System power supply circuit for high voltage battery

Abstract

The present invention discloses a system power supply circuit suitable for high-voltage batteries, including a step-down chip, a P-channel MOS tube, a first integrated dual diode, a first inductor coil and a second integrated dual diode, wherein the first pin of the step-down chip is connected to one end of a fifth capacitor, the third pin of the step-down chip is simultaneously connected to one end of a fourth resistor and one end of a ninth capacitor, the first anode of the first integrated dual diode is connected to the system power supply output end via a sixth resistor, the first anode of the second integrated dual diode is connected to a USB power supply end, the gate of the P-channel MOS tube is simultaneously connected to a switch button end, one end of a third capacitor and one end of a thirty-second resistor, and the source of the P-channel MOS tube is simultaneously connected to the other end of the third capacitor, the other end of the thirty-second resistor and the second input end of the battery voltage. The present invention can protect the system end from high voltage burning the system, and the output voltage is relatively stable, and has the advantages of low shutdown leakage.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery power supply, and in particular relates to a system power supply circuit suitable for a high-voltage battery. Background Art

[0002] At present, most tablets are basically low-voltage battery (3.7V / 3.8V) products. When the battery voltage is high (7.2V-8.4V), it cannot directly power the system. It is necessary to reduce the battery voltage to the standard input voltage of the IC in order to power the system and the machine can work normally.

[0003] Therefore, there is an urgent need for a system power supply circuit suitable for high-voltage batteries. Summary of the invention

[0004] The main purpose of the present invention is to propose a system power supply circuit suitable for high-voltage batteries, aiming to solve the technical problems mentioned in the background technology, protect the system end from high voltage burning the system chip, and at the same time, the output voltage is relatively stable and has the advantage of low shutdown leakage.

[0005] A system power supply circuit suitable for a high-voltage battery of the present invention comprises a step-down chip, a P-channel MOS tube, a first integrated dual diode, a first inductor coil and a second integrated dual diode, wherein the first pin of the step-down chip is connected to one end of a fifth capacitor, the sixth pin of the step-down chip is simultaneously connected to the other end of the fifth capacitor and one end of the first inductor coil, the third pin of the step-down chip is simultaneously connected to one end of a fourth resistor, one end of a third resistor and one end of a ninth capacitor, the other end of the first inductor coil is simultaneously connected to one end of a sixth capacitor, one end of a seventh capacitor, one end of an eighth capacitor, the other end of a ninth capacitor, one end of the third resistor and a system power supply input end, the fifth pin of the step-down chip is simultaneously connected to the first input end of a battery voltage, and the fifth pin of the step-down chip is simultaneously connected to the first input end of a battery voltage. The fourth pin of the step-down chip is connected to one end of the fourth capacitor, the drain of the P-channel MOS tube, one end of the second resistor and the cathode of the first integrated double diode at the same time, the first anode of the first integrated double diode is connected to the system power supply output end via the sixth resistor, the second anode of the first integrated double diode is connected to the cathode of the second integrated double diode via the fifth resistor, the first anode of the second integrated double diode is connected to the USB power supply end, the gate of the P-channel MOS tube is connected to the switch button end, one end of the third capacitor and one end of the thirty-second resistor at the same time, and the source of the P-channel MOS tube is connected to the other end of the third capacitor, the other end of the thirty-second resistor and the second input end of the battery voltage at the same time.

[0006] Preferably, the supply voltage of the battery voltage is 7.2-8.4V.

[0007] Preferably, a filter module is further included, and the fifth pin of the buck chip is connected to the filter module and the first input terminal of the battery voltage at the same time.

[0008] Preferably, the second anode of the second integrated dual diode is connected to one end of the ninth resistor and the DC input end at the same time, and the other end of the ninth resistor is grounded.

[0009] Preferably, the model of the step-down chip is SY8120B1ABC.

[0010] The system power supply circuit suitable for high-voltage batteries of the present invention controls the back-end load of the buck chip through a P-channel MOS tube, thereby achieving the purpose of stable power supply voltage and small shutdown leakage current, and the cost is not high, and the stability and practicality of the product can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a circuit connection diagram of a system power supply circuit suitable for a high-voltage battery of the present invention.

[0012] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0013] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. It should be noted that related terms such as "first", "second", etc. can be used to describe various components, but these terms do not limit the components. These terms are only used to distinguish one component from another component. For example, without departing from the scope of the present invention, the first component can be referred to as the second component, and the second component can also be referred to as the first component similarly. The term "and / or" refers to any one or more combinations of related items and description items.

