BMS protection system with DC charging and discharging

Abstract

The utility model discloses a BMS protection system with DC charging and discharging, which is characterized in that the BMS protection system comprises a step-down conversion chip MK9019, the step-down conversion chip MK9019 comprises a GND pin, a VIN pin, an EN pin, an RT pin, an SW pin, a BOOT pin, a PGOOD pin and an FB pin, the FB pin is connected with an output voltage acquisition unit, and the VIN pin is connected with an input power supply unit. A step-down conversion chip MK9019 is mainly adopted, a main MOSFET (metal-oxide-semiconductor field effect transistor) (upper transistor) and a synchronous MOSFET (lower transistor) are integrated, output current as high as 1A can be provided, and through 3A current limitation, the MK9019 can provide 3A peak current for some special applications; when the external load discharges and the internal frequency modulation main MOS switch is turned off, the sudden change of the load voltage and the sudden change of the load current can be prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of control circuits, in particular to a BMS protection system with DC charging and discharging. Background Art

[0002] Pulse Width Modulation (PWM) DC / DC converters are widely used in portable electronic products such as cameras, camcorders, PDAs, and laptops. PWM DC / DC converters have two architectures: analog and digital. Analog architecture products have small area and low power consumption, and they dominate the market, but they are very sensitive to noise; while digital design architectures have good scalability, high stability, and are relatively insensitive to external noise, which can make up for the shortcomings of analog architectures. From the perspective of the development needs of DC / DC converters, digital control technology is a must.

[0003] DC-DC converters are often used in power management circuits of communication equipment to provide different voltage levels and ensure stable power supply. DC-DC converters are also widely used in automobiles, which can convert the voltage of automobile batteries into the voltage levels required by various in-car electronic devices. DC-DC converters are also commonly used in the field of industrial control to provide different voltage levels required by machines and other equipment. DC-DC converters are also used in solar panels, which can convert the low voltage output by solar panels into DC power to drive heaters, fans, water pumps, etc. DC-DC converters are also commonly used in electronic equipment to convert higher DC voltages into required operating voltages, such as 5.0V, 3.3V, etc. Current DC control circuits often cannot output stable currents and cannot prevent sudden changes in load voltage. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the purpose of the utility model is to provide a BMS protection system with DC charging and discharging, which can output a stable current and prevent sudden changes in load voltage.

[0005] The purpose of the utility model is achieved by the following technical solutions:

[0006] The utility model provides a BMS protection system with DC charging and discharging, including a DC control circuit, the DC control circuit including a buck conversion chip MK9019, the buck conversion chip MK9019 including a GND pin, a VIN pin, an EN pin, an RT pin, a SW pin, a BOOT pin, a PGOOD pin and an FB pin, the FB pin is connected to an output voltage acquisition unit, and the VIN pin is connected to a power input unit.

[0007] In the present utility model, as an optional embodiment, the voltage acquisition unit includes a resistor R3, a resistor R52 and a resistor R203, one end of the resistor R52 is connected to one end of the resistor R203, one end of the resistor R3 and one end of the resistor R52 are connected to the FB pin of the buck converter chip MK9019, the other end of the resistor R3 and the other end of the resistor R52 are grounded, and the other end of the resistor R203 is connected to the SW pin of the buck converter chip MK9019 through an inductor L1.

[0008] In the present invention, as an optional embodiment, the power input unit includes a diode D20 and a resistor R198, the positive electrode of the diode D20 is connected to an external power supply, the negative electrode of the diode D20 is connected to one end of the resistor R198, and the other end of the resistor R198 is connected to the VIN pin.

[0009] In the utility model, as an optional embodiment, it also includes capacitor C31, capacitor C33, capacitor C34, resistor R1, resistor R4 and resistor R202, one end of capacitor C31, one end of capacitor C33, one end of capacitor C34 and one end of resistor R1 are all connected to the other end of resistor R198, the other end of capacitor C31, the other end of capacitor C33, the other end of capacitor C34, one end of resistor R4 and one end of resistor R202 are grounded, the other end of resistor R1 is connected to the other end of resistor R4, and the other end of resistor R202 is connected to the RT pin of the buck converter chip MK9019.

