Charge and discharge current limit regulation circuit

Abstract

The present invention provides a charge and discharge current limit regulation circuit, which is applied to the charge and discharge of a battery, wherein the charge and discharge current limit regulation circuit comprises a first reference module, a second reference module, a first comparator, a second comparator, a first amplifier, a logic control module, a switch drive circuit module and a first transistor, wherein the first reference module comprises a first resistor for regulating an output current or voltage, and the second reference module comprises a second resistor for regulating an output current or voltage. Compared with the related art, the charge and discharge current limit regulation circuit of the present invention realizes independent control of charge and / or discharge current limit regulation, and has a simple application scheme and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging and discharging, and in particular to a charging and discharging current limit regulating circuit applied to a battery. Background Art

[0002] At present, with the increasing use of mobile devices such as smart phones, wearable devices, power tools, and drones, the lithium-ion battery power supply application in the mobile devices is an important part. Due to the stability problem of lithium-ion batteries, battery protection circuits are widely used in battery-powered systems. Among them, the battery protection circuit can realize a variety of protection functions, such as battery overvoltage, battery voltage overdischarge, charging current limit, discharge current limit, etc.

[0003] The battery protection circuit of the related art sets the charging and discharging current limits to the same value, or performs fixed charging and discharging currents through internal circuits. Figure 1 As shown, Figure 1 This is an application circuit diagram of a battery protection circuit of the related art. The battery protection circuit uses a fixed current limit to protect the battery. U0 is a battery protection circuit using a fixed current limit. Among them, TM is the charging power supply, RLOAD is the load resistor, the resistor R1 and the capacitor C1 form an RC circuit between the power supply voltage and the ground GND, and B is a lithium battery. From the circuit connection of the circuit diagram, it can be seen that the battery protection circuit uses a fixed current limit to protect the battery, and cannot adjust the charging and discharging current limits.

[0004] At the same time, in order to meet the IEC62368 certification, the battery application solution using a fixed current limit protection circuit requires three devices, namely a charging device, an overvoltage / overcurrent protection device, and a battery protection device. Figure 2 As shown, Figure 2 for Figure 1 Specifically, the circuit structure of the battery protection circuit is as shown in the attached Figure 2 As shown, U1 is a battery protection device, U2 is a charging device, and U3 is an overvoltage / overcurrent protection device. In this application solution, even if one of the components U2 and U3 fails, accurate battery overcurrent protection can still be achieved.

[0005] However, in the related art, the fixed current limit protection circuit cannot adjust the charging and discharging current limits separately to adapt to the charging and discharging of different types of lithium batteries. In addition, the circuit structure of the battery protection circuit is relatively complex, and the circuit application scheme is relatively complex, which limits its application scope.

[0006] Therefore, it is necessary to provide a new circuit to solve the above problems. Summary of the invention

[0007] In view of the above deficiencies in the prior art, the present invention proposes a charge and discharge current limit regulation circuit which can realize independent control of charge and / or discharge current limit regulation and has a simple application scheme and a wide application range.

[0008] In order to solve the above technical problems, the present invention provides a charge and discharge current limit adjustment circuit, which is applied to the charge and discharge of a battery. The charge and discharge current limit adjustment circuit includes a first reference module, a second reference module, a first comparator, a second comparator, a first amplifier, a logic control module, a switch drive circuit module and a first transistor;

[0009] Wherein, the first reference module includes a first resistor for adjusting the output current or voltage, and the second reference module includes a second resistor for adjusting the output current or voltage;

[0010] The output terminal of the first reference module is connected to the positive input terminal of the first comparator;

[0011] The output terminal of the second reference module is connected to the negative input terminal of the second comparator;

[0012] The output terminal of the first amplifier is connected to the negative input terminal of the first comparator and the positive input terminal of the second comparator respectively;

[0013] The output terminal of the first comparator is connected to the first input terminal of the logic control module;

[0014] The output terminal of the second comparator is connected to the second input terminal of the logic control module;

[0015] The output end of the logic control module is connected to the input end of the switch driving circuit module;

[0016] A first output terminal of the switch driving circuit module is connected to the gate of the first transistor, and a second output terminal of the switch driving circuit module is connected to the substrate of the first transistor;

[0017] The drain of the first transistor is connected to the negative input terminal of the first amplifier and serves as a charge and discharge interface terminal of the charge and discharge current limit adjustment circuit;

[0018] The source of the first transistor and the positive input terminal of the first amplifier are both connected to ground.

