WO2021088516A1 - 检测电路和集成电路 - Google Patents

检测电路和集成电路 Download PDF

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Publication number
WO2021088516A1
WO2021088516A1 PCT/CN2020/114980 CN2020114980W WO2021088516A1 WO 2021088516 A1 WO2021088516 A1 WO 2021088516A1 CN 2020114980 W CN2020114980 W CN 2020114980W WO 2021088516 A1 WO2021088516 A1 WO 2021088516A1
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Prior art keywords
capacitor
resistor
voltage
terminal
circuit
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PCT/CN2020/114980
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English (en)
French (fr)
Inventor
布克迪克
范东恩莫瑞恩
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大唐恩智浦半导体有限公司
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Application filed by 大唐恩智浦半导体有限公司 filed Critical 大唐恩智浦半导体有限公司
Priority to JP2022525894A priority Critical patent/JP7431324B2/ja
Priority to EP20885322.6A priority patent/EP4057015A4/en
Priority to US17/736,936 priority patent/US11668765B2/en
Priority to KR1020227015397A priority patent/KR20220088872A/ko
Publication of WO2021088516A1 publication Critical patent/WO2021088516A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/64—Testing of capacitors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/04—Voltage dividers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R17/00—Measuring arrangements involving comparison with a reference value, e.g. bridge
    • G01R17/02—Arrangements in which the value to be measured is automatically compared with a reference value
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/0038—Circuits for comparing several input signals and for indicating the result of this comparison, e.g. equal, different, greater, smaller (comparing pulses or pulse trains according to amplitude)
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/10—Measuring sum, difference or ratio
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
    • G01R27/2605—Measuring capacitance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/54—Testing for continuity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/56—Testing of electric apparatus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/2851—Testing of integrated circuits [IC]

Definitions

  • the invention relates to the field of integrated circuits, and in particular to a detection circuit for detecting the state of the external capacitance of the integrated circuit.
  • FIG. 1 is a schematic diagram of the structure of an integrated circuit.
  • IC Integrated Circuit
  • FIG. 1 there are shown three pins of an Integrated Circuit (IC) chip 110, which are ground pin 111, unfiltered power pin 113, and filtered power pin 112. .
  • a resistor R is connected between the unfiltered power pin 113 and the filtered power pin 112, and the resistor R belongs to the internal circuit of the integrated circuit chip 110.
  • a capacitor C is connected between the filtered power pin 112 and the ground pin 111.
  • the capacitor C is an external capacitor and does not belong to the integrated circuit chip 110.
  • the resistor R and the capacitor C can form a filter circuit to filter the unfiltered signal of the power supply pin 113 to obtain the filtered signal of the power supply pin 112; on the other hand, because the capacitor voltage drops more slowly than the power supply voltage, Therefore, the capacitor C can play the role of Brownout protection when the voltage of the power supply pin is reduced, that is, provide a certain step-down margin (Brownout Margin) for the power supply voltage.
  • connection between the capacitor C and the pins of the integrated circuit chip 110 may be disconnected, or the parameters of the capacitor C may drift when the ambient temperature, humidity, electric field, etc. change. In these cases, the ripple on the filtered power supply pin 112 will increase, which will affect the performance of the integrated circuit chip 110.
  • the technical problem to be solved by the present invention is to provide a detection circuit and integrated circuit that can conveniently detect the state of the external capacitance of the integrated circuit.
  • the technical solution adopted by the present invention to solve the above technical problems is a detection circuit for detecting the drift or open circuit of the first capacitor on the filtered second power supply terminal, and the second power supply terminal is adapted to pass through the first resistor.
  • the power supply voltage is obtained from the unfiltered first power supply terminal and is adapted to be coupled to the reference potential terminal via the first capacitor to filter the power supply voltage.
  • the detection circuit includes: a second resistor and a second capacitor connected in series, Coupled between the first power terminal and the reference potential terminal, the second resistor and the second capacitor have the same time constant as the first resistor and the first capacitor; the analog power terminal is connected to the Between the second resistor and the second capacitor; and a comparator, coupled to the second power terminal and the simulated power terminal, adapted to detect the filtered power voltage of the second power terminal and the simulated power terminal of the simulated power terminal The voltage difference of the power supply voltage, the voltage difference indicating the degree of drift or open circuit of the first capacitor.
  • the detection circuit further includes: a voltage divider circuit coupled between the comparator and the second power supply terminal to provide the comparator with the filtered power supply voltage Voltage divider; and a voltage divider resistor, coupled between the imitation power terminal and the reference potential terminal, so that the imitation power supply voltage is a divided voltage of the unfiltered power supply voltage of the first power terminal.
  • the second resistor is a variable resistor.
  • the second resistor is adjusted in advance to make the second resistor and the second capacitor have the same time constant as the first resistor and the first capacitor.
  • the capacitance value of the second capacitor is of an order of magnitude lower than the capacitance value of the first capacitor.
  • the detection circuit is integrated in an integrated circuit, and the first power supply terminal, the second power supply terminal, and the reference potential terminal are terminals of the integrated circuit.
  • the detection circuit further includes a first switch for disconnecting the voltage dividing circuit, and a second switch for disconnecting the voltage dividing resistor.
  • the present invention also proposes an integrated circuit, including: an unfiltered first power terminal; a filtered second power terminal suitable for being coupled to the first power terminal via a first resistor, And is coupled to the reference potential terminal via a first capacitor; a second resistor and a second capacitor connected in series are coupled between the first power terminal and the reference potential terminal, and the second resistor and the second capacitor are connected to the The first resistor and the first capacitor have the same time constant; the analog power terminal is connected between the second resistor and the second capacitor; and a comparator is coupled to the second power terminal and the analog power source The terminal is suitable for detecting the voltage difference between the filtered power supply voltage of the second power supply terminal and the simulated power supply voltage of the simulated power supply terminal.
  • the integrated circuit further includes: a voltage divider circuit coupled between the comparator and the second power supply terminal to provide the comparator with the filtered power supply voltage Voltage divider; and a voltage divider resistor, coupled between the imitation power terminal and the reference potential terminal, so that the imitation power supply voltage is a divided voltage of the unfiltered power supply voltage of the first power terminal.
  • the second resistor is a variable resistor.
  • the second resistor is adjusted in advance to make the second resistor and the second capacitor have the same time constant as the first resistor and the first capacitor.
  • the capacitance value of the second capacitor is of an order of magnitude lower than the capacitance value of the first capacitor.
  • it further includes a first switch for disconnecting the voltage dividing circuit, and a second switch for disconnecting the voltage dividing resistor.
  • the integrated circuit is an integrated circuit chip for automobiles.
  • the integrated circuit is a battery controller.
  • the present invention sets the internal RC circuit of the integrated circuit so that the time constant of the internal RC circuit is equal to the time constant of the external RC circuit including the external first capacitor C1.
  • the first capacitor can be detected.
  • the detection circuit and integrated circuit of the present invention can detect the drift degree or open circuit of the first capacitor C1 external to the integrated circuit without adding additional external components, and has the beneficial effects of easy integration and low cost.
  • Figure 1 is a schematic diagram of the structure of an integrated circuit
  • FIG. 2 is a schematic diagram of a circuit structure corresponding to a specific embodiment of the integrated circuit shown in FIG. 1;
  • FIG. 3A is a schematic circuit diagram of a detection circuit according to the first embodiment of the present invention.
  • 3B is a schematic circuit diagram of the detection circuit of the second embodiment of the present invention.
  • FIG. 4 is a schematic circuit diagram of the detection circuit of the third embodiment of the present invention.
  • FIG. 5 is a schematic circuit diagram of a detection circuit of the fourth embodiment of the present invention.
  • FIG. 6 is a schematic diagram of the change of the battery voltage and the voltage and current changes of the internal RC circuit and the external RC circuit when the first capacitor is open in the detection circuit of an embodiment of the present invention
  • FIG. 7 is a schematic diagram of changes in battery voltage ripple and voltage difference when a 70% drift of the first capacitor C1 occurs in the detection circuit of an embodiment of the present invention.
  • FIG. 8A is a schematic structural diagram of an integrated circuit according to the first embodiment of the present invention.
  • FIG. 8B is a schematic structural diagram of an integrated circuit according to the second embodiment of the present invention.
  • FIG. 8C is a schematic structural diagram of an integrated circuit according to the third embodiment of the present invention.
  • FIG. 8D is a schematic structural diagram of an integrated circuit according to the fourth embodiment of the present invention.
  • a component when a component is referred to as being “on another component”, “connected to another component”, “coupled to another component” or “contacting another component”, it can be directly on the other component. On, connected to or coupled to, or in contact with the other component, or an intervening component may be present. In contrast, when a component is referred to as being “directly on,” “directly connected to,” “directly coupled to,” or “directly in contact with” another component, there is no intervening component. Similarly, when the first component is referred to as “electrical contact” or “electrically coupled to” the second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow, even without direct contact between conductive components.
  • FIG. 2 is a schematic diagram of a circuit structure corresponding to a specific embodiment of the integrated circuit shown in FIG. 1.
  • the circuit includes a first power terminal 210, a second power terminal 220, a first capacitor C1 and a first resistor R1, and also includes a reference potential terminal 230.
  • both ends of the first resistor R1 are connected to the first power terminal 210 and the second power terminal 220 respectively.
  • Two ends of the first capacitor C1 are respectively connected to the second power terminal 220 and the reference potential terminal 230.