[0010] In the present utility model, as an optional embodiment, it also includes capacitor C53, capacitor C76, capacitor C69, capacitor C30, capacitor C9, capacitor C70, capacitor C32, resistor R41, diode D2, resistor R204, fuse F1, diode D17, resistor R206, one end of the capacitor C53 is connected to the BOOT pin, the other end of the capacitor C53 is connected to one end of the resistor R41, the other end of the resistor R41 and the cathode of the diode D2 are connected to one end of the inductor L1, one end of the inductor L1 is also connected to the SW pin, the anode of the diode D2 is grounded, one end of the capacitor C76, one end of the capacitor C69 are grounded, and the other end of the capacitor C53 is connected to the BOOT pin. The other end of the inductor L1 is connected to one end of the inductor L1, the other end of the capacitor C76 is connected to one end of the resistor R204, the other end of the resistor R204 is connected to the connection between the resistor R203 and the resistor R52, the other end of the capacitor C69, the other end of the capacitor C30, the other end of the capacitor C9, the other end of the capacitor C70 and the other end of the capacitor C32 are all grounded, the anode of the diode D17 is connected to the other end of the fuse F1, the cathode of the diode D17 is connected to the output, and the resistor R206 is connected in parallel to the two ends of the diode D17.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The BMS protection system disclosed in the utility model mainly adopts the step-down conversion chip MK9019, which integrates the main MOSFET (upper tube) and a synchronous MOSFET (lower tube), and can provide an output current of up to 1A. Through the 3A current limit, MK9019 can provide 3A peak current for certain special applications; when the external load is discharged and the internal frequency-modulated main MOS switch is turned off, sudden changes in load voltage and load current can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic diagram of a circuit structure of a BMS protection system with DC charging and discharging according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] Below, in conjunction with the accompanying drawings and specific implementation methods, the utility model is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except for special instructions, the materials and equipment used in this embodiment can be purchased from the market. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0015] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0016] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0017] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0018] The embodiment of the present application provides a BMS protection system with DC charging and discharging. The disclosed BMS protection system mainly adopts the buck conversion chip MK9019, which integrates the main MOSFET (upper tube) and a synchronous MOSFET (lower tube), and can provide an output current of up to 1A. Through 3A current limiting, MK9019 can provide 3A peak current for certain special applications; when the external load is discharged, the internal frequency modulation main MOS switch is turned off, which can prevent the load voltage mutation and load current mutation.

[0019] Please refer to Figure 1 As shown, the present embodiment provides a BMS protection system with DC charging and discharging, which includes a DC control circuit, which includes a buck converter chip MK9019, and the buck converter chip MK9019 includes a GND pin, a VIN pin, an EN pin, an RT pin, a SW pin, a BOOT pin, a PGOOD pin and an FB pin, the FB pin is connected to an output voltage acquisition unit, and the VIN pin is connected to a power input unit.

[0020] Preferably, the voltage acquisition unit includes a resistor R3, a resistor R52 and a resistor R203, one end of the resistor R52 is connected to one end of the resistor R203, one end of the resistor R3 and one end of the resistor R52 are connected to the FB pin of the buck converter chip MK9019, the other end of the resistor R3 and the other end of the resistor R52 are grounded, and the other end of the resistor R203 is connected to the SW pin of the buck converter chip MK9019 via an inductor L1.

[0021] Furthermore, the power input unit includes a diode D20 and a resistor R198, wherein the anode of the diode D20 is connected to the external power supply, the cathode of the diode D20 is connected to one end of the resistor R198, and the other end of the resistor R198 is connected to the VIN pin.

[0022] In the embodiment, capacitor C31, capacitor C33, capacitor C34, resistor R1, resistor R4 and resistor R202 are also included. One end of capacitor C31, one end of capacitor C33, one end of capacitor C34 and one end of resistor R1 are all connected to the other end of resistor R198, the other end of capacitor C31, the other end of capacitor C33, the other end of capacitor C34, one end of resistor R4 and one end of resistor R202 are grounded, the other end of resistor R1 is connected to the other end of resistor R4, and the other end of resistor R202 is connected to the RT pin of the buck converter chip MK9019.

[0023] Furthermore, it also includes capacitor C53, capacitor C76, capacitor C69, capacitor C30, capacitor C9, capacitor C70, capacitor C32, resistor R41, diode D2, resistor R204, fuse F1, diode D17, resistor R206, one end of capacitor C53 is connected to the BOOT pin, the other end of capacitor C53 is connected to one end of resistor R41, the other end of resistor R41 and the negative electrode of diode D2 are connected to one end of inductor L1, one end of inductor L1 is also connected to the SW pin, the positive electrode of diode D2 is grounded, one end of capacitor C76, one end of capacitor C69, capacitor C30 are ... connected to the SW pin, the positive electrode of diode D2 is grounded, one end of capacitor C76, one end of capacitor C69, capacitor C30 are connected to the BOOT pin, the other end of capacitor C53 is connected to one end of resistor R41, the other end of resistor R41 and the negative electrode of diode D2 are connected to one end of inductor L1, the other end of inductor L1 is connected to the SW pin, the positive electrode of diode D2 is grounded, one end of capacitor C76, one end of capacitor C69, capacitor C30 are connected to the BOOT pin, the other end of capacitor C53 is connected to One end of capacitor C9, one end of capacitor C70, one end of capacitor C32 and one end of fuse F1 are all connected to the other end of inductor L1, the other end of capacitor C76 is connected to one end of resistor R204, the other end of resistor R204 is connected to the connection between resistor R203 and resistor R52, the other end of capacitor C69, the other end of capacitor C30, the other end of capacitor C9, the other end of capacitor C70 and the other end of capacitor C32 are all grounded, the anode of diode D17 is connected to the other end of fuse F1, the cathode of diode D17 is connected to the output, and resistor R206 is connected in parallel to both ends of diode D17.

