JP6814858B2 - Electronic control system - Google Patents

Description

The present invention relates to a semiconductor device and an electronic control system including the semiconductor device, and accurately detects the presence or absence of a short-circuit failure of a resolver by using, for example, the potential of an existing external terminal provided on a chip forming an RD converter. The present invention relates to a semiconductor device suitable for the above and an electronic control system including the same.

Vehicles such as automobiles are equipped with an electronic control system that detects the rotation angle of a rotating body such as a rotor and performs predetermined processing based on the detection result. The electronic control system includes a resolver that detects the rotation angle of the rotating body, and an RD converter (Resolver to Digital Converter) that converts the detection result of the resolver into a digital signal. Further, the electronic control system determines whether or not a ceiling fault has occurred in which the resolver and the power supply voltage side are short-circuited, and whether or not a ground fault has occurred in which the resolver and the ground voltage side are short-circuited. It is equipped with a failure detection circuit to detect.

Related techniques are disclosed in Patent Document 1 and Patent Document 2. Patent Document 1 discloses a configuration of a position detection device having a detection function for detecting the presence or absence of disconnection of wiring. Further, Patent Document 2 discloses a configuration of a resolver failure detection device that detects a resolver failure.

JP-A-2015-94718 JP-A-2009-162670

By the way, the RD converter is provided with an amplifier circuit for amplifying the detection result of the resolver, but it is required that the gain of the amplifier circuit can be freely adjusted according to the type of the resolver, the design specifications and the like. There is. Therefore, for example, the gain of the amplifier circuit can be adjusted by providing the input resistance among the feedback resistor and the input resistor that determine the gain of the amplifier circuit in a replaceable state outside the chip of the RD converter.

Here, in order to prevent an increase in the number of external terminals on the chip forming the RD converter, the potential of the existing external terminals used in the RD converter is used without providing a dedicated external terminal to which the potential of the resolver is directly supplied. A method of detecting the presence or absence of a short-circuit failure of the resolver can be considered. However, in this method, the potential of the resolver cannot be accurately detected due to the influence of the input resistance provided outside the chip, and as a result, the presence or absence of a short-circuit failure of the resolver cannot be accurately detected. There was a problem. Other challenges and novel features will become apparent from the description and accompanying drawings herein.

According to one embodiment, in the semiconductor device, one and the other of the pair of voltage signals according to the detection result of the detection device provided outside are supplied via the first and second input resistors, respectively. And a second external terminal, an operational amplifier that amplifies the potential difference between the pair of voltage signals supplied to the first and second external terminals, and a first unit provided between the output terminal and one input terminal of the operational amplifier. The first and second switches provided between the feedback resistor, the two input terminals of the operational amplifier, and the first and second external terminals, respectively, and the first and second switches were turned off. A short-circuit failure detection circuit for detecting whether or not a short-circuit failure has occurred in the detection device based on the respective voltage levels of the first and second external terminals at the time is provided.

According to one embodiment, the semiconductor device is provided to a first external terminal to which a voltage signal corresponding to a detection result of a detection device provided externally is supplied via a first input resistor, and to the first external terminal. An operational amplifier that amplifies the supplied voltage signal, a first feedback resistor provided between the output terminal and one input terminal of the operational amplifier, and a first provided between the operational amplifier and the first external terminal. It includes a switch and a short-circuit failure detection circuit that detects whether or not a short-circuit failure has occurred in the detection device based on the voltage level of the first external terminal when the first switch is turned off.

According to one embodiment, the semiconductor device includes first and second external terminals, a first switch whose one end is connected to the first external terminal, and a second switch whose one end is connected to the second external terminal. An operational amplifier having a switch, a first input terminal connected to the other end of the first switch, and a second input terminal connected to the other end of the second switch, an output terminal of the operational amplifier, and the first. Supply to the first external terminal based on the feedback resistor provided between the other end of the switch and the voltage level of the signal supplied to the first external terminal during the period when the first switch is turned off. It is provided with an abnormality detection circuit for detecting an abnormality of the signal to be output.

According to the above embodiment, a semiconductor device capable of accurately detecting the presence or absence of a short-circuit failure of a resolver by using the potential of an existing external terminal provided on a chip forming a converter, and a semiconductor device thereof are provided. An electronic control system can be provided.

It is a figure which shows the configuration example of the electronic control system which concerns on Embodiment 1. FIG. It is a figure which shows the specific configuration example of the RD converter provided in the electronic control system shown in FIG. It is a figure which shows an example of the waveform of the switching signal which switches on / off of a switch. 6 is a timing chart showing the operation of the electronic control system shown in FIG. 1 in a normal state. 6 is a timing chart showing the operation of the electronic control system shown in FIG. 1 in a ground fault state. It is a timing chart which shows the operation of the electronic control system shown in FIG. 1 in the heavenly state. It is a figure which shows the modification of the RD converter shown in FIG. It is a figure which shows the configuration example of the electronic control system which concerns on Embodiment 2. FIG. It is a figure which shows the configuration example of the electronic control system which concerns on Embodiment 3. FIG. It is a figure which shows the configuration example of the electronic control system which concerns on the concept before reaching the embodiment. FIG. 5 is a timing chart showing the operation of the electronic control system shown in FIG. 10 in a ground fault state. FIG. 5 is a timing chart showing the operation of the electronic control system shown in FIG. 10 in a heavenly state.

