Gate drive device
AssigneesDenso Corporation, Toyota Jidosha Kabushiki Kaisha, MIRISE Technologies Corporation
InventorHironori Akiyama
Life of this patent
Estimating the term…
Abstract
A change rate control circuit computes a first drive speed, which is a gate drive speed of a gate of a drive-subject element, for controlling a change rate of an element voltage of the drive-subject element at a target change rate during a change period. A timing generating circuit acquires, in advance, a delay time caused when the gate is driven and determines a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element and generates a timing signal representing the switching timing. A speed change circuit changes the gate drive speed from the first drive speed to a second drive speed at the switching timing during turn-off of the drive-subject element.
Claims17
A gate drive device comprising:
- a gate drive circuit configured to drive a gate of a drive-subject element, which is one of two semiconductor switching elements included in an upper and lower arm of a half bridge circuit;
- a sensing circuit configured to
- acquire a physical quantity related to the drive-subject element and
- sense an element voltage, which is a voltage between main terminals of the drive-subject element, on a basis of the physical quantity;
- a change rate control circuit configured to compute, on a basis of a sensing value of the sensing circuit and a target change rate which is a target value of a change rate of the element voltage during a change period in which the element voltage changes, a first drive speed which is a gate drive speed of the drive-subject element for controlling the change rate of the element voltage during the change period, such that the change rate becomes the target change rate;
- a timing generating circuit configured to
- acquire, in advance, a delay time caused in each circuit when the gate of the drive-subject element is driven,
- determine, on a basis of the target change rate and the delay time, a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element, and
- generate a timing signal representing the switching timing;
- and
- a speed change circuit configured to change the gate drive speed of the drive-subject element from the first drive speed to a second drive speed, which is different from the first drive speed, at the switching timing represented by the timing signal during turn-off of the drive-subject element.
A gate drive device comprising:
- a gate drive circuit configured to drive a gate of a drive-subject element, which is one of two semiconductor switching elements included in an upper and lower arm of a half bridge circuit;
- a sensing circuit configured to
- acquire a physical quantity related to a non-drive-subject element which is the other one of the two semiconductor switching elements and
- sense an element voltage, which is a voltage between main terminals of the non-drive-subject element, on a basis of the physical quantity;
- a change rate control circuit configured to compute, on a basis of a sensing value of the sensing circuit and a target change rate which is a target value of a change rate of the element voltage during a change period in which the element voltage changes, a first drive speed which is a gate drive speed of the drive-subject element for controlling the change rate of the element voltage during the change period such that the change rate becomes the target change rate;
- a timing generating circuit configured to
- acquire, in advance, a delay time caused in each circuit when the gate of the drive-subject element is driven,
- determine, on a basis of the target change rate and the delay time, a switching timing at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-on of the drive-subject element, and
- generate a timing signal representing the switching timing;
- and
- a speed change circuit configured to change the gate drive speed of the drive-subject element from the first drive speed to a second drive speed, which is different from the first drive speed, at the switching timing represented by the timing signal during turn-on of the drive-subject element.
Dependencies are inferred from the claim text.