[0024] MK9019 operates in a wide input voltage range from 4.5V to 100V. By integrating the main MOSFET (upper tube) and a synchronous MOSFET (lower tube), MK9019 can provide up to 1A output current. Through 3A current limit, MK9019 can provide 3A peak current for some special applications; switching frequency: Fsw (KHZ) = 2.56 * Vout (V) / Rt (MΩ); output voltage: Vout (V) = 1.2 * (1 + R3 / R52); by adjusting the resistance values ​​of R3 and R52, we can achieve the required operating voltage; when the external load is discharged and the internal frequency-modulated main MOS switch is turned off, the inductor L1 can prevent the load current from changing suddenly, and C32 can prevent the load voltage from changing suddenly. In addition to the internal MOS switch frequency modulation, the MK90195-pin FB collects the external output voltage in real time, and adjusts the switch of the MK9019 main MOS at the same time through the internal op amp comparison. When the collected FB voltage is lower than 1.2V (that is, the output voltage is low), the internal op amp output is high, and the lower tube is controlled to be closed, reducing the voltage and current consumption of the lower tube, and increasing the SW voltage and current; when the collected FB voltage is higher than 1.2V (that is, the output voltage is high), the op amp output is low, and the lower tube is controlled to be turned on, increasing the voltage and current consumption of the lower tube, and reducing the SW voltage and current; among them, D2 can achieve the freewheeling effect during the period when the lower tube is closed, which can fully reduce the temperature rise of the internal diode of the lower tube.

[0025] Although only certain components and embodiments of the present application have been illustrated and described, many modifications and changes may be conceived by those skilled in the art without actually departing from the scope and spirit of the claims, such as changes in the size, dimensions, structure, shape and proportion of the various elements, mounting arrangements, material usage, color, orientation, etc.

[0026] The above-mentioned implementation mode is only a preferred implementation mode of the embodiment of the utility model, and cannot be used to limit the scope of protection of the embodiment of the utility model. Any non-substantial changes and replacements made by technical personnel in this field on the basis of the embodiment of the utility model shall fall within the scope of protection required by the embodiment of the utility model.

Claims

1. A BMS protection system with DC charging and discharging, characterized in that: It includes a DC control circuit, which includes a buck conversion chip MK9019. The buck conversion chip MK9019 includes a GND pin, a VIN pin, an EN pin, a RT pin, a SW pin, a BOOT pin, a PGOOD pin and an FB pin. The FB pin is connected to an output voltage acquisition unit, and the VIN pin is connected to a power input unit.

2. The BMS protection system according to claim 1, characterized in that: The voltage acquisition unit includes a resistor R3, a resistor R52 and a resistor R203, one end of the resistor R52 is connected to one end of the resistor R203, one end of the resistor R3 and one end of the resistor R52 are connected to the FB pin of the buck converter chip MK9019, the other end of the resistor R3 and the other end of the resistor R52 are grounded, and the other end of the resistor R203 is connected to the SW pin of the buck converter chip MK9019 through an inductor L1.

3. The BMS protection system according to claim 2, characterized in that: The power input unit includes a diode D20 and a resistor R198, wherein the anode of the diode D20 is connected to an external power source, the cathode of the diode D20 is connected to one end of the resistor R198, and the other end of the resistor R198 is connected to the VIN pin.

4. The BMS protection system according to claim 3, characterized in that: It also includes capacitor C31, capacitor C33, capacitor C34, resistor R1, resistor R4 and resistor R202. One end of capacitor C31, one end of capacitor C33, one end of capacitor C34 and one end of resistor R1 are all connected to the other end of resistor R198, the other end of capacitor C31, the other end of capacitor C33, the other end of capacitor C34, one end of resistor R4 and one end of resistor R202 are grounded, the other end of resistor R1 is connected to the other end of resistor R4, and the other end of resistor R202 is connected to the RT pin of the step-down converter chip MK9019.

5. The BMS protection system according to claim 4, characterized in that: It also includes capacitor C53, capacitor C76, capacitor C69, capacitor C30, capacitor C9, capacitor C70, capacitor C32, resistor R41, diode D2, resistor R204, fuse F1, diode D17, and resistor R206. One end of the capacitor C53 is connected to the BOOT pin, the other end of the capacitor C53 is connected to one end of the resistor R41, the other end of the resistor R41 and the cathode of the diode D2 are connected to one end of the inductor L1, one end of the inductor L1 is also connected to the SW pin, the anode of the diode D2 is grounded, one end of the capacitor C76, one end of the capacitor C69, one end of the capacitor C30 are connected The other end of the inductor L1 is connected to one end of the inductor L1, the other end of the capacitor C76 is connected to one end of the resistor R204, the other end of the resistor R204 is connected to the connection between the resistor R203 and the resistor R52, the other end of the capacitor C69, the other end of the capacitor C30, the other end of the capacitor C9, the other end of the capacitor C70 and the other end of the capacitor C32 are all grounded, the anode of the diode D17 is connected to the other end of the fuse F1, the cathode of the diode D17 is connected to the output, and the resistor R206 is connected in parallel to the two ends of the diode D17.

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