公开(公告)号：US08653801B2

公开(公告)日：2014-02-18

申请号：US13857361

申请日：2013-04-05

Applicant: STMicroelectronics, Inc.

Inventor： Jianwen Shao ,  Thomas L. Hopkins

IPC: G05F5/00

CPC classification number: G05F5/00 ,  H02M1/4225 ,  Y02B70/126

Abstract: A boost circuit is used for power factor correction (PFC). In a low power application, transition mode control is utilized. However, switching frequency varies with different input voltages, and over a wide input voltage range, the switching frequency can become too high to be practical. To address this issue, a boost circuit is provided whose effective inductance changes as a function of input voltage. By changing the inductance, control is exercised over switching frequency.

Abstract translation: 升压电路用于功率因数校正（PFC）。 在低功率应用中，利用了过渡模式控制。 然而，开关频率随着不同的输入电压而变化，并且在宽的输入电压范围内，开关频率可能变得太高而不实际。 为了解决这个问题，提供升压电路，其有效电感作为输入电压的函数而变化。 通过改变电感，对开关频率进行控制。

公开(公告)号：US20130214756A1

公开(公告)日：2013-08-22

申请号：US13857361

申请日：2013-04-05

Applicant: STMicroelectronics, Inc.

Inventor： Jianwen Shao ,  Thomas L. Hopkins

IPC: G05F5/00

CPC classification number: G05F5/00 ,  H02M1/4225 ,  Y02B70/126

Abstract: A boost circuit is used for power factor correction (PFC). In a low power application, transition mode control is utilized. However, switching frequency varies with different input voltages, and over a wide input voltage range, the switching frequency can become too high to be practical. To address this issue, a boost circuit is provided whose effective inductance changes as a function of input voltage. By changing the inductance, control is exercised over switching frequency.

Abstract translation: 升压电路用于功率因数校正（PFC）。 在低功率应用中，利用了过渡模式控制。 然而，开关频率随着不同的输入电压而变化，并且在宽的输入电压范围内，开关频率可能变得太高而不实际。 为了解决这个问题，提供升压电路，其有效电感作为输入电压的函数而变化。 通过改变电感，对开关频率进行控制。

公开(公告)号：US09204505B2

公开(公告)日：2015-12-01

申请号：US14226316

申请日：2014-03-26

Applicant: STMicroelectronics, Inc.

Inventor： Thomas Stamm ,  Jianwen Shao

IPC: H05B37/02 ,  H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/0824 ,  H05B33/0845 ,  H05B33/0887 ,  Y02B20/341 ,  Y02B20/347

Abstract: An AC/DC power converter is coupled between a fluorescent ballast circuit and a set of light emitting diodes (LEDs) forming an LED lamp. The power converter converts an AC output from the ballast circuit to a DC current applied to drive operation of the LEDs. The power converter transforms and rectifies the AC output from the ballast circuit to generate a DC output current. An open load protection circuit is coupled to protect the ballast circuit when the LED lamp is not connected. Current control is provided by a transistor having a source/drain conduction path coupled to shunt the DC output current in response to a control signal having a duty cycle generated as a function of a zero-crossing of the AC output and a sensed value of the DC output current applied to the LED lamp.

Abstract translation: AC / DC电力转换器耦合在荧光镇流器电路和形成LED灯的一组发光二极管（LED）之间。 功率转换器将镇流器电路的AC输出转换为驱动LED驱动的直流电流。 电源转换器对镇流器电路的交流输出进行变换和整流，以产生直流输出电流。 当LED灯未连接时，开路负载保护电路被连接以保护镇流器电路。 电流控制由具有源极/漏极导电路径的晶体管提供，该晶体管具有耦合以分流直流输出电流的响应于具有作为AC输出的过零点的函数产生的占空比的控制信号，以及 直流输出电流施加到LED灯。

公开(公告)号：US20140320007A1

公开(公告)日：2014-10-30

申请号：US14226316

申请日：2014-03-26

Applicant: STMicroelectronics, Inc.

Inventor： Thomas Stamm ,  Jianwen Shao

IPC: H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/0824 ,  H05B33/0845 ,  H05B33/0887 ,  Y02B20/341 ,  Y02B20/347

Abstract: An AC/DC power converter is coupled between a fluorescent ballast circuit and a set of light emitting diodes (LEDs) forming an LED lamp. The power converter converts an AC output from the ballast circuit to a DC current applied to drive operation of the LEDs. The power converter transforms and rectifies the AC output from the ballast circuit to generate a DC output current. An open load protection circuit is coupled to protect the ballast circuit when the LED lamp is not connected. Current control is provided by a transistor having a source/drain conduction path coupled to shunt the DC output current in response to a control signal having a duty cycle generated as a function of a zero-crossing of the AC output and a sensed value of the DC output current applied to the LED lamp.

Abstract translation: AC / DC电力转换器耦合在荧光镇流器电路和形成LED灯的一组发光二极管（LED）之间。 功率转换器将镇流器电路的AC输出转换为驱动LED驱动的直流电流。 电源转换器对镇流器电路的交流输出进行变换和整流，以产生直流输出电流。 当LED灯未连接时，开路负载保护电路被连接以保护镇流器电路。 电流控制由具有源极/漏极导电路径的晶体管提供，该晶体管具有耦合以分流直流输出电流的响应于具有作为AC输出的过零点的函数产生的占空比的控制信号，以及 直流输出电流施加到LED灯。