CN115800464A - Charging system, charging protection circuit and charging equipment thereof - Google Patents

Charging system, charging protection circuit and charging equipment thereof Download PDF

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Publication number
CN115800464A
CN115800464A CN202211607868.9A CN202211607868A CN115800464A CN 115800464 A CN115800464 A CN 115800464A CN 202211607868 A CN202211607868 A CN 202211607868A CN 115800464 A CN115800464 A CN 115800464A
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China
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voltage
charging
control module
module
temperature
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林智敏
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Shanghai Yaohuo Microelectronics Co Ltd
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Shanghai Yaohuo Microelectronics Co Ltd
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Priority to CN202211607868.9A priority Critical patent/CN115800464A/en
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

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Abstract

The invention provides a charging system, a charging protection circuit and charging equipment thereof, wherein the charging system is integrated with the charging protection circuit in a charging wire, the charging protection circuit is characterized in that a voltage input end and a voltage output end are connected through a switch module, the voltage input end and/or the voltage output end are connected with an over-temperature detection module, the voltage input end is connected with an overvoltage detection module, so that the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time, the overvoltage detection module is used for detecting the voltage of the voltage input end in real time, and only when the temperature detected by the over-temperature detection module is higher than a preset temperature value and/or the voltage detected by the overvoltage detection module is higher than a preset voltage value, the control module controls the switch module to be disconnected, so that over-temperature and over-voltage protection is provided for a circuit at the rear end. Aiming at the charging protection technology, the invention also ensures that the conduction impedance of the charging path is smaller under the condition of realizing accurate overvoltage and overtemperature protection in the charging circuit.

Description

Charging system, charging protection circuit and charging equipment thereof
Technical Field
The invention relates to the technical field of charging, in particular to a charging system, a charging protection circuit and charging equipment thereof
Background
In recent years, a charging protection technology is widely used in the technical field of charging, particularly in the technical field of high-power charging and the field of automobile charging.
The existing charging protection generally adopts the following modes: a PTC resistor is added in the male terminal of the charging wire and is connected with a load in series, so that the circuit realizes the function of over-temperature protection. When the charging equipment is charged, the male head of the charging wire and the female charging seat of the charging equipment are in metal contact connection, so that when the charging port is heated due to short circuit or electric leakage of the charging port of the equipment, high temperature can be synchronously conducted to the PTC resistor in the male head of the charging wire, the resistance value of the PTC resistor is suddenly increased, the current flowing through the charging wire is quickly reduced, the charging path is similar to disconnection, and the power supply to the charging equipment is stopped, so that the charging port is prevented from being burnt out at high temperature; when the fault is eliminated, the PTC resistor also automatically restores to the low resistance state, and the circuit restores to normal operation.
The above prior art has the following problems:
1) The initial resistance value distribution range of the PTC resistor is large, which causes obvious difference in charging efficiency between the same charging devices, and after multiple protection actions, the resistance value of the PTC resistor is obviously higher than the initial resistance, so that the performance parameters of the charging device are reduced or broken, and the resistance connected in series in the charging circuit increases the impedance of the charging path, so that the circuit design cannot be applied to a power supply circuit with low charging path impedance (such as rapid charging).
2) The curie temperature point of the PTC resistor is relatively fixed and cannot be set to a temperature at which the over-temperature protection mechanism is triggered.
3) When the circuit is over-voltage, the PTC resistor cannot have a protection action to protect the back-end circuit.
Therefore, how to ensure that the on-resistance of the charging path is small under the condition of realizing accurate over-voltage and over-temperature protection in the charging circuit has become a technical problem to be solved in the industry at present.
Disclosure of Invention
The invention provides a charging system, a charging protection circuit and charging equipment thereof, which aim to solve the problem that the conduction impedance of a charging path is small under the condition that accurate overvoltage and overtemperature protection is realized in the charging circuit.
According to a first aspect of the present invention, a charging system is provided, which includes an adapter and a charging wire, where the charging wire is used to connect the adapter and a charging device, and a charging protection circuit is integrated in the charging wire; wherein, the charge protection circuit includes: the device comprises a voltage input end, a voltage output end, a switch module, an over-temperature detection module, an overvoltage detection module and a control module;
the voltage input end is connected with the first end of the switch module, the second end of the switch module is connected with the voltage output end, the voltage input end and/or the voltage output end is connected with the first end of the over-temperature detection module, the voltage input end is also connected with the first end of the overvoltage detection module, the second end of the over-temperature detection module and the second end of the overvoltage detection module are respectively connected with the first end and the second end of the control module, the third end of the control module is connected with the third end of the switch module, and the third end of the overvoltage detection module and the third end of the over-temperature detection module are both grounded; wherein:
the voltage input end is used for connecting the adapter;
the voltage output end is used for connecting the charging equipment;
the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time and outputting a first signal to the control module according to the detected temperature; wherein the first signal is indicative of a magnitude of the detected temperature;
the overvoltage detection module is used for detecting the voltage of the voltage input end in real time and outputting a second signal to the control module according to the detected voltage; wherein the second signal is used to characterize the magnitude of the detected voltage;
the control module is configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, controlling the switch module to be switched off; otherwise, controlling the switch module to be conducted.
