阅读说明：本技术 一种电压过冲检测电路 (Voltage overshoot detection circuit ) 是由 吴春红 于 2020-12-22 设计创作，主要内容包括：本申请实施例公开一种电压过冲检测电路,涉及电压检测技术领域,为便于提高对电压检测的准确性而发明。检测电路,第一电荷泵与第二电荷泵与参考电压相连,第一电荷泵第二端用于与被检测电压相连,第二电荷泵的第二端接地,第一电荷泵和第二电荷泵与电容的第一端相连,电容的第二端接地；电容的第一端为检测电路的输出端；被检测电压和参考电压控制第一电荷泵的第三端的灌电流、参考电压控制第二电荷泵的第三端的抽电流；被检测电压在预设电压范围内,灌电流和抽电流使输出端输出第一电平电压；被检测电压超过预设电压范围时,灌电流和抽电流使输出端输出第二电平电压；第二电平电压与第一电平电压的高低状态相反。本申请适用于检测电压过冲。(The embodiment of the application discloses a voltage overshoot detection circuit, relates to the technical field of voltage detection, and aims to improve the accuracy of voltage detection. The detection circuit comprises a first charge pump, a second charge pump, a capacitor and a detection circuit, wherein the first charge pump and the second charge pump are connected with a reference voltage; the first end of the capacitor is the output end of the detection circuit; the detected voltage and the reference voltage control the sink current of the third end of the first charge pump, and the reference voltage controls the pumping current of the third end of the second charge pump; when the detected voltage is within a preset voltage range, the current is pumped and the output end outputs a first level voltage; when the detected voltage exceeds the preset voltage range, the current is pumped and pumped so that the output end outputs a second level voltage; the second level voltage is opposite to the high-low state of the first level voltage. The application is applicable to detecting voltage overshoot.)

1. A voltage overshoot detection circuit, comprising: the detection module comprises a first charge pump, a second charge pump and a capacitor, wherein a first end of the first charge pump and a first end of the second charge pump are respectively connected with a reference voltage, a second end of the first charge pump is used for being connected with a detected voltage, a second end of the second charge pump is grounded, a third end of the first charge pump and a third end of the second charge pump are respectively connected with a first end of the capacitor, and a second end of the capacitor is grounded; the first end of the capacitor is the output end of the voltage overshoot detection circuit;

the detected voltage and the reference voltage control the sink current of the third end of the first charge pump, and the reference voltage controls the pump current of the third end of the second charge pump;

the detected voltage is within a preset voltage range, and the input current and the extraction current enable the output end to output a first level voltage;

when the detected voltage exceeds the preset voltage range, the input current and the extraction current enable the output end to output a second level voltage; wherein the second level voltage is opposite to the high-low state of the first level voltage.

2. The detection circuit of claim 1, wherein the first charge pump comprises a P-type metal oxide semiconductor field effect transistor and the second charge pump comprises an N-type metal oxide semiconductor field effect transistor;

the drain electrode of the P-type metal oxide semiconductor field effect transistor and the drain electrode of the N-type metal oxide semiconductor field effect transistor are respectively connected with the first end of the capacitor, the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor are connected with reference voltage, the source electrode of the P-type metal oxide semiconductor field effect transistor is used for being connected with detected voltage, and the source electrode of the N-type metal oxide semiconductor field effect transistor is grounded.

3. The detection circuit of claim 2, further comprising a first buffer, the first buffer comprising: a first inverter and a second inverter; the output end of the first phase inverter is connected with the input end of the second phase inverter;

and the input end of the first inverter is connected with the output end of the voltage overshoot detection circuit.

4. The detection circuit of claim 3, further comprising a voltage undershoot positive feedback module; the first end of the voltage undershoot positive feedback module is connected with the grid of the P-type metal oxide semiconductor field effect transistor and the grid of the N-type metal oxide semiconductor field effect transistor respectively, the second end of the voltage undershoot positive feedback module is connected with the input end of the first phase inverter, the third end of the voltage undershoot positive feedback module is connected with the output end of the first phase inverter, and the fourth end of the voltage undershoot positive feedback module is grounded.

5. The detection circuit of claim 4, wherein the voltage undershoot positive feedback module comprises: the source electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the second N-type metal oxide semiconductor field effect transistor;

the grid electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor respectively, the drain electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the input end of the first phase inverter, the grid electrode of the second N-type metal oxide semiconductor field effect transistor is connected with the output end of the first phase inverter, and the source electrode of the second N-type metal oxide semiconductor field effect transistor is grounded.

6. The detection circuit of claim 3, further comprising an overshoot voltage positive feedback module; the first end of the voltage overshoot positive feedback module is connected with the grid of the P-type metal oxide semiconductor field effect transistor and the grid of the N-type metal oxide semiconductor field effect transistor respectively, the second end of the voltage overshoot positive feedback module is connected with the input end of the first phase inverter, the third end of the voltage overshoot positive feedback module is connected with the output end of the first phase inverter, and the fourth end of the voltage overshoot positive feedback module is connected with the first power supply.