Hereinafter, embodiments will be described with reference to the drawings. Since the drawings are simple, the technical scope of the embodiments should not be narrowly interpreted based on the description of the drawings. Further, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

In the following embodiments, when necessary for convenience, the description will be divided into a plurality of sections or embodiments, but unless otherwise specified, they are not unrelated to each other, and one is the other. There is a relationship between a part or all of the modified examples, application examples, detailed explanations, supplementary explanations, and the like. In addition, in the following embodiments, when the number of elements (including the number, numerical value, quantity, range, etc.) is referred to, when it is specified in particular, or when it is clearly limited to a specific number in principle, etc. Except, the number is not limited to the specific number, and may be more than or less than the specific number.

Furthermore, in the following embodiments, the components (including operation steps and the like) are not necessarily essential unless otherwise specified or clearly considered to be essential in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of a component or the like, the shape is substantially the same unless otherwise specified or when it is considered that it is not apparent in principle. Etc., etc. shall be included. This also applies to the above numbers (including the number, numerical value, quantity, range, etc.).

<Preliminary examination by the inventors>
Before explaining the details of the RD converter and the electronic control system provided with the RD converter according to the first embodiment, the RD converter 50 and the electronic control system 5 provided with the RD converter 50 which the present inventors have previously examined will be described.

FIG. 10 is a diagram showing a configuration example of the electronic control system 5 according to the concept before reaching the embodiment. The electronic control system 5 is mounted on a vehicle such as an automobile, detects the rotation angle of a rotating body (detection target) such as a rotor, performs predetermined processing based on the detection result, and rotates the rotating body. It has a function to detect the presence or absence of a short circuit failure in the resolver.

Specifically, the electronic control system 5 is composed of a resolver (detection device) 11 that detects the rotation angle of a rotor (not shown), an RD converter 50 that converts the detection result of the resolver 11 into a digital signal, and an RD converter 50. The present invention includes a microcomputer (hereinafter, simply referred to as a microcomputer) 13 that performs predetermined processing based on the output digital signal.

The resolver 11 includes, for example, an excitation signal source 12 and coils L10 to L12. The coils L10 to L12 are arranged so as to surround the rotor made of a magnetic material. The excitation signal source 12 sends a sinusoidal excitation signal (excitation signal of 10 kHz in this example) used as a carrier wave to the coil L10. This excitation signal is transmitted to the coils L11 and L12 by electromagnetic induction, and appears as carrier waves having 90-degree phases different from each other. Here, the amplitude of the carrier waves of the coils L11 and L12 changes according to the rotation angle of the rotor. That is, in the coils L11 and L12, signals including information on the rotation angle of the rotor on the carrier wave appear as received signals having different phases by 90 degrees.

Specifically, a cos waveform reception signal is generated at one end S1R of the coil L11, and a reception signal of the opposite phase is generated at the other end S3R of the coil L11. On the other hand, a sin waveform reception signal is generated at one end S2R of the coil L12, and a reception signal of the opposite phase is generated at the other end S4R of the coil L12.

The RD converter 50 includes external terminals S51 to S54, T51, T53, operational amplifiers AP51, AP52, feedback resistors R53, R54, resistor elements R51, R52, an angle calculation circuit 501, and an angle calculation circuit 501 provided on the chip CHP5. It includes a short-circuit failure detection circuit 502 and input resistors R1 to R4 provided outside the chip CHP5. The amplifier circuit 55 is composed of the operational amplifier AP51, the input resistors R1 and R3, the resistance element R51, and the feedback resistor R53. The amplifier circuit 56 is composed of the operational amplifier AP52, the input resistors R2 and R4, the resistance element R52, and the feedback resistor R54.

The amplifier circuit 55 amplifies the received signal of the coil L11 including the rotation angle information. The amplifier circuit 56 amplifies the received signal of the coil L12 including the rotation angle information. In other words, the amplifier circuit 55 amplifies the potential difference between the pair of voltage signals output from both ends S1R and S3R of the coil L11. The amplifier circuit 56 amplifies the potential difference between the pair of voltage signals output from both ends S2R and S4R of the coil L12.

Specifically, outside the chip CHP5, the input resistor R1 is provided between the end portion S1R of the coil L11 and the external terminal S51. The input resistor R2 is provided between the end portion S2R of the coil L12 and the external terminal S52. The input resistor R3 is provided between the end portion S3R of the coil L11 and the external terminal S53. The input resistor R4 is provided between the end portion S4R of the coil L12 and the external terminal S54.

Further, on the chip CHP5, the non-inverting input terminal of the operational amplifier AP51 is connected to the external terminal S51, the inverting input terminal of the operational amplifier AP51 is connected to the external terminal S53, and the output terminal and the inverting input terminal of the operational amplifier AP51 provide a feedback resistor R53. Connected via. Further, a common voltage COM is supplied to the non-inverting input terminal of the operational amplifier AP51 via the resistance element R51. The non-inverting input terminal of the operational amplifier AP52 is connected to the external terminal S52, the inverting input terminal of the operational amplifier AP52 is connected to the external terminal S54, and the output terminal and the inverting input terminal of the operational amplifier AP52 are connected via the feedback resistor R54. Further, a common voltage COM is supplied to the non-inverting input terminal of the operational amplifier AP52 via the resistance element R52.

The common voltage COM indicates a voltage level greater than the reference voltage and less than the supply voltage. In this example, the common voltage COM indicates 2.5V, which is an intermediate voltage between a reference voltage of 0V and a power supply voltage of 5V. Therefore, the amplitude center voltage of the voltage signal input to the amplifier circuits 55 and 56 is 2.5 V, which is the common voltage COM.