[0019] Preferably, the first transistor is a power switch tube.

[0020] Preferably, the first transistor is an NMOS transistor.

[0021] Preferably, the logic control module is a digital circuit, and the first reference module, the second reference module, the first comparator, the second comparator, the first amplifier and the switch driving circuit module are all analog circuits.

[0022] Preferably, the first reference module also includes a first current source, an input end of the first current source is connected to the power supply voltage, an output end of the first current source is connected to the first end of the first resistor and serves as the output end of the first reference module, and a second end of the first resistor is connected to ground; the second reference module also includes a second current source, an input end of the second current source is connected to the power supply voltage, an output end of the second current source is connected to the first end of the second resistor and serves as the output end of the second reference module, and a second end of the second resistor is connected to ground.

[0023] Preferably, the first reference module also includes a first current mirror circuit unit, a second transistor and a second amplifier; the first output end of the first current mirror circuit unit is connected to the drain of the second transistor, and the second output end of the first current mirror circuit unit serves as the output end of the first reference module; the source of the second transistor is respectively connected to the positive input end of the second amplifier and the first end of the first resistor, and the gate of the second transistor is connected to the output end of the second amplifier; the second end of the first resistor is connected to ground; the negative input end of the second amplifier serves as the first reference voltage input end; the second reference module also includes a second current mirror circuit unit, a third transistor and a third amplifier; the first output end of the second current mirror circuit unit is connected to the drain of the third transistor, and the second output end of the second current mirror circuit unit serves as the output end of the second reference module; the source of the third transistor is respectively connected to the positive input end of the third amplifier and the first end of the second resistor, and the gate of the third transistor is connected to the output end of the third amplifier; the second end of the second resistor is connected to ground; the negative input end of the third amplifier serves as the second reference voltage input end.

[0024] Compared with the related art, the charge and discharge current limit regulation circuit of the present invention includes a first reference module, a second reference module, a first comparator, a second comparator, a first amplifier, a logic control module, a switch drive circuit module and a first transistor. The charge and discharge current limit regulation circuit is configured by setting the first resistor for adjusting the output current or voltage in the first reference module, and at the same time, setting the second resistor for adjusting the output current or voltage in the second reference module. Thus, the circuit can realize independent control of the charge and / or discharge current limit regulation, thereby meeting the application requirements of different types of batteries and different systems, so that the charge and discharge current limit regulation circuit has a wide range of applications. At the same time, when conducting IEC62368 certification, the charge and discharge current limit regulation circuit in the present invention can replace the overvoltage / overcurrent protection circuit, thereby simplifying the battery application scheme, so that the application scheme of the charge and discharge current limit regulation circuit is simple and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings:

[0026] Figure 1 An application circuit diagram of a battery protection circuit of the related art;

[0027] Figure 2 for Figure 1 Circuit structure block diagram;

[0028] Figure 3 It is a circuit structure diagram of the charge and discharge current limit regulating circuit of the present invention;

[0029] Figure 4 It is an application circuit block diagram of the charge and discharge current limit regulating circuit of the present invention;

[0030] Figure 5 1 is a circuit structure diagram of a first embodiment of a charge and discharge current limit regulating circuit of the present invention;

[0031] Figure 6 1 is a circuit structure diagram of a second embodiment of a charge and discharge current limit regulating circuit of the present invention;

[0032] Figure 7 It is an application circuit diagram of the charge and discharge current limit regulating circuit of the present invention. DETAILED DESCRIPTION

[0033] The specific implementation of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] The specific implementation modes / embodiments recorded herein are specific implementation modes of the present invention, which are used to illustrate the concept of the present invention, are explanatory and exemplary, and should not be interpreted as limiting the implementation modes of the present invention and the scope of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims and the specification of this application, and these technical solutions include any obvious replacement and modification of the embodiments recorded herein, which are within the protection scope of the present invention.

