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CN-113009953-B - Semiconductor integrated circuit for regulator and fan motor system

CN113009953BCN 113009953 BCN113009953 BCN 113009953BCN-113009953-B

Abstract

The application provides a semiconductor integrated circuit for a regulator and a fan motor system, which can detect the rotation locking state of a fan motor even if a motor driver fails. The semiconductor integrated circuit for a regulator includes: a voltage control transistor (Q1) connected between a voltage input terminal to which a DC voltage is input and an output terminal to which an external load is connected; and a control circuit (11) for controlling the voltage control transistor based on the output feedback voltage, wherein the control circuit is configured to output a rotation lock detection signal or set a flag indicating an abnormality when a current flowing through the voltage control transistor is smaller than a preset rotation lock detection current value in a regulator semiconductor integrated circuit for configuring a power supply device for supplying an operation voltage to a drive circuit (23) for a rotation drive motor.

Inventors

  • TAKANO YOICHI
  • Mu Shenyilang

Assignees

  • 三美电机株式会社
  • 三美电机株式会社

Dates

Publication Date
20231103
Application Date
20201217
Priority Date
20191218

Claims (6)

  1. 1. A fan motor system, characterized in that, the fan motor system is provided with: a motor that rotates the fan; a drive circuit that rotationally drives the motor; and a semiconductor integrated circuit for a regulator, which supplies an operating voltage of the driving circuit, the semiconductor integrated circuit for a regulator includes: a voltage control transistor connected between a voltage input terminal to which a direct-current voltage is input and an output terminal; a control circuit for controlling the voltage control transistor according to the output feedback voltage; a first transistor provided in parallel with the voltage control transistor and configured to flow a current reduced in proportion to a current flowing through the voltage control transistor; a first comparison circuit that determines magnitudes of a current flowing through the first transistor and a predetermined current value; and a first output terminal for outputting a determination result of the first comparison circuit to the outside, a second transistor provided in parallel with the voltage control transistor and the first transistor, and configured to flow a current reduced in proportion to a current flowing through the voltage control transistor; a second current-voltage conversion element that converts a current flowing through the second transistor into a voltage; and a second comparison circuit that compares the voltage converted by the second current-voltage conversion element with a second comparison voltage corresponding to a voltage obtained by current-voltage conversion of a preset abnormality detection current value to determine the magnitude of the voltage, an inverting circuit for inverting an output of the first comparing circuit when a current smaller than a rotation lock detection current value of the driving circuit set in advance flows through the first transistor; wherein the inverter circuit is provided in a preceding stage of the output transistor and generates a signal to be input to a gate terminal of the output transistor, when a current larger than the abnormality detection current value of the regulator semiconductor integrated circuit flows through the second transistor, an output of the second comparison circuit is inverted; and is also provided with When the output of one of the first comparison circuit and the second comparison circuit is inverted, an abnormality detection signal is output from the first output terminal.
  2. 2. The fan motor system of claim 1, wherein, the semiconductor integrated circuit for a regulator includes a first external terminal for connecting a first current-voltage conversion element for converting a current flowing through the first transistor into a voltage, the first comparison circuit is configured to compare a voltage converted by the first current-voltage conversion element connected to the first external terminal with a voltage corresponding to the predetermined current value.
  3. 3. The fan motor system of claim 2, wherein, a first capacitive element is connected in parallel with the first current-voltage conversion element at the first external terminal.
  4. 4. The fan motor system according to claim 1, wherein the fan motor system includes a delay circuit that delays an output of the second comparing circuit, and the abnormality detection signal is a signal obtained by adding a logic sum of an output signal of the first comparing circuit and a signal delayed by the delay circuit.
  5. 5. The fan motor system of claim 4, wherein, the regulator semiconductor integrated circuit includes a second external terminal for connecting a second capacitor element constituting the delay circuit.
  6. 6. A fan motor system, characterized in that, the fan motor system is provided with: a motor that rotates the fan; a drive circuit that rotationally drives the motor; and a semiconductor integrated circuit for a regulator, which supplies an operating voltage of the driving circuit, the semiconductor integrated circuit for a regulator includes: a voltage control transistor connected between a voltage input terminal to which a direct-current voltage is input and an output terminal to which an external load is connected; a control circuit for controlling the voltage control transistor according to the output feedback voltage; a rotation lock detection circuit that detects that a current flowing through the voltage control transistor is smaller than a preset rotation lock detection current value of the drive circuit; and an external terminal outputting a detection result of the rotation lock detection circuit, an abnormal current detection circuit that detects that the current flowing through the voltage control transistor is greater than an abnormal current detection value, outputting an abnormal signal from the external terminal to the driving circuit in a case where the rotation lock detection circuit detects a rotation lock state, in the case where the abnormal current detection circuit detects an abnormal current, the regulator performs an overcurrent protection operation with the semiconductor integrated circuit or outputs an abnormal signal from the external terminal.