Here, in this example, of the input resistors R1 and R3 and the feedback resistors R53 that determine the gain of the amplifier circuit 55, the input resistors R1 and R3 are provided on the board outside the chip CHP5 in a replaceable state. .. As a result, the gain of the amplifier circuit 55 can be freely adjusted according to the type of resolver, design specifications, and the like. Similarly, of the input resistors R2 and R4 and the feedback resistors R54 that determine the gain of the amplifier circuit 56, the input resistors R2 and R4 are provided on the board outside the chip CHP5 in a replaceable state. As a result, the gain of the amplifier circuit 56 can be freely adjusted according to the type of resolver, design specifications, and the like.

Further, in the example of FIG. 10, resistance elements RH1, RH2, RL1, RL2 are provided for detecting disconnection of the coils L11 and L12.

Specifically, the resistance element RH1 is between a node on the signal line between one end S1R of the coil L11 and the external terminal S51 and a power supply voltage terminal to which a power supply voltage (5V in this example) is supplied. Is provided. A resistance element RL1 is provided between a node on the signal line between the other end S3R of the coil L11 and the external terminal S53 and a reference voltage terminal to which a reference voltage (0V in this example) is supplied. .. A resistance element RH2 is provided between a node on the signal line between one end S2R of the coil L12 and the external terminal S52 and a power supply voltage terminal to which a power supply voltage (5V in this example) is supplied. .. A resistance element RL2 is provided between a node on the signal line between the other end S4R of the coil L12 and the external terminal S54 and a reference voltage terminal to which a reference voltage (0V in this example) is supplied. ..

Here, the resistance elements RH1, RH2, RL1 and RL2 have a resistance ratio such that the amplitude center voltage of the coils L11 and L12 shows a common voltage COM in a normal state, and are sufficiently larger than the resistance elements R1 to R4 and R51 to R54. It is adjusted to a high resistance value.

The angle calculation circuit 501 converts the output signals (analog signals) of the amplifier circuits 55 and 56 including the rotation angle information into digital signals I51 and outputs them. The microcomputer 13 performs a predetermined process based on the digital signal I51. The microcomputer 13 may be provided on the chip CHP5.

The short-circuit failure detection circuit 502 determines whether or not a ceiling fault has occurred in which the resolver 11 and the power supply voltage side are short-circuited, and whether or not a ground fault has occurred in which the resolver 11 and the reference voltage side are short-circuited. , Is detected and the detection result D51 is output. When the detection result D51 determines that a short-circuit failure has occurred, the microcomputer 13 performs processing such as stopping the operation of the resolver 11. Here, in this example, in order to prevent an increase in the number of external terminals of the chip CHP5, a dedicated external terminal to which the potential of the resolver 11 is directly supplied is not provided, but is provided on the chip CHP5 forming the RD converter. The presence or absence of a short-circuit failure of the resolver 11 is detected by using the potentials of the existing external terminals S51 to S54.

However, in the configuration of FIG. 10, the potential of the resolver 11 cannot be accurately detected due to the influence of the input resistance provided outside the chip, and as a result, the presence or absence of a short-circuit failure of the resolver 11 can be accurately detected. There was a problem that it could not be done.

FIG. 11 is a timing chart showing the operation of the electronic control system 5 in a ground fault state. In the example of FIG. 11, the upper timing chart shows the potentials of the ends S1R and S3R of the coil L11, and the lower timing chart shows the potentials of the external terminals S51 and S53. The relationship between the potentials of the ends S2R and S4R and the external terminals S52 and S54 is basically the same as the relationship between the potentials of the ends S1R and S3R and the external terminals S51 and S53, except that they are in opposite phase. Therefore, the description thereof will be omitted.

As shown in FIG. 11, in the normal state (time t50 to t51), the potentials of the ends S1R and S3R of the coil L11 show the shape of a sine wave having an amplitude center potential of about 2.5 V. At this time, the potentials of the external terminals S51 and S53 also show the shape of a sine wave having an amplitude center potential of about 2.5 V.

After that, when the end portion S1R has a ground fault (time t51), the potential of the end portion S1R of the coil L11 is fixed at 0 V (time t51 to t52). On the other hand, the potential of the external terminal S51 corresponding to the end portion S1R is not 0V but an intermediate potential corresponding to the resistance values of the resistance elements R51 and R1 (time t51 to t52). In the example of FIG. 11, the potential of the external terminal S51 in the ground fault state shows about 1.6 V, but it may fluctuate due to the influence of the resistance ratio of the resistance elements R51 and R1 and the variation of the resistance element R51. There is. Therefore, it is difficult to appropriately set the threshold voltage for determining that the end portion S1R is in a ground fault state at the external terminal S51. Similarly, it is difficult to appropriately set the threshold voltage for determining that the end portion S3R is in a ground fault state at the external terminal S53. That is, the electronic control system 5 has a problem that the ground fault of the resolver 11 cannot be accurately detected by using the potential of the existing external terminal of the chip CHP5 forming the RD converter 50.

FIG. 12 is a timing chart showing the operation of the electronic control system 5 in the heavenly state. In the example of FIG. 12, the upper timing chart shows the potentials of the ends S1R and S3R of the coil L11, and the lower timing chart shows the potentials of the external terminals S51 and S53. The relationship between the potentials of the ends S2R and S4R and the external terminals S52 and S54 is basically the same as the relationship between the potentials of the ends S1R and S3R and the external terminals S51 and S53, except that they are in opposite phase. Therefore, the description thereof will be omitted.

As shown in FIG. 12, in the normal state (time t60 to t61), the potentials of the ends S1R and S3R of the coil L11 show the shape of a sine wave having an amplitude center potential of about 2.5 V. At this time, the potentials of the external terminals S51 and S53 also show the shape of a sine wave having an amplitude center potential of about 2.5 V.