[0035] Please refer to Figure 3 As shown, the present invention provides a charge and discharge current limit adjustment circuit 100. Applicable to the charge and discharge of battery B. The charge and discharge current limit adjustment circuit 100 includes a first reference module S1, a second reference module S2, a first comparator COMP1, a second comparator COMP2, a first amplifier AMP1, a logic control module LOG, a switch drive circuit module DVR and a first transistor M1.

[0036] The first reference module S1 includes a first resistor R3 for adjusting the output current or voltage, and the second reference module S2 includes a second resistor R2 for adjusting the output current or voltage.

[0037] The specific circuit structure of the charge and discharge current limit adjustment circuit 100 is:

[0038] The output terminal of the first reference module S1 is connected to the positive input terminal of the first comparator COMP1.

[0039] The output terminal of the second reference module S2 is connected to the negative input terminal of the second comparator COMP2.

[0040] The output terminal of the first amplifier AMP1 is connected to the negative input terminal of the first comparator COMP1 and the positive input terminal of the second comparator COMP2 respectively.

[0041] An output terminal of the first comparator COMP1 is connected to a first input terminal of the logic control module LOG.

[0042] An output terminal of the second comparator COMP2 is connected to a second input terminal of the logic control module LOG.

[0043] The output end of the logic control module LOG is connected to the input end of the switch driving circuit module DVR.

[0044] A first output terminal of the switch driving circuit module DVR is connected to the gate of the first transistor M1 , and a second output terminal of the switch driving circuit module DVR is connected to the substrate of the first transistor M1 .

[0045] The drain of the first transistor M1 is connected to the negative input terminal of the first amplifier AMP1 and serves as the charge and discharge interface terminal VM of the charge and discharge current limit adjustment circuit 100 .

[0046] A source of the first transistor M1 and a positive input terminal of the first amplifier AMP1 are both connected to the ground GND.

[0047] The drain of the first transistor M1 is used as the charge and discharge interface terminal VM. The charge and discharge interface terminal VM is used to output the charge or discharge current. The first transistor M1 is a power switch tube. Of course, it is not limited to this, and the first transistor M1 can also be an NMOS tube.

[0048] Specifically, the logic control module LOG is a digital circuit. The first reference module S1, the second reference module S2, the first comparator COMP1, the second comparator COMP2, the first amplifier AMP1 and the switch drive circuit module DVR are all analog circuits. It should be noted that the logic control module LOG, the first comparator COMP1, the second comparator COMP2, the first amplifier AMP1 and the switch drive circuit module DVR, the first resistor R3, the second resistor R2 and the first transistor M1 are all commonly used devices or circuit modules in the field, and the specific models need to be selected according to the actual design, and are not described in detail here.

[0049] Please refer to Figure 4 As shown, Figure 4 The figure is an application circuit block diagram of the charge and discharge current limit regulating circuit 100 of the present invention. Compared with the battery protection circuit of the related art, the technical solution of the charge and discharge current limit regulating circuit 100 of the present invention can realize the independent setting of the charge and discharge current limits of the battery protection circuit. When the battery protection circuit has independent adjustment of the charge and discharge current limits, in the application circuit block diagram, the charge and discharge current limit regulating circuit 100 of the present invention reduces the overvoltage / overcurrent protection device U3 as a component relative to the battery protection circuit of the related art.

[0050] In the charge and discharge current limit regulating circuit 100 of the present invention, U1 is a battery protection device, and U2 is a charging device. In this way, the two components can realize double overcurrent protection for the battery. Even if one of the components U1 or U2 fails, this application scheme is still safe and reliable, so that when performing IEC62368 certification, the charge and discharge current limit regulating circuit 100 of the present invention can replace the overvoltage / overcurrent protection circuit, thereby simplifying the battery application scheme, so that the application scheme of the charge and discharge current limit regulating circuit is simple and has a wide range of applications.

[0051] The first resistor R3 and the second resistor R2 use different working circuits to adjust the output charging or discharging current limit, which is described in detail below through two embodiments. The circuits of the two embodiments are basically the same, and the difference between the two embodiments is the specific circuits of the first reference module S1 and the second reference module S2.

