Optimizing isolated power supply loop gains for opto-coupler current transfer ratio variations
AssigneeAstec International Limited
InventorsAntonio Remetio Soleno, Jonathan Ross Bernardo Fauni
Life of this patent
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Abstract
A method of optimizing a gain adjustment value Kadj for a digital controller in an isolated switched mode power supply. The power supply includes an opto-coupler having a current transfer ratio (CTRX) within a range defined by a minimum current transfer ratio (CTRMIN) and a maximum current transfer ratio (CTRMAX). The method includes determining the CTRX of the opto-coupler, determining an optimal gain adjustment value KadjX based on the determined CTRX of the opto-coupler, and storing the optimal gain adjustment value KadjX in the digital controller. The method can be performed by the digital controller or by a programming device external to the power supply.
Claims19
A method of optimizing a gain adjustment value Kadj for a digital controller in an isolated switched mode power supply, the power supply including an opto-coupler having a current transfer ratio CTRX within a range defined by a minimum current transfer ratio CTRMIN and a maximum current transfer ratio CTRMAX, the method comprising:
- determining the CTRX of the opto-coupler;
- determining an optimal gain adjustment value KadjX based on the determined CTRX and the CTRMAX of the opto-coupler;
- and
- storing the optimal gain adjustment value KadjX in the digital controller.
An isolated switched mode power supply comprising a digital controller and an opto-coupler having a current transfer ratio CTRX within a range defined by a minimum current transfer ratio CTRMIN and a maximum current transfer ratio CTRMAX, the digital controller configured to determine the CTRX of the opto-coupler, determine an optimal gain adjustment value KadjX based on the determined CTRX and the CTRMAX of the opto-coupler, and store the optimal gain adjustment value KadjX.
An isolated switched mode power supply comprising:
- a power circuit having an output terminal;
- and
- a control circuit for the power circuit, the control circuit including a digital controller and an opto-coupler having a current transfer ratio CTRX within a range defined by a minimum current transfer ratio CTRMIN and a maximum current transfer ratio CTRMAX, the digital controller having a feedback terminal coupled to the output terminal of the power circuit, and an error voltage terminal coupled to the opto-coupler, the control circuit configured to determine the CTRX of the opto-coupler when the output terminal is coupled to a known load, determine an optimal gain adjustment value KadjX based on the determined CTRX and the CTRMAX, and store the determined optimal gain adjustment value KadjX for subsequent use by the digital controller in controlling operation of the power circuit.
Dependencies are inferred from the claim text.