Power factor correction control circuit and driving method thereof

Patent metadata

Field	Value
Publication number	US-2016081154-A1
Application number	US-201514819616-A
Country	US
Kind code	A1
Filing date	Aug 6, 2015
Priority date	Sep 15, 2014
Publication date	Mar 17, 2016
Grant date	—

Abstract

A circuit for adjusting a frequency of an AC direct lighting apparatus is provided. The circuit may include a reference voltage generation unit configured to receive a dimming voltage having a first frequency and a first voltage range, and generate a reference voltage having a second voltage range, a sensing section determining unit configured to generate first and second section reference voltages based on the reference voltage, and determine a driving current sensing section using the first and second section reference voltages, and a driving signal generation unit configured to generate a switching device driving signal having a second frequency through the determined driving current sensing section.

First claim

What is claimed is:

1 . A circuit for adjusting a frequency of an AC direct lighting apparatus, comprising:
a reference voltage generation unit configured to receive a dimming voltage having a first frequency and a first voltage range, and generate a reference voltage having a second voltage range; a sensing section determining unit configured to generate first and second section reference voltages based on the reference voltage, and determine a driving current sensing section using the first and second section reference voltages; and a driving signal generation unit configured to generate a switching device driving signal having a second frequency through the determined driving current sensing section.

2 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 1 , wherein the reference voltage generation unit is further configured to convert the dimming voltage into a current and mirrors the converted current to generate a first mirroring current.

3 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 2 , wherein the reference voltage generation unit is further configured to convert the first mirroring current into a voltage through a digital-analog converter and generate the reference voltage through an OP amplifier.

4 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 1 , wherein the sensing section determining unit comprises:
a section reference voltage generation module configured to distribute the reference voltage by voltage drop across a series of resistors, and generate the first and second section reference voltages based on the resistance ratio between the series of resistors; and a frequency determining module configured to mirror a current having the same magnitude as that of the current flowing to the section reference voltage generation module to induce a second mirroring current, and charge or discharge a first capacitor having a first capacitance through the second mirroring current to determine a second frequency.

5 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 4 , wherein the frequency determining module is further configured to generate a predetermined period using a capacitance ratio of the first and second capacitors through a procedure to charge or discharge a second capacitor having a second capacitance.

6 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 5 , wherein the frequency determining module is further configured to charge the first capacitor during the predetermined period and the second capacitor during the driving current sensing section.

7 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 1 , wherein the driving signal generation unit comprises:
an enable signal generation module configured to generate and transmit first to fourth enable signals to control first and second switching devices of the sensing section determining unit in order to charge first and second capacitors and to control third and fourth switching devices of the sensing section determining unit in order to discharge the first and second capacitors; and a driving signal generation module configured to generate the switching device driving signal having a second frequency based on voltages applied across the first and second capacitors and the driving current sensing section.

8 . The circuit for adjusting a frequency of an AC direct lighting apparatus of claim 7 , wherein the driving signal generation unit senses a driving current at a range of the driving current sensing section and charges the second capacitor to control a voltage spike occurrence.

9 . A method for adjusting a frequency of an AC direct lighting apparatus, comprising:
generating a reference voltage having a second voltage range based on receiving a dimming voltage having a first frequency and a first voltage range; generating first and second section reference voltages based on the reference voltage and determining a driving current sensing section based on the first and second section reference voltages; and generating a switching device driving signal having a second frequency through the determined driving current sensing section.

10 . The method for adjusting a frequency of an AC direct lighting apparatus, wherein the generating the first and second section reference voltages based on the reference voltage and determining the driving current sensing section based on the first and second section reference voltages comprises:
distributing the reference voltage into a plurality of resistance elements through a reference current to generate first and second section reference voltages; and mirroring the reference current to induce a second mirroring current, and charging or discharging a first capacitor having a first capacitance through the second mirroring current to determine a second frequency.

11 . The method for adjusting a frequency of an AC direct lighting apparatus of claim 9 , wherein the generating the switching device driving signal having the second frequency through the determined driving current sensing section comprises:
generating and transmitting first to fourth enable signals to control first and second switching devices in order to charge the first and second capacitors and to control third and fourth switching devices in order to discharge the first and second capacitors; and generating the driving signal having a second frequency based on voltages applied across the first and second capacitors and driving current sensing section.

12 . A lighting circuit comprising:
a voltage frequency adjusting circuit configured to generate a reference voltage based on a received dimming voltage, generate a first and second section reference voltages based on the generated reference voltage, wherein the first and second section reference voltages are used to detect a current sensing section, and control a switching device that provides a driving current at an adjusted frequency through the current sensing section; and a light emitting diode (LED) unit configured to receive the driving current at an inductor when the switching device is switched on, wherein the inductor acts as a current source to an LED module when the switching device is switched off.

13 . The lighting circuit of claim 12 , wherein the voltage frequency adjusting circuit comprises:
a reference voltage generation unit configured to receive the dimming voltage having a first frequency and a first voltage range, and generate the reference voltage having a second voltage range; a sensing section determining unit configured to generate the first and second section reference voltages based on the reference voltage, and determine the driving current sensing section using the first and second section reference voltages; and a driving signal generation unit configured to generate a switching device driving signal having the adjusted frequency through the determined driving current sensing section.

14 . The lighting circuit of claim 13 , wherein the sensing section determining unit comprises:
a section reference voltage generation module configured to distribute the reference voltage by voltage drop across a series of resistors, and generate the first and second section reference voltages based on the resistance ratio between the series of resistors; and a frequency determining module configured to mirror a current having the same magnitude as that of the current flowing to the section reference voltage generation module to induce a second mirroring current, and charg

Assignees

• Magnachip Semiconductor Ltd

Inventors

• Lim Gyu Ho
• Kang Tae Kyoung
• Cui zhi yuan

Classifications

• H05B45/10 Primary

  Controlling the intensity of the light · CPC title

• H05B33/0809

  Electricity · mapped topic

• H05B33/0884

  Electricity · mapped topic

• H05B33/0845 Primary

  Electricity · mapped topic

• H05B45/397

  Current mirror circuits · CPC title