After that, when the end portion S1R is entangled (time t61), the potential of the end portion S1R of the coil L11 is fixed at 5 V (time t61 to t62). On the other hand, the potential of the external terminal S51 corresponding to the end portion S1R shows an intermediate potential corresponding to the resistance values of the resistance elements R51 and R1 instead of 5V (time t61 to t62). In the example of FIG. 12, the potential of the external terminal S51 in the ceiling-wound state shows about 3.3 V, but it may fluctuate due to the influence of the resistance ratio of the resistance elements R51 and R1 and the variation of the resistance element R51. There is. Therefore, it is difficult to appropriately set the threshold voltage for determining that the end portion S1R is in the ceiling-wound state at the external terminal S51. Similarly, it is difficult to appropriately set the threshold voltage for determining that the end portion S3R is in the ceiling state at the external terminal S53. That is, the electronic control system 5 has a problem that the ceiling fault of the resolver 11 cannot be accurately detected by using the potential of the existing external terminal of the chip CHP5 forming the RD converter 50.

If the chip CHP5 is provided with a dedicated external terminal to which the potentials of the ends S1R and S3R are directly supplied, the potential of the dedicated external terminal at the time of a short-circuit failure of the ends S1R and S3R is 0V or It is fixed at 5V. Therefore, it is possible to appropriately set the threshold voltage for determining that the ends S1R and S3R are in the short-circuited state at the dedicated external terminal. However, in this case, the number of external terminals of the chip CHP5 increases, and the circuit scale increases.

Therefore, the RD converter 10 according to the first embodiment can be used so that the presence or absence of a short-circuit failure of the resolver 11 can be accurately detected by using the potential of the existing external terminal provided on the chip forming the RD converter. And an electronic control system 1 equipped with it has been found.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration example of the electronic control system 1 according to the first embodiment. The electronic control system 1 is mounted on a vehicle such as an automobile, detects a rotation angle of a rotating body (detection target) such as a rotor, performs predetermined processing based on the detection result, and forms an RD converter. It has a function to accurately detect the presence or absence of a short-circuit failure of the resolver by using the potential of an existing external terminal provided on the chip. Hereinafter, a specific description will be given.

Specifically, the electronic control system 1 is composed of a resolver (detection device) 11 that detects the rotation angle of a rotor (not shown), an RD converter 10 that converts the detection result of the resolver 11 into a digital signal, and an RD converter 10. A microcomputer 13 that performs predetermined processing based on an output digital signal is provided. Since the components other than the RD converter 10 among the components of the electronic control system 1 have already been described, the RD converter 10 will be mainly described below.

The RD converter 10 includes external terminals S1 to S4, T1 to T3, operational amplifiers AP11 and AP12, feedback resistors R13 and R14, resistor elements R11 and R12, switches SW1 to SW4, and the like, which are provided on the chip CHP1. It includes an angle calculation circuit 101, a short circuit failure detection circuit (abnormality detection circuit) 102, a timing control circuit 103, and input resistors R1 to R4 provided outside the chip CHP1. The amplifier circuit 15 is composed of the operational amplifier AP11 and the resistance elements R1, R3, R11, and R13. The amplifier circuit 16 is composed of the operational amplifier AP12 and the resistance elements R2, R4, R12, and R14.

The amplifier circuit 15 amplifies the received signal of the coil L11 including the rotation angle information. The amplifier circuit 16 amplifies the received signal of the coil L12 including the rotation angle information. In other words, the amplifier circuit 15 amplifies the potential difference between the pair of voltage signals output from both ends S1R and S3R of the coil L11. The amplifier circuit 16 amplifies the potential difference between the pair of voltage signals output from both ends S2R and S4R of the coil L12.

Specifically, outside the chip CHP1, the input resistor R1 is provided between the end portion S1R of the coil L11 and the external terminal S1. The input resistor R2 is provided between the end portion S2R of the coil L12 and the external terminal S2. The input resistor R3 is provided between the end portion S3R of the coil L11 and the external terminal S3. The input resistor R4 is provided between the end portion S4R of the coil L12 and the external terminal S4.

Further, on the chip CHP1, a switch SW1 is provided between the non-inverting input terminal of the operational amplifier AP11 and the external terminal S1. A switch SW3 is provided between the inverting input terminal of the operational amplifier AP11 and the external terminal S3. A feedback resistor R13 is provided between the output terminal and the inverting input terminal of the operational amplifier AP11. Further, a common voltage COM is supplied to the non-inverting input terminal of the operational amplifier AP11 via the resistance element R11. A switch SW2 is provided between the non-inverting input terminal of the operational amplifier AP12 and the external terminal S2. A switch SW4 is provided between the inverting input terminal of the operational amplifier AP12 and the external terminal S4. A feedback resistor R14 is provided between the output terminal and the inverting input terminal of the operational amplifier AP12. Further, a common voltage COM is supplied to the non-inverting input terminal of the operational amplifier AP12 via the resistance element R12.

The common voltage COM indicates a voltage level greater than the reference voltage and less than the supply voltage. In this example, the common voltage COM indicates 2.5V, which is an intermediate voltage between a reference voltage of 0V and a power supply voltage of 5V. Therefore, the amplitude center voltage of the voltage signal input to the amplifier circuits 15 and 16 is 2.5 V, which is the common voltage COM. The common voltage COM can be appropriately changed according to the design specifications and the like.

