second input terminals;
• producing an output voltage between first and second output terminals;
• controlling operation of a switching stage in an asynchronous operation mode by driving a low-side switching transistor alternately to a conductive state and a non-conductive state and driving a high-side switching transistor steadily to a non-conductive state;
• coupling a variable load circuit between said first and second output terminals when said switching stage is controlled in said asynchronous operation mode;
• and
• sinking, via a variable load circuit, a load current having a value that is a function of a value of said input voltage.

A method of trimming a DC-DC boost converter circuit, comprising:

• i) operating the converter circuit in an asynchronous operation mode for a selected value of an input voltage with no external load coupled to an output node;
• ii) increasing a current output by the converter circuit until switching activity of the converter circuit does not skip pulses;
• iii) storing a current value of the current output by the converter circuit at which the converter circuit stops skipping pulses;
• iv) repeating steps i) to iii) for different selected values of the input voltage and storing the respective current values of the current output by the converter circuit at which the converter circuit stops skipping pulses;
• v) determining at least one of a slope trimming value and an offset trimming value for a variable load circuit so that the variable load circuit sinks, at said selected values of the input voltage, a load current equal to or higher than said current output by the converter circuit;
• and
• vi) trimming one or more trimmable resistors of the variable load circuit as a function of said slope trimming value, and/or trimming a trimmable current mirror circuit arrangement of the variable load circuit as a function of said offset trimming value.

A method of trimming a DC-DC boost converter circuit, comprising:

• i) operating the converter circuit in an asynchronous operation mode for a selected value of an input voltage with no external load coupled to an output node;
• ii) increasing a current output by the converter circuit until switching activity of the converter circuit does not skip pulses;
• iii) storing a current value of the current output by the converter circuit at which the converter circuit stops skipping pulses;
• iv) repeating steps i) to iii) for different selected values of the input voltage and storing the respective values of the current value of the output current by the converter circuit at which the converter circuit stops skipping pulses;
• v) determining at least one of a slope trimming value and an offset trimming value for a variable load circuit so that the variable load circuit sinks, at said selected values of the input voltage, a load current equal to or higher than said current output by the converter circuit;
• and
• vi) trimming a trimmable current source of the variable load circuit as a function of said offset trimming value, and/or trimming trimmable input transistors of the variable load circuit as a function of said slope trimming value.