Optionally, the over-temperature detection module includes a current source, a thermistor, and a first comparator; wherein:
the first end of the current source is connected with the voltage input end, the second end of the current source is connected with the first end of the thermistor, and the second end of the thermistor is grounded;
the first input end of the first comparator is connected with the first end of the thermistor, the second input end of the first comparator is connected with a first reference voltage, and the output end of the first comparator is connected with the first end of the control module; the first comparator is used for comparing the voltage at the first end of the thermistor with the first reference voltage and outputting the first signal to the control module.
Optionally, the current source is a high-precision current source.
Optionally, the overvoltage detection module includes a voltage dividing resistor and a second comparator; wherein:
the voltage dividing resistor comprises a first resistor and a second resistor which are connected in series, the first end of the first resistor is connected with the voltage input end, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is grounded;
the first input end of the second comparator is connected with the second end of the first resistor, the second input end of the second comparator is connected with a second reference voltage, and the output end of the second comparator is connected with the second end of the control module; the second comparator is used for comparing the voltage of the second end of the first resistor with the second reference voltage and outputting the second signal to the control module.
Optionally, the switch module includes an NMOS switch tube, wherein a drain of the NMOS switch tube is connected to the voltage input end, a source of the NMOS switch tube is connected to the voltage output end, and a third end of the control module is connected to a gate of the NMOS switch tube.
Optionally, the device further comprises a charge pump, and a third end of the control module is connected to the gate of the NMOS switching tube through the charge pump.
Optionally, the control module is specifically configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, outputting a low level to the grid electrode of the NMOS switch tube through the third end of the NMOS switch tube, and controlling the NMOS switch tube to be switched off; otherwise, outputting a high level to the grid electrode of the NMOS switch tube through the third end of the NMOS switch tube, and controlling the NMOS switch tube to be conducted.
Optionally, the switch module includes a PMOS switch tube, wherein a source of the PMOS switch tube is connected to the voltage input end, a drain of the PMOS switch tube is connected to the voltage output end, and a gate of the PMOS switch tube is connected to the third end of the control module.
Optionally, the control module is specifically configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, outputting a high level to the grid electrode of the PMOS switching tube through the third end of the PMOS switching tube, and controlling the PMOS switching tube to be switched off; otherwise, outputting a low level to the grid electrode of the PMOS switching tube through the third end of the PMOS switching tube, and controlling the conduction of the PMOS switching tube.
Optionally, the control module is further configured to:
and when the temperature represented by the first signal is lower than a preset temperature value and the voltage represented by the second signal is lower than a preset voltage value, controlling the switch module to be switched on again after the switch module is switched on again.
According to a second aspect of the present invention, there is provided a charging protection circuit, comprising a voltage input terminal, a voltage output terminal, a switch module, an over-temperature detection module, an over-voltage detection module and a control module;
the voltage input end is connected with the first end of the switch module, the second end of the switch module is connected with the voltage output end, the voltage input end and/or the voltage output end is connected with the first end of the over-temperature detection module, the voltage input end is also connected with the first end of the overvoltage detection module, the second end of the over-temperature detection module and the second end of the overvoltage detection module are respectively connected with the first end and the second end of the control module, the third end of the control module is connected with the third end of the switch module, and the third end of the overvoltage detection module and the third end of the over-temperature detection module are both grounded; wherein:
the voltage input end is used for connecting the adapter;
the voltage output end is used for being connected with the charging equipment;
the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time and outputting a first signal to the control module according to the detected temperature; wherein the first signal is indicative of a magnitude of the detected temperature;
the overvoltage detection module is used for detecting the voltage of the voltage input end in real time and outputting a second signal to the control module according to the detected voltage; wherein the second signal is used to characterize the magnitude of the detected voltage;
the control module is configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, controlling the switch module to be switched off; otherwise, controlling the switch module to be conducted.
Optionally, the over-temperature detection module includes a current source, a thermistor, and a first comparator; wherein:
the first end of the current source is connected with the voltage input end, the second end of the current source is connected with the first end of the thermistor, and the second end of the thermistor is grounded;
the first input end of the first comparator is connected with the first end of the thermistor, the second input end of the first comparator is connected with a first reference voltage, and the output end of the first comparator is connected with the first end of the control module; the first comparator is used for comparing the voltage at the first end of the thermistor with the first reference voltage and outputting the first signal to the control module.