7. The detection circuit of claim 6, wherein the overshoot positive feedback voltage module comprises: the transistor comprises a first P-type metal oxide semiconductor field effect transistor and a second P-type metal oxide semiconductor field effect transistor, wherein the drain electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the second P-type metal oxide semiconductor field effect transistor;

the grid electrode of the second P-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor respectively, the drain electrode of the second P-type metal oxide semiconductor field effect transistor is connected with the input end of the first phase inverter, the grid electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the output end of the first phase inverter, and the source electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the first power supply.

8. The detection circuit of claim 3, further comprising: a reference voltage selection module comprising an up reference voltage branch and an down reference voltage branch;

the upper punch reference voltage branch comprises an upper punch reference voltage and a first switch, and the upper punch reference voltage is connected with a first end of the first switch;

the undershoot reference voltage branch comprises an undershoot reference voltage and a second switch, and the undershoot reference voltage is connected with a first end of the second switch;

and after the second end of the first switch is connected with the second end of the second switch, the second end of the first switch is respectively connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor.

9. The detection circuit of claim 8, further comprising: the first end of the positive feedback module is connected with the first end of the mode control module, the second end of the positive feedback module is connected with the second end of the mode control module, the third end of the positive feedback module is connected with the second end of the first switch, the fourth end of the positive feedback module is connected with the second end of the second switch, the fifth end of the positive feedback module is connected with the input end of the first phase inverter, the sixth end of the positive feedback module is connected with the output end of the first phase inverter, the seventh end of the positive feedback module is connected with the second power supply, and the eighth end of the positive feedback module is grounded.

10. The detection circuit of claim 9, wherein the mode control module comprises a third inverter, a first terminal of the third inverter being configured to be coupled to the mode control signal;

the positive feedback module comprises: a third P-type metal oxide semiconductor field effect transistor and a fourth P-type metal oxide semiconductor field effect transistor, wherein the source electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the second power supply, the drain electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the fourth P-type metal oxide semiconductor field effect transistor, the drain electrode of the fourth P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the third N-type metal oxide semiconductor field effect transistor, the drain electrode of the third N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the fourth N-type metal oxide semiconductor field effect transistor, the source electrode of the fourth N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the fifth N-type metal oxide semiconductor field effect transistor, the source electrode of the fifth N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the sixth N-type metal oxide semiconductor field effect transistor, and the source electrode of the sixth N-type metal oxide semiconductor field effect transistor is grounded;

the grid electrode of the fourth P-type metal oxide semiconductor field effect transistor is connected with the second end of the first switch, the grid electrode of the third N-type metal oxide semiconductor field effect transistor is connected with the second end of the third phase inverter, the grid electrode of the fourth N-type metal oxide semiconductor field effect transistor is connected with the first end of the third phase inverter, the grid electrode of the fifth N-type metal oxide semiconductor field effect transistor is connected with the second end of the second switch, and the grid electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the sixth N-type metal oxide semiconductor field effect transistor and then connected with the output end of the first phase inverter;

and the first end of the third phase inverter is connected with the second switch, and the second end of the third phase inverter is connected with the first switch.

11. The detection circuit of claim 3, further comprising: and the input end of the second buffer is connected with the output end of the first buffer.

Technical Field

The application relates to the technical field of voltage detection, in particular to a voltage overshoot detection circuit.

Background

In large scale integrated circuits, it is generally desirable that the voltage be stable without much jitter, but due to the complexity of the circuit, the voltage is always inevitably subject to overshoot or undershoot, and the voltage needs to be monitored. When the voltage is higher than the designated voltage or lower than the designated voltage, an indication signal can be given, so that the whole circuit can be adjusted in time, and the robustness of the circuit is enhanced.

As shown in fig. 1, in the prior art, when detecting a voltage, a detection module (detection circuit) is used to compare a power supply voltage with a reference voltage, and then the comparison result is output through several stages of buffers, wherein the detection module is usually implemented by a conventional analog circuit such as a differential circuit. Fig. 2 is a circuit for detecting voltage undershoot, voltage is divided by resistors and compared with reference voltage VrefL, when the voltage is lower than VrefL, output voltage VOUT generates a low pulse to represent that voltage undershoot on the power supply is detected, and on the basis of fig. 2, the circuit for detecting voltage overshoot on the power supply can be obtained by slightly adjusting, as shown in fig. 3, the process for detecting voltage overshoot on the power supply is similar to the process for detecting voltage undershoot. Because the detection module in the prior art usually adopts a differential circuit, and due to the manufacturing and other reasons of the geminate transistors in the differential circuit, all parameters cannot be completely the same, when detecting the voltage, direct current offset exists, and thus, the accuracy of detecting the voltage is lower.

Disclosure of Invention

In view of this, embodiments of the present application provide a voltage overshoot detection circuit, which facilitates improving accuracy of voltage detection.

