Low power zero inductor current detection circuit
AssigneeTexas Instruments Incorporated
InventorsRanjit Kumar Dash, Keith Edmund Kunz
Life of this patent
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Abstract
Methods and apparatus for detecting a zero inductor current to control switch transitions for a power converter. An example method includes outputting a first voltage and a first current, receiving the first voltage and output a second voltage into an input of a comparator, when the second voltage is above a third voltage, outputting a first output voltage, when the second voltage is below the third voltage, outputting a second output voltage, determining when the first current is zero based the output of the comparator, enabling a set of switches based on when the first current is zero.
Claims21
An apparatus comprising:
- a resonance circuit to output a first voltage and a first current;
- a high pass filter to receive the first voltage and output a second voltage into an input of a comparator;
- the comparator to:
- when the second voltage is above a third voltage, output a first output voltage;
- and
- when the second voltage is below the third voltage, output a second output voltage;
- and
- a switch controller to:
- determine when the first current is zero based the output of the comparator;
- and
- enable a set of switches based on when the first current is zero;
- wherein the resonance circuit includes the set of switches, the set of switches controlling the first voltage;
- wherein only one switch of the set of switches is enabled at a time;
- wherein the set of switches includes:
- a first switch, wherein enabling the first switch charges an inductor associated with the resonance circuit;
- a second switch, wherein enabling the second switch increases the first voltage;
- and
- a third switch, wherein enabling the third switch decreases the first voltage.
A method comprising:
- outputting a first voltage and a first current;
- receiving the first voltage and output a second voltage into an input of a comparator;
- when the second voltage is above a third voltage, outputting a first output voltage;
- when the second voltage is below the third voltage, outputting a second output voltage;
- determining when the first current is zero based the output of the comparator;
- and
- enabling a set of switches based on when the first current is zero;
- wherein enabling the set of switches includes enabling only one switch of the set of switches at a time;
- wherein the set of switches includes:
- a first switch, wherein enabling the first switch charges an inductor associated with the resonance circuit;
- a second switch, wherein enabling the second switch increases the first voltage;
- and
- a third switch, wherein enabling the third switch decreases the first voltage.
A computer readable medium comprising instructions that, when executed, cause a machine to at least:
- output a first voltage and a first current;
- receive the first voltage and output a second voltage into an input of a comparator;
- when the second voltage is above a third voltage, output a first output voltage;
- when the second voltage is below the third voltage, output a second output voltage;
- determine when the first current is zero based the output of the comparator;
- and
- enable a set of switches based on when the first current is zero;
- wherein enabling the set of switches includes enabling only one switch of the set of switches at a time;
- wherein the set of switches includes a first switch, a second switch, and a third switch, wherein the instructions cause the machine to:
- charge an inductor associated with the resonance circuit by enabling the first switch;
- increase the first voltage by enabling the second switch;
- and
- decrease the first voltage by enabling the third switch.
Dependencies are inferred from the claim text.