Variable minimum input voltage based switching in an electronic power control system

• US 8,866,452 B1
• Filed: 08/10/2011
• Issued: 10/21/2014
• Est. Priority Date: 08/11/2010
• Status: Active Grant

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Kost, Michael A., Milbrandt, Celite
• Primary Examiner(s): Behm, Harry
• Application Number:
  US13/206,836
• Time in Patent Office: 1,168 Days
• Field of Search: 323/237, 323/239, 323241-244, 323/246, 323/299, 323/300, 323/320, 323322-326
• US Class Current: 323/246
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0054 Transistor switching losses periodically suspending operation of switching converter in low power mode H02M1/0035
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An electronic system includes a controller that controls switching in a switching power converter in accordance with a dynamically determined, minimum line voltage switching threshold based on one or more operating parameters of the electronic system. In at least one embodiment, the one or more operating parameters of the electronic system include power utilization of a load. The controller utilizes the dynamically determined, minimum line voltage switching threshold to determine when to enable and disable switching in the switching power converter. Since the controller bases determination of the dynamically determined, minimum line voltage switching threshold on power utilization of the load, the controller operates more efficiently by reducing switching losses while still meeting power demand by the load.

Claims

1. A method comprising:

determining power utilization of a load coupled to a switching power converter, wherein determining power utilization of the load comprises;

sensing a link voltage of the switching power converter;

comparing the link voltage to a reference voltage to generate a comparison value between the link voltage and the reference voltage; and

determining the power utilization of the load based on the comparison value;

generating a switch control signal to control the switching power converter when an input voltage to the switching power converter is greater than a threshold value, wherein the threshold value is based on power utilization of the load; and

disabling generation of the switch control signal when the input voltage to the switching power converter is less than the threshold value.

2. An apparatus comprising:

a controller configured to;

determine power utilization of a load coupled to a switching power converter, wherein to determine power utilization of the load comprises;

to sense a link voltage of the switching power converter;

to compare the link voltage to a reference voltage to generate a comparison value between link voltage and the reference voltage; and

to determine the power utilization of the load based on the comparison value;

generate a switch control signal to control the switching power converter when an input voltage to the switching power converter is greater than a threshold value, wherein the threshold value is based on power utilization of the load; and

disable generation of the switch control signal when the input voltage to the switching power converter is less than the threshold value.