The embodiment of the application provides a voltage overshoot detection circuit, includes: the detection module comprises a first charge pump, a second charge pump and a capacitor, wherein a first end of the first charge pump and a first end of the second charge pump are respectively connected with a reference voltage, a second end of the first charge pump is used for being connected with a detected voltage, a second end of the second charge pump is grounded, a third end of the first charge pump and a third end of the second charge pump are respectively connected with a first end of the capacitor, and a second end of the capacitor is grounded; the first end of the capacitor is the output end of the voltage overshoot detection circuit; the detected voltage and the reference voltage control the sink current of the third end of the first charge pump, and the reference voltage controls the pump current of the third end of the second charge pump; the detected voltage is within a preset voltage range, and the input current and the extraction current enable the output end to output a first level voltage; when the detected voltage exceeds the preset voltage range, the input current and the extraction current enable the output end to output a second level voltage; wherein the second level voltage is opposite to the high-low state of the first level voltage.

According to a specific implementation manner of the embodiment of the application, the first charge pump comprises a P-type metal oxide semiconductor field effect transistor, and the second charge pump comprises an N-type metal oxide semiconductor field effect transistor; the drain electrode of the P-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the N-type metal oxide semiconductor field effect transistor to form an output end, the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor are used for being connected with reference voltage, the source electrode of the P-type metal oxide semiconductor field effect transistor is used for being connected with detected voltage, and the source electrode of the N-type metal oxide semiconductor field effect transistor is grounded.

According to a specific implementation manner of the embodiment of the present application, the apparatus further includes a first buffer, where the first buffer includes: a first inverter and a second inverter; the output end of the first phase inverter is connected with the input end of the second phase inverter; and the input end of the first inverter is connected with the output end of the voltage overshoot detection circuit.

According to a specific implementation manner of the embodiment of the application, the device further comprises a voltage undershoot positive feedback module; the first end of the voltage undershoot positive feedback module is connected with the grid of the P-type metal oxide semiconductor field effect transistor and the grid of the N-type metal oxide semiconductor field effect transistor respectively, the second end of the voltage undershoot positive feedback module is connected with the input end of the first phase inverter, the third end of the voltage undershoot positive feedback module is connected with the output end of the first phase inverter, and the fourth end of the voltage undershoot positive feedback module is grounded.

According to a specific implementation manner of the embodiment of the present application, the voltage undershoot positive feedback module includes: the source electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the second N-type metal oxide semiconductor field effect transistor; the grid electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor respectively, the drain electrode of the first N-type metal oxide semiconductor field effect transistor is connected with the input end of the first phase inverter, the grid electrode of the second N-type metal oxide semiconductor field effect transistor is connected with the output end of the first phase inverter, and the source electrode of the second N-type metal oxide semiconductor field effect transistor is grounded.

According to a specific implementation manner of the embodiment of the application, the device further comprises a voltage overshoot positive feedback module; the first end of the voltage overshoot positive feedback module is connected with the grid of the P-type metal oxide semiconductor field effect transistor and the grid of the N-type metal oxide semiconductor field effect transistor respectively, the second end of the voltage overshoot positive feedback module is connected with the input end of the first phase inverter, the third end of the voltage overshoot positive feedback module is connected with the output end of the first phase inverter, and the fourth end of the voltage overshoot positive feedback module is connected with the first power supply.

According to a specific implementation manner of the embodiment of the present application, the positive feedback module on voltage includes: the transistor comprises a first P-type metal oxide semiconductor field effect transistor and a second P-type metal oxide semiconductor field effect transistor, wherein the drain electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the second P-type metal oxide semiconductor field effect transistor; the grid electrode of the second P-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor respectively, the drain electrode of the second P-type metal oxide semiconductor field effect transistor is connected with the input end of the first phase inverter, the grid electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the output end of the first phase inverter, and the source electrode of the first P-type metal oxide semiconductor field effect transistor is connected with the first power supply.

According to a specific implementation manner of the embodiment of the application, the method further includes: a reference voltage selection module comprising an up reference voltage branch and an down reference voltage branch; the upper punch reference voltage branch comprises an upper punch reference voltage and a first switch, and the upper punch reference voltage is connected with a first end of the first switch; the undershoot reference voltage branch comprises an undershoot reference voltage and a second switch, and the undershoot reference voltage is connected with a first end of the second switch; and after the second end of the first switch is connected with the second end of the second switch, the second end of the first switch is respectively connected with the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor.

According to a specific implementation manner of the embodiment of the application, the method further includes: the first end of the positive feedback module is connected with the first end of the mode control module, the second end of the positive feedback module is connected with the second end of the mode control module, the third end of the positive feedback module is connected with the second end of the first switch, the fourth end of the positive feedback module is connected with the second end of the second switch, the fifth end of the positive feedback module is connected with the input end of the first phase inverter, the sixth end of the positive feedback module is connected with the output end of the first phase inverter, the seventh end of the positive feedback module is connected with the second power supply, and the eighth end of the positive feedback module is grounded.