[0052] Embodiment 1

[0053] Please refer to Figure 5 As shown, this embodiment 1 provides a charge and discharge current limit adjustment circuit 200.

[0054] The charge and discharge current limit adjustment circuit 200 includes a first reference module 2S1 and a second reference module 2S2. The first reference module 2S1 and the second reference module 2S2 are both used to generate a reference voltage. The first reference module 2S1 includes the first resistor R3. The second reference module 2S2 includes the second resistor R2.

[0055] Specifically, the first reference module 2S1 further includes a first current source IREF1. An input terminal of the first current source IREF1 is connected to a power supply voltage VDD.

[0056] The circuit connection relationship of the first reference module 2S1 is as follows: the output end of the first current source IREF1 is connected to the first end of the first resistor R3 and serves as the output end DSG of the first reference module 2S1. The second end of the first resistor R3 is connected to the ground GND.

[0057] The circuit composed of the first current source IREF1 and the first resistor R3 is used to generate a discharge current limit reference voltage VDSG. The discharge current limit reference voltage VDSG is the voltage of the output terminal DSG of the first reference module 2S1, and is used to set the discharge current limit.

[0058] The second reference module 2S2 further includes a second current source IREF2.

[0059] The circuit connection relationship of the second reference module 2S2 is as follows: the input end of the second current source IREF2 is connected to the power supply voltage VDD. The output end of the second current source IREF2 is connected to the first end of the second resistor R2 and serves as the output end CHG of the second reference module 2S2. The second end of the second resistor R2 is connected to the ground GND.

[0060] The circuit composed of the second current source IREF2 and the second resistor R2 is used for charging current limit reference voltage VCHG. The charging current limit reference voltage VCHG is the voltage of the output terminal CHG of the second reference module S2. The charging current limit reference voltage VCHG is used to set the charging current limit.

[0061] The first comparator COMP1 is a comparator for the discharge current limit adjustment function. The first comparator COMP1 is used to compare the discharge current limit reference with the charge and discharge current sampling signal ICS. The output signal of the first comparator COMP1 is an ODSG signal. When the ODSG signal is at a high level, it means that the discharge current of the charge and discharge interface terminal VM connected to the first transistor M1 is greater than the set discharge current limit.

[0062] Similarly, the second comparator COMP2 is a comparator for the charging current limit adjustment function. The second comparator COMP2 is used to set the charging current limit. The output signal of the second comparator COMP2 is an OCHG signal. When the ODSG signal is at a high level, it indicates that the charging current of the charging and discharging interface terminal VM connected to the first transistor M1 is greater than the set charging current limit.

[0063] The logic control module LOG is a digital circuit, and of course, the logic control module LOG can also be a digital-analog hybrid circuit. The logic control module LOG is used to control the on and off of the first transistor M1.

[0064] The first transistor M1 is a power switch and is used to implement charge and discharge control in battery applications.

[0065] The switch driving circuit module DVR is a gate driving circuit of the first transistor M1.

[0066] The first amplifier AMP1 samples and amplifies the current of the first transistor M1 , and the first transistor M1 outputs a charge-discharge current sampling signal ICS and sends it to the first comparator COMP1 and the second comparator COMP2 .

[0067] The following is the circuit working principle of the charge and discharge current limit adjustment circuit 200:

[0068] When the reference current IREF1 of the first current source IREF1 and the reference current IREF2 of the second current source IREF2 flow through the first resistor R3 and the second resistor R2 respectively, the discharge current limit reference voltage signals VDSG and VCHG are generated (where V DSG =I REF1 R3, V CHG =IREF2 When the first transistor M1 is turned on, the first amplifier AMP1 samples the current when the first transistor M1 is turned on, and outputs a VICS signal, where V ICS =I M1 ·K, K is the amplification factor of the first amplifier AMP1. In the battery application circuit, when the battery is in a discharge state, the VICS signal is input to the first comparator COMP1 and compared with the VDSG signal. When VICS>VDSG, the first comparator COMP1 outputs the signal ODSG as a high level, and the first transistor M1 is controlled to be turned off through the logic control module LOG and the switch drive circuit module DVR, disconnecting the conduction current between the charge and discharge interface terminal VM-ground GND, and realizing battery discharge current protection. At this time, the power switch discharge protection current is determined to be:

[0069] According to this formula, the battery discharge current limit can be adjusted by the first resistor R3 of the charge and discharge current limit adjustment circuit 200.