  • the first power terminal 210, the second power terminal 220 and the first resistor R1 shown in FIG. 2 may all be included in the integrated circuit chip 110 shown in FIG. 1.
  • the first power terminal 210 is connected to the unfiltered power pin 113
  • the second power terminal 220 is connected to the filtered power pin 112
  • the reference potential terminal 230 is connected to the ground pin 111.
  • the resistor R in FIG. 1 is equivalent to the first resistor R1 in FIG. 2, which is connected between the unfiltered power pin 113 and the filtered power pin 112 inside the integrated circuit chip 110.
  • the first capacitor C1 shown in FIG. 2 is equivalent to the capacitor C outside the integrated circuit chip 110 shown in FIG. 1.
  • the first capacitor C1 is external to the integrated circuit chip 110 and is connected between the filtered power pin 112 and the ground pin 111.
  • the first resistor R1 is provided inside the integrated circuit chip 110.
  • the first resistor R1 may also be arranged outside the integrated circuit chip 110, connected between the unfiltered power supply pin 113 and the filtered power supply pin 112, and forms together with the first capacitor C1
  • the RC circuit can act as a low-pass filter.
  • the first power terminal 210 is usually connected to a power source, and the power source may be, for example, a battery. Therefore, the voltage detected on the first power supply terminal 210 is the power supply voltage, and is the unfiltered power supply voltage Vbat1.
  • the filter circuit composed of a first resistor R1 located inside the integrated circuit chip 110 and a first capacitor C1 located outside the integrated circuit chip 110 performs filtering processing on the unfiltered power supply voltage Vbat1 of the first power supply terminal 210, and performs a filtering process on the second
  • the power supply terminal 220 obtains the filtered power supply voltage Vbat2.
  • the reference potential Vss can be detected at the reference potential terminal 230.
  • the reference potential terminal 230 may further include an analog reference potential terminal 231 and a digital reference potential terminal 232.
  • the analog reference potential Vssa can be detected at the analog reference potential terminal 231
  • the digital reference potential Vssd can be detected at the digital reference potential terminal 232.
  • an electrostatic discharge (ESD, Electro-Static Discharge) protection circuit 201 formed by two mutually opposite diodes in parallel is connected between the first power terminal 210 and the second power terminal 220, where The diode is called an ESD diode.
  • ESD Electro-Static Discharge
  • an ESD protection circuit 201 is also connected between the analog reference potential terminal 231 and the digital reference potential terminal 232, which also plays a role of electrostatic discharge protection.
  • the circuit shown in FIG. 2 may also include an internal sensitive circuit (Internal Sensitive Circuit).
  • the internal sensitive circuit (not shown) can be connected between the filtered second power terminal 220 and the reference potential terminal 230.
  • the function of the internal sensitive circuit is to reduce the ripple interference on the second power terminal 220 and provide a longer undervoltage protection time. Specifically, when the circuit is under-voltage, the internal sensitive circuit can make the voltage on the second power terminal 220 drop more slowly than the voltage on the first power terminal 210.
  • the current sensor used for current measurement needs to be connected to the power supply terminal, that is, the current sensor needs to be able to withstand a sufficiently high voltage. Moreover, it is difficult to obtain an accurate current value without affecting other circuit components.
  • FIG. 3A is a schematic circuit diagram of the detection circuit according to the first embodiment of the present invention.
  • the detection circuit includes the integrated circuit structure shown in FIG. 2, and also includes a second resistor R2, a second capacitor C2, an analog power terminal 310, and a comparator 320. Since the ESD diode in FIG. 2 is not necessary, the ESD protection circuit 201 in FIG. 2 is not included in the embodiment shown in FIG. 3A.
  • the reference potential terminal 230 is shown as a separate terminal, which means that the reference potential terminal 230 is not divided into an analog reference potential terminal and a digital reference potential terminal.
  • the second resistor R2 and the second capacitor C2 are connected in series with each other, and are coupled between the first power terminal 210 and the reference potential terminal 230.
  • one end of the second capacitor C2 is connected to one end of the second resistor R2, and the other end of the second capacitor C2 is connected to the reference potential terminal 230.
  • the other end of the second resistor R2 is connected to the first resistor R1 and at the same time is connected to the first power terminal 210.
  • FIG. 3B is a schematic circuit diagram of the detection circuit of the second embodiment of the present invention.
  • the embodiment shown in FIG. 3B adds an electrostatic discharge protection circuit 201 composed of ESD diodes in FIG. 2, and further divides the reference potential terminal 230 into an analog reference potential terminal 231 and Digital reference potential terminal 232.
  • One end of the second capacitor C2 is connected to one end of the second resistor R2, and the other end of the second capacitor C2 is connected to the analog reference potential terminal 231.
  • the detection circuit is incorporated in an integrated circuit, and the first power terminal 210, the second power terminal 220, and the reference potential terminal 230 are terminals of the integrated circuit, respectively. 1 to 3B, the detection circuit can be integrated in the integrated circuit chip 110, and the first power supply terminal 210 is equivalent to the unfiltered power supply pin 113, and the second power supply terminal 220 is equivalent to the filtered power supply pin. 112.
  • the reference potential terminal 230 is equivalent to the ground pin 111.
  • the first resistor R1 and the first capacitor C1 form a first RC circuit
  • the second resistor R2 and the second capacitor C2 form a second RC circuit.
  • the first time constant ⁇ 1 of the first RC circuit and the second time constant ⁇ 2 of the second RC circuit are equal.
  • R1 10Ohm
  • C1 10 ⁇ F
  • R2 1MOhm
  • C2 100pF
  • the imitation power terminal 310 is located between the second resistor R2 and the second capacitor C2.
  • the analog power terminal 310 is connected to an input terminal 321 of the comparator 320, and the voltage signal of the analog power terminal 310, that is, the analog power voltage V0, is used as an input of the comparator 320.
  • the two input terminals 321 and 322 of the comparator 320 are respectively coupled to the analog power terminal 310 and the second power terminal 220, and are suitable for detecting the filtered power voltage Vbat2 of the second power terminal 220 and the analog power voltage V0 of the analog power terminal 310
  • the voltage difference V_diff can be used to indicate the degree of drift or open circuit of the first capacitor C1.
  • V_diff
  • the two inputs of the comparator 320 are analog voltage signals, and the output thereof may be an analog voltage signal or a digital signal.
  • the comparator 320 can compare the input voltages on the two input terminals 321 and 322, and perform a subtraction operation on the two input voltages to obtain a voltage difference V_diff.
  • the output terminal 323 of the comparator 320 can directly output the voltage difference V_diff, or it can set a detection threshold V_th for the comparator 320 as required.
  • the comparator 320 determines the required output terminal 323 according to the relationship between the voltage difference V_diff and the detection threshold V_th. The output result.
  • the output terminal 323 of the comparator 320 when the voltage difference V_diff is greater than the detection threshold V_th, the output terminal 323 of the comparator 320 outputs 1, and when the voltage difference V_diff is less than the detection threshold V_th, the output terminal 323 of the comparator 320 outputs 0. Therefore, according to the output of the comparator 323, the magnitude and the difference between the two input voltages at the input terminals 321 and 322 can be determined.
  • the second resistor R2, the second capacitor C2, and the comparator 320 shown in FIGS. 3A and 3B are all located inside the integrated circuit chip 110.
  • the circuit structure shown in FIGS. 3A and 3B except for the first capacitor C1, all other electronic components belong to the internal circuits of the integrated circuit chip 110.
  • the output terminal 323 of the comparator 320 may be connected to an external component through a pin of the integrated circuit chip 110, or may be inside the integrated circuit chip 110.
  • the first RC circuit composed of the first resistor R1 and the first capacitor C1 is called the external RC circuit
  • the second RC circuit composed of the second resistor R2 and the second capacitor C2 is called the internal RC. Circuit.
  • the inside or outside here refers to the inside or outside of the integrated circuit chip 110. It should be noted that the first resistor R1 in the external RC circuit may belong to the internal circuit of the integrated circuit chip 110.
  • the capacitance value of the second capacitor C2 in the internal RC circuit is orders of magnitude lower than the capacitance value of the first capacitor C1 in the external RC circuit. This is because, on the one hand, the internal RC circuit does not need to transmit power and therefore does not require a large capacitance value; on the other hand, the capacitance of a small capacitance value is also small in size, which can reduce the size of the integrated circuit chip 110.
  • various electronic components including capacitors, resistors, diodes, and comparators can all adopt electronic components commonly used in the art. Moreover, these electronic components are suitable for integration in integrated circuit chips.
  • the time due to the internal RC circuit formed inside the integrated circuit chip 110 The constant is equal to the time constant of the external RC circuit.
  • the output result of the output terminal 323 is also zero.
  • V_diff When the parameters of the first capacitor C1 drift or open, the voltage on the first capacitor C1 is not equal to the voltage on the second capacitor C2. Accordingly, Vbat2 ⁇ V0, then V_diff ⁇ 0.
  • a detection threshold V_th can be set as needed, and the voltage difference V_diff is compared with the detection threshold V_th to determine the degree of drift or open circuit of the first capacitor C1. For example, a first detection threshold V_th1 is set, and if V_diff>V_th1, it is determined that the first capacitor C1 has drifted, and the greater the difference between V_diff and V_th1, the more serious the drift.
  • a second detection threshold V_th2 is set, and if V_diff>V_th2, it is determined that the first capacitor C1 is open.
  • the comparator 320 it can be determined whether the first capacitor C1 is open circuit or drifting, and the degree of drifting.