The on / off of switches SW1 to SW4 is controlled by a switching signal from the timing control circuit 103. For example, during the period when the short circuit failure is detected, all the switches SW1 to SW4 are controlled to be off, and during the period when the normal operation is performed, all the switches SW1 to SW4 are controlled to be on. In addition, referring to FIG. 3, the detection of the short circuit failure is performed by the instruction C1 from the microcomputer 13, or is performed periodically.

Here, in the present embodiment, the input resistors R1 and R3 of the input resistors R1 and R3 and the feedback resistors R13 that determine the gain of the amplifier circuit 15 are provided on the board outside the chip CHP1 in a replaceable state. ing. As a result, the gain of the amplifier circuit 15 can be freely adjusted according to the type of resolver, design specifications, and the like. Similarly, of the input resistors R2 and R4 and the feedback resistors R14 that determine the gain of the amplifier circuit 16, the input resistors R2 and R4 are provided on the board outside the chip CHP1 in a replaceable state. As a result, the gain of the amplifier circuit 16 can be freely adjusted according to the type of resolver, design specifications, and the like.

Further, in the present embodiment, resistance elements RH1, RH2, RL1, RL2 are provided for detecting disconnection of the coils L11 and L12.

Specifically, the resistance element RH1 is between a node on the signal line between one end S1R of the coil L11 and the external terminal S1 and a power supply voltage terminal to which a power supply voltage (5V in this example) is supplied. Is provided. A resistance element RL1 is provided between a node on the signal line between the other end S3R of the coil L11 and the external terminal S3 and a reference voltage terminal to which a reference voltage (0V in this example) is supplied. .. A resistance element RH2 is provided between a node on the signal line between one end S2R of the coil L12 and the external terminal S2 and a power supply voltage terminal to which a power supply voltage (5V in this example) is supplied. .. A resistance element RL2 is provided between a node on the signal line between the other end S4R of the coil L12 and the external terminal S4 and a reference voltage terminal to which a reference voltage (0V in this example) is supplied. ..

Here, the resistance elements RH1, RH2, RL1 and RL2 have a resistance ratio such that the amplitude center voltage of the coils L11 and L12 shows a common voltage COM in a normal state, and are more sufficient than the resistance elements R1 to R4 and R11 to R14. It is adjusted to a high resistance value.

The angle calculation circuit 101 converts the output signals (analog signals) of the amplifier circuits 15 and 16 including the rotation angle information into digital signals I1 and outputs the signals. The microcomputer 13 performs a predetermined process based on the digital signal I1. The microcomputer 13 may be provided on the chip CHP1.

(Specific configuration example of the angle calculation circuit 101)
FIG. 2 is a diagram showing a specific configuration example of the RD converter 10.
FIG. 2 shows a specific configuration example of the angle calculation circuit 101.

As shown in FIG. 2, the angle calculation circuit 101 includes an angle deviation calculation circuit 1011, a PI (Proportion-Integral) control circuit 1012, an accumulator counter 1013, a ROM 1014, and a ROM 1015.

The angle deviation calculation circuit 1011 outputs a control signal having a duty ratio according to the difference between the angle φ represented by the digital signal I1 output from the angle calculation circuit 101 and the angle θ detected by the resolver 11. For example, the angle deviation calculation circuit 1011 outputs an L-level control signal when the angle φ is larger than the angle θ, and outputs an H-level control signal when the angle φ is smaller than the angle θ. Therefore, when the angle φ and the angle θ match, the angle deviation calculation circuit 1011 outputs a control signal having a duty ratio of 50%.

More specifically, in the angle deviation calculation circuit 1011 the following equation (1) is executed. However, f (t) indicates an exciting component. f (t) · cosθ indicates the received signal component of the coil L11. f (t) · sin θ indicates the received signal component of the coil L12. cosφ is a value read from ROM 1014 based on the angle φ represented by the digital signal I1. sinφ is a value read from ROM 1015 based on the angle φ represented by the digital signal I1.

f (t), sinθ, cosφ-f (t), cosθ, sinφ ... (1)
= F (t) · sin (θ−φ)
= F (t) · (θ−φ)
= F (t) ・ ε

After that, the exciting component f (t) is removed by synchronous detection, and the value of the control signal of the angle deviation calculation circuit 1011 becomes ε (= θ−φ).

The PI control circuit 1012 serves as a so-called low-pass filter, and outputs the high-frequency component of the control signal from the angle deviation calculation circuit 1011 after removing it. The accumulator counter 1013 integrates the output signal of the PI control circuit 1012 and outputs it as a digital signal I1. The angle φ represented by the digital signal I1 is fed back to the angle deviation calculation circuit 1011 as described above, and forms a closed loop in which sin (θ−φ) = 0. Therefore, the angle calculation circuit 101 calculates φ such that θ = φ and outputs it as a digital signal I1.

Returning to FIG. 1, in the short-circuit failure detection circuit 102, whether or not a ceiling fault has occurred in which the resolver 11 and the power supply voltage side are short-circuited, and a ground fault in which the resolver 11 and the reference voltage side are short-circuited have occurred. It detects whether or not it is doing so and outputs the detection result D1. When the microcomputer 13 determines from the detection result D1 that a short-circuit failure has occurred, the microcomputer 13 performs processing such as stopping the operation of the resolver 11.

Here, in order to prevent the number of external terminals of the chip CHP1 from increasing, the short-circuit failure detection circuit 102 is provided on the chip CHP1 that forms the RD converter 10 without using the potential of the dedicated external terminals. The presence or absence of a short-circuit failure of the resolver 11 is detected by using the potentials of the terminals S1 to S4.

