Motor driving apparatus and motor apparatus using the same

Patent metadata

Field	Value
Publication number	US-9035582-B2
Application number	US-201213440154-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	Apr 5, 2011
Publication date	May 19, 2015
Grant date	May 19, 2015

Abstract

A motor driving apparatus includes an automatic gain control circuit on a signal path for transmitting a rotor-position detecting signal (hall voltage signal), and the automatic gain control circuit includes: an amplifier, configured to perform differential amplification on an input signal (step-angle hall current signal) to generate an output signal (amplified hall current signal); and a feedback control portion, configured to monitor the output signal (monitored current signal) to decide a gain of the amplifier.

First claim

What is claimed is:

1. A motor driving apparatus, comprising an automatic gain control circuit on a signal path for transmitting a rotor-position detecting signal, wherein the automatic gain control circuit comprises:
a difference amplifier, for differential amplifying a differential input signal to generate an amplified hall current signal;
a current mirror section, for generating a monitoring current signal equivalent to the amplified hall current signal;
a full wave rectifier, for full wave rectifying the monitoring current signal to generate a rectified monitoring current signal;
a feedback control portion, for monitoring an accumulated rectified monitoring current signal to decide a gain of the difference amplifier, the accumulated rectified monitoring current signal is obtained by adding the rectified monitoring current signal of three phases comprising a first phase, a second phase, and a third phase; and
a current/voltage conversion portion, for generating a sine wave voltage signal from the amplified hall current signal,
wherein the automatic gain control circuit outputs the sine wave voltage signal as an output signal.

2. The motor driving apparatus according to claim 1 , wherein the feedback control portion decides the gain of the difference amplifier, so as to enable the accumulated rectified monitoring current signal to become a specific signal level.

3. The motor driving apparatus according to claim 1 , further comprising a phase adjustment circuit for performing phase adjustment on the rotor-position detecting signal.

4. The motor driving apparatus according to claim 3 , wherein the phase adjustment circuit performs the phase adjustment on the rotor-position detecting signal of the first phase by adding the rotor-position detecting signal of the second phase and the rotor-position detecting signal of the first phase at a specific ratio.

5. The motor driving apparatus according to claim 4 , wherein the ratio is variably controlled according to a control voltage.

6. The motor driving apparatus according to claim 1 , further comprising: a pulse width modulation (PWM) signal generation circuit, for comparing the output signal of the automatic gain control circuit and a triangle wave signal at a specific frequency, to generate a PWM signal; and a driving circuit, for generating a motor driving signal according to the PWM signal.

7. The motor driving apparatus according to claim 6 , further comprising: an over current detection circuit, for detecting whether a motor driving current is in an over current state; and an over current protection circuit, for forcing the driving circuit to stop when the over current is detected.

8. The motor driving apparatus according to claim 7 , wherein the over current protection circuit forces the driving circuit to suspend at least for a specific release period when the over current state of the motor driving current lasts a specific mute period.

9. The motor driving apparatus according to claim 8 , wherein the over current protection circuit comprises: a first counter, for counting the mute period; and a second counter, for counting the release period.

10. A motor apparatus, comprising:
a motor;
a rotor-position detecting component, for generating a rotor-position detecting signal; and
the motor driving apparatus according to claim 1 , for receiving input of the rotor-position detecting signal to perform driving control on the motor.

11. The motor driving apparatus according to claim 10 , wherein the rotor-position detecting component is a hall component.

Assignees

• Yamato Tetsuo
• Fujimura Takashi
• Rohm Co Ltd

Inventors

• Yamato Tetsuo
• Fujimura Takashi

Classifications

• H02P6/10

  Arrangements for controlling torque ripple, e.g. providing reduced torque ripple · CPC title

• H02P6/08 Primary

  Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) · CPC title

• H02P6/16 Primary

  Circuit arrangements for detecting position · CPC title