Description

Semiconductor integrated circuit for regulator and fan motor system Technical Field The present application relates to a technique that is effectively used in a semiconductor integrated circuit (regulator IC) constituting a dc power supply device and a voltage regulator such as a series regulator for converting a dc voltage, and in a fan motor system using the semiconductor integrated circuit. Background As a power supply device for controlling a transistor provided between a dc voltage input terminal and an output terminal and outputting a dc voltage of a desired potential, there is a series regulator (hereinafter simply referred to as a regulator). As an application of the regulator, there is a power supply device for supplying dc power to a device cooling blower (fan motor system) mounted on an automobile or a computer, for example. The blower device includes a motor for rotating the fan and a driver IC (motor driver) to which the regulator supplies a power supply voltage. The rotation speed control method of the fan includes a method of changing the output voltage (power supply voltage) of the regulator and a method of controlling the driving circuit by PWM (pulse width modulation) pulses. In the blower device, if a so-called rotation lock state in which rotation of the fan is stopped is generated in a state in which a power supply voltage is supplied to the drive circuit, the cooled equipment may be abnormally heated and damaged. Accordingly, an application related to a motor driver provided with a lock detection circuit that outputs a protection signal for stopping a drive signal of a motor for a certain period of time when a lock state is detected has been proposed (for example, patent document 1). In addition, a motor system has been proposed in which a rotation control controller detects a rotation lock state from a signal from a hall element or an encoder. On the other hand, conventionally, there are regulators having a function of detecting a short-circuit state of an output terminal and an overcurrent protection function, but there has been no proposed regulator having a circuit for detecting a locked state of a motor. Further, as an application related to a regulator IC having a short-circuit abnormality detection function and an overcurrent protection function (current limiting circuit), for example, an application described in patent document 2 is known. Patent document 1: japanese patent application laid-open No. 2015-70727 Patent document 2: japanese patent laid-open No. 2017-45096 In a motor system using a motor driver including a lock detection circuit described in patent document 1, if the motor driver fails, it cannot be detected on the power supply device side, and therefore, there is a problem in that abnormal heat generation of the device cannot be avoided. In addition, in the case of a motor system in which a rotation control controller (microcomputer) can detect a rotation lock state based on a signal from a hall element or an encoder, it is necessary to use a motor having a hall element or an encoder, and wiring for inputting a signal from the motor side to the microcomputer is required, which causes a problem of an increase in cost. Disclosure of Invention The present application has been made in view of the above-described problems, and an object of the present application is to detect a rotation lock state of a motor even when a motor driver having a motor lock detection function fails in a semiconductor integrated circuit (regulator IC) constituting a dc power supply device such as a series regulator. Another object of the present application is to provide an IC for a regulator that can constitute a motor system capable of detecting a rotation lock state without increasing the cost. In order to achieve the above object, the present application provides a semiconductor integrated circuit for a regulator, including a voltage control transistor connected between a voltage input terminal to which a direct current voltage is input and an output terminal, and a control circuit for controlling the voltage control transistor based on an output feedback voltage, the regulator semiconductor integrated circuit includes: a first transistor provided in parallel with the voltage control transistor and configured to flow a current reduced in proportion to a current flowing through the voltage control transistor; a first comparison circuit that determines magnitudes of a current flowing through the first transistor and a predetermined current value; and a first output terminal for outputting a determination result of the first comparison circuit to the outside, the regulator semiconductor integrated circuit is configured such that when a current smaller than a preset rotation lock detection current value flows through the first transistor, an output of the first comparison circuit is inverted. Another aspect of the present application is a semiconductor integrated circuit for a regulator, inc