A charging port power supply control circuit of a battery type device

Abstract

The application provides a charging port power supply control circuit of a battery type device, a DC-DC power module is connected with a battery of the battery type device and a power supply pin of a charging port, a switch circuit is connected between an input pin and an enable pin of the DC-DC power module, a high-low level control circuit is connected between the enable pin of the DC-DC power module and the power supply pin of the charging port, a voltage dividing circuit is connected between the battery of the battery type device and the power supply pin of the charging port, the DC-DC power module is connected with the power supply pin of the charging port, the high-low level control circuit is connected with a current sampling detection circuit through a comparison and amplification circuit, and the current sampling detection circuit is connected with a state detection pin of the charging port. When the battery type electronic product is powered off in a charging state of an external electronic device, the USB port of the battery type electronic product continues to charge externally, and when the external electronic device is fully charged, the battery type electronic product is automatically powered off, so that the battery of the external electronic device charges externally with zero power consumption, and the endurance time of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery electronic products with USB charging functions, and in particular to a charging port power supply control circuit for battery equipment. Background Art

[0002] When a battery-powered electronic product is powered on, its USB port can charge an external electronic device. However, when the external electronic device is charging and the battery-powered electronic product is powered off, its USB port stops supplying power, preventing it from continuing to charge, affecting the battery life of the external electronic device. Summary of the Invention

[0003] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a charging port power supply control circuit for battery-type devices, which detects the charging current / voltage of external electronic devices through an operational amplifier, thereby solving the problem of stopping charging of external electronic devices after the battery-type device is turned off.

[0004] The present invention provides a charging port power supply control circuit for a battery-type device, comprising a DC-DC power supply module, a switching circuit, a current sampling detection circuit, a comparison amplifier circuit, a high-low level control circuit, and a voltage divider circuit. An input pin of the DC-DC power supply module is connected to a battery of the battery-type device, the switching circuit is connected between the input pin and an enable pin of the DC-DC power supply module, the high-low level control circuit is connected between the enable pin of the DC-DC power supply module and a power supply pin of the charging port, the voltage divider circuit is connected between the battery of the battery-type device and the power supply pin of the charging port, the DC-DC power supply module is connected to the power supply pin of the charging port, the high-low level control circuit is connected to the comparison amplifier circuit, the comparison amplifier circuit is connected to the current sampling detection circuit, and the current sampling detection circuit is connected to a status detection pin of the charging port.

[0005] Furthermore, the current sampling detection circuit includes a sampling resistor, and the sampling resistor is connected to the status detection pin of the charging port and the comparison amplifier circuit.

[0006] Furthermore, the comparison amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a first capacitor. The first resistor is connected to the positive input terminal of the operational amplifier, the second resistor is connected to the negative input terminal of the operational amplifier, the third resistor is connected between the output terminal and the negative input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the fourth resistor, the fourth resistor is connected to the high and low level control circuit, the sampling resistor is connected between the first resistor and the second resistor, one end of the fifth resistor and one end of the first capacitor are both connected between the fourth resistor and the high and low level control circuit, and the other end of the fifth resistor and the other end of the first capacitor are both grounded.

[0007] Furthermore, the high and low level control circuit includes a first transistor, a sixth resistor, a seventh resistor, a second transistor, an eighth resistor, and a second capacitor. The fourth resistor is connected to the base of the first transistor, the emitter of the first transistor is grounded, one end of the sixth resistor is connected to the power supply pin of the charging port, the other end of the sixth resistor is connected to the collector of the first transistor, one end of the seventh resistor, and one end of the second capacitor, the other end of the second capacitor is grounded, the other end of the seventh resistor is connected to one end of the eighth resistor and the base of the second transistor, the other end of the eighth resistor is grounded, the emitter of the second transistor is grounded, and the collector of the second transistor is connected to the voltage divider circuit and the enable pin of the DC-DC power supply module.

[0008] Furthermore, the voltage divider circuit includes a first voltage divider resistor and a second voltage divider resistor, the first voltage divider resistor and the second voltage divider resistor are connected in series, the first voltage divider resistor is connected to the power supply pin of the charging port, the second voltage divider resistor is connected to the battery of the battery-type device, and the collector of the second transistor is connected between the first voltage divider resistor and the second voltage divider resistor.