Further, in the mode in which the short-circuit failure is detected (short-circuit failure detection mode), all the switches SW1 to SW4 are controlled to be off. The period for turning off the switches SW1 to SW4 is, for example, about 100 us each time. As a result, in the short-circuit failure detection mode, the common voltage COM is not applied to the external terminals S1 to S4, so that the external terminal connected to the coil end in the ground fault state is fixed to about 0 V, and the coil in the ceiling fault state. The external terminal connected to the end is fixed at about 5V. Therefore, it is possible to appropriately set the threshold voltage for determining that the coil end is in the short-circuited state at the external terminals S1 to S4. As a result, the short-circuit failure detection circuit 102 can accurately detect the short-circuit failure in the resolver 11 by using the potentials of the existing external terminals S1 to S4 of the chip CHP1 forming the RD converter 10.

(Timing chart)
FIG. 4 is a timing chart showing the operation of the electronic control system 1 in a normal state. FIG. 5 is a timing chart showing the operation of the electronic control system 1 in a ground fault state. FIG. 6 is a timing chart showing the operation of the electronic control system 1 in the heavenly state. In the examples of FIGS. 4 to 6, the upper timing chart shows the potentials of the ends S1R and S3R of the coil L11, and the lower timing chart shows the potentials of the external terminals S1 and S3. The relationship between the potentials of the ends S2R and S4R and the external terminals S2 and S4 is basically the same as the relationship between the potentials of the ends S1R and S3R and the external terminals S1 and S3, except that they are in opposite phase. Therefore, the description thereof will be omitted.

First, referring to FIG. 4, in a normal state in which the resolver 11 is not short-circuited, the switches SW1 to SW4 are turned on in the normal operation mode (time t10 to t11, t12 to t13), and the switches SW1 to SW4 are turned off. In any of the short-circuit failure detection modes (time t11 to t12), the potentials of the ends S1R and S3R of the coil L11 show the shape of a sine wave having an amplitude center potential of about 2.5. At this time, the potentials of the external terminals S1 and S3 also show the shape of a sine wave having an amplitude center potential of about 2.5 V.

Next, referring to FIG. 5, in the state where the end portion S1R of the coil L11 is grounded, either the normal operation mode (time t20 to t21, t22 to t23) or the short circuit failure detection mode (time t21 to t22) Even in the case of, the potential of the end portion S1R of the coil L11 is fixed at 0V. On the other hand, in the normal operation mode (time t20 to t21, t22 to t23), the potential of the external terminal S1 corresponding to the end portion S1R shows an intermediate potential according to the resistance values of the resistance elements R11 and R1, but a short-circuit failure occurs. In the detection mode (time t21 to t22), it is fixed at 0V. Therefore, in the short-circuit failure detection mode, the threshold voltage for determining that the end S1R is in a ground fault state can be appropriately set at the external terminal S1. Similarly, in the short-circuit failure detection mode, the threshold voltage for determining that the end S3R is in a ground fault state can be appropriately set at the external terminal S3. Therefore, the electronic control system 1 can accurately detect the ground fault of the resolver 11 by using the existing external terminals S1 and S3 of the chip CHP1 forming the RD converter 10.

Next, referring to FIG. 6, in a state where the end portion S1R of the coil L11 is entangled, either the normal operation mode (time t30 to t31, t32 to t33) or the short circuit failure detection mode (time t31 to t32) Even in the case of, the potential of the end portion S1R of the coil L11 is fixed at 5V. On the other hand, the potential of the external terminal S1 corresponding to the end portion S1R shows an intermediate potential corresponding to the resistance values of the resistance elements R11 and R1 in the normal operation mode (time t30 to t31, t32 to t33), but a short-circuit failure occurs. In the detection mode (time t31 to t32), it is fixed at 5V. Therefore, in the short-circuit failure detection mode, it is possible to appropriately set the threshold voltage at the external terminal S1 for determining that the end portion S1R is in the ceiling fault state. Similarly, in the short-circuit failure detection mode, the threshold voltage for determining that the end S3R is in the ceiling-related state can be appropriately set at the external terminal S3. Therefore, the electronic control system 1 can accurately detect the ceiling fault of the resolver 11 by using the existing external terminals S1 and S3 of the chip CHP1 forming the RD converter 10.

As described above, in the short circuit failure detection mode, the RD converter 10 and the electronic control system 1 provided with the RD converter 10 according to the present embodiment separate the external terminals S1 to S4 from the operational amplifiers AP11 and AP12, and then connect the external terminals S1. The presence or absence of a short-circuit failure of the resolver 11 is detected using the potentials of ~ S4. As a result, the RD converter 10 according to the present embodiment and the electronic control system 1 provided with the RD converter 10 can accurately detect the presence or absence of a short-circuit failure of the resolver 11 without using the potential of the dedicated external terminal. It is possible to suppress an increase in circuit scale.

In the present embodiment, the case where the power supply voltage is 5V, the reference voltage is 0V, and the common voltage is 2.5V has been described as an example, but the present invention is not limited to this, and the common voltage is set to be smaller than the power supply voltage and larger than the reference voltage. If so, the power supply voltage, reference voltage, and common voltage can be changed to arbitrary values. The same can be said for other embodiments.