  • the technical effect of the first and second embodiments shown in FIGS. 3A and 3B is that there is no need to directly measure the current of the first capacitor C1, but the internal RC circuit formed inside the integrated circuit chip 110 makes the internal RC circuit It has the same time constant as the external RC circuit including the first capacitor C1.
  • the voltage of the second capacitor C2 of the internal RC circuit With the voltage of the first capacitor C1 of the external RC circuit, it is possible to determine the value of the first capacitor C1.
  • the degree of drift or open circuit is possible to determine the value of the first capacitor C1.
  • the first power supply terminal 210 and the second power supply terminal 220 are connected to the power supply. Accordingly, the voltage applied to the first capacitor C1 is equal to the power supply voltage, which means that the second capacitor C2 inside the integrated circuit chip 110
  • the voltage on the power supply should also be equal to the power supply voltage. Therefore, for the first and second embodiments shown in FIGS. 3A and 3B, on the one hand, if the power supply voltage is greater than the maximum operating voltage of the total integrated capacitor in the integrated circuit, the second capacitor C2 needs to have a high rated voltage; on the other hand, On the one hand, a capacitor with a high rated voltage has a larger volume, which will increase the volume of the integrated circuit chip 110. In response to this problem, the present invention further proposes the embodiment shown in FIG. 4.
  • Fig. 4 is a schematic circuit diagram of the detection circuit of the third embodiment of the present invention.
  • the third embodiment shown in FIG. 4 adds a voltage divider circuit and a voltage divider resistor on the basis of the detection circuit structure shown in FIG. 3B.
  • the voltage divider circuit is coupled between the comparator 320 and the second power terminal 220 to provide the comparator 320 with a divided voltage of the filtered power supply voltage Vbat2;
  • the voltage divider resistor is coupled between the analog power terminal 310 and the reference potential terminal 230
  • the imitation power supply voltage V0 be the divided voltage of the unfiltered power supply voltage Vbat1 of the first power supply terminal 210.
  • the voltage divider circuit includes a third resistor R3 and a fourth resistor R4.
  • the third resistor R3 and the fourth resistor R4 are connected in series with each other, and are connected between the second power terminal 220 and the reference potential terminal 230 together.
  • One end of the third resistor R3 is connected to the second power supply terminal 220, and the other end is connected to one end of the fourth resistor R4 and an input terminal 322 of the comparator 320; one end of the fourth resistor R4 and one end of the third resistor R3 are connected to each other.
  • One input terminal 322 of the comparator 320 is connected, and the other terminal is connected to the reference potential terminal 230. As shown in FIG.
  • the voltage dividing resistor includes a fifth resistor R5, one end of which is connected to one end of the second resistor R2 and the analog power terminal 310, and the other end is connected to the reference potential terminal 230. Furthermore, one end of the fifth resistor R5 is connected to an input terminal 321 of the comparator 320 through the analog power terminal 310.
  • the voltages input to the two input terminals 321 and 322 of the comparator are divided by a voltage divider circuit and a voltage divider resistor, respectively.
  • the voltage divider circuit (the third resistor R3 and the fourth resistor R4) divides the voltage on the first capacitor C1, which can reduce the voltage on the first capacitor C1;
  • the voltage divider (the fifth resistor R5) divides the voltage on the first capacitor C1;
  • the voltage on the second capacitor C2 is divided, which can reduce the voltage on the second capacitor C2.
  • the present invention does not limit the degree of voltage division required by the voltage divider circuit and the voltage divider resistance, and the desired voltage division result can be controlled by setting specific resistance values and capacitance values.
  • the first RC circuit (external RC circuit) includes a first capacitor C1, a first resistor R1, a third resistor R3, and a fourth resistor R4;
  • the second RC circuit (internal RC circuit) includes a second capacitor C1, a first resistor R1, a third resistor R3, and a fourth resistor R4.
  • the time constant of the first RC circuit can be made equal to the time constant of the second RC circuit, and the voltage input to the two input terminals 321 and 322 of the comparator 320 can be reduced to half of the original value.
  • the voltage divider circuit and the voltage divider resistor also provide a second level of ESD protection for the circuit, so that the comparator 320 Low input voltage transistors can be used at the input.
  • the resistance values therein are set to be relatively high, for example, MOhm-level resistors are used.
  • the detection circuit of the present invention further includes a first switch S1 for disconnecting the voltage dividing circuit and a second switch S2 for disconnecting the voltage dividing resistor.
  • the first switch S1 can be connected in series with the voltage dividing circuit
  • the second switch S2 can be connected in series with the voltage dividing resistor.
  • the first switch S1 and the second switch S2 can be kept closed, and when the voltage divider circuit and the voltage divider resistor are not required, the first switch S1 and the second switch S2 can be kept closed.
  • the second switch S2 is opened to cut off the connection between the voltage divider circuit and the voltage divider resistor and other circuits, thereby avoiding the generation of leakage current.
  • variable capacitors and/or variable resistors may be used in the internal RC circuit. However, due to the large volume of the variable capacitors, variable resistors are used in the embodiments of the present invention.
  • the second resistor R2 may be a variable resistor.
  • the second resistor R2 can be adjusted in advance to make the second resistor R2 and the second capacitor C2 have the same time constant as the first resistor R1 and the first capacitor C1. Specifically, it is possible to measure the time T1 and T2 for the voltage Vc1 on the first capacitor C1 and the voltage Vc2 on the second capacitor C2 to reach a certain preset voltage, respectively.
  • the voltage Vc2 of the second capacitor C2 is greater than that of the first capacitor C1
  • the voltage Vc1 reaches the preset voltage in advance, that is, T2 ⁇ T1, which means that the time constant of the internal RC circuit is smaller than the time constant of the external RC circuit.
  • the size of the second resistor R2 can be adjusted according to the relationship between T1 and T2, so that the time constant of the internal RC circuit is equal to the time constant of the external RC circuit. It can be understood that the method for adjusting the time constant here is only for example, and other methods can also be used to adjust the size of the second resistor R2 so that the time constant of the internal RC circuit is equal to the time constant of the external RC circuit.
  • the fifth resistor R5 and/or the second resistor R2 in the internal RC circuit shown in FIG. 4 may be variable resistors.
  • Fig. 5 is a schematic circuit diagram of a detection circuit of the fourth embodiment of the present invention.
  • the embodiment shown in FIG. 5 adds a sixth resistor R6 in the internal RC circuit.
  • One end of the sixth resistor R6 is simultaneously connected to one end of the second resistor R2 and one end of the fifth resistor R5, and the other end of the sixth resistor R6 is connected to one end of the second capacitor C2 and the analog power terminal 310.
  • the second resistor R2, the fifth resistor R5, the sixth resistor R6, and the second capacitor C2 together form an internal RC circuit. Therefore, each resistance value and capacitance value should be set so that the time constant of the internal RC circuit is equal to the time constant of the external RC circuit.
  • the sixth resistor R6 may be a variable resistor.
  • the resistance value of the sixth resistor R6 can be adjusted between 0 and 300 kOhm.
  • the embodiment shown in FIG. 5 can also be used when the actual capacitance value of the first capacitor C1 and/or the second capacitor C2 is not equal to the nominal value. According to the adjustment method described above, by adjusting the resistance of the sixth resistor R6 Value so that the time constant of the internal RC circuit is actually equal to the time constant of the external RC circuit.
  • an electrostatic discharge protection circuit 201 may be added to the embodiments shown in FIGS. 4 and 5, and the reference potential terminal 230 may be classified as an analog reference For the potential terminal and the digital reference potential terminal, the end of the second capacitor C2 connected to the reference potential terminal 230 is connected to the analog reference potential terminal 231.
  • a detection threshold V_th may be set for the comparator 320, and the comparator 320 will input the voltage difference V_diff on its two input terminals 321, 322 and the detection threshold V_th is compared to determine the degree of drift or open circuit of the first capacitor C1.
  • the detection threshold V_th can be set as needed. The following uses an integrated circuit for car battery management as an example to illustrate a method for determining the detection threshold V_th.
  • the integrated circuit used for car battery management, it includes all the electronic components in the detection circuit described above, and the detection circuit can detect the drift or open circuit of the first capacitor externally connected to the integrated circuit. It can be understood that the integrated circuit can also be applied to other fields other than automobiles that require battery management.
  • FIG. 6 is a schematic diagram of the change of the battery voltage and the voltage and current changes of the internal RC circuit and the external RC circuit when the first capacitor is open in the detection circuit of an embodiment of the present invention.
  • the voltage and current shown in FIG. 6 are based on the detection circuit of the embodiment shown in FIG. 4.
  • the horizontal axis represents time and the unit is ms; the left vertical axis is voltage, and the unit is mV or V; the right vertical axis is current, and the unit is nA.
  • Fig. 6 mainly includes upper and lower parts.
  • the upper part shows the voltage difference V_diff on the two input terminals 321 and 322 of the comparator 320 and the change curve of the current I_C2 on the second capacitor C2 over time; the lower part shows It is the change curve of car battery voltage with time.
  • the supply voltage provided to the car battery changes with a certain slope as the driving current increases.
  • the rate of change of the voltage dV/dt is a constant.
  • the rate of change dV/dt is 0.4V/ms under normal conditions, and can reach 5V/ms under extreme conditions.
  • the unfiltered power supply voltage Vbat1 first decreases at a rate of 0.4V/ms, from about 5.4V at 0ms to about 1.7V, and then increases at a rate of 0.4V/ms. When it is close to 20ms, Vbat1 rises to the original voltage of 5.4 Around V.