[0009] Furthermore, the switching circuit includes a switch, and the switch is connected between an input pin and an enable pin of the DC-DC power supply module.

[0010] Furthermore, it also includes a filtering circuit, which includes a first filter capacitor, a second filter capacitor, and a third filter capacitor. One end of a parallel circuit of the first filter capacitor and the second filter capacitor is connected between the battery of the battery-type device and the input pin of the DC-DC power supply module, and the other end of the parallel circuit is connected to one end of the third filter capacitor, the second voltage divider resistor and the ground, and the other end of the third filter capacitor is connected to the enable pin of the DC-DC power supply module.

[0011] Furthermore, it also includes a self-starting circuit, which includes a self-starting capacitor, and the self-starting capacitor is connected between the self-boosting pin of the DC-DC power supply module and the inductor connection feedback input pin.

[0012] Furthermore, it also includes an RC absorption circuit, which includes a ninth resistor and a third capacitor, the ninth resistor and the third capacitor are connected in series, the third capacitor is grounded, and the ninth resistor is connected to the inductor connection feedback input pin of the DC-DC power supply module.

[0013] Furthermore, the device further includes an LC filter circuit, the LC filter circuit including a filter capacitor and a filter inductor, the filter capacitor being connected to the filter inductor, the filter capacitor being connected to the inductor connection feedback input pin of the DC-DC power supply module, the power supply pin of the charging port being connected between the filter capacitor and the filter inductor, and the filter capacitor being grounded;

[0014] The system further includes a feedback circuit, which includes a first feedback resistor, a second feedback resistor, and a third feedback resistor. The first feedback resistor, the second feedback resistor, and the third feedback resistor are connected in series in sequence. The first feedback resistor is connected between the filter inductor and the filter capacitor, and the third feedback resistor is grounded. The voltage feedback input terminal of the DC-DC power supply module is connected between the first feedback resistor and the second feedback resistor.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a power supply control circuit for a charging port of a battery-based device. This circuit incorporates a current sampling detection circuit to detect the charging current (voltage) of an external electronic device. This circuit then controls the conduction and cutoff of a transistor by comparing the output voltage of an amplifier circuit, thereby controlling the power supply voltage of the USB port. When the external electronic device is charging and the battery-based electronic product is powered off, the USB port of the battery-based electronic product continues to charge externally. When the external electronic device is fully charged, the battery-based electronic product automatically shuts down, achieving zero external power consumption for the external electronic device's battery and extending battery life.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the description, the following preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. The specific implementation methods of the present invention are given in detail by the following embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of a power supply control circuit for a charging port of a battery device of the present invention;

[0020] Figure 2 This is a power supply control circuit diagram of a charging port of a battery device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0022] A power supply control circuit for the charging port of a battery device can be used to charge the internal batteries of external electronic devices such as Android phones and laptops. Figure 1 、 Figure 2 As shown, the device includes a DC-DC power module U1, a switching circuit, a current sampling and detection circuit, a comparison and amplifier circuit, a high- and low-level control circuit, and a voltage divider circuit. The DC-DC power module is connected to the battery BAT+ pin of a battery-type device and the power supply pin VBUS of the charging port. In this embodiment, the charging port is a USB-A plug. The switching circuit is connected between the DC-DC power module's input pin IN and the enable pin EN. The high- and low-level control circuit is connected between the DC-DC power module's enable pin and the power supply pin of the charging port. The voltage divider circuit is connected between the battery of the battery-type device and the power supply pin of the charging port. The DC-DC power module is connected to the power supply pin of the charging port. The high- and low-level control circuit is connected to the comparison and amplifier circuit, which is connected to the current sampling and detection circuit, which is connected to the status detection pin of the charging port.

[0023] The charging port is connected to the current sampling detection circuit. The current sampling detection circuit inputs the detected voltage into the comparison amplifier circuit for voltage comparison and amplification. The comparison amplifier circuit then outputs the voltage to control the high and low level control circuit. The high and low levels generated by the high and low level control circuit control the enable pin EN of the DC-DC power supply module. When the enable pin EN is high, the USB port charges the external electronic device. When the enable pin EN is low, the USB port does not charge the external electronic device and automatically shuts down, thereby achieving zero external power consumption of the electronic product battery and extending the battery life.

[0024] like Figure 2 As shown, the switch circuit includes a switch SW1, which is connected between an input pin and an enable pin of the DC-DC power module.

