JPH04236185A - Hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To detect the open (disconnection) of a motor from both terminals. CONSTITUTION:A gate circuit 8 is provided between output terminals of a driving circuit 2, an output corresponding to an open or non-open of a motor 6 is produced at the output side of the circuit, and the output is compared with a reference value by an open detector 3, thereby judging the open, non-open of the motor. A pull-up resistor and a pull-down resistor are connected between the output terminals of the circuit 2 and first, second power sources, an output corresponding to the open, the non-open of the motor is produced from the output terminal side of the circuit connected with the pull-down resistor, the output is compared with a reference value by the open detector to judge the open, the non-open of the motor.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit, and more particularly to a hybrid integrated circuit suitable for use, for example, in a motor driver.

0002

2. Description of the Related Art FIG. 3 is an equivalent circuit showing a conventional hybrid integrated circuit. In the figure, (1) is a hybrid integrated circuit for motor driver, (2) is a drive circuit for driving motor (6), and (3) is for detecting open circuit (disconnection) of motor (6). (4) is a voltage detection resistor for detecting voltage when the motor (6) is open; (5) is a detection resistor attached to the motor (6).

Next, the operation will be explained. When the drive circuit (2) in the motor driver hybrid integrated circuit (1) operates, the motor (6) operates. Open detection of the motor (6) at point a in Figure 3 is performed using the voltage detection resistor (4) and the detection resistor (5) attached to the motor when point P is the voltage detection point. Although it is possible to detect the voltage at point P, the motor (6) at point b
Open detection is impossible even if the voltage at point P is detected. For example, if the voltage detection resistor (4) and the detection resistor (5) attached to the motor are each 2 kΩ, when the motor is stopped and normal, the P point is 1/2 Vcc,
Since point P becomes Vcc when point a is open, it can be detected. However, when point b is open, point P is 1/2Vcc.
Therefore, the voltage is the same as during normal operation, and open detection is impossible. Here, the open detection circuit (3) has a comparator configuration (not shown), has a certain comparison reference voltage,
For example, if the detected voltage is larger than this comparison reference voltage, the motor (6) is determined to be in an open state, and if it is smaller than this, the motor (6) is determined to be in a non-open state.

0004

Since the conventional hybrid integrated circuit is constructed as described above, there is a problem in that open detection at point b in FIG. 2 is impossible.

The present invention was made to solve the above-mentioned problems, and its object is to obtain a hybrid integrated circuit capable of detecting an open circuit at both point a and point b.

[0006]

[Means for Solving the Problems] A hybrid integrated circuit according to a first aspect of the invention includes a drive circuit for driving a motor, and a first circuit connected between one of the output terminals of the drive circuit and a power source.
a second resistor connected between the other output terminal of the drive circuit and the power supply, a gate circuit connected between the output terminals of the drive circuit, and a second resistor connected between the other output terminal of the drive circuit and the power supply; It is equipped with an open detection circuit. A hybrid integrated circuit according to a second invention includes a drive circuit for driving a motor, a pull-up resistor connected to one of the output terminals of the drive circuit, and a pull-down resistor connected to the other output terminal of the drive circuit. The device includes a resistor and an open detection circuit connected to the other output terminal of the drive circuit.

[0007]

[Operation] In the first invention, a gate circuit is provided between the output terminals of the drive circuit, an output corresponding to whether the motor is open or not is taken out from the output side of the gate circuit, and this output is compared by an open detection circuit. Determine whether the motor is open or not by comparing it with the reference voltage. Further, in the second invention, each output terminal of the drive circuit and the first
A pull-up resistor and a pull-down resistor are connected between the power source and the second power source, respectively, and the motor is opened from the output terminal side of the drive circuit to which the pull-down resistor is connected.
An output corresponding to non-open is taken out, and this output is compared with a comparison reference voltage in an open detection circuit to determine whether the motor is open or not.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed explanation thereof will be omitted. In this embodiment, the other output terminal (point b side) of the drive circuit (2) and the power supply terminal Vcc
A voltage detection resistor (7) is provided between the output terminals of the drive circuit (2) and the open detection circuit (3) for the same purpose as the resistor (4), and a gate circuit such as an OR circuit is provided between the output terminals of the drive circuit (2) and the open detection circuit (3). (8), connect the two input terminals of the OR circuit (8) to each output terminal of the drive circuit (2), and connect the OR circuit (8) to each output terminal of the drive circuit (2).
Connect the output end of the circuit to the open detection circuit (3).