Optionally, the current source is a high-precision current source.
Optionally, the overvoltage detection module includes a voltage dividing resistor and a second comparator;
the voltage dividing resistor comprises a first resistor and a second resistor which are connected in series, the first end of the first resistor is connected with the voltage input end, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is grounded;
the first input end of the second comparator is connected with the second end of the first resistor, the second input end of the second comparator is connected with a second reference voltage, and the output end of the second comparator is connected with the second end of the control module; the second comparator is used for comparing the voltage of the second end of the first resistor with the second reference voltage and outputting the second signal to the control module.
Optionally, the switch module includes an NMOS switch tube, wherein a drain of the NMOS switch tube is connected to the voltage input end, a source of the NMOS switch tube is connected to the voltage output end, and a third end of the control module is connected to a gate of the NMOS switch tube.
Optionally, the device further comprises a charge pump, and a third end of the control module is connected to the gate of the NMOS switching tube through the charge pump.
Optionally, the switch module includes a PMOS switch tube, wherein a source of the PMOS switch tube is connected to the voltage input end, a drain of the PMOS switch tube is connected to the voltage output end, and a gate of the PMOS switch tube is connected to the third end of the control module.
According to a third aspect of the present invention, there is provided a charging apparatus including the charge protection circuit provided in any one of the second aspects of the present invention.
According to the charging system provided by the invention, the charging protection circuit is integrated in the charging wire, and the charging wire is connected with the adapter and the charging equipment; the charging protection circuit is characterized in that a voltage input end and a voltage output end are connected through a switch module, the voltage input end and/or the voltage output end are connected with an over-temperature detection module, and the voltage input end is connected with an overvoltage detection module, so that the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time, the overvoltage detection module is used for detecting the voltage of the voltage input end in real time, and only when the temperature detected by the over-temperature detection module is higher than a preset temperature value and/or the voltage detected by the overvoltage detection module is higher than a preset voltage value, the control module controls the switch module to be disconnected, so that over-temperature and over-voltage protection is provided for a circuit of charging equipment; therefore, the charging circuit between the adapter and the charging equipment can be protected accurately under overvoltage and overtemperature conditions, and the conduction impedance of the charging path is ensured to be small.
The charging protection circuit provided by the invention can realize that the conduction impedance of a charging path is relatively small under the condition of realizing accurate overvoltage and overtemperature protection in the charging circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic diagram of a configuration of a charge protection circuit in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a charge protection circuit according to a first embodiment of the present invention;
FIG. 3 is a schematic diagram of a charge protection circuit according to a second embodiment of the present invention;
fig. 4 is a schematic configuration diagram of a charge protection circuit in a third embodiment of the present invention;
fig. 5 is a schematic configuration diagram of a charge protection circuit in a fourth embodiment of the present invention;
fig. 6 is a schematic configuration diagram of a charging system in an embodiment of the invention;
description of reference numerals:
10-a charge protection circuit;
101-an over-temperature detection module;
102-an overvoltage detection module;
103-a switch module;
104-a control module;
VBUS-supply pin;
GND-ground;
VIN-voltage input terminal;
VOUT-voltage output terminal;
an RT-thermistor;
NTC-negative temperature coefficient thermistor;
R u -a first resistance;
R d -a second resistance;
CMP1 — first comparator;
CMP2 — second comparator;
VREF1 — first reference voltage;
VREF 2-second reference voltage.
R1 — a first NTC resistance;
r2 — a second NTC resistance;
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
In view of the prior art, the problem that the conduction impedance of the charging path is ensured to be small under the condition that accurate overvoltage and overtemperature protection is difficult to ensure in the charging circuit exists. The invention provides a charging protection circuit, which is characterized in that a voltage input end and a voltage output end are connected through a switch module, the voltage input end and/or the voltage output end are connected with an over-temperature detection module, the voltage input end is connected with an overvoltage detection module, so that the temperature of the voltage input end and/or the voltage output end is detected in real time by the over-temperature detection module, the voltage of the voltage input end is detected in real time by the overvoltage detection module, and only when the temperature detected by the over-temperature detection module is higher than a preset temperature value and/or the voltage detected by the overvoltage detection module is higher than a preset voltage value, a control module controls the switch module to be disconnected, so that over-temperature and over-voltage protection is provided for a circuit at the rear end; the invention can realize accurate overvoltage and overtemperature protection in the charging circuit and also ensure that the conduction impedance of the charging path is smaller.
In addition, the charging protection circuit is integrated into the charging wire of the charging system, so that the conduction impedance of the charging path is ensured to be smaller under the condition that the charging circuit between the adapter and the charging equipment is accurately protected by overvoltage and overtemperature.