  • the comparator 320 is a self-return-to-zero comparator.
  • FIG. 6 also shows the change curve of the current I_C2 on the second capacitor C2 over time. While the unfiltered power supply voltage Vbat1 starts to increase at a rate of 0.4V/ms from about 11ms, the current I_C2 is basically maintained at about 20nA.
  • the detection threshold V_th can be determined by analyzing the ripple of the battery voltage.
  • high-frequency ripple interference will be caused due to the inverse conversion flow, and the frequency of the ripple interference is related to the driving speed of the car.
  • Most of the harmonics in this ripple are between 1.6kHz and 15kHz.
  • the peak-to-peak ripple can reach 0.5Vpp.
  • FIG. 7 is a schematic diagram of changes in battery voltage ripple and voltage difference when the first capacitor C1 drifts by 70% in the detection circuit of an embodiment of the present invention.
  • the detection circuit shown in FIG. 7 is also based on the embodiment shown in FIG. 4.
  • the horizontal axis represents time and the unit is ms; the left vertical axis is voltage and the unit is mV or V.
  • Fig. 7 mainly includes upper and lower parts. The upper part shows the change curve of the car battery voltage Vbat1 with time; the lower part shows that when the actual value of the first capacitor C1 is 70% of the nominal value, the comparator 320 The time curve of the voltage difference V_diff on the two input terminals 321 and 322 of. It can be seen from the upper part of Figure 7 that the battery voltage has a significant ripple due to the reverse conversion current.
  • the ripple generated by the vehicle inverter can be used to detect the open circuit or drift of the first capacitor C1, and no additional current generator is required.
  • V_th such as 10mV
  • the car battery voltage Vbat1 will produce more obvious ripples.
  • the ripple amplitude in the car battery voltage Vbat1 is low, and the voltage difference V_diff is too small to be detected.
  • the drift or open circuit of the first capacitor C1 affects the accuracy of the circuit The control effect is also small, so it can be ignored.
  • FIG. 8A is a schematic structural diagram of an integrated circuit according to the first embodiment of the present invention.
  • the integrated circuit 800 includes an unfiltered first power terminal 210; a filtered second power terminal 220, which is adapted to be coupled to the first power terminal 210 via a first resistor R1, and is coupled to the first power terminal 210 via a first resistor R1.
  • the capacitor C1 is coupled to the reference potential terminal 230; the second resistor R2 and the second capacitor C2 connected in series are coupled between the first power terminal 210 and the reference potential terminal 230, and the second resistor R2 and the second capacitor C2 are connected to the first
  • the resistor R1 and the first capacitor C1 have the same time constant; the analog power terminal 310 is connected between the second resistor R2 and the second capacitor C2; the comparator 320 is coupled to the second power terminal 320 and the analog power terminal 310, suitable For detecting the voltage difference between the filtered power supply voltage Vbat2 of the second power supply terminal 220 and the simulated power supply voltage V0 of the simulated power supply terminal 310.
  • the first capacitor C1 is externally connected to the integrated circuit 800.
  • the first RC circuit composed of the first resistor R1 and the first capacitor C1 is referred to as an external RC circuit
  • the second RC circuit composed of the second resistor R2 and the second capacitor C2 is referred to as an internal RC circuit.
  • the integrated circuit 800 shown in FIG. 8A includes the detection circuit shown in FIG. 3A. Therefore, the description of the detection circuit shown in FIG. 3A in this specification is applicable to the integrated circuit shown in FIG. 8A. Circuit.
  • FIG. 8B is a schematic structural diagram of an integrated circuit according to the second embodiment of the present invention.
  • the embodiment shown in FIG. 8B adds an electrostatic discharge protection circuit 201 composed of ESD diodes in FIG. 2, and further divides the reference potential terminal 230 into an analog reference potential terminal 231 and Digital reference potential terminal 232.
  • One end of the second capacitor C2 is connected to one end of the second resistor R2, and the other end of the second capacitor C2 is connected to the analog reference potential terminal 231.
  • the integrated circuit 810 shown in FIG. 8B includes the detection circuit shown in FIG. 3B. Therefore, the description of the detection circuit shown in FIG. 3B in this specification is applicable to the integrated circuit shown in FIG. 8B. Circuit.
  • FIG. 8C is a schematic structural diagram of an integrated circuit according to the third embodiment of the present invention.
  • the integrated circuit 820 of this embodiment adds a voltage divider circuit and a voltage divider resistor on the basis of the embodiment shown in FIG. 8A.
  • the voltage dividing circuit is coupled between the comparator 230 and the second power terminal 220 to provide the comparator 230 with a divided voltage of the filtered power supply voltage Vbat2; and the voltage dividing resistor is coupled between the analog power terminal 310 and the reference potential terminal 230 , So that the simulated power supply voltage V0 is the divided voltage of the unfiltered power supply voltage Vbat1 of the first power supply terminal 210.
  • the integrated circuit 820 shown in Figure 8C includes the detection circuit shown in Figure 4, so the description of the detection circuit shown in Figure 4 in this specification is applicable to the integrated circuit shown in Figure 8C Circuit.
  • the second resistor R2 in FIGS. 8A-8C is a variable resistor.
  • the second resistor R2 is adjusted in advance so that the second resistor R2 and the second capacitor C2 have the same time constant as the first resistor R1 and the first capacitor C1.
  • the capacitance value of the second capacitor C2 is orders of magnitude lower than the capacitance value of the first capacitor C1.
  • FIG. 8C it further includes a first switch S1 for disconnecting the voltage dividing circuit, and a second switch S2 for disconnecting the voltage dividing resistor.
  • FIG. 8D is a schematic structural diagram of an integrated circuit according to the fourth embodiment of the present invention. Compared with the embodiment shown in FIG. 8C, the embodiment shown in FIG. 8D adds a sixth resistor R6 in the internal RC circuit. With reference to Figures 5 and 8D, the integrated circuit 830 shown in Figure 8D includes the detection circuit shown in Figure 5, so the description of the detection circuit shown in Figure 5 in this specification is applicable to the integrated circuit shown in Figure 8D Circuit.
  • FIGS. 8A-8D is a list corresponding to the embodiment of the detection circuit shown in FIGS. 3A-5.
  • an electrostatic discharge protection circuit 201 can be added to FIGS. 8C and 8D, and the reference potential terminal 230 is divided into an analog reference potential terminal and a digital reference potential terminal, so that the second capacitor C2 is connected to the reference potential terminal 230 One end of is connected to the analog reference potential terminal 231.
  • the integrated circuit shown in Figures 8A-8D is a battery controller.
  • the degree of drift or open circuit of the first capacitor C1 of the external capacitor can be detected.
  • the detection threshold V_th for the comparator 320 and how to use the obtained voltage difference V_diff to determine the state of the first capacitor C1
  • the detection circuit and integrated circuit of the present invention can be used in any circuit that requires functional safety protection, can detect the drift or open circuit of the external capacitor of the integrated circuit, and is not limited to the car battery management integrated circuit in the specific embodiment of the present invention.
  • this application uses specific words to describe the embodiments of this application.
  • “one embodiment”, “an embodiment”, and/or “some embodiments” mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that “an embodiment” or “an embodiment” or “an alternative embodiment” mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. .
