Patent ID: 11870425
Assignee: DENSO CORPORATION
Field: Basic communication processes (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. 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.