SEMICONDUCTOR DEVICE, DRIVING MECHANISM AND MOTOR DRIVING CONTROL METHOD

• US 20140021892A1
• Filed: 07/19/2013
• Published: 01/23/2014
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Inventors: YAMASHITA, TAKASHI
• Granted Patent: US 9,716,451 B2
• Time in Patent Office: Days
• US Class Current: 318/400.22
• CPC Class Codes: H02P 6/14 Electronic commutators
• CPC Class Codes: H02P 6/24 Arrangements for stopping
• CPC Class Codes: H02P 6/34 Modelling or simulation for control purposes

Abstract

A semiconductor device that controls a motor driving device. The semiconductor device includes: a position detection section that detects changes in a turning position of a rotor provided at a motor and outputs detection signals corresponding to the changing turning position; a first switching section that, in accordance with the detection signals, outputs ground switching signals, which switch which end portion of a coil is connected to a ground side, to a first switching circuit; and a second switching section that, in accordance with the detection signals, outputs connection switching signals, which switch which end portion of the coil is connected to a driving power supply side, to a third switching circuit that controls the switching of connections between the end portions of the coil and the driving power supply side by a second switching circuit.

Claims

1. A semiconductor device that controls a motor driving device, the motor driving device including:

a first switching circuit that switches which of end portions of a coil provided at a motor is connected to a ground side; and

a second switching circuit that switches which of the end portions of the coil is connected to a driving power supply side, and

the semiconductor device comprising;

a position detection section that detects changes in a turning position of a rotor provided at the motor and outputs detection signals corresponding to the changing turning position;

a first switching section that, in accordance with the detection signals, outputs ground switching signals, which switch which end portion of the coil is connected to the ground side, to the first switching circuit; and

a second switching section that, in accordance with the detection signals, outputs connection switching signals, which switch which end portion of the coil is connected to the driving power supply side, to a third switching circuit that controls the switching of connections between the end portions of the coil and the driving power supply side by the second switching circuit.

2. The semiconductor device of claim 1, wherein

the first switching circuit includes:

a first ground switching section that, when a first ground switching signal for switching a direction of current flowing in the coil of the motor to a first direction is inputted, switches a first end portion of the coil from being connected to the driving power supply side to the ground side; and

a second ground switching section that, when a second ground switching signal for switching the direction of the current to a second direction, which is opposite to the first direction, is inputted, switches a second end portion of the coil from being connected to

the driving power supply side to the ground side,

the second switching circuit includes;

a first power supply switching section that, when a first power supply switching signal for switching the direction of the current flowing in the coil of the motor to a first direction is inputted, switches the first end portion from being connected to the ground side to the driving power supply side; and

a second power supply switching section that, when a second power supply switching signal for switching the direction of the current to a second direction opposite to the first direction is inputted, switches the second end portion from being connected to the ground side to the driving power supply side, and

the third switching circuit includes;

a first signal input section that inputs the first power supply switching signal to the first power supply switching section; and

a second signal input section that inputs the second power supply switching signal to the second power supply switching section,

and wherein

the motor driving device, by alternatingly

performing switching to switch the connection state of the first end portion from the driving power supply side to the ground side and switch the connection state of the second end portion from the ground side to the driving power supply side, and

performing switching to switch the connection state of the first end portion from the ground side to the driving power supply side and switch the connection state of the second end portion from the driving power supply side to the ground side,

switches the direction of the current flowing in the coil and drives the motor,

the first switching section detects changes in the turning position of the motor, inputs the first ground switching signal to the first ground switching section in accordance with a first detection signal, which corresponds to a change of the current flowing in the coil to the first direction, such that the current flowing in the coil flows in the first direction, and inputs the second ground switching signal to the second ground switching section in accordance with a second detection signal, which corresponds to a change to the second direction, such that the current flowing in the coil flows in the second direction, and

the second switching section inputs a first connection switching signal to the first signal input section in accordance with the first detection signal such that the current flowing in the coil flows in the first direction, and inputs a second connection switching signal to the second signal input section in accordance with the second detection signal such that the current flowing in the coil flows in the second direction.

3. The semiconductor device of claim 1, wherein the output of the ground switching signals by the first switching section and the output of the connection switching signals by the second switching section are delayed by pre-specified durations from the output of the detection signals.

4. The semiconductor device of claim 1, wherein

the output of the ground switching signals by the first switching section is delayed by a pre-specified duration from the input of the detection signals, and

the second switching section outputs the connection switching signals when the first switching section outputs the ground switching signals.

5. The semiconductor device of claim 1, wherein the first switching section outputs the ground switching signals to switching elements that are provided at the first switching circuit and used for switching the connections, the switching elements connecting the coil to the ground side, and the first switching section outputting PWM pulses that control to turn the switching elements on and off.

6. The semiconductor device of claim 1, further comprising:

an overcurrent detection section that outputs an overcurrent detection signal when the current flowing in the motor exceeds a pre-specified value; and

an emergency stop section that, in accordance with the overcurrent detection signal outputted from the overcurrent detection section, short-circuits the two ends of the coil.

7. The semiconductor device of claim 6, wherein the emergency stop section outputs a cut-off signal, which controls the first switching circuit to cut off the connection between the ground side and the coil, to the first switching section, and outputs a short-circuit signal, which controls the second switching circuit to connect the two ends of the coil to the driving power supply side and short-circuit the two ends, to the second switching section.

8. The semiconductor device of claim 6, wherein the emergency stop section outputs a cut-off signal, which controls the second switching circuit to cut off the connection between the driving power supply side and the coil, to the second switching section, and outputs a short-circuit signal, which controls the first switching circuit to connect the two ends of the coil to the ground side and short-circuit the two ends, to the first switching section.

9. The semiconductor device of claim 1, wherein the motor is a brushless motor.

10. A driving mechanism comprising:

a semiconductor device;

a motor driving device including

a first switching circuit that switches which of end portions of a coil provided at a motor is connected to a ground side and

a second switching circuit that switches which of the end portions of the coil is connected to a driving power supply side,

the motor driving device controlling current flowing in the coil with the first switching circuit and the second switching circuit;

a third switching circuit; and

the motor,

wherein the semiconductor device controls the motor driving device, and the semiconductor device includes;

a position detection section that detects changes in a turning position of a rotor provided at the motor and outputs detection signals corresponding to the changing turning position;

a first switching section that, in accordance with the detection signals, outputs ground switching signals, which switch which end portion of the coil is connected to the ground side, to the first switching circuit; and

a second switching section that, in accordance with the detection signals, outputs connection switching signals, which switch which end portion of the coil is connected to the driving power supply side, to the third switching circuit, which controls the switching of connections between the end portions of the coil and the driving power supply side by the second switching circuit.

11. A motor driving control method at a semiconductor device that controls a motor driving device, the motor driving device including:

a first switching circuit that switches which of end portions of a coil provided at a motor is connected to a ground side; and

a second switching circuit that switches which of the end portions of the coil is connected to a driving power supply side,

the motor driving device controlling current flowing in the coil with the first switching circuit and the second switching circuit, and the motor driving control method comprising;

detecting changes in a turning position of a rotor provided at the motor and outputting detection signals corresponding to the changing turning position;

in accordance with the detection signals, outputting ground switching signals, which switch which end portion of the coil is connected to the ground side, to the first switching circuit; and

in accordance with the detection signals, outputting connection switching signals, which switch which end portion of the coil is connected to the driving power supply side, to a third switching circuit that controls the switching of connections between the end portions of the coil and the driving power supply side by the second switching circuit.