  • some features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

Abstract

一种检测电路和集成电路，用于检测经过滤的第二电源端（220）上的第一电容（C1）的漂移或开路，第二电源端（220）适于经第一电阻（R1）从未过滤的第一电源端（210）获取电源电压，且适于经第一电容（C1）耦接到参考电位端（230）以过滤电源电压。检测电路包括串联的第二电阻（R2）和第二电容（C2），耦接在第一电源端（210）和参考电位端（230）之间，第二电阻（R2）和第二电容（C2）与第一电阻（R1）和第一电容（C1）具有相同的时间常数；仿电源端（310），连接在第二电阻（R2）和第二电容（C2）之间；以及比较器（320），耦接第二电源端（220）和仿电源端（310），适于检测第二电源端（220）的经过滤电源电压和仿电源端（310）的仿电源电压的电压差，电压差指示第一电容（C1）的漂移程度或开路。可以对集成电路外接电容的漂移程度或开路进行检测，具有易于集成和低成本的优点。

Description

检测电路和集成电路 技术领域
本发明涉及集成电路领域，尤其涉及一种用于检测集成电路外接电容状态的检测电路。
背景技术
图1是一种集成电路的结构示意图。参考图1所示，其中示出了一集成电路(IC，Integrated Circuit)芯片110的三个管脚，分别是接地管脚111、未经滤波的电源管脚113和经滤波的电源管脚112。在未经滤波的电源管脚113和经滤波的电源管脚112之间连接有一电阻R，该电阻R属于该集成电路芯片110的内部电路。在经滤波的电源管脚112和接地管脚111之间连接有一电容C，该电容C为一外接电容，不属于该集成电路芯片110。电阻R和电容C一方面可以组成滤波电路对未经滤波的电源管脚113的信号进行滤波，获得经滤波的电源管脚112的信号；另一方面，由于电容电压下降的比电源电压慢，因此电容C可以在电源管脚的电压降低时起到欠压(Brownout)保护的作用，即为电源电压提供一定的降压空间(Brownout Margin)。
在某些情况下，电容C与集成电路芯片110的管脚之间的连接会断开，或者当环境温度、湿度、电场等发生改变时电容C的参数会发生漂移。在这些情况下，经滤波的电源管脚112上的纹波(Ripple)会增加，从而对集成电路芯片110的性能产生影响。
在ISO 26262《道路车辆功能安全》国际标准中，通常要求车用集成电路具有诊断其管脚短路或开路的功能。为了测量车用集成电路芯片的电源管脚和外接电容之间的开路状态，可以在电源管脚上增加一个交流(AC，Alternating Current)电流负载并测量其交流纹波，但是这种方法需要相当高的电流，并且所产生的交流纹波对芯片的性能会造成不良的影响。因此，需要采用更加可靠、便捷的方法来测量芯片管脚和外接电容之间的开路状态以及外接电容的参数漂移状态。
发明内容
本发明所要解决的技术问题是提供一种可以方便检测集成电路外接电容状态的检测电路和集成电路。
本发明为解决上述技术问题而采用的技术方案是一种检测电路，用于检测经过滤的第二电源端上的第一电容的漂移或开路，所述第二电源端适于经第一电阻从未过滤的第一电源端获取电源电压，且适于经所述第一电容耦接到参考电位端以过滤所述电源电压，所述检测电路包括：串联的第二电阻和第二电容，耦接在所述第一电源端和所述参考电位端之间，所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数；仿电源端，连接在所述第二电阻和第二电容之间；以及比较器，耦接所述第二电源端和所述仿电源端，适于检测所述第二电源端的经过滤电源电压和所述仿电源端的仿电源电压的电压差，所述电压差指示所述第一电容的漂移程度或开路。
在本发明的一实施例中，所述检测电路还包括：分压电路，耦接在所述比较器与所述第二电源端之间以向所述比较器提供所述经过滤电源电压的分压；以及分压电阻，耦接在所述仿电源端与所述参考电位端之间，以使所述仿电源电压为所述第一电源端的未过滤电源电压的分压。
在本发明的一实施例中，所述第二电阻是可变电阻。
在本发明的一实施例中，所述第二电阻被预先调整到使所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数。
在本发明的一实施例中，所述第二电容的电容值的数量级低于所述第一电容的电容值。
在本发明的一实施例中，所述检测电路是结合在集成电路中，且所述第一电源端、第二电源端和参考电位端是所述集成电路的端子。
在本发明的一实施例中，所述检测电路还包括用于断开所述分压电路的第一开关，以及断开所述分压电阻的第二开关。
本发明为解决上述技术问题还提出了一种集成电路，包括：未经过滤的第一电源端；经过滤的第二电源端，适于经第一电阻耦接到所述第一电源端，且经第一电容耦接到参考电位端；串联的第二电阻和第二电容，耦接在所述第一电源端和所述参考电位端之间，所述第二电阻和第二电容与所述第一电阻和第一电容具有相同 的时间常数；仿电源端，连接在所述第二电阻和第二电容之间；以及比较器，耦接所述第二电源端和所述仿电源端，适于检测所述第二电源端的经过滤电源电压和所述仿电源端的仿电源电压的电压差。
在本发明的一实施例中，所述集成电路还包括：分压电路，耦接在所述比较器与所述第二电源端之间以向所述比较器提供所述经过滤电源电压的分压；以及分压电阻，耦接在所述仿电源端与所述参考电位端之间，以使所述仿电源电压为所述第一电源端的未过滤电源电压的分压。
在本发明的一实施例中，所述第二电阻是可变电阻。
在本发明的一实施例中，所述第二电阻被预先调整到使所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数。
在本发明的一实施例中，所述第二电容的电容值的数量级低于所述第一电容的电容值。
在本发明的一实施例中，还包括用于断开所述分压电路的第一开关，以及断开所述分压电阻的第二开关。
在本发明的一实施例中，所述集成电路是用于汽车的集成电路芯片。
在本发明的一实施例中，所述集成电路是电池控制器。
本发明通过对集成电路的内部RC电路进行设置，使内部RC电路的时间常数等于包括外接第一电容C1在内的外部RC电路的时间常数，通过比较内部电容和外部电容的电压，可以检测第一电容C1的漂移程度或开路状态。本发明的检测电路和集成电路无需增加额外的外部元件，即可实现对集成电路外接第一电容C1的漂移程度或开路进行检测，具有易于集成、成本低的有益效果。
附图概述
为让本发明的上述目的、特征和优点能更明显易懂，以下结合附图对本发明的具体实施方式作详细说明，其中：
图1是一种集成电路的结构示意图；
图2是对应于图1所示的集成电路的一种具体实施例的电路结构示意图；
图3A是本发明实施例一的检测电路的电路示意图；
图3B是本发明实施例二的检测电路的电路示意图；
图4是本发明实施例三的检测电路的电路示意图；
图5是本发明实施例四的检测电路的电路示意图；
图6是本发明一实施例的检测电路在第一电容开路时电池电压的变化及内部RC电路和外部RC电路的电压电流变化示意图；
图7是本发明一实施例的检测电路在第一电容C1发生70％漂移时的电池电压纹波和电压差的变化示意图；
图8A是本发明实施例一的集成电路的结构示意图；
图8B是本发明实施例二的集成电路的结构示意图；
图8C是本发明实施例三的集成电路的结构示意图；
图8D是本发明实施例四的集成电路的结构示意图。
本发明的较佳实施方式
为了更清楚地说明本申请的实施例的技术方案，下面将对实施例描述中所需要使用的附图作简单的介绍。显而易见地，下面描述中的附图仅仅是本申请的一些示例或实施例，对于本领域的普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图将本申请应用于其他类似情景。除非从语言环境中显而易见或另做说明，图中相同标号代表相同结构或操作。
如本申请和权利要求书中所示，除非上下文明确提示例外情形，“一”、“一个”、“一种”和/或“该”等词并非特指单数，也可包括复数。一般说来，术语“包括”与“包含”仅提示包括已明确标识的步骤和元素，而这些步骤和元素不构成一个排它性的罗列，方法或者设备也可能包含其他的步骤或元素。
除非另外具体说明，否则在这些实施例中阐述的部件和步骤的相对布置、数字表达式和数值不限制本申请的范围。同时，应当明白，为了便于描述，附图中所示出的各个部分的尺寸并不是按照实际的比例关系绘制的。对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论，但在适当情况下，所述技术、方法和设备应当被视为授权说明书的一部分。在这里示出和讨论的所有示例中，任何具体值应被解释为仅仅是示例性的，而不是作为限制。因此，示例性实施例的其它示例可以具有不同的值。应注意到：相似的标号和字母在 下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步讨论。
应当理解，当一个部件被称为“在另一个部件上”、“连接到另一个部件”、“耦合于另一个部件”或“接触另一个部件”时，它可以直接在该另一个部件之上、连接于或耦合于、或接触该另一个部件，或者可以存在插入部件。相比之下，当一个部件被称为“直接在另一个部件上”、“直接连接于”、“直接耦合于”或“直接接触”另一个部件时，不存在插入部件。同样的，当第一个部件被称为“电接触”或“电耦合于”第二个部件，在该第一部件和该第二部件之间存在允许电流流动的电路径。该电路径可以包括电容器、耦合的电感器和/或允许电流流动的其它部件，甚至在导电部件之间没有直接接触。
此外，需要说明的是，使用“第一”、“第二”等词语来限定零部件，仅仅是为了便于对相应零部件进行区别，如没有另行声明，上述词语并没有特殊含义，因此不能理解为对本申请保护范围的限制。此外，尽管本申请中所使用的术语是从公知公用的术语中选择的，但是本申请说明书中所提及的一些术语可能是申请人按他或她的判断来选择的，其详细含义在本文的描述的相关部分中说明。此外，要求不仅仅通过所使用的实际术语，而是还要通过每个术语所蕴含的意义来理解本申请。