According to a specific implementation manner of the embodiment of the present application, the mode control module includes a third inverter, and a first end of the third inverter is configured to be connected to a mode control signal; the positive feedback module comprises: a third P-type metal oxide semiconductor field effect transistor and a fourth P-type metal oxide semiconductor field effect transistor, wherein the source electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the second power supply, the drain electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the fourth P-type metal oxide semiconductor field effect transistor, the drain electrode of the fourth P-type metal oxide semiconductor field effect transistor is connected with the source electrode of the third N-type metal oxide semiconductor field effect transistor, the drain electrode of the third N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the fourth N-type metal oxide semiconductor field effect transistor, the source electrode of the fourth N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the fifth N-type metal oxide semiconductor field effect transistor, the source electrode of the fifth N-type metal oxide semiconductor field effect transistor is connected with the drain electrode of the sixth N-type metal oxide semiconductor field effect transistor, and the source electrode of the sixth N-type metal oxide semiconductor field effect transistor is grounded; the grid electrode of the fourth P-type metal oxide semiconductor field effect transistor is connected with the second end of the first switch, the grid electrode of the third N-type metal oxide semiconductor field effect transistor is connected with the second end of the third phase inverter, the grid electrode of the fourth N-type metal oxide semiconductor field effect transistor is connected with the first end of the third phase inverter, the grid electrode of the fifth N-type metal oxide semiconductor field effect transistor is connected with the second end of the second switch, and the grid electrode of the third P-type metal oxide semiconductor field effect transistor is connected with the grid electrode of the sixth N-type metal oxide semiconductor field effect transistor and then connected with the output end of the first phase inverter; and the first end of the third phase inverter is connected with the second switch, and the second end of the third phase inverter is connected with the first switch.

According to a specific implementation manner of the embodiment of the application, the method further includes: and the input end of the second buffer is connected with the output end of the first buffer.

In the voltage overshoot detection circuit provided by the embodiment of the application, the detection module includes a first charge pump, a second charge pump and a capacitor, a first end of the first charge pump and a first end of the second charge pump are respectively connected with a reference voltage, a second end of the first charge pump is used for being connected with a detected voltage, a second end of the second charge pump is grounded, a third end of the first charge pump and a third end of the second charge pump are respectively connected with a first end of the capacitor, and a second end of the capacitor is grounded, wherein the first end of the capacitor is an output end of the voltage overshoot detection circuit, the detected voltage and the reference voltage control a sink current of the third end of the first charge pump, the reference voltage control a pump current of the third end of the second charge pump, the detected voltage is within a preset voltage range, and the sink current and the pump current enable the output end to output a first level voltage; when the detected voltage exceeds the preset voltage range, the current is pumped and pumped so that the output end outputs a second level voltage; the output voltage is turned over from a normal state when the detected voltage is in an up-rush state or an down-rush state, and accordingly the detected voltage can be judged to be in an up-rush state or an down-rush state.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of voltage overshoot detection in the prior art;

FIG. 2 is a circuit for detecting voltage undershoot;

FIG. 3 is a circuit for detecting voltage overshoot;

fig. 4 is a schematic structural diagram of a voltage overshoot detection circuit according to an embodiment of the present application;

FIG. 5 is a diagram illustrating simulation results when the detection circuit of the embodiment of the present application detects voltage undershoot;

fig. 6 is a schematic structural diagram of a voltage overshoot detection circuit according to yet another embodiment of the present application;

fig. 7 is a schematic structural diagram of a voltage undershoot detection circuit according to an embodiment of the present disclosure;

FIG. 8 is a diagram showing simulation results when the detection circuit of FIG. 6 is applied to detect voltage undershoot;

fig. 9 is a schematic diagram of a simulation result when a detection circuit before and after a positive feedback module is added detects voltage undershoot according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of an overshoot voltage detection circuit according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a detection circuit according to yet another embodiment of the present application.

Detailed Description

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to make those skilled in the art better understand the technical concepts, embodiments and advantages of the examples of the present application, the following detailed description is given by way of specific examples.

Fig. 4 is a schematic structural diagram of a voltage overshoot detection circuit according to an embodiment of the present application, and fig. 5 is a schematic structural diagram of a simulation result when the detection circuit according to an embodiment of the present application is applied to detect a voltage undershoot, as shown in fig. 4 and 5, the voltage overshoot detection circuit according to the present embodiment includes: the detection module 1 comprises a first charge pump 10, a second charge pump 12 and a capacitor 14, wherein a first end of the first charge pump 10 and a first end of the second charge pump 12 are respectively connected with a reference voltage, a second end of the first charge pump 10 is used for being connected with a detected voltage, a second end of the second charge pump 12 is grounded, a third end of the first charge pump 10 and a third end of the second charge pump 12 are respectively connected with a first end of the capacitor 14, and a second end of the capacitor is grounded; wherein, the first end of the capacitor 14 is the output end of the voltage overshoot detection circuit; the detected voltage and the reference voltage control the sink current of the third end of the first charge pump 10, and the reference voltage controls the pumping current of the third end of the second charge pump 12;

when the detected voltage is within a preset voltage range, the current is pumped and the output end outputs a first level voltage; when the detected voltage exceeds the preset voltage range, the current is pumped and pumped so that the output end outputs a second level voltage; wherein, the second level voltage is opposite to the high-low state of the first level voltage.