[0025] The current sampling detection circuit includes a sampling resistor R6, which is connected to the status detection pin ID of the charging port and the comparison amplifier circuit.

[0026] The comparison amplifier circuit includes an operational amplifier U2-A, a first resistor R4, a second resistor R5, a third resistor R3, a fourth resistor R2, a fifth resistor R1, and a first capacitor C1. The first resistor is connected to the positive input terminal of the operational amplifier, the second resistor is connected to the negative input terminal of the operational amplifier, the third resistor is connected between the output terminal and the negative input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the fourth resistor, the fourth resistor is connected to the high and low level control circuit, the sampling resistor is connected between the first resistor and the second resistor, one end of the fifth resistor and one end of the first capacitor are both connected between the fourth resistor and the high and low level control circuit, and the other end of the fifth resistor and the other end of the first capacitor are both grounded.

[0027] The high and low level control circuit includes a first transistor Q1, a sixth resistor R7, a seventh resistor R14, a second transistor Q2, an eighth resistor R17, and a second capacitor C2. The fourth resistor is connected to the base of the first transistor, the emitter of the first transistor is grounded, one end of the sixth resistor is connected to the power supply pin of the charging port, the other end of the sixth resistor is connected to the collector of the first transistor, one end of the seventh resistor, and one end of the second capacitor, the other end of the second capacitor is grounded, the other end of the seventh resistor is connected to one end of the eighth resistor and the base of the second transistor, the other end of the eighth resistor is grounded, the emitter of the second transistor is grounded, and the collector of the second transistor is connected to the voltage divider circuit and the enable pin of the DC-DC power supply module.

[0028] The voltage divider circuit includes a first voltage divider resistor R8 and a second voltage divider resistor R15. The first voltage divider resistor and the second voltage divider resistor are connected in series. The first voltage divider resistor is connected to the power supply pin of the charging port, and the second voltage divider resistor is connected to the battery of the battery-type device. The collector of the second transistor is connected between the first voltage divider resistor and the second voltage divider resistor.

[0029] In one embodiment, a filtering circuit is further included, which includes a first filter capacitor C8, a second filter capacitor C5, and a third filter capacitor C4. One end of a parallel circuit of the first filter capacitor and the second filter capacitor is connected between a battery of a battery-type device and an input pin of a DC-DC power module, and the other end of the parallel circuit is connected to one end of the third filter capacitor, a second voltage divider resistor, and ground. The other end of the third filter capacitor is connected to an enable pin of the DC-DC power module.

[0030] It also includes a self-starting circuit, which includes a self-starting capacitor C7. The self-starting capacitor is connected between the self-boosting pin BS of the DC-DC power supply module and the inductor connection feedback input pin LX.

[0031] It also includes an RC absorption circuit, which includes a ninth resistor R13 and a third capacitor C6. The ninth resistor is connected in series with the third capacitor, the third capacitor is grounded, and the ninth resistor is connected to the inductor connection feedback input pin FB of the DC-DC power supply module.

[0032] The LC filter circuit includes a filter capacitor L1 and a filter inductor C9, the filter capacitor is connected to the filter inductor, the filter capacitor is connected to the inductor feedback input pin of the DC-DC power module, the power supply pin of the charging port is connected between the filter capacitor and the filter inductor, and the filter capacitor is grounded;

[0033] It also includes a feedback circuit, which includes a first feedback resistor R9, a second feedback resistor R10, and a third feedback resistor R11. The first feedback resistor, the second feedback resistor, and the third feedback resistor are connected in series in sequence. The first feedback resistor is connected between the filter inductor and the filter capacitor, and the third feedback resistor is grounded. The voltage feedback input terminal of the DC-DC power supply module is connected between the first feedback resistor and the second feedback resistor.

[0034] The device further includes a frequency selection circuit, which includes a frequency selection pin FS and a resistor R12; one end of the resistor R12 is electrically connected to the frequency selection pin FS, and the other end of the resistor R12 is grounded.

