Current detection circuit, motor driving device, magnetic disk storage device, and electronic appliance

摘要

A current detection circuit for detecting a maximum current value in a three-phase motor includes an identifier configured to identify a maximum current phase having the maximum current value among phases of the motor, and a detector configured to detects the maximum current value by summing current values of phases other than the maximum current phase when the current direction in the maximum current phase is a predetermined first direction.

主权项

1. A motor driving device comprising:
a current detection circuit for detecting a maximum current value in a three-phase motor; a power supply line; and a motor drive unit configured to perform drive operation for driving the three-phase motor using a voltage supplied to the power supply line, wherein the motor drive unit includes:
three-phase upper switches for switching connection/disconnection between each phase of the three-phase motor and the power supply line; andthree-phase lower switches for switching connection/disconnection between each phase of the three-phase motor and a ground point, and wherein the current detection circuit includes:
an identifier configured to identify a maximum current phase having a maximum current value among phases of the motor during motor brake during which the three-phase lower switches are all on; anda detector configured to:
detect the maximum current value by adding current values of phases other than the maximum current phase when a current direction in the maximum current phase is a predetermined first direction, anddetect a current value of the maximum current phase as the maximum current value when a current direction in the maximum current phase is a second direction opposite to the first direction.