The voltage overshoot may include a voltage overshoot and a voltage undershoot, such as a voltage in the range of 4.9V to 5.1V for a normal voltage, a voltage overshoot occurring when a voltage of 5.5V occurs, and a voltage undershoot occurring when a voltage of 4.5V occurs.

The detected voltage is in a preset voltage range, namely the voltage is in the range and is the normal working voltage.

The pumping current may be the current flowing out of the capacitor and the sinking current may be the current flowing into the capacitor.

The capacitor 14 may be an independent capacitor product, and when the voltage overshoot detection circuit of the embodiment is connected to the back end component or the circuit, and the back end component or the circuit has a parasitic capacitor, the capacitor of the embodiment may be the parasitic capacitor.

The second level voltage is opposite to the high-low state of the first level voltage, namely the first level voltage is in the high level state and the second level voltage is in the low level state; or, the first level voltage is in a low level state and the second level voltage is in a high level state.

The Detected voltage VDD _ Detected is the voltage that needs to be Detected and may have voltage overshoot or undershoot. In one example, the detected voltage may be a supply voltage in a large integrated circuit.

The reference voltage Vref set at the time of the detection voltage overshoot is larger than the reference voltage Vref set at the time of the detection voltage undershoot. When the detection voltage is rushed up, the reference voltage can be set to be larger than the normal value of the detected voltage, and when the detection voltage is rushed down, the reference voltage can be set to be smaller than the normal value of the detected voltage.

The detected voltage and the reference voltage control the sink current of the third end of the first charge pump 1, and the reference voltage controls the pumping current of the second charge pump 2.

Detecting the working process of the uprush: when the detected voltage is in a preset voltage range, the difference value between the current flowing into the first charge pump 1 and the current pumped by the second charge pump is small, and then, the charges accumulated by the capacitor are less, so that the voltage output by the first end of the capacitor, namely the output end of the voltage overshoot detection circuit, is low level voltage, when the voltage overshoot occurs, the detected voltage is increased (the reference voltage is unchanged), the current flowing into the first charge pump is increased, the charges accumulated by the capacitor are increased, and the voltage output by the output end of the voltage overshoot detection circuit is high level voltage, namely, when the voltage overshoot occurs, the output voltage realizes the inversion of the level state from low to high.

The working process when undershoot is detected: when the detection voltage is in a preset voltage range, the sink current of the first charge pump 1 is larger than the pumping current of the second charge pump, and then, more charges are accumulated by the capacitor, so that the voltage output by the first end of the capacitor, namely the output end of the voltage overshoot detection circuit, is a high level voltage, when voltage undershoot occurs, the detected voltage is reduced (the reference voltage is unchanged), the difference value between the sink current of the first charge pump and the pumping current of the second charge pump is small, the charges accumulated by the capacitor are reduced, and when the voltage output by the output end of the voltage overshoot detection circuit is a low level voltage, namely the undershoot occurs, the output voltage realizes the inversion of the level state from high to low.

In this embodiment, the detection module includes a first charge pump, a second charge pump and a capacitor, a first end of the first charge pump and a first end of the second charge pump are respectively connected to a reference voltage, a second end of the first charge pump is used for being connected to a detected voltage, a second end of the second charge pump is grounded, a third end of the first charge pump and a third end of the second charge pump are respectively connected to a first end of the capacitor, and a second end of the capacitor is grounded, wherein the first end of the capacitor is an output end of the voltage overshoot detection circuit, the detected voltage and the reference voltage control a sink current of the third end of the first charge pump, the reference voltage control a sink current of the third end of the second charge pump, the detected voltage and the reference voltage control the sink current of the third end of the second charge pump, and the sink current enable the output end to output a first level voltage within a; when the detected voltage exceeds the preset voltage range, the current is pumped and pumped so that the output end outputs a second level voltage; wherein, the second level voltage is opposite to the high-low state of the first level voltage, when the detected voltage is rushed up or down, the output voltage is turned over from the normal state, so as to judge the overshoot or undershoot of the detected voltage, since the second terminal of the first charge pump is available for connection to the detected voltage, the first terminal of the first charge pump and the first terminal of the second charge pump are connected to the reference voltage respectively, when the voltage to be detected is detected, the detection result is not influenced by the consistency of the parameters of the used device, therefore, the accuracy of voltage detection is improved, the problem that in the prior art, the accuracy of voltage detection is low due to the fact that a differential circuit is used for generating direct current offset is solved, and in addition, the problem that in the prior art, circuits are complex due to the fact that a correction circuit needs to be added for the effect of small direct current offset is solved.

Referring to fig. 6, in one example, the first charge pump 10 includes a P-type metal oxide semiconductor field effect transistor and the second charge pump 12 includes an N-type metal oxide semiconductor field effect transistor; the drain electrode of the P-type metal oxide semiconductor field effect transistor and the drain electrode of the N-type metal oxide semiconductor field effect transistor are respectively connected with the first end of the capacitor, the grid electrode of the P-type metal oxide semiconductor field effect transistor and the grid electrode of the N-type metal oxide semiconductor field effect transistor are used for being connected with reference voltage, the source electrode of the P-type metal oxide semiconductor field effect transistor is used for being connected with detected voltage, and the source electrode of the N-type metal oxide semiconductor field effect transistor is grounded.

A Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), abbreviated as a MOSFET, is a Field-Effect Transistor that can be widely used in analog circuits and digital circuits. Depending on the polarity of the channel, the channel can be divided into an N-channel type with a majority of electrons and a P-channel type with a majority of holes, which are commonly referred to as N-type metal oxide semiconductor field effect transistor (NMOSFET) and P-type metal oxide semiconductor field effect transistor (PMOSFET).

When the detection voltage is rushed up, the working process of the detection circuit of the embodiment is as follows: when the detected voltage is within the preset range, the difference value between the drain current of the PMOSFET and the drain current of the NMOSFET is small, so that the voltage Vx of the output end is low level, when the detected voltage is overshot, namely, the difference value is larger than the maximum value of the preset voltage range, the drain current of the PMOSFET10 is larger than the drain current of the NMOSFET, so that the voltage Vx of the output end is high level, namely, the output voltage Vx is changed from low to high, and the voltage overshot can be detected.

When detecting voltage undershoot, the working process of the detection circuit of this embodiment: when the detected voltage is within the preset range, the drain current of the PMOSFET is larger than that of the NMOSFET, so that the voltage Vx of the output end is high level, when the detected voltage undershoots, namely, is smaller than the minimum value of the preset voltage range, the drain current of the PMOSFET is smaller due to the fact that the detected voltage is reduced, and the drain current of the NMOSFET is unchanged, so that the voltage Vx of the output end is low level, namely, the output voltage Vx is lowered by high voltage, and the voltage undershoot can be detected.

In this embodiment, the drain of the P-type mosfet and the drain of the N-type mosfet are respectively connected to the first end of the capacitor, the gate of the P-type mosfet and the gate of the N-type mosfet are used to be connected to a reference voltage, the source of the P-type mosfet is used to be connected to a detected voltage, and the source of the N-type mosfet is grounded.

In order to increase the driving capability of the output voltage of the detection module, and facilitate subsequent processing of the output voltage of the detection module, an embodiment of the present application is substantially the same as the above embodiment, except that the detection circuit of the present embodiment further includes a first buffer 2, and the first buffer 2 includes: a first inverter 20 and a second inverter 22; wherein, the output end of the first inverter 20 is connected with the input end of the second inverter 22;

the input of the first inverter 20 is connected to the output of the voltage overshoot detection circuit.

It is understood that the capacitance of the present embodiment may be a parasitic capacitance in the first inverter 20, and specifically, may be a parasitic capacitance of a PMOS transistor and/or a NMOS transistor.

The first inverter 20 and the second inverter 22 can convert the level of the input signal, in this embodiment, the output voltage of the detection module is converted from high level to low level by the first inverter 20, and then from low level to high level by the second inverter 22; alternatively, the output voltage of the detection module is converted from low level to high level by the first inverter 20, and then converted from high level to low level by the second inverter 22.

The Detected voltage VDD _ Detected and the input voltage VDD1 of the first inverter 20 and the second inverter 22 may be from the same power source or from different power sources, and may be determined according to application requirements.

Referring to fig. 5, in the detection module of the above embodiment, when the Detected voltage VDD _ Detected undershoots, the voltage Vx output by the detection module drops relatively slowly, and further, the response of the output voltage Vy of the first inverter is relatively slow, and the inversion of Vy is highly influenced by the sizes of PMOSFET and NMOSFET in the first buffer, so that the processing of PMOSFET and NMOSFET is likely to degrade the detection accuracy of voltage overshoot.

Referring to fig. 7 and 8, in order to improve the detection accuracy of voltage undershoot, the detection circuit according to an embodiment of the present application is substantially the same as the above-described embodiment, except that the detection circuit according to the present embodiment further includes a voltage undershoot positive feedback module 3; the first end of the voltage undershoot positive feedback module 3 is respectively connected with the grid of the P-type metal oxide semiconductor field effect transistor and the grid of the N-type metal oxide semiconductor field effect transistor, the second end of the voltage undershoot positive feedback module 3 is connected with the input end of the first phase inverter 20, the third end of the voltage undershoot positive feedback module 3 is connected with the output end of the first phase inverter 20, and the fourth end of the voltage undershoot positive feedback module 3 is grounded.

It is understood that the voltage undershoot positive feedback module 3 of the present embodiment is provided for detecting voltage undershoot.

Referring to fig. 8, when the detection circuit of this embodiment detects a voltage to be detected, when a voltage undershoot occurs, the output voltage Vx of the detection module changes from a high level to a low level, and since the first end of the voltage undershoot positive feedback module 3 is connected to the output voltage Vx of the detection module and the second end is connected to the input end of the first inverter 20, the output voltage Vx is rapidly pulled down from the high level to the low level.