图2是对应于图1所示的集成电路的一种具体实施例的电路结构示意图。参考图2所示，该电路包括第一电源端210、第二电源端220、第一电容C1和第一电阻R1，还包括参考电位端230。其中，第一电阻R1的两端分别和第一电源端210、第二电源端220相连接。第一电容C1的两端分别和第二电源端220、参考电位端230相连接。结合图1和图2所示，图2中所示的第一电源端210、第二电源端220和第一电阻R1都可以包含在图1所示的集成电路芯片110内部。其中，第一电源端210和未经滤波的电源管脚113相连接，第二电源端220和经滤波的电源管脚112相连接，参考电位端230和接地管脚111相连接。
图1中的电阻R相当于图2中的第一电阻R1，其在集成电路芯片110内部连接于未经滤波的电源管脚113和经滤波的电源管脚112之间。图2中所示的第一电容C1相当于图1中所示的处于集成电路芯片110外部的电容C。该 第一电容C1在集成电路芯片110的外部，并且连接于经滤波的电源管脚112和接地管脚111之间。
通常，为了降低成本、缩小电路尺寸，会尽量减少集成电路外接电子元件的数量。因此，在图1和图2所示的电路结构中，第一电阻R1设置在集成电路芯片110内部。在一些实施例中，该第一电阻R1也可以设置在集成电路芯片110的外部，连接在未经滤波的电源管脚113和经滤波的电源管脚112之间，和第一电容C1一起构成RC电路，可以起到低通滤波器的作用。
参考图2所示，第一电源端210通常和电源相连接，该电源可以是例如电池。因此在第一电源端210上所检测到的电压为电源电压，并且是未经过滤的电源电压Vbat1。由位于集成电路芯片110内部的第一电阻R1和位于集成电路芯片110外部的第一电容C1组成的滤波电路对第一电源端210的未经过滤的电源电压Vbat1进行滤波处理，并在第二电源端220获得经过滤波电源电压Vbat2。
参考图2所示，在参考电位端230可以检测到参考电位Vss。在该检测电路中，参考电位端230可以进一步地包括模拟参考电位端231和数字参考电位端232。相应地，在模拟参考电位端231可以检测到模拟参考电位Vssa，在数字参考电位端232可以检测到数字参考电位Vssd。
在一些实施例中，在第一电源端210和第二电源端220之间还连接有由两个相互反向的二极管并联形成的静电放电(ESD，Electro-Static Discharge)保护电路201，这里的二极管被称为ESD二极管。在发生静电放电时，电路中的静电尖峰电压可以被ESD保护电路201中的ESD二极管钳制在规定范围内，从而保护芯片的稳定工作。在一些实施例中，在模拟参考电位端231和数字参考电位端232和之间也连接有ESD保护电路201，同样起到静电放电保护的作用。
在图2所示的电路中，还可以包括内部敏感电路(Internal Sensitive Circuit)。该内部敏感电路(图未示)可以连接在经过滤的第二电源端220和参考电位端230之间。内部敏感电路的功能在于可以减少第二电源端220上的纹波干扰，并且提供更长的欠压保护时间。具体地，在电路发生欠压时，内部敏感电路可以使第二电源端220上的电压下降比第一电源端210上的电压下降更慢。
通常，为了测量第一电容C1与集成电路芯片110的连接情况，即检测第一电容C1是否开路或参数发生漂移，需要测量流经第一电容C1的电流。然而，根据现有的测量技术，用于电流测量的电流传感器需要和电源端相连接，也就是说，该电流传感器需要能够承受足够高的电压。并且，在不影响其它电路元件的情况下，很难得到准确的电流值。
图3A是本发明实施例一的检测电路的电路示意图。参考图3A所示，该检测电路包括图2所示的集成电路结构，并且还包括第二电阻R2、第二电容C2、仿电源端310和比较器320。由于图2中的ESD二极管并不是必须的，因此，在图3A所示的实施例中不包括图2中的静电放电保护电路201。并且，在图3A所示的实施例中，参考电位端230显示为一个单独的端子，表示该参考电位端230没有区分为模拟参考电位端和数字参考电位端。
在图3A所示的实施例中，第二电阻R2和第二电容C2相互串联，并且耦接在第一电源端210和参考电位端230之间。如图3A所示，第二电容C2的一端和第二电阻R2的一端相连接，第二电容C2的另一端连接到参考电位端230。第二电阻R2的另一端和第一电阻R1相连接，同时连接到第一电源端210。
图3B是本发明实施例二的检测电路的电路示意图。与图3A所示的实施例相比，图3B所示的实施例中增加了图2中由ESD二极管构成的静电放电保护电路201，并且将参考电位端230进一步分为模拟参考电位端231和数字参考电位端232。其中，第二电容C2的一端和第二电阻R2的一端相连接，第二电容C2的另一端连接到模拟参考电位端231。
在一些实施例中，检测电路是结合在集成电路中，且第一电源端210、第二电源端220和参考电位端230分别是该集成电路的端子。结合图1至图3B所示，检测电路可以结合在集成电路芯片110中，并且第一电源端210相当于未经滤波的电源管脚113，第二电源端220相当于经滤波的电源管脚112，参考电位端230相当于接地管脚111。
第一电阻R1和第一电容C1组成第一RC电路，第二电阻R2和第二电容C2组成第二RC电路。在本发明的实施例中，第一RC电路的第一时间常数τ1和第二RC电路的第二时间常数τ2相等。例如，在一具体实施例中，R1＝10Ohm、C1＝10μF、R2＝1MOhm、C2＝100pF，则
τ1＝R1*C1＝100μs；
τ2＝R2*C2＝100μs；
τ1＝τ2。
仿电源端310位于第二电阻R2和第二电容C2之间。仿电源端310与比较器320的一个输入端321相连接，仿电源端310的电压信号，即仿电源电压V0，作为比较器320的一个输入。
比较器320的两个输入端321、322分别和仿电源端310、第二电源端220耦接，适于检测第二电源端220的经过滤波电源电压Vbat2和仿电源端310的仿电源电压V0的电压差V_diff，该电压差V_diff可以用于指示第一电容C1的漂移程度或开路。即，
V_diff＝|Vbat2-V0|
其中，||表示取绝对值。
通常，比较器320的两路输入为模拟电压信号，其输出可以是模拟电压信号或数字信号。比较器320可以对两个输入端321、322上的输入电压进行比较，对两个输入电压进行相减运算得到电压差V_diff。比较器320的输出端323可以直接输出该电压差V_diff，也可以根据需要为比较器320设置一检测阈值V_th，比较器320根据电压差V_diff和检测阈值V_th的大小关系来决定其输出端323所要输出的结果。例如，当电压差V_diff大于该检测阈值V_th时，比较器320的输出端323输出为1，当电压差V_diff小于该检测阈值V_th时，比较器320的输出端323输出为0。因此，根据比较器323的输出可以判断其输入端321、322上的两个输入电压的大小及其差距。
在一些实施例中，结合图1至图3B所示，在图3A和3B中所示的第二电阻R2、第二电容C2和比较器320都位于集成电路芯片110的内部。在这些实施例中，在图3A和3B所示的电路结构中，除第一电容C1外，其余电子元件全都属于集成电路芯片110的内部电路。比较器320的输出端323可以通过集成电路芯片110的一个管脚与外部元件相连接，也可以在集成电路芯片110的内部。
在本说明书中的一些地方将第一电阻R1和第一电容C1所组成的第一RC电路称为外部RC电路，将第二电阻R2和第二电容C2组成的第二RC电路称为内部RC电路。这里的内部或外部是指处于集成电路芯片110的内部或外部。 需要注意的是，外部RC电路中的第一电阻R1可以属于集成电路芯片110的内部电路。
在一些实施例中，内部RC电路中的第二电容C2的电容值的数量级低于外部RC电路中的第一电容C1的电容值。这是由于，一方面，内部RC电路无需传递功率，因此不需要大的电容值；另一方面，电容值小的电容体积也较小，可以减小集成电路芯片110的尺寸。
在图3A和3B所示的实施例中，各个电子元件包括电容、电阻、二极管以及比较器等都可以采用本领域常用的电子元件。并且，这些电子元件都适于集成在集成电路芯片中。
根据图3A和3B所示的实施例，当第一电容C1正常地连接于第二电源端220和参考电位端230之间时，由于在集成电路芯片110的内部所形成的内部RC电路的时间常数等于外部RC电路的时间常数，当内部RC电路和外部RC电路的输入电压相等时，则第二电容C2和第一电容C1上的电压也应该相等，相应地，Vbat2＝V0，从而使比较器320的两个输入端321、322上的输入电压相等。相应地，电压差V_diff为零，从而进一步地影响比较器323的输出端323的输出结果。例如，对于输出端323直接输出电压差V_diff的比较器320来说，该输出端323的输出结果也为零。
当第一电容C1的参数发生漂移或开路时，第一电容C1上的电压不等于第二电容C2上的电压，相应地，Vbat2≠V0，则V_diff≠0。对于可以设置检测阈值V_th的比较器320来说，可以根据需要设置一检测阈值V_th，并将电压差V_diff和检测阈值V_th进行比较，从而判断第一电容C1的漂移程度或开路。例如，设置一第一检测阈值V_th1，如果V_diff＞V_th1，则判断第一电容C1发生漂移，并且V_diff和V_th1的差值越大，该漂移程度越严重。例如，设置一第二检测阈值V_th2，如果V_diff＞V_th2，则判断第一电容C1发生开路。
因此，根据比较器320的输出结果可以判断第一电容C1是否开路或发生漂移，以及发生漂移的程度等。
图3A和3B所示的实施例一和二的技术效果在于，不需要直接对第一电容C1的电流进行测量，而是通过在集成电路芯片110内部形成的内部RC电路，使该内部RC电路和包括第一电容C1在内的外部RC电路具有相同的时间常 数，通过比较内部RC电路的第二电容C2的电压和外部RC电路的第一电容C1的电压，即可以判断第一电容C1的漂移程度或开路。
