公开(公告)号：US20190089261A1

公开(公告)日：2019-03-21

申请号：US15859005

申请日：2017-12-29

Applicant: Texas Instruments Incorporated

Inventor： Maurizio Granato ,  Giavanni Frattini ,  Shailendra Kumar Baranwal

IPC: H02M3/335 ,  H02M1/088

CPC classification number: H02M3/33592 ,  H02M1/088 ,  H02M3/337 ,  H02M2001/0054 ,  H02M2001/0058

Abstract: In described examples, an isolated DC-DC converter includes: an input node for receiving an input voltage; a transformer including a primary side having first and second terminals and a primary side ground; and first and second low-side switches. The first low-side switch is coupled between the first terminal and the primary side ground. The second low-side switch is coupled between the second terminal and the primary side ground. A first voltage is across the first low-side switch, and a second voltage is across the second low-side switch. Also, the isolated DC-DC converter includes first and second high-side switches. The first high-side switch is coupled between the first terminal and the input node and is configured to be activated by a voltage at the second terminal. The second high-side switch is coupled between the second terminal and the input node and is configured to be activated by a voltage at the first terminal. Further, the isolated DC-DC converter includes a switch controller to cause the first and second voltages to alternatingly be zero by opening and closing the first and second low-side switches, as follows. The first low-side switch is closed when the first voltage is zero. During a first phase, the first low-side switch is opened at a time to enable a current through the primary side to charge the first terminal to the input voltage while discharging the second terminal to reduce the second voltage to zero. The second low-side switch is closed when the second voltage is zero. During a second phase, the second low-side switch is opened at a time to enable the current through the primary side to charge the second terminal to the input voltage while discharging the first terminal to reduce the first voltage to zero.

公开(公告)号：US20190089263A1

公开(公告)日：2019-03-21

申请号：US15859145

申请日：2017-12-29

Applicant: Texas Instruments Incorporated

Inventor： Maurizio Granato ,  Giavanni Frattini ,  Shailendra Kumar Baranwal

IPC: H02M3/335 ,  H02M1/088

Abstract: In described examples, an isolated DC-DC converter includes an input node for receiving an input voltage, and a transformer including a primary side having first and second terminals and a ground. First and second high-side switches are coupled between the input node and the first and second terminals, respectively. A first low-side switch is coupled between the first terminal and the ground, and through a first voltage limiter to be activated by a voltage at the second terminal. A second low-side switch is coupled between the second terminal and the ground, and through a second voltage limiter to be activated by a voltage at the first terminal A switch controller controls the high-side switches so that voltages across the high-side switches are alternatingly zero, using a current through the primary side to alternatingly charge one terminal to an input voltage and discharge the other terminal to a ground voltage.