Abnormality processing circuit for integrated circuit and integrated circuit

Abstract

To provide an abnormality processing circuit capable of processing occurrence of short to the ground failure at a feedback terminal as abnormality at startup of an integrated circuit.SOLUTION: An abnormality processing circuit 30 processes operation abnormality of an integrated circuit 1 equipped with a first DC power supply 10 and a second DC power supply 20. In the integrated circuit 1, an output terminal vo1 of the first DC power supply 10 is connected to an input terminal vi2 of the second DC power supply 20 through a first circuit 11, and the input terminal vi2 of the second DC power supply 20 is connected to a feedback terminal FB1 of the first DC power supply 10 through a second circuit 12. The abnormality processing circuit 30 stops the operation of the first DC power supply 10 if the voltage Vi2 at the input terminal vi2 of the second DC power supply 20 exceeds a threshold value voltage Vth.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an integrated circuit fault processing circuit and an integrated circuit. [Background technology]

[0002] There are known semiconductor integrated circuits (hereinafter referred to as "integrated circuits") that incorporate multiple DC power supplies such as DC-DC converter circuits, linear power supply circuits, etc. For example, the integrated circuit described in Non-Patent Document 1 incorporates two step-down DC-DC converter circuits as a first DC power supply and a second DC power supply. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] ROHM BD64547MUV System Motor Driver Datasheet <URL=https: / / fscdn.rohm.com / jp / products / databook / datasheet / ic / motor / printer / bd64547muv-j.pdf>

[0004] [overview] An integrated circuit such as that described in Non-Patent Document 1 may be used in a configuration in which the output of a first DC power supply is connected as the input of a second DC power supply. In such a configuration, if a ground fault occurs in the feedback terminal of the first DC power supply, the output voltage of the first DC power supply may rise during startup, such as during a soft start of the integrated circuit, potentially destroying the integrated circuit. When the integrated circuit is operating, a low voltage at the feedback terminal is an abnormality, so the first DC power supply can be shut down. However, during startup of the integrated circuit, a low voltage at the feedback terminal is a normal state, so the ground fault cannot be treated as an abnormality.

[0005] An object of the present disclosure is to provide an abnormality processing circuit for an integrated circuit, and the integrated circuit, which can process the occurrence of a ground fault abnormality in a feedback terminal as an abnormality when the integrated circuit is started up.

[0006] In order to solve the above-mentioned problems, one aspect of the present disclosure is an abnormality processing circuit that processes an operational abnormality of an integrated circuit equipped with a first DC power supply and a second DC power supply. The integrated circuit is configured such that an output terminal of the first DC power supply is connected to an input terminal of the second DC power supply via a first circuit, and the input terminal of the second DC power supply is connected to a feedback terminal of the first DC power supply via a second circuit. The abnormality processing circuit stops operation of the first DC power supply when the voltage at the input terminal of the second DC power supply exceeds a threshold voltage.

[0007] Another aspect of the present disclosure is an integrated circuit equipped with a first DC power supply and a second DC power supply, and including a first circuit, a second circuit, and an abnormality processing circuit. The first circuit connects an output terminal of the first DC power supply to an input terminal of the second DC power supply. The second circuit connects the input terminal of the second DC power supply to a feedback terminal of the first DC power supply. The abnormality processing circuit stops operation of the first DC power supply when the voltage at the input terminal of the second DC power supply exceeds a threshold voltage. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a circuit diagram showing the configuration of an integrated circuit according to a comparative example. [Figure 2] FIG. 2 is a time chart showing the operation at startup when the feedback terminal of the integrated circuit in the comparative example is not grounded. [Figure 3] FIG. 3 is a time chart showing the operation at startup when a ground fault occurs at the feedback terminal of the integrated circuit in the comparative example. [Figure 4] FIG. 4 is a circuit diagram showing the configuration of an integrated circuit according to an embodiment. [Figure 5] FIG. 5 is a time chart showing the operation at startup when a ground fault occurs at the feedback terminal of the integrated circuit according to the embodiment.

[0009] [Detailed explanation] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are comprehensive or specific examples. The numerical values, components, installation positions, and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in the independent claims that represent the highest concepts will be described as optional components. Furthermore, the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions. Furthermore, the following comparative examples and embodiments may include similar components, and the same symbols will be assigned to the similar components, and redundant explanations will be omitted.

[0010] (Comparative Example) Before describing the integrated circuit according to the embodiment, the configuration of an integrated circuit according to a comparative example will be described with reference to FIG.