In some examples, the voltage undershoot positive feedback module 3 includes: a first NMOSFET30 and a second NMOSFET32, the source of the first NMOSFET30 being connected to the drain of the second NMOSFET 32;

the gate of the first NMOSFET30 is connected to the gate of the PMOSFET and the gate of the NMOSFET, respectively, the drain of the first NMOSFET30 is connected to the input of the first inverter 20, the gate of the second NMOSFET32 is connected to the output of the first inverter 20, and the source of the second NMOSFET32 is grounded.

When detecting voltage undershoot, the working process of the detection circuit of this embodiment: when the detected voltage undershoots, the output voltage Vx of the detection module drops from a high level, the output voltage Vx is at a high level through the first inverter Vy, the second NMOSFET32 is conducted under the action of Vy, and further the first NMOSFET30 is conducted, so that the voltage of Vx is pulled down to a low level.

Referring to fig. 9, in the detection circuit of this embodiment, due to the arrangement of the voltage undershoot positive feedback module, the decrease of the output voltage Vx of the detection module can be steeper, and further, the influence of the device process change on the inversion of the output voltage Vy of the first inverter is reduced, so that the detection accuracy of the voltage undershoot is improved, and in addition, the response to the voltage undershoot is more timely.

Referring to fig. 10, in order to improve the detection accuracy of the overshoot voltage, the detection circuit according to an embodiment of the present application is basically the same as the above-mentioned embodiment, except that the detection circuit according to the embodiment further includes an overshoot positive feedback module 4; the first end of the voltage overshoot positive feedback module 4 is connected with the gate of the PMOSFET and the gate of the NMOSFET respectively, the second end of the voltage overshoot positive feedback module 4 is connected with the input end of the first inverter 20, the third end of the voltage overshoot positive feedback module 4 is connected with the output end of the first inverter 20, and the fourth end of the voltage overshoot positive feedback module 4 is connected with the first power supply.

The first power supply may be from the same power supply as the Detected voltage VDD _ Detected, the input voltage VDD1 of the first inverter 20 and the second inverter 22, or may be from a different power supply, and may be determined according to application needs.

It is understood that the overshoot positive feedback module 4 of the present embodiment is provided for detecting the overshoot of voltage.

When the detection circuit of the embodiment detects the detected voltage, when the voltage overshoot occurs, the output voltage Vx of the detection module is changed from a low level to a high level, the second end of the voltage overshoot positive feedback module 4 is connected with the input end of the first phase inverter 20, namely the output voltage Vx of the detection module, the third end of the voltage overshoot positive feedback module 4 is connected with the output end of the first phase inverter 20, and the output voltage Vx can be rapidly pulled to the high level from the low level.

In some examples, the voltage overshoot positive feedback module 4 includes: a first PMOSFET40 and a second PMOSFET42, the drain of the first PMOSFET40 being connected to the source of the second PMOSFET 42;

the gate of the second PMOSFET42 is connected to the gate of the PMOSFET and the gate of the NMOSFET, respectively, the drain of the second PMOSFET42 is connected to the input of the first inverter 20, the gate of the first PMOSFET40 is connected to the output of the first inverter 20, and the source of the first PMOSFET40 is connected to the first power supply.

When the detection voltage is rushed up, the working process of the detection circuit of the embodiment is as follows: when the detected voltage is overshot, the output voltage Vy of the detection module is increased from low level, the output voltage Vy is low level through the first inverter Vy, the first PMOSFET40 is conducted under the action of the first power supply and Vy, and further, the second PMOSFET42 is conducted, so that the voltage of Vx is pulled to high level.

The detection circuit of this embodiment, because the setting of the positive feedback module on voltage, can make the rising of the output voltage Vx of detection module become more precipitous, and then, the upset of the output voltage Vy of first inverter is reduced by the influence of device process change to, improve the detection precision on voltage uprush, in addition, the response to voltage uprush is more timely.

Referring to fig. 11, in order to improve the flexibility of applying the reference voltage of the detection circuit of the present embodiment, in one example, the method further includes: a reference voltage selection module 5, the reference voltage selection module 5 comprising an up reference voltage branch 50 and an down reference voltage branch 52; the overshoot reference voltage branch 50 includes an overshoot reference voltage VrefH and a first switch, and the overshoot reference voltage VrefH is connected to a first end of the first switch; undershoot reference voltage branch 52 includes undershoot reference voltage VrefL and a second switch, undershoot reference voltage VrefL being connected to a first terminal of the second switch; and after the second end of the first switch is connected with the second end of the second switch, the second end of the first switch is respectively connected with the grid electrode of the PMOSFET and the grid electrode of the NMOSFET.

The overshoot reference voltage branch 50 can provide an overshoot reference voltage VrefH for the detection module 1, and when the first switch is closed, the overshoot reference voltage VrefH is connected to the gate of the PMOSFET and the gate of the NMOSFET; undershoot reference voltage branch 52 is capable of providing an overshoot reference voltage VrefL for detection module 1. when the second switch is closed, undershoot reference voltage VrefL is coupled into the gate of the PMOSFET and the gate of the NMOSFET. It is understood that one of the first switch and the second switch is in a closed state and the other is in an open state.