[0070] Similarly, when the battery is in the charging working mode, the VICS signal is input to the second comparator COMP2 and compared with the VCHG signal. When VICS>VCHG, the second comparator COMP2 outputs a signal OCHG of a high level, and the logic control module LOG and the switch drive circuit module DVR control the first transistor M1 to be turned off, disconnecting the conduction current between the charge and discharge interface terminal VM and the ground GND, thereby realizing the battery charging current protection. At this time, the charging protection current of the charge and discharge interface terminal VM is determined to be: Therefore, the battery charging current limit can be adjusted by the second resistor R2 of the charging and discharging current limit adjustment circuit 200 .

[0071] Embodiment 2

[0072] Please refer to Figure 6 As shown, this second embodiment provides a charge and discharge current limit adjustment circuit 300.

[0073] The charge and discharge current limit adjustment circuit 300 includes a first reference module 3S1 and a second reference module 2S2. The first reference module 3S1 and the second reference module 3S2 are both used to generate a reference current. The first reference module 3S1 includes the first resistor R3, and the second reference module 3S2 includes the second resistor R2. The reference current can be directly generated by the first resistor R3 and the second resistor R2.

[0074] The specific circuit structures of the first reference module 3S1 and the second reference module 3S2 are as follows:

[0075] The first reference module 3S1 further includes a first current mirror circuit unit CM1, a second transistor M2 and a second amplifier AMP2.

[0076] The first reference module 3S1 is used to generate a discharge current limit reference current IDSG. The discharge current limit reference current IDSG is the current of the output terminal DSG of the first reference module S1.

[0077] The circuit connection relationship of the first reference module 3S1 is as follows: the first output end of the first current mirror circuit unit CM1 is connected to the drain of the second transistor M2. The second output end of the first current mirror circuit unit CM1 serves as the output end DSG of the first reference module 3S1. The source of the second transistor M2 is respectively connected to the positive input end of the second amplifier AMP2 and the first end of the first resistor R3. The gate of the second transistor M2 is connected to the output end of the second amplifier AMP2. The second end of the first resistor R3 is connected to the ground GND. The negative input end of the second amplifier AMP2 serves as the first reference voltage input end VREF1.

[0078] The second reference module 3S2 further includes a second current mirror circuit unit CM2, a third transistor M3 and a third amplifier AMP3.

[0079] The second reference module 3S2 is used to generate a charging current limit reference current ICHG. The charging current limit reference current ICHG is the current at the output terminal CHG of the second reference module 3S2.

[0080] The circuit connection relationship of the second reference module 3S2 is as follows: the first output terminal of the second current mirror circuit unit CM2 is connected to the drain of the third transistor M3. The second output terminal of the second current mirror circuit unit CM2 serves as the output terminal CHG of the second reference module 3S2. The source of the third transistor M3 is respectively connected to the positive input terminal of the third amplifier AMP3 and the first terminal of the second resistor R2. The gate of the third transistor M3 is connected to the output terminal of the third amplifier AMP3. The second terminal of the second resistor R2 is connected to the ground GND. The negative input terminal of the third amplifier AMP3 serves as the second reference voltage input terminal VREF2.

[0081] The first comparator COMP1 is a comparator for the discharge current limit adjustment function. The first comparator COMP1 is used to compare the discharge current limit reference with the charge and discharge current sampling signal ICS. The output signal of the first comparator COMP1 is an ODSG signal. When the ODSG signal is at a high level, it means that the discharge current of the charge and discharge interface terminal VM connected to the first transistor M1 is greater than the set discharge current limit.

[0082] Similarly, the second comparator COMP2 is a comparator for the charging current limit adjustment function. The second comparator COMP2 is used to set the charging current limit. The output signal of the second comparator COMP2 is an OCHG signal. When the ODSG signal is at a high level, it indicates that the charging current of the charging and discharging interface terminal VM connected to the first transistor M1 is greater than the set charging current limit.