[0011] The integrated circuit 1 is equipped with a first DC power supply 10 and a second DC power supply 20. The first DC power supply 10 and the second DC power supply 20 are each a step-down DC-DC converter circuit.

[0012] An input terminal vi1 of the first DC power supply 10 is connected to a power supply terminal IN to which an external power supply is connected. A first end of an input capacitor Ci and a first end of a smoothing capacitor C0 are connected to the connection point between the input terminal vi1 of the first DC power supply 10 and the power supply terminal IN. A second end of the input capacitor Ci and a second end of the smoothing capacitor C0 are connected to ground.

[0013] An output terminal vo1 of the first DC power supply 10 is connected to an input terminal vi2 of the second DC power supply 20 via a first circuit 11. When the first DC power supply 10 is a step-down DC-DC converter circuit, the first circuit 11 includes a reactor L1, a regulating diode D1, and a capacitor C1. A first terminal of the reactor L1 is connected to the output terminal vo1 of the first DC power supply 10, and a second terminal of the reactor L1 is connected to the input terminal vi2 of the second DC power supply 20. The regulating diode D1 has a cathode connected to the first terminal of the reactor L1 and an anode connected to ground. A first terminal of the capacitor C1 is connected to the second terminal of the reactor L1 and a second terminal connected to ground.

[0014] The constant voltage diode D1 may be omitted depending on the configuration of the first DC power supply 10. Furthermore, when the first DC power supply 10 is a linear power supply circuit such as a linear regulator, the first circuit 11 may be an electric wire.

[0015] The input terminal vi2 of the second DC power supply 20 is connected to the feedback terminal FB1 of the first DC power supply 10 via the second circuit 12. The second circuit 12 is a voltage divider circuit that is a series circuit of resistors R11 and R12. A first terminal of the resistor R11 is connected to the input terminal vi2 of the second DC power supply 20, and a second terminal of the resistor R11 is connected to a first terminal of the resistor R12. The second terminal of the resistor R12 is connected to ground. The second terminal of the resistor R11, which is the connection point between the resistors R11 and R12, and the first terminal of the resistor R12 are connected to the feedback terminal FB1 of the first DC power supply 10.

[0016] The output terminal vo2 of the second DC power supply 20 is connected to the external terminal OUT via a third circuit 21. When the second DC power supply 20 is a step-down DC-DC converter circuit, the third circuit 21 includes a reactor L2, a constant voltage diode D2, and a capacitor C2. A first terminal of the reactor L2 is connected to the output terminal vo2 of the second DC power supply 20, and a second terminal of the reactor L2 is connected to the external terminal OUT. The constant voltage diode D2 has a cathode connected to the first terminal of the reactor L2 and an anode connected to ground. The capacitor C2 has a first terminal connected to the second terminal of the reactor L2 and a second terminal connected to ground.

[0017] The constant voltage diode D2 may be omitted depending on the configuration of the second DC power supply 20. Furthermore, when the second DC power supply 20 is a linear power supply circuit such as a linear regulator, the third circuit 21 may be an electric wire.

[0018] The external terminal OUT is connected to the feedback terminal FB2 of the second DC power supply 20 via a fourth circuit 22. The fourth circuit 22 is a voltage divider circuit that is a series circuit of resistors R21 and R22. A first terminal of the resistor R21 is connected to the external terminal OUT, and a second terminal of the resistor R21 is connected to a first terminal of the resistor R22. A second terminal of the resistor R22 is connected to ground. The second terminal of the resistor R21, which is the connection point between the resistors R21 and R22, and the first terminal of the resistor R22 are connected to the feedback terminal FB2 of the second DC power supply 20.

[0019] An enable terminal EN1 of the first DC power supply 10 is connected to an external terminal E0, and an enable signal Ve10 is input from the external terminal E0. For example, when the enable signal Ve10 is at an H level (e.g., 5 V), the operation of the first DC power supply 10 is enabled, and when the enable signal Ve10 is at an L level (e.g., 0 V), the operation of the first DC power supply 10 is disabled and forcibly stopped.

[0020] The DC voltage Vout supplied to the external terminal OUT is supplied as a DC power supply for, for example, an external electronic device.

[0021] Next, with reference to FIG. 2, a description will be given of the operation of the integrated circuit 1 in the comparative example at startup by soft start when the feedback terminal FB1 of the first DC power supply 10 is not grounded.