Referring to fig. 1, an embodiment of the invention provides a charging protection circuit 10, which includes a voltage input terminal VIN, a voltage output terminal VOUT, an over-temperature detection module 101, an over-voltage detection module 102, a switch module 103, and a control module 104;
the voltage input end VIN is connected with a first end of the switch module 103, a second end of the switch module 103 is connected with the voltage output end VOUT, the voltage input end VIN and/or the voltage output end VOUT is connected with a first end of the over-temperature detection module 101, the voltage input end VIN is further connected with a first end of the overvoltage detection module 102, a second end of the over-temperature detection module 101 and a second end of the overvoltage detection module 102 are respectively connected with a first end and a second end of the control module 104, a third end of the control module 104 is connected with a third end of the switch module 103, and the third end of the overvoltage detection module 102 and the third end of the over-temperature detection module 101 are both grounded; wherein:
the voltage input end VIN is used for connecting the adapter;
the voltage output end VOUT is used for being connected with the charging equipment;
the over-temperature detection module 101 is configured to detect a temperature of the voltage input terminal VIN and/or the voltage output terminal VOUT in real time, and output a first signal to the control module 104 according to the detected temperature; wherein the first signal is indicative of a magnitude of the detected temperature;
the overvoltage detection module 102 is configured to detect a voltage of the voltage input terminal VIN in real time, and output a second signal to the control module 104 according to the detected voltage; wherein the second signal is used to characterize the magnitude of the detected voltage;
when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, the control module 104 controls the switch module 103 to be switched off; otherwise, the switch module 103 is controlled to be turned on.
In one embodiment, as shown in fig. 2, the over-temperature detection module 101 includes a current source, a thermistor RT, and a first comparator CMP1; wherein:
the first end of the current source is connected with the voltage input end, the second end of the current source is connected with the first end of the thermistor RT, and the second end of the thermistor RT is grounded;
the first input of the first comparator CMP1 is connected to the first end of the thermistor RT, the second input thereof is connected to the first reference voltage VREF1, and the output thereof is connected to the first end of the control module 104; the first comparator CMP1 is configured to compare the voltage VN at the first end of the thermistor RT with the first reference voltage VREF1, and output the first signal to the control module 104.
Wherein, thermistor RT can set up in voltage input end VIN and/or voltage output VOUT department, when adapter or battery charging outfit arouses the port that charges to scald because the port short circuit that charges or electric leakage, high temperature can conduct thermistor RT in step for thermistor RT's resistance changes.
In a preferred embodiment, the current source is a high-precision current source, and the current of the high-precision current source is much smaller than that of the charging path, so that the additional power consumption generated by the operation of the thermistor RT is low, and no additional heat is added to the circuit.
As an example, the current of the high-precision current source is controllable, so that the additional power consumption generated by the thermistor RT is controllable.
As a preferred embodiment, the second input terminal of the first comparator CMP1 is connected to a reference resistance value, and the first comparator CMP1 compares the current resistance value of the thermistor RT with the reference resistance value, and outputs the first signal to the control module 104.
In one embodiment, the thermistor RT is an NTC resistor. The NTC resistor is a negative temperature coefficient thermistor, and when a charging port is excessively heated due to a current flowing through a charging wire during charging caused by short circuit or leakage, the resistance of the NTC resistor is lowered. On the basis, the current voltage VN of the NTC resistor is measured, and the voltage VN is supplied to the positive input terminal of the first comparator CMP1 to be compared with the first reference voltage VREF1 at the negative input terminal of the first comparator CMP 1. When the temperature of the voltage input end or the voltage output end is less than or equal to a preset temperature value, the voltage VN is greater than the first reference voltage VREF1, so that a first signal output by the first comparator CMP1 is at a high level; when the temperature of the voltage input end or the voltage output end is higher than a preset temperature value, the voltage VN is smaller than the first reference voltage VREF1, so that the first signal output by the first comparator CMP1 is at a low level.
The value of the first reference voltage VREF1 may be a product of a resistance value of the NTC resistor at a preset temperature value and a current value of the current source, and the value is independent of voltage fluctuation or environmental temperature change of the voltage input terminal VIN. Therefore, when the first signal received by the control module 104 is at a high level, the control module 104 can accurately determine that the current temperature of the voltage input terminal or the voltage output terminal is normal, and the voltage represented by the second signal is less than or equal to a preset voltage value, the switch module 103 is controlled to be turned on, otherwise, the current temperature of the voltage input terminal or the voltage output terminal is determined to be too high, and the switch module 103 is controlled to be turned off.