[0083] The logic control module LOG is a digital circuit, and of course, the logic control module LOG can also be a digital-analog hybrid circuit. The logic control module LOG is used to control the on and off of the first transistor M1.

[0084] The first transistor M1 is a power switch and is used to implement charge and discharge control in battery applications.

[0085] The switch driving circuit module DVR is a gate driving circuit of the first transistor M1.

[0086] The first amplifier AMP1 samples and amplifies the current of the first transistor M1 , and the first transistor M1 outputs a charge-discharge current sampling signal ICS and sends it to the first comparator COMP1 and the second comparator COMP2 .

[0087] The following is the circuit working principle of the charge and discharge current limit adjustment circuit 300:

[0088] When the reference voltage of the first reference voltage input terminal VREF1 and the reference voltage of the second reference voltage input terminal VREF2 flow through the first resistor R3 and the second resistor R2 respectively, the discharge current limit reference current signals IDSG and ICHG are generated. When the first transistor M1 is turned on, the first amplifier AMP1 samples the current when the first transistor M1 is turned on, and outputs IICS, where I ICS =I M1·K, K is the gain of the first amplifier AMP1. In the battery application circuit, when the battery is in a discharge state, IICS is input to COMP1 and compared with IDSG. When IICS>IDSG, the first comparator COMP1 outputs a signal ODSG at a high level, and the first transistor M1 is controlled to be turned off through the logic control module LOG and the switch drive circuit module DVR, disconnecting the conduction current between the charge and discharge interface terminal VM-ground GND, thereby realizing battery discharge current protection. At this time, the power switch discharge protection current is determined to be: According to this formula, the battery discharge current limit can be adjusted by the first resistor R3 in the charge and discharge current limit adjustment circuit 300.

[0089] Similarly, when the battery is in the charging working mode, IICS is input to the second comparator COMP2 and compared with ICHG. When IICS>ICHG, the second comparator COMP2 outputs a signal OCHG of a high level, and the logic control module LOG and the switch drive circuit module DVR control the first transistor M1 to be turned off, disconnecting the conduction current between the charge and discharge interface terminal VM and the ground GND, thereby realizing the battery charging current protection. At this time, the charging protection current of disconnecting the charge and discharge interface terminal VM is determined to be: Therefore, the battery charging current limit can be adjusted by the second resistor R2 in the charging and discharging current limit adjustment circuit 300 .

[0090] As can be seen from the above-mentioned Embodiment 1 and Embodiment 2, the charge and discharge current limit adjustment circuit 100 is configured by providing the first resistor R3 for adjusting the output current or voltage in the first reference module S1, and simultaneously providing the second resistor R2 for adjusting the output current or voltage in the second reference module S2. Thus, the circuit can independently control the charge and / or discharge current limit adjustment, thereby meeting the application requirements of different types of batteries and different systems, and thus making the charge and discharge current limit adjustment circuit have a wide range of applications.

[0091] In order to make the charge and discharge current limit adjustment circuit 100 more convenient to use and easier to adjust the charge and discharge current limit, the first resistor R3 and the second resistor R2 can be set in the application circuit, and the circuit modules and components of the charge and discharge current limit adjustment circuit 100 except the first resistor R3 and the second resistor R2 can be integrated and packaged into one, for example, a separate chip U4 can be manufactured. Figure 7 As shown, Figure 71 is an application circuit diagram of the charge and discharge current limit regulating circuit of the present invention. In the application circuit diagram, the chip U4, the first resistor R3 and the second resistor R2 together constitute the charge and discharge current limit regulating circuit 100. This configuration is conducive to adjusting the charge and discharge current limit through the first resistor R3 and the second resistor R2, so that the application scheme of the charge and discharge current limit regulating circuit 100 of the present invention is simple and has a wide range of applications.