[0022] When the integrated circuit 1 of the comparative example is soft-started with no ground fault at the feedback terminal FB1 of the first DC power supply 10, a DC voltage Vin of, for example, 32 V input to the power supply terminal IN is input to the input terminal vi1 of the first DC power supply 10. Then, a voltage Vo1 of, for example, 5 V that periodically changes at high frequency is output to the output terminal vo1 of the first DC power supply 10. Then, a voltage Vi2, which is a DC voltage of 5 V obtained by smoothing the 5 V voltage Vo1 that periodically changes at high frequency by the first circuit 11, is input to the input terminal vi2 of the second DC power supply 20. Furthermore, a feedback voltage Vf1 of, for example, 0.8 V obtained by dividing the voltage Vi2 by the second circuit 12 is input to the feedback terminal FB1 of the first DC power supply 10.

[0023] Next, with reference to FIG. 3, a description will be given of the operation of the integrated circuit 1 in the comparative example at startup by soft start when a ground fault abnormality occurs in which the feedback terminal FB1 of the first DC power supply 10 is grounded.

[0024] In the integrated circuit 1 of the comparative example, when the integrated circuit 1 is soft-started while a ground fault abnormality occurs in which the feedback terminal FB1 of the first DC power supply 10 is grounded, the 32V DC voltage Vin input to the power supply terminal IN is input to the input terminal vi1 of the first DC power supply 10. At this time, since the feedback terminal FB1 of the first DC power supply 10 is grounded, the feedback voltage Vf1 becomes 0V. Then, the output terminal vo1 of the first DC power supply 10 outputs a voltage Vo1 that rapidly increases from 0V to 32V and maintains that value. This voltage Vo1 that rapidly increases from 0V to 32V and maintains that value is input to the input terminal vi2 of the second DC power supply 20 as the voltage Vi2. This behavior may damage the integrated circuit 1.

[0025] (Embodiment) Next, referring to FIG. 4, the configuration of the integrated circuit 1 in the embodiment will be described.

[0026] The integrated circuit 1 in the embodiment is different from the comparative example in that an abnormality processing circuit 30 is provided. Since the configuration of the integrated circuit 1 in other embodiments is the same as that of the comparative example, the description thereof is omitted.

[0027] The abnormality processing circuit 30 includes, for example, a comparator 31 and an AND circuit 32. The + input terminal of the comparator 31 is connected to the input terminal vi2 of the second DC power supply 20, and the voltage Vi2 is input. The - input terminal of the comparator 31 is connected to the terminal TH, and a threshold voltage Vth of, for example, 32V is input. A signal obtained by inverting the output of the comparator 31 is input to the first input terminal of the AND circuit 32. The second input terminal of the AND circuit 32 is connected to the external terminal E1, and an enable signal Ve10 is input from the external terminal E1. The output terminal of the AND circuit 32 is connected to the enable terminal EN1 of the first DC power supply 10.

[0028] When Vi2 < Vth, the comparator 31 outputs an L-level signal to the output terminal, and an H-level signal is input to the first input terminal of the AND circuit 32. When the enable signal Ve10 is at the H level, the output signal Ve11 of the AND circuit 32 becomes the H level, and the operation of the first DC power supply 10 becomes effective. On the other hand, when the enable signal Ve10 is at the L level, the output signal Ve11 of the AND circuit 32 becomes the L level, and the operation of the first DC power supply 10 becomes ineffective and is forcibly stopped.

[0029] When the voltage Vi2 input to the input terminal vi2 of the second DC power supply 20 rises and reaches a predetermined threshold voltage Vth, and Vi2=Vth holds, the signal output to the output terminal of the comparator 31 switches from L level to H level. Also, the signal input to the first input terminal of the AND circuit 32 switches from H level to L level. Then, regardless of whether the enable signal Ve10 is H level or L level, an L-level output signal Ve11 from the AND circuit 32 is input to the enable terminal EN1, and the operation of the first DC power supply 10 is disabled and forcibly stopped.

[0030] The set value of the threshold voltage Vth should be greater than the maximum value of the voltage Vi2 at the input terminal vi2 of the second DC power supply 20 during normal operation, and less than or equal to the maximum value of the voltage Vi2 when a ground fault occurs at the feedback terminal FB1 when the integrated circuit 1 is started up.

[0031] When the voltage Vi2 becomes large, an attenuator that attenuates the voltage Vi2 at a predetermined attenuation rate may be provided between the input terminal vi2 of the second DC power supply 20 and the positive input terminal of the comparator 31. By providing the attenuator, the voltage input to the positive input terminal of the comparator 31 can be made smaller than the voltage Vi2, thereby reducing the withstand voltage of the comparator 31. In this case, the set value of the threshold voltage Vth can be set to a small value in accordance with the attenuation rate of the attenuator.