Further, in the present embodiment, the case where the resistance elements RH1, RH2, RL1 and RL2 are provided outside the chip CHP1 has been described as an example. Specifically, the resistance elements RH1 and RH2 are provided between the node on the signal line between the resolver 11 and the external terminals S1 and S2 and the power supply voltage terminal, and the resistance elements RL1 and RL2 are the resolver 11. The case where the voltage is provided between the node on the signal line between the external terminals S3 and S4 and the reference voltage terminal has been described, but the present invention is not limited to this. The resistance elements RH1, RH2, RL1 and RL2 may be provided inside the chip CHP1. Specifically, the resistance elements RH1 and RH2 are provided between the node on the signal line between the external terminals S1 and S2 and the switches SW1 and SW2 and the power supply voltage terminal, and the resistance elements RL1 and RL2 are It may be provided between the node on the signal line between the external terminals S3 and S4 and the switches SW3 and SW4 and the reference voltage terminal. The same can be said for other embodiments.

Further, in the present embodiment, the case where the amplifier circuit provided in the RD converter amplifies the potential difference of the differential voltage signal supplied as the detection result of the detection device has been described as an example, but the present invention is not limited to this. .. The amplifier circuit provided in the RD converter can be appropriately changed to a configuration that amplifies the single-ended voltage signal supplied as the detection result of the detection device. The same can be said for other embodiments.

(Modification example of RD converter 10)
Subsequently, a modified example of the RD converter 10 will be described with reference to FIG. 7.
FIG. 7 is a diagram showing a modified example of the RD converter 10 as the RD converter 10a.

As shown in FIG. 7, the RD converter 10a includes an angle calculation circuit 101a instead of the angle calculation circuit 101 as compared with the RD converter 10. The angle calculation circuit 101a further includes a clock generation circuit 1016 and a selection circuit 1017 as compared with the angle calculation circuit 101. Since the other configurations of the RD converter 10a are the same as those of the RD converter 10, the description thereof will be omitted.

The clock generation circuit 1016 outputs a clock signal having a duty ratio of 50% as a control signal.

The selection circuit 1017 selects and outputs either the output signal of the angle deviation calculation circuit 1011 or the output signal of the clock generation circuit 1016 based on the switching signal from the timing control circuit 103. For example, the selection circuit 1017 selects and outputs the output signal of the angle deviation calculation circuit 1011 in the normal operation mode, and selects and outputs the output signal of the clock generation circuit 1016 in the short circuit failure detection mode.

Here, in the case of the short-circuit failure detection mode, the clock signal having a duty ratio of 50% is used as the control signal, so that the angle calculation circuit 101a is similar to the state when the angle φ and the angle θ match. In order to determine the state, the value of the digital signal I1 is maintained at the value immediately before the transition to the short circuit failure detection mode. As a result, in the short-circuit failure detection mode, it is possible to prevent the value of the digital signal I1 output from the angle calculation circuit 101a from being unintentionally greatly fluctuated or the angle calculation circuit 101a from being unable to follow the angle. it can.

The period of the clock signal of the clock generation circuit 1016 needs to be sufficiently short so that the digital signal I1 can maintain a stable state. Specifically, the period of the clock signal is, for example, about 2 us.

<Embodiment 2>
FIG. 8 is a diagram showing a configuration example of the electronic control system 2 according to the second embodiment.
The electronic control system 2 is an angle sense system using a hall sensor.

As shown in FIG. 8, the electronic control system 2 includes a hall sensor (detection device) 21, an AD converter 20, and a microcomputer 13. The Hall sensor 21 outputs a voltage signal having an amplitude corresponding to the rotation angle of the rotating body from the ends S1R and S3R. The AD converter 20 converts the detection result (analog signal) of the hall sensor 21 into a digital signal I1 and outputs it, and detects the presence or absence of a short-circuit failure of the hall sensor 21 and outputs the detection result D1. The microcomputer 13 performs a predetermined process based on the digital signal I1 including the angle information output from the AD converter 20. Further, when the AD converter 20 detects a short-circuit failure of the hall sensor 21, the microcomputer 13 performs processing such as stopping the operation of the hall sensor 21.

The AD converter 20 includes an amplifier circuit 15, an angle calculation circuit 101, a short circuit failure detection circuit 102, a timing control circuit 103, and switches SW1 and SW3 among the components of the RD converter 10. The chip CHP2 corresponds to the chip CHP1. Since the operation of the AD converter 20 is basically the same as the operation of the amplifier circuit 15, the angle calculation circuit 101, the short circuit failure detection circuit 102, the timing control circuit 103, and the switches SW1 and SW3 in the RD converter 10. The description will be omitted.

The AD converter 20 and the electronic control system 2 provided with the AD converter 20 according to the present embodiment use the potentials of the external terminals S1 and S3 after disconnecting the external terminals S1 and S3 and the operational amplifier AP11 in the short circuit failure detection mode. The presence or absence of a short-circuit failure of the Hall sensor 21 is detected. As a result, the AD converter 20 according to the present embodiment and the electronic control system 2 provided with the AD converter 20 can accurately detect the presence or absence of a short-circuit failure of the Hall sensor 21 without using the potential of the dedicated external terminal. , The increase in circuit scale can be suppressed.

<Embodiment 3>
FIG. 9 is a diagram showing a configuration example of the electronic control system 3 according to the third embodiment.
The electronic control system 3 is a pressure detection system using a semiconductor pressure sensor.

As shown in FIG. 9, the electronic control system 3 includes a bridge circuit 32 composed of a plurality of resistance elements including a pressure-sensitive resistance element, a constant current source 31 for passing a constant current through the bridge circuit 32, an AD converter 30, and a microcomputer. 13 and. A semiconductor pressure sensor (detector) is configured by the constant current source 31 and the bridge circuit 32.