在实际应用中，第一电源端210和第二电源端220是和电源相连接，相应地施加给第一电容C1的电压等于电源电压，这意味着处于集成电路芯片110内部的第二电容C2上的电压也要等于电源电压。因此，对于图3A和3B所示的实施例一和二来说，一方面，如果电源电压大于集成电路中的总集成电容的最大工作电压，则第二电容C2需要具有高额定电压；另一方面，高额定电压的电容体积较大，会使集成电路芯片110的体积增大。针对这一问题，本发明进一步地提出了图4所示的实施例。
图4是本发明实施例三的检测电路的电路示意图。图4所示的实施例三在图3B所示的检测电路结构的基础上增加了分压电路和分压电阻。其中，分压电路耦接在比较器320与第二电源端220之间以向比较器320提供经过滤电源电压Vbat2的分压；分压电阻耦接在仿电源端310与参考电位端230之间，以使该仿电源电压V0为该第一电源端210的未过滤电源电压Vbat1的分压。具体地，参考图4所示，分压电路包括第三电阻R3和第四电阻R4。其中，第三电阻R3和第四电阻R4相互串联，并且一起连接于第二电源端220和参考电位端230之间。第三电阻R3的一端和第二电源端220相连接，另一端和第四电阻R4的一端以及比较器320的一个输入端322相连接；第四电阻R4的一端和第三电阻R3的一端以及比较器320的一个输入端322相连接，另一端和参考电位端230相连接。参考图4所示，分压电阻包括第五电阻R5，其一端和第二电阻R2的一端以及仿电源端310相连接，另一端和参考电位端230相连接。进一步地，第五电阻R5的一端通过仿电源端310和比较器320的一个输入端321相连接。
可以理解，根据图4所示的实施例，输入到比较器的两个输入端321、322的电压分别经过分压电路和分压电阻的分压。其中，分压电路(第三电阻R3和第四电阻R4)对第一电容C1上的电压进行了分压，可以降低第一电容C1上的电压；分压电阻(第五电阻R5)对第二电容C2上的电压进行了分压，可以降低第二电容C2上的电压。本发明对分压电路和分压电阻所要进行分压的程度不做限制，可以通过设置具体的电阻值和电容值来控制想要获得的分压结 果。
在这些实施例中，第一RC电路(外部RC电路)中包括第一电容C1、第一电阻R1、第三电阻R3和第四电阻R4；第二RC电路(内部RC电路)中包括第二电容C2、第二电阻R2和第五电阻R5。通过理论计算的结果来设置第一RC电路和第二RC电路中的各个电子元件的具体值，可以使第二RC电路的时间常数等于第一RC电路的时间常数。
例如，在一具体实施例中，在没有增加分压电路和分压电阻时，R1＝10Ohm、C1＝10μF、R2＝1MOhm、C2＝100pF。在增加了分压电路和分压电阻后，使R3＝1MOhm、R4＝1MOhm、R5＝1MOhm，并调整C2＝200pF。根据这些设置，可以使第一RC电路的时间常数等于第二RC电路的时间常数，并且使输入到比较器320的两个输入端321、322的电压都降低到原来的一半。
根据图4所示的实施例，不仅可以降低第一电容C1和第二电容C2所要承受的电压，分压电路和分压电阻还为电路提供了第二重的ESD保护，使比较器320的输入端可以使用低输入电压晶体管。为了避免由于分压电路和分压电阻所造成的漏电流，其中的电阻值都设置的比较高，例如都采用MOhm级的电阻。
在一些实施例中，本发明的检测电路还包括用于断开分压电路的第一开关S1以及断开分压电阻的第二开关S2。第一开关S1可以和分压电路串联，第二开关S2可以和分压电阻串联。在这些实施例中，当需要接入本发明的检测电路时，可以使第一开关S1和第二开关S2保持关闭，当不需要使用分压电路和分压电阻时则使第一开关S1和第二开关S2打开，从而切断该分压电路和分压电阻与其它电路之间的连接，进而避免漏电流的产生。
集成电路内部的电阻和电容通常具有约±30％的误差或容忍公差(Tolerance)，集成电路外部的电容则具有约±50％的误差或容忍公差。换句话来说，电阻和电容的实际电阻值和电容值与其标称的电阻值和电容值之间存在一定的误差。因此，为了使内部RC电路的时间常数实际上等于外部RC电路的时间常数，需要对其中的电阻和/或电容进行调整。在一些实施例中，可以在内部RC电路中采用可变电容和/或可变电阻，然而，由于可变电容的体积较大，因此，在本发明的实施例中使用可变电阻。
对于图3A、3B和图4所示的检测电路的实施例来说，其中的第二电阻R2 可以采用可变电阻。在这些实施例中，第二电阻R2可以被预先调整到使第二电阻R2和第二电容C2与第一电阻R1和第一电容C1具有相同的时间常数。具体地，可以测量第一电容C1上的电压Vc1和第二电容C2上的电压Vc2分别到达某一预设电压所花费的时间T1和T2，如果第二电容C2的电压Vc2比第一电容C1的电压Vc1提前到达该预设电压，即T2＜T1，则表示内部RC电路的时间常数小于外部RC电路的时间常数。并且可以根据T1和T2之间的关系来调整第二电阻R2的大小，使内部RC电路的时间常数等于外部RC电路的时间常数。可以理解，这里用于调整时间常数的方法只是用于示例，还可以采用其它的方法来调整第二电阻R2的大小，使内部RC电路的时间常数等于外部RC电路的时间常数。
在一些实施例中，可以使图4中所示的内部RC电路中的第五电阻R5和/或第二电阻R2为可变电阻。
图5是本发明实施例四的检测电路的电路示意图。与图4所示的实施例相比，图5所示的实施例在内部RC电路中增加了第六电阻R6。第六电阻R6的一端同时和第二电阻R2的一端、第五电阻R5的一端相连接，第六电阻R6的另一端和第二电容C2的一端以及仿电源端310相连接。在该实施例中，第二电阻R2、第五电阻R5、第六电阻R6和第二电容C2一起组成了内部RC电路。因此，各个电阻值和电容值的设置应该使该内部RC电路的时间常数等于外部RC电路的时间常数。
在一些实施例中，该第六电阻R6可以是可变电阻。例如，当R1＝10Ohm、C1＝10μF、R3＝1MOhm、R4＝1MOhm、C2＝100pF时，设置R2＝700kOhm、R5＝700kOhm、R6＝0～300kOhm。第六电阻R6的电阻值可以在0到300kOhm之间调整。图5所示的实施例也可用于第一电容C1和/或第二电容C2的实际电容值和标称值不相等的情况，根据前文所述的调整方法，通过调整第六电阻R6的电阻值，使内部RC电路的时间常数实际上和外部RC电路的时间常数相等。
可以理解，与图3B所示的实施例类似地，在其他的实施例中，可以在图4、5所示的实施例中增加静电放电保护电路201，并且将参考电位端230区分为模拟参考电位端和数字参考电位端，使第二电容C2的与参考电位端230连 接的一端连接到模拟参考电位端231。
在图3A至图5所示的检测电路的实施例中，可以为比较器320设置一检测阈值V_th，比较器320将输入到其两个输入端321、322上的电压差V_diff和该检测阈值V_th进行比较，从而判断第一电容C1的漂移程度或开路。本领域技术人员可以根据需要来设置该检测阈值V_th。下面以一种用于汽车电池管理的集成电路为例来说明一种确定检测阈值V_th的方法。
对于用于汽车电池管理的集成电路来说，其中包括了前文所述的检测电路中的所有电子元件，该检测电路可以检测外接于集成电路的第一电容的漂移程度或开路。可以理解，该集成电路也可以是应用于汽车以外的其它需要进行电池管理的领域。
图6是本发明一实施例的检测电路在第一电容开路时电池电压的变化及内部RC电路和外部RC电路的电压电流变化示意图。需要说明，图6所示的电压电流是基于图4所示的实施例的检测电路。参考图6所示，横轴表示时间，单位是ms；左纵轴为电压，单位是mV或V；右纵轴为电流，单位为nA。图6主要包括上下两部分，上半部分所示为比较器320的两个输入端321、322上的电压差V_diff以及第二电容C2上的电流I_C2随时间的变化曲线；下半部分所示为汽车电池电压随时间的变化曲线。
对于汽车电池来说，提供给汽车电池的供给电压随着驱动电流的增加以一定的斜率变化。假设该供给电压为V，则随着驱动电流的增加，该电压的变化率dV/dt为一常数。该变化率dV/dt在正常情况下为0.4V/ms，在极端情况下可以达到5V/ms。参考图4所示，通常供给电压V通过第一电源端210提供给该检测电路，也就是Vbat1＝V，则相应地，dVbat1/dt＝dV/dt。根据图6的下半部分所示，通过对第一电源端210的未过滤电源电压Vbat1进行测量，得到了Vbat1随时间变化的曲线。未过滤电源电压Vbat1首先以0.4V/ms的速度下降，从0ms时的5.4V左右下降到1.7V左右，然后再以0.4V/ms的速度上升，在接近20ms时Vbat1上升到原来的电压5.4V左右。
图6的上半部分和下半部分共用同一根横轴。因此，在未过滤电源电压Vbat1下降的过程中，比较器320所获得的电压差V_diff为-20mV左右，该电压差V_diff的绝对值为20mV。由于图6所示是在第一电容C1开路的状态下测量的结果， 因此，为了测量第一电容C1的漂移程度或开路，需要设置比较器320的检测阈值V_th＜20mV。当第一电容C1和/或第二电容C2的电容值存在30％的误差时，测量得到的电压差V_diff可能和实际的电压差相差6mV左右。在这种情况下，通过设置合适的检测阈值V_th仍然可以对第一电容C1的漂移程度或开路进行检测。在一些实施例中，比较器320为自归零比较器。
图6的上半部分还示出了第二电容C2上的电流I_C2随时间的变化曲线。在未过滤电源电压Vbat1从11ms左右开始以0.4V/ms的速度上升的过程中，电流I_C2基本维持在20nA左右。
在一些实施例中，可以通过分析电池电压的纹波来确定该检测阈值V_th。对于汽车电池管理的集成电路来说，由于逆变换流会造成高频纹波干扰，该纹波干扰的频率和汽车的行驶速度有关。该纹波中大部分的谐波在1.6kHz到15kHz之间。对于每一个电池单元来说，纹波的峰峰值可以达到0.5Vpp。
