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EP-4738671-A1 - A RECTIFIER AND METHOD FOR A RECTIFIER

EP4738671A1EP 4738671 A1EP4738671 A1EP 4738671A1EP-4738671-A1

Abstract

This disclosure generally relates to a rectifier, a method for a rectifier, and a computer program and more specifically adjusting at least one switching time for a rectifier.

Inventors

  • VALLET, MATHIEU
  • Bulzomi, Domenico
  • LEFEVRE, XAVIER

Assignees

  • NXP B.V.

Dates

Publication Date
20260506
Application Date
20241031

Claims (15)

  1. A rectifier (300) comprising: a first input (LA), a first switch (PS 1), wherein the rectifier (300) is configured to activate the first switch (PS1) based on a first switching signal (swap, sw_clone) at a first time to provide an output voltage (VRECT) at the output (310), the rectifier (300) further comprising: an offset circuit (320) configured to generate an offset current signal (ioffset) based on the output voltage (VRECT).
  2. The rectifier (300) of claim 1, wherein the offset current signal (ioffset) is proportional to the output voltage (VRECT).
  3. The rectifier (300) of one of the previous claims, wherein the offset circuit (320) further comprises: a reference current generator (350, 450) with a current convertor (410) for converting the output voltage (VRECT) into a reference current (iref), at least one first node (401) coupled to the output voltage (VRECT), an output node (360, 460) that provides the offset current signal (ioffset) based on the reference current (iref).
  4. The rectifier (300) of claim 3, wherein the offset circuit (320) further comprises a voltage divider (420) coupled between the at least one first node (401) and at least one second node (403) coupled to ground, the voltage divider (420) configured to provide a second voltage (V2) proportional to the output voltage (VRECT), wherein the voltage divider provides the second voltage (V2) to an input node (404) of the current convertor (410).
  5. The rectifier (300) of one of the previous claims, wherein the offset current signal (ioffset) is further based on a second current (idac).
  6. The rectifier (300) of claim 5, wherein the second current (idac) is based on: the first input (LA) at the first time and the output voltage (VRECT) at the first time.
  7. The rectifier (300) of claim 5 or claim 6, wherein the offset circuit (320) further comprises: a calibration current source (340, 440) configured for continuously providing the second current (idac).
  8. The rectifier (300) of one of the previous claims, wherein the rectifier (300) further comprises a first switching signal generator (305) which generates a first activation signal (swap) based on the first switching signal (sw_clone), wherein the first activation signal (swap) activates the first switch (PS1) at a second time based on the first time.
  9. The rectifier (300) of one of the previous claims, wherein the first switching signal (swap, sw_clone) is generated based on: the first input (LA), the output voltage (VRECT), and the offset current signal (ioffset).
  10. The rectifier (300) of claim 9, wherein the first switching signal (swap, sw_clone) is generated based on a comparison between the first input (LA) and the output voltage (VRECT), wherein the comparison is biased by the offset current signal (ioffset).
  11. The rectifier (300) of any of claims 5-10, further comprising: a calibration circuit (330) for providing the second current (idac), the calibration circuit (330) comprising: a comparator (370) coupled to the first input (LA) and to the output voltage (VRECT), the comparator further comprising a trigger input (341) coupled to the first switching signal (swap, sw_clone), wherein the comparator (370) is configured to provide a comparator signal (380) based on a comparison of the output voltage (VRECT) and the first input (LA) in reaction to the trigger signal on the trigger input (341), wherein the calibration circuit (330) is configured for providing the second current (idac) based on the comparator signal (380).
  12. The rectifier (300) of one of the previous claims, wherein the rectifier (300) further comprises: a second input (LB), a second switch (PS2) between the second input (LB) and the output (310), wherein the rectifier (300) comprises a second switching signal generator (306) which is configured to generate a third switching signal (swbp) at a third time, wherein the rectifier (300) is configured to activate the second switch (PS2) based on the third switching signal to provide the output voltage (VRECT) at the output (310), wherein the third time is based on the offset current signal (ioffset) and preferably further based on the second input (LB) and/or preferably further based on the output voltage (VRECT).
  13. A method (500) for adjusting a switching time of a rectifier (300) with a first switch (PS1) between a first input (LA) and an output (310), the method comprising: activating (510) the first switch based on a first switching signal (swap, sw_clone) at a first time to provide an output voltage (VRECT) at the output (310) of the rectifier (300), generating (520) an offset current signal (ioffset) based on the output voltage (VRECT).
  14. The method of claim 13, further comprising: providing a second current (idac) to modify the offset current signal (ioffset), wherein the second current (idac) is preferably determined in a calibration step based on: the first input (LA) at the first time and the output voltage (VRECT) at the first time; wherein further preferably the second current (idac) is continuously provided when no calibration step is carried out.
  15. The method of claim 13 or claim 14, further comprising: generating a first activation signal (swap) based on the first switching signal (sw_clone), wherein the first switching signal (swap, sw_clone) is generated based on: the first input (LA), the output voltage (VRECT), and the offset current signal (ioffset); activating, by the first activation signal (swap), the first switch (PS1) at a second time based on the first time.

