Sense current measurement in switch mode power converters

• US 9,543,830 B2
• Filed: 01/23/2014
• Issued: 01/10/2017
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Buthker, Henricus Cornelis Johannes
• Primary Examiner(s): PATEL, RAJNIKANT B
• Application Number:
  US14/162,627
• Publication Number:
  US 20140225585A1
• Time in Patent Office: 1,083 Days
• Field of Search: 323/209, 323/222, 323266-268, 323282-289, 323/299, 323/351
• US Class Current: 1/1
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A switch mode power converter configured for operation with a plurality of outputs is disclosed. The switch mode power converter includes an inductive element and a resistance in series with the inductive element. The resistance is series with the inductive element is used for determining a current through the inductive element. The resistance is a resistance between the main terminals of a switch in an on-state. The switch have two main terminals and a control terminal and being arranged for directing current through the inductive element to a one of the plurality of outputs.

Claims

1. A switch mode power converter configured for operation with a plurality of outputs and comprising:

an inductive element; and

a plurality of switches in series with the inductive element, the plurality of switches arranged for directing current through the inductive element to a one of the plurality of outputs, each switch of the plurality of switches having two main terminals and a control terminal;

a plurality of amplifiers, at least one amplifier connected across the main terminals of each switch, for determining a current through the respective switch from the voltage across the main terminals of the respective switch.

2. A switch mode power converter as claimed in claim 1, wherein the switches are relatively low power reference switches, either being configured for operation in parallel with and in synchronisation with or being a part of relatively high power power switches.

3. A switch mode power supply as claimed in claim 2, wherein the relatively high power power switches are arranged for directing current through the inductive element to one of the plurality of outputs.

4. A solar inverter comprising a switch mode power converter as claimed in claim 1.

5. A method of operating a switch mode power supply having an inductive element and a plurality of outputs, the method comprising

directing current through the inductive element to one of the plurality of outputs by means of a plurality of switches, each switch having two main terminals and a control terminal;

and

determining a current through the inductive element by measuring a resistance in series with the inductive element,

wherein the resistance is a resistance between the main terminals of one of the plurality of switches when the switch is in an on-state.