When a pressure is applied to the semiconductor pressure sensor, the resistance value of the pressure-sensitive resistance element in the bridge circuit 32 changes according to the pressure. As a result, the bridge circuit 32 outputs a voltage signal at a level corresponding to the pressure from the ends S1R and S3R. The AD converter 30 converts the detection result (analog signal) of the semiconductor pressure sensor into a digital signal I1 and outputs it, and detects the presence or absence of a short-circuit failure of the semiconductor pressure sensor and outputs the detection result D1. The microcomputer 13 performs a predetermined process based on the digital signal I1 including the pressure information output from the AD converter 30. Further, when the AD converter 30 detects a short-circuit failure of the semiconductor pressure sensor, the microcomputer 13 performs processing such as stopping the operation of the semiconductor pressure sensor.

The AD converter 30 includes an amplifier circuit 15, a short-circuit failure detection circuit 102, a timing control circuit 103, and switches SW1 and SW3 among the components of the RD converter 10, and includes an AD converter 301 instead of the angle calculation circuit 101. .. The AD converter 301 converts the output signal of the amplifier circuit 15 (a signal obtained by amplifying the voltage signal from the semiconductor pressure sensor) into a digital signal I1 and outputs the signal. The chip CHP3 corresponds to the chip CHP1. The other operations of the AD converter 30 are basically the same as the operations of the amplifier circuit 15, the short circuit failure detection circuit 102, the timing control circuit 103, and the switches SW1 and SW3 in the RD converter 10. Omit.

The AD converter 30 and the electronic control system 3 provided with the AD converter 30 according to the present embodiment use the potentials of the external terminals S1 and S3 after disconnecting the external terminals S1 and S3 and the operational amplifier AP11 in the short circuit failure detection mode. It detects the presence or absence of a short-circuit failure of the semiconductor pressure sensor. As a result, the AD converter 30 according to the present embodiment and the electronic control system 3 provided with the AD converter 30 can accurately detect the presence or absence of a short-circuit failure of the semiconductor pressure sensor without using the potential of the dedicated external terminal. , The increase in circuit scale can be suppressed.

As described above, the converter according to the first to third embodiments and the electronic control system provided with the converter disconnect the existing external terminal provided on the chip forming the converter from the operational amplifier in the short circuit failure detection mode. After that, the presence or absence of a short-circuit failure of the detection device is detected using the existing external terminal. As a result, the converter according to the first to third embodiments and the electronic control system provided with the converter can accurately detect the presence or absence of a short-circuit failure of the detection device without using the potential of the dedicated external terminal. It is possible to suppress an increase in circuit scale.

Although the invention made by the present inventor has been specifically described above based on the embodiments, the present invention is not limited to the embodiments already described, and various changes can be made without departing from the gist thereof. It goes without saying that it is possible.

1 Electronic control system 2 Electronic control system 3 Electronic control system 10 RD converter 10a RD converter 11 Resolver 12 Excitation signal source 13 Microcomputer 15 Amplifier circuit 16 Amplifier circuit 21 Hall sensor 20 AD converter 30 AD converter 31 Constant current source 32 Bridge circuit 101 Angle Calculation circuit 101a Angle calculation circuit 102 Short circuit failure detection circuit 103 Timing control circuit 301 AD converter 1011 Angle deviation calculation circuit 1012 PI control circuit 1013 Amplifier rate counter 1014 ROM
1015 ROM
1016 Clock generation circuit 1017 Selection circuit S1R, S2R, S3R, S4R terminal RH1, RH2 resistance element RL1, RL2 resistance element R1 to R4 resistance element S1 to S4 external terminal T1 to T3 external terminal SW1 to SW4 switch AP11, AP12 CHP2, CHP3 Chip R11-R14 Resistor element

Claims (4)

A detection device configured to output a pair of voltage signals corresponding to the detection results via the first and second signal lines.
The first and second terminals coupled to the first and second signal lines to which the pair of voltage signals are supplied, and the first and second terminals coupled to the first and second terminals, respectively. A semiconductor chip having a detection result converter that generates a detection result conversion signal based on the pair of voltage signals supplied via the terminals, respectively.
A microcomputer configured to perform a predetermined process based on the detection result conversion signal from the semiconductor chip.
A first resistance element coupled between the first signal line and the high potential side power supply terminal,
A second resistance element coupled between the second signal line and the low potential side power supply terminal, and
A first input resistor provided on the first signal line between the first terminal of the semiconductor chip and the detection device, and
A second input resistor provided on the second signal line between the second terminal of the semiconductor chip and the detection device, and
Have,
The detection result converter is
An operational amplifier having first and second input terminals and amplifying a potential difference between the first and second input terminals.
A first feedback resistor coupled between the output of the operational amplifier and the second input terminal of the operational amplifier,
A first switch coupled between the first terminal and the first input terminal of the operational amplifier,
A second switch coupled between the second terminal and the second input terminal of the operational amplifier,
A third resistance element provided between the terminal to which the common voltage is supplied and the first input terminal of the operational amplifier.
When both the first switch and the second switch are in the off state, a short-circuit failure of the detection device is detected based on the respective voltage levels of the first and second terminals of the semiconductor chip. Including a short circuit failure detection circuit configured as
Electronic control system. The electronic control system according to claim 1, further comprising a timing control circuit that controls on / off of the first and second switches. The electronic control system according to claim 1, wherein the first and second switches are on / off controlled based on an instruction from the microcomputer. The detection device is a resolver that detects the rotation angle of the rotor, and the detection result converter further adds an angle calculation circuit that converts the output of the operational amplifier into a digital signal and outputs the digital signal to the microcomputer. The electronic control system according to claim 1.

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