Description

TECHNICAL FIELD This disclosure generally relates to a rectifier, a method for a rectifier, and a computer program and more specifically adjusting at least one switching time for a rectifier. BACKGROUND A rectifier converts alternating current, AC, into direct current, DC. Rectifiers are one of the key elements of many electrical systems, for example wireless charging systems. For various applications, high efficiency rectifiers are desired. SUMMARY According to a first aspect of the present disclosure, there is provided a rectifier comprising: a first input, a first switch, wherein the rectifier is configured to activate the first switch based on a first switching signal at a first time to provide an output voltage at the output, the rectifier further comprising: an offset circuit configured to generate an offset current signal based on the output voltage. In one or more embodiments, the offset current signal is proportional to the output voltage. In one or more embodiments, the offset circuit further comprises: a reference current generator with a current convertor for converting the output voltage into a reference current, at least one first node coupled to the output voltage, an output node that provides the offset current signal based on the reference current. In one or more embodiments, the offset circuit further comprises a voltage divider coupled between the at least one first node and at least one second node coupled to ground, the voltage divider configured to provide a second voltage proportional to the output voltage, wherein the voltage divider provides the second voltage to an input node of the current convertor. In one or more embodiments, the offset current signal is further based on a second current. In one or more embodiments, the second current is based on: the first input at the first time and the output voltage at the first time. In one or more embodiments, the offset circuit further comprises: a calibration current source configured for continuously providing the second current. In one or more embodiments, the rectifier further comprises a first switching signal generator which generates a first activation signal based on the first switching signal, wherein the first activation signal activates the first switch at a second time based on the first time. In one or more embodiments, the first switching signal is generated based on: the first input, the output voltage, and the offset current signal. In one or more embodiments, the first switching signal is generated based on a comparison between the first input and the output voltage, wherein the comparison is biased by the offset current signal. In one or more embodiments, the rectifier further comprises: a calibration circuit for providing the second current, the calibration circuit comprising: a comparator coupled to the first input and to the output voltage, the comparator further comprising a trigger input coupled to the first switching signal,wherein the comparator is configured to provide a comparator signal based on a comparison of the output voltage and the first input in reaction to the trigger signal on the trigger input,wherein the calibration circuit is configured for providing the second current based on the comparator signal. In one or more embodiments, the rectifier further comprises: a second input,a second switch between the second input and the output,wherein the rectifier comprises a second switching signal generator which is configured to generate a third switching signal at a third time,wherein the rectifier is configured to activate the second switch based on the third switching signal to provide the output voltage at the output,wherein the third time is based on the offset current signal and preferably further based on the second input and/or preferably further based on the output voltage. According to a second aspect of the present disclosure, there is provided a method for adjusting a switching time of a rectifier with a first switch between a first input and an output, the method comprising: activating the first switch based on a first switching signal at a first time to provide an output voltage at the output of the rectifier,generating an offset current signal based on the output voltage. In one or more embodiments, the method further comprises: providing a second current to modify the offset current signal, wherein the second current is preferably determined in a calibration step based on: the first input at the first time and the output voltage at the first time;wherein further preferably the second current is continuously provided when no calibration step is carried out. In one or more embodiments, the method further comprises: generating a first activation signal based on the first switching signal, wherein the first switching signal is generated based on: the first input, the output voltage, and the offset current signal;activating, by the first activation signal, the first switch at a second time based on