As another specific implementation, please refer to fig. 3, the voltage VN of the second terminal of the NTC resistor is respectively applied to the positive input terminal of the first comparator CMP1 and the positive input terminal of the third comparator CMP 3; the voltage VN is respectively compared with a first reference voltage VREF1 at a negative input terminal of the first comparator CMP1 and a third reference voltage VREF3 at a negative input terminal of the third comparator, and the first comparator CMP1 and the third comparator CMP3 respectively output a first signal and a third signal to the control module 104 according to comparison results;
wherein the first signal is indicative of whether the detected temperature exceeds a shutdown temperature value; the third signal is used for indicating whether the detected temperature exceeds a conduction temperature value or not.
The control module 104 is further configured to: when the temperature represented by the first signal is greater than the turn-off temperature value and/or the voltage represented by the second signal is higher than the preset voltage value, controlling the switch module 103 to be switched off; when the temperature represented by the third signal is less than or equal to the conduction temperature value and the voltage represented by the second signal is less than or equal to the preset voltage value, controlling the switch module 103 to recover conduction.
In this case, when the temperature of the voltage input terminal or the voltage output terminal is less than or equal to the turn-off temperature, the voltage VN is greater than or equal to the first reference voltage VREF1, so that the first signal output by the first comparator CMP1 is at a high level; when the temperature of the voltage input terminal or the voltage output terminal is greater than the turn-off temperature, the voltage VN is less than the first reference voltage VREF1, so that the first signal output by the first comparator CMP1 is at a low level; when the temperature of the voltage input terminal or the voltage output terminal is less than or equal to the turn-on temperature, the voltage VN is greater than or equal to the third reference voltage VREF3, so that the third signal output by the third comparator CMP3 is at a high level; when the temperature of the voltage input terminal or the voltage output terminal is higher than the turn-on temperature, the voltage VN is smaller than the third reference voltage VREF3, so that the third signal output by the third comparator CMP3 is at a low level;
wherein the first reference voltage VREF1 may be set as the voltage VN of the second terminal of the NTC resistance at the turn-off temperature, and the third reference voltage VREF3 may be set as the voltage VN of the second terminal of the NTC resistance at the turn-on temperature;
therefore, when the first signal and the third signal received by the control module 104 are both at a high level, it is determined that the temperature of the current voltage input terminal or the current voltage output terminal is normal, and the voltage represented by the second signal is less than or equal to a preset voltage value, so that the switch module 103 is controlled to be turned on; in this case, if the first signal received by the control module 104 is at a high level and the third signal is at a low level, the control module 104 may accurately determine that the current temperature of the voltage input end or the voltage output end is in a high temperature environment, and the voltage represented by the second signal is less than or equal to a preset voltage value, and then the control module 104 controls the switch module 103 to continue to be turned on;
when the first signal and the third signal received by the control module 104 are both at a low level, it is determined that the current temperature of the voltage input terminal or the voltage output terminal is too high, and the switch module 103 is controlled to be turned off; in this case, if the first signal received by the control module 104 is at a high level and the third signal is at a low level, the control module 104 can accurately determine that the current temperature of the voltage input terminal or the voltage output terminal is still in a high temperature environment, and control the switch module 103 to continue to be turned off.
The configuration can ensure that the charging path has a high-temperature working interval, prevent the charging protection circuit from generating multiple protection actions in a short time under the condition that the fault of the charging path is not relieved, and realize accurate over-temperature protection and recovery functions.
As another specific implementation, please refer to fig. 4, wherein two NTC resistors R1 and R2 are respectively disposed at the voltage input terminal VIN and/or the voltage output terminal VOUT, current voltages VN and VM of the first NTC resistor R1 and the second NTC resistor R2 are respectively measured, the voltage VN is sent to the positive input terminal of the first comparator CMP1 to be compared with a first reference voltage VREF1 at the negative input terminal of the first comparator CMP1, and the voltage VM is sent to the positive input terminal of the third comparator CMP3 to be compared with a third reference voltage VREF3 at the negative input terminal of the third comparator CMP 3. When the temperatures of the voltage input end and the voltage output end are less than or equal to a preset temperature value, the voltage VN and the voltage VM are respectively greater than the first reference voltage VREF1 and the third reference voltage VREF3, so that the first signal and the third signal output by the first comparator CMP1 and the third comparator CMP3 are both at a high level; conversely, when the temperature of the voltage input terminal and/or the voltage output terminal is higher than the preset temperature value, the first signal correspondingly output by the first comparator CMP1 and/or the third signal correspondingly output by the third comparator CMP3 is at a low level.
Therefore, when the first signal and the third signal received by the control module 104 are both high level, and the voltage represented by the second signal is less than or equal to a preset voltage value, the switch module 103 is controlled to be continuously turned on; when the first signal and/or the third signal received by the control module 104 is at a low level, it is determined that the current temperature of the voltage input terminal and/or the voltage output terminal is too high, and the switch module 103 is controlled to be turned off.
