公开(公告)号：US20240372469A1

公开(公告)日：2024-11-07

申请号：US18285796

申请日：2022-02-16

Applicant: Hitachi Astemo, Ltd.

Inventor： Masato KITA ,  Yoichiro KOBAYASHI

IPC: H02M3/158 ,  H02M1/08

Abstract: Provided are a highly reliable load drive circuit that includes a switching circuit that selects a power supply voltage, and is capable of seamlessly switching the power supply voltage without using a switch or a determination circuit, an electronic control device using the load drive circuit, and a control method for the electronic control device. The load drive circuit includes: a booster circuit that boosts an output from a power supply; and a voltage switching circuit that switches the output from the power supply and an output from the booster circuit, in which the voltage switching circuit includes a first MOSFET, a second MOSFET, and a gate voltage generation circuit that generates gate voltages of the first MOSFET and the second MOSFET, gate terminals of the first MOSFET and the second MOSFET are connected to the gate voltage generation circuit, source terminals of the first MOSFET and the second MOSFET are connected to the same node, a drain terminal of the first MOSFET is connected to an output terminal of the booster circuit, a drain terminal of the second MOSFET is connected to an output terminal of the power supply, and the output from the power supply and the output from the booster circuit are seamlessly switched according to an output voltage from the power supply.

公开(公告)号：US20240161956A1

公开(公告)日：2024-05-16

申请号：US18282585

申请日：2022-03-04

Applicant: Hitachi Astemo, Ltd.

Inventor： Yasuo SHIMA ,  Yoichiro KOBAYASHI

IPC: H01F7/18

CPC classification number: H01F7/1844 ,  H01F7/1811 ,  H01F2007/1888

Abstract: A load drive device that drives and controls an inductive load based on a PWM signal from a microcomputer is provided, and the load drive device has excellent reliability and responsiveness capable of quickly detecting disconnection of the inductive load. The load drive device includes a microcomputer and a driver circuit that drives an inductive load by a pulse width modulation signal of a constant cycle based on a control command from the microcomputer, in which the driver circuit includes a current monitoring circuit that monitors a current flowing through the inductive load, and a disconnection diagnosis circuit that detects disconnection of the inductive load based on a current value detected by the current monitoring circuit, and the disconnection diagnosis circuit obtains a change amount of a current value detected by the current monitoring circuit, and when the change amount is equal to or less than a predetermined threshold, determines that the inductive load is disconnected and notifies the microcomputer of the disconnection.

公开(公告)号：US20230016629A1

公开(公告)日：2023-01-19

申请号：US17786009

申请日：2020-12-11

Applicant: Hitachi Astemo, Ltd.

Inventor： Keishi KOMORIYAMA ,  Yoichiro KOBAYASHI

IPC: H03K17/082 ,  H03F3/45

Abstract: Achieved is a load drive device capable of suppressing local concentration of temperature at the time of absorbing a counter electromotive force of an inductive load while suppressing a size of a power transistor. The load drive device includes a first transistor connected between a first control electrode and an inductive load. Further, the load drive device includes an active clamp circuit that becomes conductive when a terminal voltage of a second control electrode between the first transistor and the inductive load exceeds a threshold. Furthermore, the load drive device includes a second transistor connected to the second control electrode and connected in parallel to the first transistor.