[0032] The configuration of the abnormality processing circuit 30 is not limited to the above, and it is sufficient if the integrated circuit 1 is started by soft starting, and the operation of the first DC power supply 10 can be stopped when the voltage Vi2 input to the input terminal vi2 of the second DC power supply 20 reaches a predetermined threshold voltage Vth.

[0033] The operation of the integrated circuit 1 in the embodiment during startup by soft start when the feedback terminal FB1 of the first DC power supply 10 is not grounded is the same as the operation of the integrated circuit 1 in the comparative example shown in Fig. 2, and therefore a description thereof will be omitted. If the feedback terminal FB1 of the first DC power supply 10 is not grounded, the voltage Vi2 does not rise to the threshold voltage Vth when the integrated circuit 1 is started, and therefore the abnormality processing circuit 30 does not operate. Therefore, when the feedback terminal FB1 of the first DC power supply 10 is not grounded, the integrated circuit 1 operates in the same way in the comparative example and the embodiment.

[0034] Next, with reference to FIG. 5, a description will be given of the operation of the integrated circuit 1 in this embodiment at startup by soft start when a ground fault abnormality occurs in which the feedback terminal FB1 of the first DC power supply 10 is grounded.

[0035] In the integrated circuit 1 according to the embodiment, when the integrated circuit 1 is soft-started while a ground fault occurs at the feedback terminal FB1 of the first DC power supply 10, the DC voltage Vin, for example, 32 V input to the power supply terminal IN is input to the input terminal vi1 of the first DC power supply 10. At this time, because the feedback terminal FB1 of the first DC power supply 10 is grounded, the feedback voltage Vf1 becomes 0 V. The output terminal vo1 of the first DC power supply 10 outputs a voltage Vo1 that rapidly rises from 0 V to 32 V. This voltage Vo1 rapidly rising from 0 V to 32 V is input to the input terminal vi2 of the second DC power supply 20 as the voltage Vi2 and also input to the positive terminal of the comparator 31 of the abnormality processing circuit 30. When the voltage Vi2 reaches, for example, 32 V, which is set as the threshold voltage Vth, the output of the comparator 31 switches from low to high, and the output signal Ve11 of the AND circuit 32 switches from high to low. When an L-level output signal Ve11 is input to the enable terminal EN1 of the first DC power supply 10, the operation of the first DC power supply 10 is disabled and forcibly stopped, so that the voltage Vo1 output by the first DC power supply 10 and the voltage Vi2 input to the second DC power supply 20 become 0V.

[0036] For example, consider a case where a ground fault anomaly is to be determined for the feedback terminal FB1 of the first DC power supply 10 based on the feedback voltage Vf1 at the feedback terminal FB1. In this case, it is difficult to determine whether the slow rise in the feedback voltage Vf1 at the start of the integrated circuit 1 is due to a high load connected to the output terminal vo1 of the first DC power supply 10 or to the occurrence of a ground fault anomaly at the feedback terminal FB1.

[0037] In contrast to this, in the embodiment, when the integrated circuit 1 is started up, if the voltage Vi2 at the input terminal vi2 of the second DC power supply 20 exceeds the threshold voltage Vth, the abnormality processing circuit 30 determines that a ground fault abnormality has occurred at the feedback terminal FB1 and stops the operation of the first DC power supply 10.

[0038] This allows the abnormality processing circuit 30 to reliably process the occurrence of a ground fault abnormality at the feedback terminal FB1 of the first DC power supply 10 as an abnormality when the integrated circuit 1 is started up.

[0039] (Appendix 1) The abnormality processing circuit 30 processes an operational abnormality in the integrated circuit 1 equipped with the first DC power supply 10 and the second DC power supply 20. The integrated circuit 1 is configured such that the output terminal vo1 of the first DC power supply 10 is connected to the input terminal vi2 of the second DC power supply 20 via a first circuit 11, and the input terminal vi2 of the second DC power supply 20 is connected to a feedback terminal FB1 of the first DC power supply 10 via a second circuit 12. The abnormality processing circuit 30 stops the operation of the first DC power supply 10 when the voltage at the input terminal of the second DC power supply 20 exceeds a threshold voltage.

[0040] The abnormality processing circuit 30 can process the occurrence of a ground fault abnormality in the feedback terminal FB1 when the integrated circuit 1 is started as an abnormality.

[0041] (Appendix 2) The abnormality processing circuit 30 described in Supplementary Note 1 includes a comparator 31 having a first input terminal to which a voltage corresponding to the voltage at the input terminal of the second DC power supply 20 is input, and a second input terminal to which a voltage corresponding to a threshold voltage is input. When the voltage Vi2 at the input terminal vi2 of the second DC power supply 20 exceeds the threshold voltage Vth, the abnormality processing circuit 30 stops the operation of the first DC power supply 10 in response to the level of the output voltage of the comparator 31 being switched.

