公开(公告)号：US20250149993A1

公开(公告)日：2025-05-08

申请号：US18386949

申请日：2023-11-03

Applicant: STMicroelectronics International N.V.

Inventor： Claudio Adragna

IPC: H02M3/335 ,  H02M1/00 ,  H02M1/08

Abstract: According to an embodiment, a converter includes a bootstrap capacitor, a high-side switch, a low-side switch, an auxiliary switch, and a controller. The bootstrap capacitor has a first terminal coupled to a floating ground node. The high-side switch has a source terminal coupled to the bootstrap capacitor through the floating ground node. The auxiliary switch has a drain terminal coupled to the bootstrap capacitor through the floating ground node. The controller provides a first control signal to a control terminal of the high-side switch, provides a second control signal to a control terminal of the low-side switch, and provides a third control signal to a control terminal of the auxiliary switch. The third control signal is based on a condition associated with the converter after the first control signal and the second control signal deactivate the high-side switch and the low-side switch respectively.

公开(公告)号：US20250149990A1

公开(公告)日：2025-05-08

申请号：US18386945

申请日：2023-11-03

Applicant: STMicroelectronics International N.V.

Inventor： Claudio Adragna

IPC: H02M3/335 ,  H02M1/00

Abstract: According to an embodiment, a converter is provided. The converter includes a bootstrap capacitor having a first terminal coupled to a floating ground node; a high-side switch, a source terminal of the high-side switch coupled to the bootstrap capacitor through the floating ground node; a low-side switch; and a controller. The controller is configured to provide a first control signal to a control terminal of the high-side switch, and a second control signal to a control terminal of the low-side switch, wherein a transitioning of the second control signal to turn OFF the low-side switch is delayed after a duration from a transitioning of the first control signal to turn OFF the high-side switch, wherein the delay is automatically adjusted by detecting a condition associated with the converter, wherein the delay begins in response to a voltage at the floating ground node being less than zero.

公开(公告)号：US20250149991A1

公开(公告)日：2025-05-08

申请号：US18500343

申请日：2023-11-02

Applicant: STMicroelectronics International N.V.

Inventor： Claudio Adragna

IPC: H02M3/335 ,  H02M1/00 ,  H02M1/38

Abstract: According to an embodiment, a method is proposed that includes sensing a reverse current through a main switch of an active clamp flyback (ACF) converter. The ACF converter includes a flyback transformer and an auxiliary switch. The method further includes determining whether a sense voltage corresponding to the reverse current exceeds a threshold; decreasing a duration for the reverse current by an incremental time interval, the duration of the reverse current including a first incremental time interval, the duration of the reverse current corresponding to a duration that the auxiliary switch is activated; increasing the duration by a second incremental time interval greater than the first incremental time interval, the increasing being in response to the reverse current not exceeding the threshold; and activating the auxiliary switch for the duration to achieve zero voltage switching (ZVS).