Next, the operation will be explained. Drive circuit (2) inside the motor driver hybrid integrated circuit (1)
When the motor (6) operates, the motor (6) operates. As a motor open detection method, for example, the voltage detection point is
In the case of a point, resistors (4) and (5) are each 10kΩ.
, 5kΩ, if the motor is stopped normally, point a will also be b.
Since the point is also about 1/2 Vcc (Lo voltage), the Pa point becomes Lo voltage. On the other hand, when point a is open, point a is approximately Vc
c (Hi voltage), so point Pa is Hi voltage, and even if point b is open, point b is approximately Vcc (Hi voltage), so Pa
The voltage at the point also becomes Hi, and therefore, even if points a and b are both open, since the points a and b are both approximately Vcc, the voltage at point Pa is also high.
i voltage. From this, it can be detected if points a and b become open. In other words, as mentioned above, the open detection circuit (3) detects, for example, that if the detected voltage is larger than the comparison reference voltage, the motor (6) is in the open state, and if it is smaller, the motor (6) is in the open state.
6) is determined to be a non-open state, so in this case, the comparison reference voltage VREF1 is 1/2Vcc.
Assuming that there is a relationship of <VREF1<Vcc, the open detection circuit (3) will detect the motor (6) when the detection voltage is Vcc.
When the motor (6) is in an open state and the detected voltage is 1/2 Vcc, it is determined that the motor (6) is in a non-open state.

FIG. 2 is a block diagram showing a second embodiment of the present invention. In the figure, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed explanation thereof will be omitted. In this example,
An open detection circuit (3) is connected to a connection point Pb of one of the output terminals (point b side) of the drive circuit (2), and a pull-down resistor (9) is connected between this connection point Pb and the ground. This pull-down resistor (9) is connected to P when point b is open.
This is a resistor to prevent point a from becoming high impedance. The open detection circuit (3A) has the opposite setting to the open detection circuit (3), and if the detected voltage is smaller than the comparison reference voltage, the motor (6) is in the open state, and if it is larger, the motor (6) is in the non-open state. Shall act as a judge.

Next, the operation will be explained. The drive circuit (2) in the motor driver hybrid integrated circuit (1)
) operates, the motor (6) operates. As an open detection method for the motor (6), for example, when the voltage detection point is the Pb point, the voltage detection resistor (4) as a pull-up resistor and the detection resistor (5) attached to the motor (6) are used. ) are 5 kΩ each, and the value of the pull-down resistor (9) is 100 kΩ, when the motor is stopped, the voltage at point Pb is approximately 1/2 Vcc if it is normal, and when point a is open, the voltage at point Pa is 0 V. Even when point b is open, the voltage at point Pa becomes 0V. From this, it is detected if points a and b become open. In other words, the comparison reference voltage VREF2 of the open detection circuit (3A) is 0<VRE.
Assuming that F2<1/2Vcc, the open detection circuit (3A) indicates that the motor (6) is in the open state when the detection voltage is 0V, and that the motor (6) is in the open state when the detection voltage is 1/2Vcc.
) is determined to be in a non-open state.

0012

As described above, according to the first invention, a drive circuit for driving a motor, a first resistor connected between one of the output terminals of the drive circuit and a power supply,
a second resistor connected between the other output terminal of the drive circuit and the power supply; a gate circuit connected between the output terminals of the drive circuit; and an open detection circuit connected to the gate circuit. With this arrangement, an open state can be detected at either point a or point b, that is, at any output end of the motor, and the quality is improved. According to a second invention, there is provided a drive circuit for driving the motor, a pull-up resistor connected to one of the output terminals of the drive circuit, and a pull-down resistor connected to the other output terminal of the drive circuit. and an open detection circuit connected to the other output terminal of the drive circuit, it is possible to detect an open at either point a or point b, that is, at any output terminal of the motor. Compared to the invention of No. 1, since the gate circuit is not required, it is possible to improve the quality and simplify the circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the invention.

FIG. 3 is a configuration diagram showing a conventional hybrid integrated circuit.

[Explanation of symbols]

2 Drive circuit 3 Open detection circuit 4 Voltage detection resistor 6 Motor 7 Voltage detection resistor 8 OR circuit

Claims (2)

[Claims] 1. A drive circuit for driving a motor, a first resistor connected between one of the output terminals of the drive circuit and a power supply, and a first resistor connected between the other output terminal of the drive circuit and the power supply. 1. A hybrid integrated circuit comprising: a second resistor, a gate circuit connected between the output terminals of the drive circuit, and an open detection circuit connected to the gate circuit. 2. A drive circuit for driving a motor, a pull-up resistor connected to one of the output terminals of the drive circuit, a pull-down resistor connected to the other output terminal of the drive circuit, and the drive circuit. and an open detection circuit connected to the other output terminal of the circuit.