Inductor over-current protection using a volt-second value representing an input voltage to a switching power converter
First Claim
1. An apparatus comprising:
- a controller, wherein the controller is configured to;
detect an over-current condition of an inductor current in a switching power converter using a volt-second value that is representative of an input voltage to the switching power converter and a comparison of the volt-second value to a predetermined threshold value;
accumulate samples of an input voltage signal received by the controller to determine the volt-second value; and
determine if an increase in an accumulation of input voltage signal values compared to the predetermined threshold value indicates the over-current condition; and
during an inductor flyback time, decrement the accumulation of input signal values from an accumulation of link voltage signal samples minus input voltage signal samples taken during the inductor flyback time to determine if the switching power converter is operating in discontinuous conduction mode, wherein a link voltage signal received by the controller represents a link voltage of the switching power converter.
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Accused Products
Abstract
A power control system includes a switching power converter and a controller. The controller is configured to detect an over-current condition of an inductor current in the switching power converter using at least one non-inductor-current signal. In at least one embodiment, the switching power converter does not have a resistor or resistor network to sense the inductor current. In at least one embodiment, the controller indirectly determines a state of the inductor current using at least one non-inductor-current signal. Potentially damaging inductor current values that are, for example, greater than a normal maximum value or at a value that causes a discontinuous conduction mode system to operate in continuous conduction mode represent exemplary inductor over-current conditions addressed by one embodiment of the power control system.
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Citations
24 Claims
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1. An apparatus comprising:
a controller, wherein the controller is configured to; detect an over-current condition of an inductor current in a switching power converter using a volt-second value that is representative of an input voltage to the switching power converter and a comparison of the volt-second value to a predetermined threshold value; accumulate samples of an input voltage signal received by the controller to determine the volt-second value; and determine if an increase in an accumulation of input voltage signal values compared to the predetermined threshold value indicates the over-current condition; and during an inductor flyback time, decrement the accumulation of input signal values from an accumulation of link voltage signal samples minus input voltage signal samples taken during the inductor flyback time to determine if the switching power converter is operating in discontinuous conduction mode, wherein a link voltage signal received by the controller represents a link voltage of the switching power converter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method comprising:
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detecting an over-current condition of an inductor current in a switching power converter using a volt-second value that is representative of an input voltage to the switching power converter and a comparison of the volt-second value to a predetermined threshold value; accumulating a line input voltage to the switching power converter during a period of time when the inductor current is increasing and determine from an accumulation of the line input voltage if the inductor current has reached the over-current condition, wherein the input voltage to the switching power converter is the line input voltage; and after the period of time when the inductor current is increasing, accumulating a link voltage minus a final line input voltage accumulation value to determine if the switching power converter is operating in discontinuous conduction mode, wherein the final line input voltage accumulation value is the final value of the accumulation of the line input voltage prior to a period of time when the inductor current is decreasing. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method comprising:
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detecting an over-current condition of an inductor current in a switching power converter using a volt-second value that is representative of an input voltage to the switching power converter and a comparison of the volt-second value to a predetermined threshold value, wherein an input voltage signal represents the input voltage to the switching power converter and a link voltage signal represents an output voltage of the switching power converter; accumulating the input voltage signal during an ON time of a power regulation switch of the switching power converter; determining if an accumulation value of the input voltage signal reaches an over-current threshold; turning the power regulation switch OFF if the accumulation value of the input voltage signal reaches the over-current threshold; accumulating previous values of the accumulation value and sampled differences between the input voltage signal and the link voltage signal to determine if the switching power converter is operating in continuous conduction mode; preventing the power regulation switch from conducting if the switching power converter is operating in continuous conduction mode; and causing the power regulation switch to conduct after the circuit detects the switching power converter exiting continuous conduction mode.
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Specification