[0014] like Figure 1 As shown, Figure 1The circuit connection diagram of the system power supply circuit applicable to the high-voltage battery of the present invention. A system power supply circuit applicable to the high-voltage battery of the present invention comprises a buck chip U302, a P-channel MOS tube Q301, a first integrated dual diode D301, a first inductor L301 and a second integrated dual diode D302, a first pin BS of the buck chip is connected to one end of the fifth capacitor C305, a sixth pin LX of the buck chip is simultaneously connected to the other end of the fifth capacitor C305 and one end of the first inductor L301, a third pin FB of the buck chip is simultaneously connected to one end of the fourth resistor R304, one end of the third resistor R303 and one end of the ninth capacitor C309, the other end of the first inductor L301 is simultaneously connected to one end of the sixth capacitor C306, one end of the seventh capacitor C307, one end of the eighth capacitor C308, the other end of the ninth capacitor C309, one end of the third resistor R303 and the system power supply input terminal SYS_4.1V, and a fifth pin VI of the buck chip is simultaneously connected to one end of the fourth resistor R304, one end of the third resistor R303 and one end of the ninth capacitor C309. N is connected to the first input terminal P1 of the battery voltage, the fourth pin EN of the buck chip is simultaneously connected to one end of the fourth capacitor C304, the drain D of the P-channel MOS tube, one end of the second resistor R302 and the cathode of the first integrated dual diode D301, the first anode A of the first integrated dual diode is connected to the system power supply output terminal VLDO28_PMU via the sixth resistor R306, the second anode B of the first integrated dual diode is connected to the cathode of the second integrated dual diode D302 via the fifth resistor R305, the first anode C of the second integrated dual diode is connected to the USB power supply terminal +VUSB, the gate G of the P-channel MOS tube is simultaneously connected to the switch button terminal PWR_ON, one end of the third capacitor C303 and one end of the thirty-second resistor R3302, and the source S of the P-channel MOS tube is simultaneously connected to the other end of the third capacitor, the other end of the thirty-second resistor and the second input terminal P2 of the battery voltage. The system power supply circuit suitable for high-voltage batteries of the present invention controls the back-end load of the buck chip through a P-channel MOS tube, thereby achieving the purpose of stable power supply voltage and small shutdown leakage current, and the cost is not high, and the stability and practicality of the product can be greatly improved.

[0015] like Figure 1As shown; the switch button end and the P-channel MOS tube constitute a switch control circuit: the second input end P2 of the battery voltage is given to the S pole of the P-channel MOS tube through the first resistor R301 and the thirty-second resistor R3302, so that the P-channel MOS tube is in a closed state. When the switch button is pressed, the switch button end sends a start signal, then the drain of the P-channel MOS tube is connected to the ground, the P-channel MOS tube is turned on to control the control pin of the buck chip, and the EN pin of the buck chip is opened. Specifically, the switch control principle is: when the device switch button is pressed (the drain of the P-channel MOS tube is connected to the ground), the second input terminal P2 of the battery voltage passes through the first resistor R301 to the source S of Q301. Since Q301 is a P-channel MOS tube, the current flows from the S pole to the D pole, and the S pole voltage increases. The drain G is 0V due to pressing the switch button, and the drain G and source S of Q301 generate a negative voltage difference. The P-channel MOS tube works normally and is turned on. The second input terminal P2 of the battery voltage goes from the S pole to the D pole, and the D pole is connected to the fourth pin EN control pin of the buck chip U302. The EN pin voltage of the buck chip U302 increases, and the buck chip U302 outputs a voltage to the system power supply input terminal SYS_4.1V. Specifically, the 7.2-8.4V provided by the high-voltage battery is converted to 4.1V and output stably.

[0016] like Figure 1 As shown, preferably, it also includes a filtering module, and the fifth pin of the buck chip is connected to the filtering module and the first input terminal of the battery voltage at the same time; the filtering module includes the first capacitor C301, the second capacitor C302 and the thirty-third capacitor C3033, and the fifth pin VIN of the buck chip U302 is connected to one end of the thirty-third capacitor C3033, one end of the first capacitor C301 and one end of the second capacitor C302 at the same time, the other end of the thirty-third capacitor C3033 is grounded, the other end of the first capacitor C301 is grounded, and the other end of the second capacitor C302 is grounded. The filtering module achieves filtering through three capacitors. Figure 1 As shown, the sixth capacitor C306, the seventh capacitor C307 and the eighth capacitor C308 can filter out the ripple.

[0017] like Figure 1As shown, the working principle of the buck chip: the pins of the buck chip U302 are defined as (the first pin is BS, the second pin is grounded, the third pin is FB for feedback, the fourth pin is EN for switch control, the fifth pin is VIN, and the sixth pin is LX for voltage output). The first input terminal P1 of the battery voltage inputs the voltage to the buck chip U302 through the filtering module. When the switch of the P-channel MOS tube Q301 is turned on, the fourth pin EN of the U302 chip is controlled to be turned on, and the sixth pin LX outputs a 4.1V voltage, which is output through the first inductor L301 and the filter capacitor (C306 / C307 / C308 to filter out the ripple) to output a stable voltage to supply power to the system power supply; the output terminal gives a feedback voltage to the 3-pin FB of U302 after voltage division through R303 and R304, so that U302 continuously outputs a stable 4.1V voltage to the system power supply.