[0042] (Appendix 3) In the abnormality processing circuit 30 described in Supplementary Note 1 or 2, the first DC power supply 10 is a DC / DC converter circuit. The first circuit 11 includes a reactor L1 having a first end connected to an output terminal vo1 of the first DC power supply 10 and a second end connected to an input terminal vi2 of the second DC power supply 20, and a capacitor C1 connected between the second end of the reactor L1 and ground.

[0043] (Appendix 4) In the abnormality processing circuit 30 described in Supplementary Note 1 or 2, the first DC power supply 10 is a linear power supply circuit, and the first circuit 11 is an electric wire connecting the output terminal vo1 of the first DC power supply 10 and the input terminal vi2 of the second DC power supply 20.

[0044] (Appendix 5) In the abnormality processing circuit 30 described in any one of Supplementary Notes 1 to 4, the second circuit 12 is a series circuit of a first resistor R11 and a second resistor R12. A first end of the series circuit is connected to the input terminal vi2 of the second DC power supply 20, and a second end of the series circuit is connected to ground. A connection point between the first resistor R11 and the second resistor R12 is connected to the feedback terminal FB1 of the first DC power supply 10.

[0045] (Appendix 6) The integrated circuit 1 is equipped with a first DC power supply 10 and a second DC power supply 20, and includes a first circuit 11, a second circuit 12, and an abnormality processing circuit 30. The first circuit 11 connects the output terminal vo1 of the first DC power supply 10 to the input terminal vi2 of the second DC power supply 20. The second circuit 12 connects the input terminal vi2 of the second DC power supply 20 to the feedback terminal FB1 of the first DC power supply 10. The abnormality processing circuit 30 stops the operation of the first DC power supply 10 when the voltage at the input terminal vi2 of the second DC power supply 20 exceeds a threshold voltage Vth.

[0046] In the integrated circuit 1, the abnormality processing circuit 30 can process the occurrence of a ground fault abnormality in the feedback terminal FB1 as an abnormality when the integrated circuit 1 is started up. [Explanation of symbols]

[0047] 1. Integrated Circuits 10 1st DC power supply 11 1st circuit 12 Second circuit 20 2nd DC power supply 21 Third circuit 22 4th circuit 30 Abnormality processing circuit 31 Comparator 32 AND Circuit Ci Input capacitor C0, C1, C2 capacitors D1, D2 constant voltage diode L1, L2 reactor R11,R12,R21,R22 Resistor

Claims

1. An abnormality processing circuit for processing an operational abnormality of an integrated circuit equipped with a first DC power supply and a second DC power supply, wherein an output terminal of the first DC power supply is connected to an input terminal of the second DC power supply via a first circuit, and the input terminal of the second DC power supply is connected to a feedback terminal of the first DC power supply via a second circuit; When the voltage at the input terminal of the second DC power supply exceeds a threshold voltage, the operation of the first DC power supply is stopped. Abnormality processing circuit.

2. a comparator having a first input terminal to which a voltage corresponding to a voltage at the input terminal of the second DC power supply is input, and a second input terminal to which a voltage corresponding to the threshold voltage is input; when the voltage at the input terminal of the second DC power supply exceeds the threshold voltage, the operation of the first DC power supply is stopped in response to switching of the output voltage level of the comparator; 2. The abnormality processing circuit according to claim 1.

3. the first DC power supply is a DC / DC converter circuit, the first circuit includes a reactor having a first end connected to the output terminal of the first DC power supply and a second end connected to the input terminal of the second DC power supply, and a capacitor connected between the second end of the reactor and ground.

2. The abnormality processing circuit according to claim 1.

4. the second circuit is a series circuit of a first resistor and a second resistor, a first end of the series circuit is connected to the input terminal of the second DC power supply; a second end of the series circuit connected to ground; a connection point between the first resistor and the second resistor is connected to the feedback terminal of the first DC power supply; The abnormality processing circuit according to any one of claims 1 to 3.

5. An integrated circuit equipped with a first DC power supply and a second DC power supply, a first circuit connecting an output terminal of the first DC power supply and an input terminal of the second DC power supply; a second circuit connecting the input terminal of the second DC power supply and a feedback terminal of the first DC power supply; an abnormality processing circuit that stops operation of the first DC power supply when the voltage at the input terminal of the second DC power supply exceeds a threshold voltage; 1. An integrated circuit comprising:

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