Referring to fig. 11, in order to increase the integration of the detection circuit of this embodiment based on improving the detection accuracy of the voltage overshoot (overshoot and undershoot), another embodiment of the present application is substantially the same as the above embodiment, except that the detection circuit of this embodiment further includes: the feedback circuit comprises a mode control module 6 and a positive feedback module 7, wherein a first end of the positive feedback module 7 is connected with a first end of the mode control module 6, a second end of the positive feedback module 7 is connected with a second end of the mode control module 6, a third end of the positive feedback module 7 is connected with a second end of a first switch, a fourth end of the positive feedback module 7 is connected with a second end of a second switch, a fifth end of the positive feedback module 7 is connected with an input end of a first phase inverter 20, a sixth end of the positive feedback module 7 is connected with an output end of the first phase inverter 20, a seventh end of the positive feedback module 7 is connected with a second power supply, and an eighth end of the positive feedback module 7 is grounded.

The mode control module 6 is configured to control a working mode of the positive feedback module 7, and specifically, the mode control module 6 may control the positive feedback module 7 to implement a positive feedback function on the output voltage Vx of the detection module for voltage overshoot, and may also control the positive feedback module 7 to implement a positive feedback function on the output voltage Vx of the detection module for voltage undershoot.

The second power source may be from the same power source as the first power source, the Detected voltage VDD _ Detected, and the input voltage VDD1 of the first inverter 20 and the second inverter 22, or may be from a different power source, and may be determined according to application requirements.

In one example, the mode control module 6 includes a third inverter 60 having a first terminal for coupling to a mode control signal.

The mode control signal may be represented by a high level to cause the detection circuit to detect a voltage undershoot and a low level to cause the detection circuit to detect a voltage overshoot.

In a further example, the positive feedback module 7 comprises: a third PMOSFET70, a fourth PMOSFET72, a source of the third PMOSFET70 is connected with a second power supply, a drain of the third PMOSFET70 is connected with a source of the fourth PMOSFET72, a drain of the fourth PMOSFET72 is connected with a source of the third NMOSFET74, a drain of the third NMOSFET74 is connected with a drain of the fourth NMOSFET76, a source of the fourth NMOSFET76 is connected with a drain of the fifth NMOSFET78, a source of the fifth NMOSFET78 is connected with a drain of the sixth NMOSFET80, and a source of the sixth NMOSFET80 is grounded;

the gate of the fourth PMOSFET72 is connected to the second end of the first switch, the gate of the third NMOSFET74 is connected to the second end of the third inverter 20, the gate of the fourth NMOSFET76 is connected to the first end of the third inverter 60, the gate of the fifth NMOSFET78 is connected to the second end of the second switch, and the gate of the third PMOSFET70 and the gate of the sixth NMOSFET80 are connected to each other and then connected to the output end of the first inverter 20;

the first end of the third phase inverter is connected with the second switch, and the second end of the third phase inverter is connected with the first switch.

When the signal input by the first end of the third inverter indicates that the detection circuit detects the voltage undershoot, the second switch corresponding to the voltage undershoot reference voltage is closed, and the first switch corresponding to the voltage overshoot reference voltage is opened; when the detection circuit detects the voltage overshoot, the first switch corresponding to the voltage overshoot reference voltage is closed, and the second switch corresponding to the voltage undershoot reference voltage is opened.

When the detection voltage undershoots, the first end of the third inverter applies a high level, the second switch is closed, the first switch is opened, and the working process of the detection circuit of the embodiment is as follows: when the detected voltage undershoots, the output voltage Vx of the detection module is lowered from a high level, the output voltage Vx is a high level through the first inverter Vy, the sixth NMOSFET is conducted under the action of Vy, further, the fourth NMOSFET is conducted, the fifth NMOSFET is conducted, the third NMOSFET is stopped, and therefore the voltage of Vx is lowered to a low level.

When the detection voltage is rushed up, the first end of the third inverter applies a low level, the first switch is closed, the second switch is opened, and the working process of the detection circuit of the embodiment is as follows: when the detected voltage is uprushed, the output voltage Vy of the detection module is increased from a low level, the output voltage Vy is a low level through the first inverter Vy, the fourth NMOSFET, the fifth NMOSFET and the sixth NMOSFET are stopped, the third NMOSFET, the third PMOSFET and the fourth PMOSFET are turned on, and therefore the voltage of Vx is pulled to a high level.

Referring to fig. 6, in order to further increase the driving capability of the output voltage of the detection module and facilitate subsequent processing of the output voltage of the detection module, an embodiment of the present application is substantially the same as the foregoing embodiment, except that the detection circuit of the present embodiment further includes: a second buffer 8, an input of the second buffer 8 being connected to an output of the first buffer 2.

The voltage of the second buffer 8 may be from the same power source as the Detected voltage VDD _ Detected and the input voltage VDD1 of the first inverter 20 and the second inverter 22, or may be from a different power source, and may be determined according to application requirements.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments.

In particular, as for the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

For convenience of description, the above devices are described separately in terms of functional division into various units/modules. Of course, the functionality of the units/modules may be implemented in one or more software and/or hardware implementations when the present application is implemented.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.