[0092] Compared with the related art, the charge and discharge current limit regulation circuit of the present invention includes a first reference module, a second reference module, a first comparator, a second comparator, a first amplifier, a logic control module, a switch drive circuit module and a first transistor. The charge and discharge current limit regulation circuit is configured by setting the first resistor for adjusting the output current or voltage in the first reference module, and at the same time, setting the second resistor for adjusting the output current or voltage in the second reference module. Thus, the circuit can realize independent control of the charge and / or discharge current limit regulation, thereby meeting the application requirements of different types of batteries and different systems, so that the charge and discharge current limit regulation circuit has a wide range of applications. At the same time, when conducting IEC62368 certification, the charge and discharge current limit regulation circuit in the present invention can replace the overvoltage / overcurrent protection circuit, thereby simplifying the battery application scheme, so that the application scheme of the charge and discharge current limit regulation circuit is simple and has a wide range of applications.

[0093] It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the present invention rather than to limit the scope of the present invention. Those skilled in the art should understand that any modification or equivalent substitution of the present invention without departing from the spirit and scope of the present invention should be included within the scope of the present invention. In addition, unless otherwise indicated by the context, words appearing in the singular include the plural form, and vice versa. In addition, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A charge and discharge current limit regulating circuit, which is applied to the charge and discharge of a battery, characterized in that: The charge and discharge current limit adjustment circuit includes a first reference module, a second reference module, a first comparator, a second comparator, a first amplifier, a logic control module, a switch drive circuit module and a first transistor; wherein the first reference module includes a first resistor for adjusting the output current or voltage, and the second reference module includes a second resistor for adjusting the output current or voltage; The output terminal of the first reference module is connected to the positive input terminal of the first comparator; The output terminal of the second reference module is connected to the negative input terminal of the second comparator; The output terminal of the first amplifier is connected to the negative input terminal of the first comparator and the positive input terminal of the second comparator respectively; The output terminal of the first comparator is connected to the first input terminal of the logic control module; The output terminal of the second comparator is connected to the second input terminal of the logic control module; The output end of the logic control module is connected to the input end of the switch driving circuit module; A first output terminal of the switch driving circuit module is connected to the gate of the first transistor, and a second output terminal of the switch driving circuit module is connected to the substrate of the first transistor; The drain of the first transistor is connected to the negative input terminal of the first amplifier and serves as a charge and discharge interface terminal of the charge and discharge current limit adjustment circuit; The source of the first transistor and the positive input terminal of the first amplifier are both connected to ground; The first transistor is a power switch tube, the logic control module is a digital circuit, and the first reference module, the second reference module, the first comparator, the second comparator, the first amplifier and the switch driving circuit module are all analog circuits; The first reference module specifically further includes a first current source, and the second reference module specifically further includes a second current source; An input terminal of the first current source is connected to a power supply voltage, an output terminal of the first current source is connected to a first terminal of the first resistor and serves as an output terminal of the first reference module, and a second terminal of the first resistor is connected to ground; An input terminal of the second current source is connected to a power supply voltage, an output terminal of the second current source is connected to a first terminal of the second resistor and serves as an output terminal of the second reference module, and a second terminal of the second resistor is connected to ground; Alternatively, the first reference module specifically further includes a first current mirror circuit unit, a second transistor and a second amplifier; the second reference module specifically further includes a second current mirror circuit unit, a third transistor and a third amplifier; The first output end of the first current mirror circuit unit is connected to the drain of the second transistor, and the second output end of the first current mirror circuit unit serves as the output end of the first reference module; The source of the second transistor is connected to the positive input terminal of the second amplifier and the first terminal of the first resistor respectively, and the gate of the second transistor is connected to the output terminal of the second amplifier; The second end of the first resistor is connected to ground; The negative input terminal of the second amplifier serves as a first reference voltage input terminal; The first output end of the second current mirror circuit unit is connected to the drain of the third transistor, and the second output end of the second current mirror circuit unit serves as the output end of the second reference module; The source of the third transistor is connected to the positive input terminal of the third amplifier and the first end of the second resistor respectively, and the gate of the third transistor is connected to the output terminal of the third amplifier; The second end of the second resistor is connected to ground; The negative input terminal of the third amplifier serves as the second reference voltage input terminal.

2. The charge and discharge current limit regulating circuit according to claim 1, characterized in that: The first transistor is an NMOS transistor.

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