Of course, it should be appreciated that the specific type of the thermistor RT is merely an example, the thermistor RT in the present invention is not limited to the NTC resistor, and those skilled in the art can select other thermistors according to practical situations, such as a PTC resistor and a CTR resistor.
In one embodiment, as shown in fig. 2, the overvoltage detection module 102 includes a voltage dividing resistor and a second comparator CMP2; wherein:
the divider resistor comprises a first resistor R connected in series u And a second resistor R d The first resistor R u Is connected to the voltage input VIN, the first resistor R u And the second terminal of the second resistor R d Is connected to the first terminal of the first resistor R, the second resistor R d The second terminal of (1) is grounded;
the first input terminal of the second comparator CMP2 is connected to the first resistor R u A second input terminal of the second terminal is connected to a second reference voltage VREF2, and an output terminal of the second terminal is connected to the second terminal of the control module 104; the second comparator CMP2 is used for comparing the first resistance R u And the voltage VX of the second terminal and the second reference voltage VREF2, and outputs the second signal to the control module 104.
The voltage dividing resistor is used for sampling the voltage of the current voltage input end VIN.
Wherein the first resistor R u Is connected to the negative input terminal of the second comparator CMP2 and is compared with the second reference voltage VREF2 at the positive input terminal of the second comparator CMP 2. When the voltage of the voltage input end VIN is normal, the first resistor R u The voltage VX of the second end of the comparator CMP2 is smaller than the second reference voltage VREF2, the comparator CMP2 outputs a high level signal, and the control module 104 controls the switch module 103 to be turned on when receiving the high level signal; when the voltage of the voltage input terminal VIN is too high, the first resistor R u The voltage VX at the second end of the switch circuit is greater than the second reference voltage VREF2, the comparator CMP2 outputs a low level signal, and the control module 104 controls the switch module 103 to turn off when receiving the low level signal, so as to prevent the excessive voltage from being transmitted to the rear-end circuit to damage the rear-end device thereof.
In one embodiment, referring to fig. 2, the switch module 103 includes an NMOS switch tube, wherein a drain of the NMOS switch tube is connected to the voltage input terminal, a source of the NMOS switch tube is connected to the voltage output terminal, and a third terminal of the control module 104 is connected to a gate of the NMOS switch tube.
In this case, when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, the third terminal of the control module 104 outputs a low level to turn off the NMOS switch, so that the charging path between the voltage input terminal VIN and the voltage output terminal VOUT is disconnected, and conversely, the third terminal of the control module 104 outputs a high level to turn on the NMOS switch.
In a preferred embodiment, referring to fig. 3, the switch module 103 includes an NMOS switch tube and a charge pump, and the third terminal of the control module 104 is connected to the gate of the NMOS switch tube through the charge pump. The charge pump is configured to boost a level output by the control module 104, so that the charge pump can drive the NMOS switch tube to be turned on.
In another embodiment, referring to fig. 5, the switch module 103 includes a PMOS switch tube, wherein a source of the PMOS switch tube is connected to the voltage input terminal, a drain of the PMOS switch tube is connected to the voltage output terminal, and a gate of the PMOS switch tube is connected to the third terminal of the control module 104.
In this case, when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, the third terminal of the control module 104 outputs a high level to the gate of the PMOS switch transistor to control the PMOS switch transistor to be turned off; otherwise, the third end of the control module 104 outputs a low level to the gate of the PMOS switch tube to control the PMOS switch tube to be turned on.
It should be understood that the switch module 103 adopts an NMOS switch tube or a PMOS switch tube to control the charging path, because the NMOS switch tube or the PMOS switch tube has small impedance and good impedance consistency, and will not change with the number of times of use, and the switch is switched on and off instantly and stably powered, and is suitable for a power circuit with low charging path impedance (such as fast charging).
In addition, the embodiment of the invention also provides electronic equipment which comprises the charging protection circuit. For example, the device may be a charging chip, a charging pile, a charging station, or other devices that need to be protected from charging.
In addition, the present invention further provides a charging system, please refer to fig. 6, which includes an adapter and a charging wire, wherein the charging wire is used for connecting the adapter and a charging device, and the charging wire is integrated with the charging protection circuit 10; the description of the charge protection circuit 10 is the same as the above description, and will not be repeated herein.
Specifically, in the example shown in fig. 6, the charging protection circuit can be made into a charging chip, and the thermistor RT can be placed outside the charging chip, for example, at a metal connector of a charging male terminal of a charging wire, so that it can reliably collect the temperature of the voltage input terminal VIN or the voltage output terminal VOUT. When the charging device is charged, the male charging terminal and the female charging terminal are in metal contact connection, so that when the charging device is heated at the charging port due to short circuit or electric leakage of the charging port, high temperature can be synchronously transmitted to the thermistor RT in the male charging terminal, so that the resistance value of the thermistor RT is rapidly changed, the charging chip detects that the resistance value or voltage of the thermistor RT is changed and then transmits the changed resistance value or voltage to the charging chip, and when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, the control module 104 controls the switch module 103 to be switched off; otherwise, the switch module 103 is controlled to be turned on, so that the charging device is protected from being damaged when an overvoltage and/or overtemperature fault state occurs.