[0018] like Figure 1 As shown, preferably, the second anode D of the second integrated dual diode D302 is simultaneously connected to one end of the ninth resistor R309 and the DC input terminal DC_IN, and the other end of the ninth resistor is grounded. Specifically, the first anode C of the second integrated dual diode D302 is simultaneously connected to one end of the eleventh resistor R311 and one end of the tenth resistor R310, the other end of the eleventh resistor R311 is grounded, and the other end of the tenth resistor R310 is connected to the USB power supply terminal +VUSB. Among them, the model of the buck chip is SY8120B1ABC.

[0019] like Figure 1 As shown, the first integrated dual diode D301 and the sixth resistor R306 constitute a holding circuit; the working principle of the holding circuit is: after the system obtains the 4.1V voltage input by the system power supply input terminal SYS_4.1V, the system is turned on. After the system is turned on, a set of voltage is output and transmitted through VLDO28_PMU, and then reaches the fourth pin EN control pin of the buck chip U302 through the first integrated dual diode, and the EN control pin is kept open, and the buck chip U302 continues to power the system; when the device is turned off and the charger is inserted, the charger is given to the fourth pin EN control pin of the buck chip U302 after voltage division, so that the continuous output voltage of the buck chip U302 powers the system.

[0020] The principle of the system holding circuit is as follows: after the sixth pin LX of the buck chip U302 outputs voltage to the system, the system outputs back 2.8V voltage through VLDO28_PMU and returns to the fourth pin EN control pin of the buck chip U302 through the sixth resistor R306 and the first integrated bipolar transistor D301, so that the buck chip U302 continuously outputs 4.1V voltage to supply power to the system power supply. At this time, the switch button is released, and the system can also continuously output voltage to continuously supply power to the system; when the device is turned off, plug in a USB or DC charger (USB power supply end + VUSB or DC), and the voltage provided by the USB is transmitted to two voltage-dividing resistors (the tenth resistor R310 and the eleventh resistor R311) through the USB power supply end + VBUS to obtain a voltage, which passes through the second integrated dual diode D302 and the first integrated dual diode D301, so that the fourth pin EN control switch of the buck chip U302 is opened, and the sixth pin LX of the buck chip U302 outputs voltage to the system. The first integrated dual diode model is BAT54C-CD, and the second integrated dual diode model is BAT54C-CD. When the system is in shutdown state, the P-channel MOS tube is not turned on, and the voltage of the step-down chip U302 will not enter the back-end load, thereby achieving the purpose of low shutdown leakage.

[0021] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A system power supply circuit suitable for a high voltage battery, characterized in that: The invention comprises a step-down chip, a P-channel MOS tube, a first integrated double diode, a first inductor coil and a second integrated double diode, wherein the first pin of the step-down chip is connected to one end of a fifth capacitor, the sixth pin of the step-down chip is simultaneously connected to the other end of the fifth capacitor and one end of the first inductor coil, the third pin of the step-down chip is simultaneously connected to one end of a fourth resistor, one end of a third resistor and one end of a ninth capacitor, the other end of the first inductor coil is simultaneously connected to one end of a sixth capacitor, one end of a seventh capacitor, one end of an eighth capacitor, the other end of a ninth capacitor, the other end of the third resistor and a system power supply input end, the fifth pin of the step-down chip is connected to the first input end of the battery voltage, the fourth pin of the step-down chip is simultaneously connected to one end of a fourth capacitor, the drain of the P-channel MOS tube, one end of a second resistor and the negative electrode of the first integrated double diode, the first anode of the first integrated double diode is connected to the system power supply output end via the sixth resistor, the second anode of the first integrated double diode is simultaneously connected to the system power supply output end, and the second anode of the first integrated double diode is simultaneously connected to the system power supply output end via the sixth resistor. The first anode of the second integrated dual diode is connected to the USB power supply end, the gate of the P-channel MOS tube is simultaneously connected to the switch button end, one end of the third capacitor and one end of the thirty-second resistor, and the source of the P-channel MOS tube is simultaneously connected to the other end of the third capacitor, the other end of the thirty-second resistor and the second input end of the battery voltage; it also includes a filtering module, the fifth pin of the buck chip is simultaneously connected to the filtering module and the first input end of the battery voltage, the filtering module includes a first capacitor C301, a second capacitor C302 and a thirty-third capacitor C3033, the fifth pin VIN of the buck chip U302 is simultaneously connected to one end of the thirty-third capacitor C3033, one end of the first capacitor C301 and one end of the second capacitor C302, the other end of the thirty-third capacitor C3033 is grounded, the other end of the first capacitor C301 is grounded, and the other end of the second capacitor C302 is grounded.

2. The system power supply circuit suitable for high-voltage battery as claimed in claim 1, characterized in that: The supply voltage of the battery voltage is 7.2-8.4V.

3. The system power supply circuit suitable for high-voltage battery as claimed in claim 1, characterized in that: The second anode of the second integrated dual diode is connected to one end of the ninth resistor and the DC input end at the same time, and the other end of the ninth resistor is grounded.

4. The system power supply circuit suitable for high-voltage battery as claimed in claim 1, characterized in that: The model of the step-down chip is SY8120B1ABC.

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