公开(公告)号：US10439483B2

公开(公告)日：2019-10-08

申请号：US16149745

申请日：2018-10-02

申请人： Littelfuse, Inc.

发明人： Anatoliy V. Tsyrganovich ,  Leonid A. Neyman ,  Md Abdus Sattar ,  Vladimir Tsukanov

IPC分类号： H02M7/537 ,  H02M1/08 ,  H03K3/012 ,  H03K17/082 ,  H03K17/16 ,  H03K17/687 ,  H03K17/0412 ,  H02M1/00

摘要： In a switching converter having an inductive load, a current may flow through the body diode of a transistor even though the gate of the transistor is being controlled to keep the transistor off. Then when the other transistor of the switch leg is turned on, a reverse recovery current flows in the reverse direction through the body diode. To reduce switching losses associated with such current flows, a gate driver integrated circuit detects when current flow through the body diode rises above a threshold current. The gate driver integrated circuit then controls the transistor to turn on. Then when the other transistor of the switch leg is made to turn on, the gate driver first turns the transistor off. When the gate-to-source voltage of the turning off transistor drops below a threshold voltage, then the gate driver integrated circuit allows and controls the other transistor to turn on.

公开(公告)号：US10447157B2

公开(公告)日：2019-10-15

申请号：US16103475

申请日：2018-08-14

申请人： Littelfuse, Inc.

发明人： Anatoliy V. Tsyrganovich

IPC分类号： H02M3/156 ,  H02M1/00

摘要： A sense resistor is placed in series with an output capacitor of a buck converter. The buck converter operates in a discontinuous mode such that there is a dead time in each switching cycle. A control circuit senses a voltage across the sense resistor and thereby generates a first signal ICS. The control circuit detects an offset voltage in ICS, where the offset voltage is the voltage of ICS during the dead time in a first switching cycle. The control circuit level shifts the entire ICS by the offset voltage, thereby generating a second signal ICLS. ICLS has the same waveform as the waveform of the inductor current. In a second cycle, ICLS is used to determine when to turn off the main switch and when the start of the dead time occurs. ICLS and the offset voltage are used together to determine when to turn the main switch on.

公开(公告)号：US10536145B2

公开(公告)日：2020-01-14

申请号：US16116807

申请日：2018-08-29

申请人： Littelfuse, Inc.

发明人： Anatoliy V. Tsyrganovich ,  Leonid A. Neyman

IPC分类号： H03K19/0185 ,  H03K17/687 ,  H03K3/012

摘要： A gate driver integrated circuit drives an output signal onto its output terminal and onto the gate of a power transistor. In a turn-on episode, a digital input signal transitions to a digital logic high level. In response, the gate driver integrated circuit couples the output terminal to a positive supply voltage terminal, thereby driving a positive voltage onto the gate of the power transistor. In response to a high-to-low transition of the digital input signal, the driver drives a negative voltage onto the output terminal and power transistor gate for a short self-timed period of time, and then couples the output terminal to a ground terminal, thereby driving the output terminal and power transistor gate up to ground potential. The output terminal and power transistor gate are then held at ground potential in anticipation of the next turn-on episode of the power transistor.

公开(公告)号：US20190260281A1

公开(公告)日：2019-08-22

申请号：US16149745

申请日：2018-10-02

申请人： Littelfuse, Inc.

发明人： Anatoliy V. Tsyrganovich ,  Leonid A. Neyman ,  Md Abdus Sattar ,  Vladimir Tsukanov

IPC分类号： H02M1/08 ,  H03K3/012 ,  H03K17/082 ,  H03K17/16 ,  H03K17/687 ,  H02M7/537

CPC分类号： H02M1/08 ,  H02M7/537 ,  H02M2001/0051 ,  H02M2001/0054 ,  H02M2001/0058 ,  H03K3/012 ,  H03K17/04123 ,  H03K17/0822 ,  H03K17/162 ,  H03K17/687 ,  H03K2217/0063 ,  H03K2217/0072 ,  Y02B70/1491

摘要： In a switching converter having an inductive load, a current may flow through the body diode of a transistor even though the gate of the transistor is being controlled to keep the transistor off. Then when the other transistor of the switch leg is turned on, a reverse recovery current flows in the reverse direction through the body diode. To reduce switching losses associated with such current flows, a gate driver integrated circuit detects when current flow through the body diode rises above a threshold current. The gate driver integrated circuit then controls the transistor to turn on. Then when the other transistor of the switch leg is made to turn on, the gate driver first turns the transistor off. When the gate-to-source voltage of the turning off transistor drops below a threshold voltage, then the gate driver integrated circuit allows and controls the other transistor to turn on.