In summary, according to the charging system, the charging protection circuit and the charging device thereof provided by the present invention, the charging protection circuit is integrated in the charging line through the charging system, the charging protection circuit is connected between the voltage input end and the voltage output end through the switch module, the voltage input end and/or the voltage output end is connected to the over-temperature detection module, and the voltage input end is connected to the overvoltage detection module, so that the over-temperature detection module is used to detect the temperature of the voltage input end and/or the voltage output end in real time, and the overvoltage detection module is used to detect the voltage of the voltage input end in real time, and only when the temperature detected by the over-temperature detection module is higher than the preset temperature value and/or the voltage detected by the overvoltage detection module is higher than the preset voltage value, the control module controls the switch module to be disconnected, so as to provide over-temperature and overvoltage protection for the circuit at the rear end. Aiming at the charging protection technology, the invention also ensures that the conduction impedance of the charging path is smaller under the condition of realizing accurate overvoltage and overtemperature protection in the charging circuit.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (18)

1. A charging system is characterized by comprising an adapter and a charging wire, wherein the charging wire is used for connecting the adapter with charging equipment, and a charging protection circuit is integrated in the charging wire; wherein, the charge protection circuit includes: the over-temperature detection module is connected with the over-voltage detection module;
the voltage input end is connected with the first end of the switch module, the second end of the switch module is connected with the voltage output end, the voltage input end and/or the voltage output end is connected with the first end of the over-temperature detection module, the voltage input end is also connected with the first end of the overvoltage detection module, the second end of the over-temperature detection module and the second end of the overvoltage detection module are respectively connected with the first end and the second end of the control module, the third end of the control module is connected with the third end of the switch module, and the third end of the overvoltage detection module and the third end of the over-temperature detection module are both grounded; wherein:
the voltage input end is used for connecting the adapter;
the voltage output end is used for being connected with the charging equipment;
the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time and outputting a first signal to the control module according to the detected temperature; wherein the first signal is indicative of a magnitude of the detected temperature;
the overvoltage detection module is used for detecting the voltage of the voltage input end in real time and outputting a second signal to the control module according to the detected voltage; wherein the second signal is used to characterize the magnitude of the detected voltage;
the control module is configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, controlling the switch module to be switched off; otherwise, controlling the switch module to be conducted.
2. The charging system of claim 1, wherein the over-temperature detection module comprises a current source, a thermistor, and a first comparator; wherein:
the first end of the current source is connected with the voltage input end, the second end of the current source is connected with the first end of the thermistor, and the second end of the thermistor is grounded;
the first input end of the first comparator is connected with the first end of the thermistor, the second input end of the first comparator is connected with a first reference voltage, and the output end of the first comparator is connected with the first end of the control module; the first comparator is used for comparing the voltage at the first end of the thermistor with the first reference voltage and outputting the first signal to the control module.
3. The charging system of claim 2, wherein the current source is a high precision current source.
4. The charging system of claim 1, wherein the overvoltage detection module comprises a voltage divider resistor and a second comparator; wherein:
the voltage dividing resistor comprises a first resistor and a second resistor which are connected in series, the first end of the first resistor is connected with the voltage input end, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is grounded;
the first input end of the second comparator is connected with the second end of the first resistor, the second input end of the second comparator is connected with a second reference voltage, and the output end of the second comparator is connected with the second end of the control module; the second comparator is used for comparing the voltage of the second end of the first resistor with the second reference voltage and outputting the second signal to the control module.
5. The charging system of claim 1, wherein the switch module comprises an NMOS switch, wherein a drain of the NMOS switch is connected to the voltage input terminal, a source of the NMOS switch is connected to the voltage output terminal, and a third terminal of the control module is connected to a gate of the NMOS switch.
6. The charging system of claim 5, further comprising a charge pump, wherein the third terminal of the control module is connected to the gate of the NMOS switch tube through the charge pump.
7. The charging system of claim 5, wherein the control module is specifically configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, outputting a low level to the grid electrode of the NMOS switch tube through the third end of the NMOS switch tube, and controlling the NMOS switch tube to be switched off; otherwise, outputting a high level to the grid electrode of the NMOS switch tube through the third end of the NMOS switch tube to control the NMOS switch tube to be conducted.