图7是本发明一实施例的检测电路在第一电容C1发生70％漂移时的电池电压纹波和电压差的变化示意图。图7所示也是基于图4所示的实施例的检测电路。参考图7所示，横轴表示时间，单位是ms；左纵轴为电压，单位是mV或V。图7主要包括上下两部分，上半部分所示为汽车电池电压Vbat1随时间的变化曲线；下半部分所示为当第一电容C1的实际值为标称值的70％时，比较器320的两个输入端321、322上的电压差V_diff随时间的变化曲线。由图7上半部分可见，由于逆变换流使电池电压产生了明显的波纹。
参考图7所示，电压差V_diff最大可以达到20mV左右。因此可以设置检测阈值V_th＝10mV。这样，当检测到电压差V_diff＞V_th，即可以表示第一电容C1发生了漂移。当第一电容C1完全断开时，在图7所示的情况下，电压差V_diff最高可以达到160mV。
根据图7所示，通过设置合理的检测阈值V_th，例如10mV，就可以利用汽车逆变所产生的纹波对第一电容C1的开路或者漂移程度进行检测，并且不需要额外的电流发生器。通常，当汽车在行驶、制动或充电时，汽车电池电压Vbat1中会产生较明显的纹波。当汽车停止运行或低负载运行时，汽车电池电压Vbat1中的纹波幅度较低，电压差V_diff太小以至于难以检测，不过在这种情况，第一电容C1的漂移或开路对电路的精确控制影响也较小，因此可以忽 略不计。
本发明的检测电路无需增加额外的外部元件，即可实现对集成电路外接第一电容C1的漂移程度或开路进行检测，具有易于集成、成本低的有益效果。图8A是本发明实施例一的集成电路的结构示意图。参考图8A所示，该集成电路800包括未经过滤的第一电源端210；经过滤的第二电源端220，适于经第一电阻R1耦接到第一电源端210，且经第一电容C1耦接到参考电位端230；串联的第二电阻R2和第二电容C2，耦接在第一电源端210和参考电位端230之间，第二电阻R2和第二电容C2与第一电阻R1和第一电容C1具有相同的时间常数；仿电源端310，连接在第二电阻R2和第二电容C2之间；比较器320，耦接第二电源端320和仿电源端310，适于检测第二电源端220的经过滤电源电压Vbat2和仿电源端310的仿电源电压V0的电压差。
需要说明的是，图8A所示的实施例中，第一电容C1外接于集成电路800。将第一电阻R1和第一电容C1所组成的第一RC电路称为外部RC电路，将第二电阻R2和第二电容C2组成的第二RC电路称为内部RC电路。
结合图3A和图8A所示，图8A所示的集成电路800包括了图3A所示的检测电路，因此本说明书关于图3A所示的检测电路的说明部分都适用于图8A所示的集成电路。
图8B是本发明实施例二的集成电路的结构示意图。与图8A所示的实施例相比，图8B所示的实施例中增加了图2中由ESD二极管构成的静电放电保护电路201，并且将参考电位端230进一步分为模拟参考电位端231和数字参考电位端232。其中，第二电容C2的一端和第二电阻R2的一端相连接，第二电容C2的另一端连接到模拟参考电位端231。
结合图3B和图8B所示，图8B所示的集成电路810包括了图3B所示的检测电路，因此本说明书关于图3B所示的检测电路的说明部分都适用于图8B所示的集成电路。
图8C是本发明实施例三的集成电路的结构示意图。参考图8C所示，该实施例的集成电路820在图8A所示的实施例的基础上，增加了分压电路和分压电阻。分压电路耦接在比较器230与第二电源端220之间以向比较器230提供经过滤电源电压Vbat2的分压；以及分压电阻耦接在仿电源端310与参考电位 端230之间，以使仿电源电压V0为第一电源端210的未过滤电源电压Vbat1的分压。结合图4和图8C所示，图8C所示的集成电路820包括了图4所示的检测电路，因此本说明书关于图4所示的检测电路的说明部分都适用于图8C所示的集成电路。
在一些实施例中，图8A-8C中的第二电阻R2是可变电阻。在这些实施例中，第二电阻R2被预先调整到使第二电阻R2和第二电容C2与第一电阻R1和第一电容C1具有相同的时间常数。
在一些实施例中，第二电容C2的电容值的数量级低于第一电容C1的电容值。
在图8C所示的实施例中，还包括用于断开分压电路的第一开关S1，以及断开分压电阻的第二开关S2。
图8D是本发明实施例四的集成电路的结构示意图。与图8C所示的实施例相比，图8D所示的实施例在内部RC电路中增加了第六电阻R6。结合图5和图8D所示，图8D所示的集成电路830包括了图5所示的检测电路，因此本说明书关于图5所示的检测电路的说明部分都适用于图8D所示的集成电路。
可以理解，图8A-8D所示的集成电路的实施例是对应于图3A-图5所示的检测电路的实施例的罗列。在其他的实施例中，可以在图8C和8D中增加静电放电保护电路201，并且将参考电位端230区分为模拟参考电位端和数字参考电位端，使第二电容C2与参考电位端230连接的一端连接到模拟参考电位端231。
在一些实施例中，图8A-8D所示的集成电路是电池控制器。
根据图8A-8D所示的集成电路，可以对外接电容第一电容C1的漂移程度或开路进行检测。其中，具体的如何为比较器320设置检测阈值V_th，以及如何利用所获得的电压差V_diff来判断第一电容C1的状态，可以参考说明书前文中关于检测电路的描述以及相应的附图。
可以理解，本发明的检测电路和集成电路可以用于任何要求功能安全保障的电路，可以检测集成电路外接电容器的漂移程度或开路，并不限于本发明具体实施例中的汽车电池管理集成电路。
虽然本发明已参照当前的具体实施例来描述，但是本技术领域中的普通技术人员应当认识到，以上的实施例仅是用来说明本发明，在没有脱离本发明精 神的情况下还可做出各种等效的变化或替换，因此，只要在本发明的实质精神范围内对上述实施例的变化、变型都将落在本申请的权利要求书的范围内。
同时，本申请使用了特定词语来描述本申请的实施例。如“一个实施例”、“一实施例”、和/或“一些实施例”意指与本申请至少一个实施例相关的某一特征、结构或特点。因此，应强调并注意的是，本说明书中在不同位置两次或多次提及的“一实施例”或“一个实施例”或“一替代性实施例”并不一定是指同一实施例。此外，本申请的一个或多个实施例中的某些特征、结构或特点可以进行适当的组合。

Claims (15)

  1. 一种检测电路，用于检测经过滤的第二电源端上的第一电容的漂移或开路，所述第二电源端适于经第一电阻从未过滤的第一电源端获取电源电压，且适于经所述第一电容耦接到参考电位端以过滤所述电源电压，所述检测电路包括：
    串联的第二电阻和第二电容，耦接在所述第一电源端和所述参考电位端之间，所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数；
    仿电源端，连接在所述第二电阻和第二电容之间；以及
    比较器，耦接所述第二电源端和所述仿电源端，适于检测所述第二电源端的经过滤电源电压和所述仿电源端的仿电源电压的电压差，所述电压差指示所述第一电容的漂移程度或开路。
  2. 如权利要求1所述的检测电路，其特征在于，还包括：
    分压电路，耦接在所述比较器与所述第二电源端之间以向所述比较器提供所述经过滤电源电压的分压；以及
    分压电阻，耦接在所述仿电源端与所述参考电位端之间，以使所述仿电源电压为所述第一电源端的未过滤电源电压的分压。
  3. 如权利要求1或2所述的检测电路，其特征在于，所述第二电阻是可变电阻。
  4. 如权利要求3所述的检测电路，其特征在于，所述第二电阻被预先调整到使所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数。
  5. 如权利要求1所述的检测电路，其特征在于，所述第二电容的电容值的数量级低于所述第一电容的电容值。
  6. 如权利要求1所述的检测电路，其特征在于，所述检测电路是结合在集成电路中，且所述第一电源端、第二电源端和参考电位端是所述集成电路的端子。
  7. 如权利要求2所述的检测电路，其特征在于，还包括用于断开所述分压电路的第一开关，以及断开所述分压电阻的第二开关。
  8. 一种集成电路，包括：
    未经过滤的第一电源端；
    经过滤的第二电源端，适于经第一电阻耦接到所述第一电源端，且经第一 电容耦接到参考电位端；
    串联的第二电阻和第二电容，耦接在所述第一电源端和所述参考电位端之间，所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数；
    仿电源端，连接在所述第二电阻和第二电容之间；以及
    比较器，耦接所述第二电源端和所述仿电源端，适于检测所述第二电源端的经过滤电源电压和所述仿电源端的仿电源电压的电压差。
  9. 如权利要求8所述的集成电路，其特征在于，还包括：
    分压电路，耦接在所述比较器与所述第二电源端之间以向所述比较器提供所述经过滤电源电压的分压；以及
    分压电阻，耦接在所述仿电源端与所述参考电位端之间，以使所述仿电源电压为所述第一电源端的未过滤电源电压的分压。
  10. 如权利要求8或9所述的集成电路，其特征在于，所述第二电阻是可变电阻。
  11. 如权利要求10所述的集成电路，其特征在于，所述第二电阻被预先调整到使所述第二电阻和第二电容与所述第一电阻和第一电容具有相同的时间常数。
  12. 如权利要求8所述的集成电路，其特征在于，所述第二电容的电容值的数量级低于所述第一电容的电容值。
  13. 如权利要求9所述的集成电路，其特征在于，还包括用于断开所述分压电路的第一开关，以及断开所述分压电阻的第二开关。
  14. 如权利要求8所述的集成电路，其特征在于，所述集成电路是用于汽车的集成电路芯片。
  15. 如权利要求8所述的集成电路，其特征在于，所述集成电路是电池控制器。
PCT/CN2020/114980 2019-11-05 2020-09-14 检测电路和集成电路 WO2021088516A1 (zh)

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