MOTOR DRIVING CIRCUIT

• US 20160261215A1
• Filed: 05/12/2016
• Published: 09/08/2016
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: ISHII, Hiroyuki, SHIMIZU, Tatsuro
• Granted Patent: US 10,164,557 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/20 Cooling means
• CPC Class Codes: H02P 6/17 and for generating speed information
• CPC Class Codes: H02P 7/29 using pulse modulation
• CPC Class Codes: H03K 5/153 Arrangements in which a pulse is delivered at the instant when a predetermined characteristic of an input signal is present or at a fixed time interval after this instant switching at zero crossing H03K17/13

Abstract

A first calculation unit subtracts third digital data which indicates the minimum value of the duty ratio from first digital data which indicates the duty ratio of the PWM driving operation. A slope calculation unit generates slope data which is dependent on the temperature based upon second digital data which indicates the temperature. A second calculation unit multiplies the slope data by the output data of the first calculation unit. A third calculation unit sums the output data of the second calculation unit and the third digital data. A selector receives the output data of the third calculation unit and the third digital data, selects one data that corresponds to the sign of the output data of the first calculation unit, and outputs the data thus selected as a duty ratio control signal.

Claims

1. -18. (canceled)

19. A semiconductor chip configured to receive a Hall signal, which comprises a first signal and a second signal that are complementary, from a Hall sensor, and to PWM (Pulse Width Modulation) drive a fan motor, the semiconductor chip comprising:

a first terminal coupled to receive a first signal which instructs a duty ratio for a PWM driving operation;

a second terminal coupled to receive a second signal indicative of temperature;

a control circuit that generates a PWM signal having a duty ratio according to the first signal and the second signal and drives the fan motor based on the PWM signal.

20. The semiconductor chip according to claim 19, wherein the semiconductor chip has a rectangular shape with a first side, a second side, a third side and a fourth side, wherein the first terminal and the second terminal are provided along with the first side.

21. The semiconductor chip according to claim 20, further comprising a third terminal coupled to the Hall sensor, wherein the third terminal is provided along with the first side.

22. The semiconductor chip according to claim 21, wherein the control circuit comprises:

a setting unit that generates the cyclic signal; and

a bridge circuit that controls the fan motor based on the cyclic signal generated by the setting unit.

23. The semiconductor chip according to claim 19, wherein the control circuit drives the fan motor by soft switching.

24. The semiconductor chip according to claim 19, wherein the control circuit generates an FG signal indicative of a rotational speed of the fan motor.

25. An apparatus comprising:

a fan motor;

a Hall sensor;

a temperature sensor; and

a semiconductor chip, wherein the semiconductor chip comprises;

a first terminal and a second terminal coupled to the fan motor;

a third terminal and a fourth terminal coupled to the Hall sensor;

a fifth terminal coupled to receive a first signal which instructs a duty ratio for a PWM driving operation;

a sixth terminal coupled to receive a second signal indicative of temperature from the temperature sensor;

a control circuit that generates a PWM signal having a duty ratio according to the first signal and the second signal and drives the fan motor based on the PWM signal.

26. The apparatus according to claim 25, wherein the semiconductor chip has a rectangular shape with a first side, a second side, a third side and a fourth side, wherein the first terminal and the second terminal are provided along with the first side.

27. The apparatus according to claim 26, wherein the third terminal is provided along with the first side.

28. The apparatus according to claim 25, wherein the control circuit comprises:

a setting unit that generates the cyclic signal; and

a bridge circuit that controls the fan motor based on the cyclic signal generated by the setting unit.

29. The apparatus according to claim 25, wherein the control circuit drives the fan motor by soft switching.

30. The apparatus according to claim 25, wherein the control circuit generates an FG signal indicative of a rotational speed of the fan motor.