8. The charging system of claim 1, wherein the switch module comprises a PMOS switch transistor, wherein a source of the PMOS switch transistor is connected to the voltage input terminal, a drain of the PMOS switch transistor is connected to the voltage output terminal, and a gate of the PMOS switch transistor is connected to the third terminal of the control module.
9. The charging system of claim 8, wherein the control module is specifically configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, outputting a high level to the grid electrode of the PMOS switching tube through the third end of the PMOS switching tube, and controlling the PMOS switching tube to be switched off; otherwise, outputting a low level to the grid electrode of the PMOS switching tube through the third end of the PMOS switching tube, and controlling the conduction of the PMOS switching tube.
10. The charging system of any of claims 1-9, wherein the control module is further configured to:
and when the temperature represented by the first signal is lower than a preset temperature value and the voltage represented by the second signal is lower than a preset voltage value, controlling the switch module to be switched on again after the switch module is switched on again.
11. A charging protection circuit is characterized by comprising a voltage input end, a voltage output end, a switch module, an over-temperature detection module, an over-voltage detection module and a control module;
the voltage input end is connected with the first end of the switch module, the second end of the switch module is connected with the voltage output end, the voltage input end and/or the voltage output end is connected with the first end of the over-temperature detection module, the voltage input end is also connected with the first end of the overvoltage detection module, the second end of the over-temperature detection module and the second end of the overvoltage detection module are respectively connected with the first end and the second end of the control module, the third end of the control module is connected with the third end of the switch module, and the third end of the overvoltage detection module and the third end of the over-temperature detection module are both grounded; wherein:
the voltage input end is used for connecting the adapter;
the voltage output end is used for being connected with the charging equipment;
the over-temperature detection module is used for detecting the temperature of the voltage input end and/or the voltage output end in real time and outputting a first signal to the control module according to the detected temperature; wherein the first signal is indicative of a magnitude of the detected temperature;
the overvoltage detection module is used for detecting the voltage of the voltage input end in real time and outputting a second signal to the control module according to the detected voltage; wherein the second signal is used to characterize the magnitude of the detected voltage;
the control module is configured to: when the temperature represented by the first signal is higher than a preset temperature value and/or the voltage represented by the second signal is higher than a preset voltage value, controlling the switch module to be switched off; otherwise, controlling the switch module to be conducted.
12. The charge protection circuit according to claim 11, wherein the over-temperature detection module comprises a current source, a thermistor, and a first comparator; wherein:
the first end of the current source is connected with the voltage input end, the second end of the current source is connected with the first end of the thermistor, and the second end of the thermistor is grounded;
the first input end of the first comparator is connected with the first end of the thermistor, the second input end of the first comparator is connected with a first reference voltage, and the output end of the first comparator is connected with the first end of the control module; the first comparator is used for comparing the voltage at the first end of the thermistor with the first reference voltage and outputting the first signal to the control module.
13. The charge protection circuit of claim 12, wherein the current source is a high precision current source.
14. The charge protection circuit according to claim 11, wherein the overvoltage detection module comprises a voltage dividing resistor and a second comparator;
the voltage dividing resistor comprises a first resistor and a second resistor which are connected in series, the first end of the first resistor is connected with the voltage input end, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is grounded;
the first input end of the second comparator is connected with the second end of the first resistor, the second input end of the second comparator is connected with a second reference voltage, and the output end of the second comparator is connected with the second end of the control module; the second comparator is used for comparing the voltage of the second end of the first resistor with the second reference voltage and outputting the second signal to the control module.
15. The charging protection circuit of claim 11, wherein the switch module comprises an NMOS switch, wherein a drain of the NMOS switch is connected to the voltage input terminal, a source of the NMOS switch is connected to the voltage output terminal, and a third terminal of the control module is connected to a gate of the NMOS switch.
16. The charge protection circuit of claim 15, further comprising a charge pump, wherein the third terminal of the control module is connected to the gate of the NMOS switch tube through the charge pump.
17. The charging protection circuit of claim 11, wherein the switch module comprises a PMOS switch transistor, wherein a source of the PMOS switch transistor is connected to the voltage input terminal, a drain of the PMOS switch transistor is connected to the voltage output terminal, and a gate of the PMOS switch transistor is connected to the third terminal of the control module.
18. A charging device characterized by comprising the charge protection circuit according to any one of claims 11 to 17.
CN202211607868.9A 2022-12-14 2022-12-14 Charging system, charging protection circuit and charging equipment thereof Pending CN115800464A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211607868.9A CN115800464A (en) 2022-12-14 2022-12-14 Charging system, charging protection circuit and charging equipment thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211607868.9A CN115800464A (en) 2022-12-14 2022-12-14 Charging system, charging protection circuit and charging equipment thereof

Publications (1)

Publication Number Publication Date
CN115800464A true CN115800464A (en) 2023-03-14

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Country Link
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