公开(公告)号：US20210067046A1

公开(公告)日：2021-03-04

申请号：US17006022

申请日：2020-08-28

Applicant: STMicroelectronics S.r.l.

Inventor： Claudio ADRAGNA

IPC: H02M3/335 ,  H02M1/08

Abstract: A driver circuit for a resonant converter includes a comparator that generates a first control signal indicating when a resonant current changes sign. A first ramp generator circuit outputs a first ramp signal, and a comparison circuit determines whether the first ramp signal reaches a reference threshold. The driver circuit drives a half-bridge via drive signals during consecutive first second switching semi-periods, each of which ends when the comparison circuit indicates the first ramp signal has reached a reference threshold. A control circuit generates in each of the first and the second switching semi-periods control signals indicating a first interval and a second interval. A correction circuit modifies the first ramp signal to have a first gradient value during the first interval and a second gradient value during the second interval. Alternatively, the correction circuit modifies a reference threshold by adding a second ramp signal to an initial threshold value.

公开(公告)号：US20250023479A1

公开(公告)日：2025-01-16

申请号：US18896371

申请日：2024-09-25

Applicant: STMICROELECTRONICS S.r.l.

Inventor： Claudio ADRAGNA ,  Massimiliano GOBBI ,  Giuseppe BOSISIO

IPC: H02M3/335 ,  H02M1/00 ,  H02M1/34

Abstract: An active flyback converter is transitioned between a plurality of operational states based on a comparison of a control voltage signal to voltage thresholds and a count of a number of consecutive switching cycles during which a clamp switch is kept off. The plurality of operational states includes a run state, an idle state, a first burst state, and a second burst state. Each set of consecutive switching cycles of the first burst state includes a determined number of switching cycles during which signals are generated to turn the power switch on and off and to maintain an off state of the clamp switch, and a switching cycle in a determined position in the set of switching cycles during which signals are sequentially generated to turn the power switch on, turn the power switch off, turn the clamp switch on and turn the clamp switch off.

公开(公告)号：US20230096383A1

公开(公告)日：2023-03-30

申请号：US17951703

申请日：2022-09-23

Applicant: STMICROELECTRONICS S.r.l.

Inventor： Claudio ADRAGNA ,  Massimiliano GOBBI ,  Giuseppe BOSISIO

IPC: H02M3/335

Abstract: An active flyback converter is transitioned between a plurality of operational states based on a comparison of a control voltage signal to voltage thresholds and a count of a number of consecutive switching cycles during which a clamp switch is kept off. The plurality of operational states includes a run state, an idle state, a first burst state, and a second burst state. Each set of consecutive switching cycles of the first burst state includes a determined number of switching cycles during which signals are generated to turn the power switch on and off and to maintain an off state of the clamp switch, and a switching cycle in a determined position in the set of switching cycles during which signals are sequentially generated to turn the power switch on, turn the power switch off, turn the clamp switch on and turn the clamp switch off.

公开(公告)号：US20140133195A1

公开(公告)日：2014-05-15

申请号：US14157244

申请日：2014-01-16

Applicant: STMICROELECTRONICS S.r.l.

Inventor： Giovanni LOMBARDO ,  Claudio ADRAGNA ,  Salvatore TUMMINARO

IPC: H02M3/335

CPC classification number: H02M3/33523 ,  H02M3/33507 ,  Y02B70/1433 ,  Y10T307/826

Abstract: A control device for controlling a switching power supply adapted to convert an input voltage into an output voltage according to a switching rate of a switching element. The control device includes first control means for switching the switching element in a first working mode at a constant frequency and second control means for switching the switching element in a second working mode at a variable frequency, under a maximum frequency, in response to the detection of a predefined operative condition of the switching power supply. The control device further includes means for selecting the first working mode or the second working mode.

Abstract translation: 一种用于控制开关电源的控制装置，其适于根据开关元件的开关速率将输入电压转换成输出电压。 控制装置包括用于以恒定频率切换第一工作模式的开关元件的第一控制装置和用于响应于检测以最大频率以可变频率在第二工作模式下切换开关元件的第二控制装置 的开关电源的预定操作条件。 控制装置还包括用于选择第一工作模式或第二工作模式的装置。

公开(公告)号：US20230123235A1

公开(公告)日：2023-04-20

申请号：US17490034

申请日：2021-09-30

Applicant: STMicroelectronics S.r.l.

Inventor： Giovanni GRITTI ,  Claudio ADRAGNA

IPC: H05B45/325 ,  H05B45/10 ,  H05B45/397

Abstract: An LED lighting system includes switching circuity adjustably driving a string of LEDs and being controlled by a reference current and an enable signal. A controller generates the reference current and enable signal based upon a PWM signal such that the switching circuitry: sources a first LED current to the string of LEDs that is proportional to a duty cycle of the PWM signal when the duty cycle is greater than a threshold duty cycle to thereby perform analog dimming; and sources a second LED current to the string of LEDs that has a duty cycle proportional to the duty cycle of the PWM signal when the duty cycle of the PWM signal is less than the threshold duty cycle, such that an average LED current delivered to the string of LEDs is proportional to the duty cycle of the PWM signal to thereby perform digital dimming.

公开(公告)号：US20150381052A1

公开(公告)日：2015-12-31

申请号：US14846389

申请日：2015-09-04

Applicant: STMicroelectronics S.r.l.

Inventor： Claudio ADRAGNA ,  Claudio SPINI ,  Aldo Vittorio NOVELLI ,  Fabrizio BOGNANNI

IPC: H02M3/158

CPC classification number: H02M3/158 ,  H02M3/33507 ,  H02M3/3376 ,  H02M2001/0035 ,  Y02B70/1433 ,  Y02B70/16

Abstract: An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Abstract translation: 一种有效的方法，在谐振转换器中，在负载较小的情况下，能够提供低负荷的节能，并采用滞后控制方案，以实现轻载时的突发模式。 当转换器的输出电压的反馈控制电流达到第一阈值时，该方法使转换器的电流控制振荡器停止振荡，并且在振荡频率和所述反馈控制电流之间的功能关系中引入非线性，或 在所述功能关系的导数中，当所述控制电流在第二阈值和所述第一阈值之间时，使得当所述控制电流等于所述第二阈值时，所述振荡频率保持等于或小于所述振荡频率 阈值。 示出了几种电路实现，所有这些都是简单的实现，而不需要任何昂贵的微控制器。