[0035] When the ON / OFF switch circuit is pressed, SW1 switches on instantly, the battery voltage is added to the EN pin of U1, U1 has a 5V voltage output, and then the 5V is fed back to the EN pin of U1 through R8. At the same time, the 5V voltage is added to C2 / 220UF through R7. The moment C2 is powered on, it is equivalent to a short circuit, Q2 is not conducting, U1 works normally, and outputs 5V voltage to the VBUS power supply pin of the USB socket. At this time, the USB socket has a load charging, and the current flows from the VBUS pin to the ID pin, and then flows out from the ID pin. When the current of 80MA flows through the sampling 0.039R When resistor R6 is used, the voltage difference across R6 is: U = IR = 0.039 × 80 = 3.12 MV. This voltage difference is sent to pins 1 and 3 of op amp U2-A, where it is amplified 221 times internally (forward amplification: G = 1 + Rf / R = 1 + 220 / 1), resulting in an output voltage of 0.69 V. This converts 80 mA of current into 0.69 V. After voltage division by R1 and R2, the voltage becomes 0.69 V × (R1 / R1 + R2) = 0.69 V × (12 / 0.68 + 12) = 0.65 V. The resistance values ​​of R1 and R2 must satisfy the transistor's forward bias condition of 0.7 V. The input resistor R4 must ensure that VOUT does not fall below 0.7 V to ensure proper conduction of the subsequent transistor. The resistance value of R5 should be the same as R4 to minimize errors and drift. This voltage is applied to the base of transistor Q1, turning Q1 on and Q2 base low level cut-off. At this time, 5V voltage is applied to the EN pin of U1 through R8, and U1 outputs 5V voltage to power the USB port. On the contrary, when the current flowing through R6 is less than about 50MA, the voltage difference across R6 is: U=IR=0.039×50=1.95MV. After this voltage is amplified 221 times by the internal operational amplifier (forward amplification: G=1+Rf / R=1+220 / 1), it outputs a voltage of 0.43V. After this voltage is divided by R1 and R2, the voltage = 0.43V×(12 / 0.68+12)=0.4V, which is added to the base of the transistor Q1, and Q1 is cut off. At this time, the 5V voltage is added to the base of Q2 through R7, Q2 is turned on, the collector and emitter are connected to ground, the EN pin voltage of U1 is pulled down to ground, U1 stops working, no 5V voltage is output to the USB port, and the external electronic device is not charged.

[0036] In this embodiment, the charging threshold is set to a sampling current greater than about 80mA, which is consistent with the minimum current range of at least 80mA-150mA for most external electronic devices to start charging. When the sampling current is less than 80mA, close to 50mA and tends to 0mA, it is assumed that the external electronic device is fully charged and automatically shuts down accurately.

[0037] The present invention converts a current signal into a voltage signal through a current sampling detection circuit, and then controls the conduction and cutoff of the transistor through the output voltage after the comparison amplifier circuit. Then, the level of the enable pin EN of the DC-DC power supply module U1 is controlled based on the principle that the transistor is at a low level when it is grounded when it is turned on, and at a high level when it is connected to a pull-up bias after it is cut off, so as to realize the shutdown of the power supply of the USB port, thereby realizing the function that the battery device of the external electronic device does not shut down during the charging process, and the battery device automatically shuts down after the external electronic device is fully charged, thereby realizing zero external power consumption of the external electronic device and extending the battery life.

[0038] The above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any ordinary technician in this industry can smoothly implement the present invention as shown in the drawings and the above. However, any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A charging port power supply control circuit for a battery device, characterized by: The device comprises a DC-DC power supply module, a switching circuit, a current sampling detection circuit, a comparison amplifier circuit, a high-low level control circuit, and a voltage divider circuit. The input pin of the DC-DC power supply module is connected to the battery of a battery-type device. The switching circuit is connected between the input pin and the enable pin of the DC-DC power supply module. The high-low level control circuit is connected between the enable pin of the DC-DC power supply module and the power supply pin of the charging port. The voltage divider circuit is connected between the battery of the battery-type device and the power supply pin of the charging port. The DC-DC power supply module is connected to the power supply pin of the charging port. The high-low level control circuit is connected to the comparison amplifier circuit. The comparison amplifier circuit is connected to the current sampling detection circuit. The current sampling detection circuit is connected to the status detection pin of the charging port. The switching circuit includes a switch connected between an input pin and an enable pin of the DC-DC power supply module; The charging port power supply control circuit further includes a filter circuit, the filter circuit including a first filter capacitor, a second filter capacitor, and a third filter capacitor, wherein a first end of a parallel circuit of the first filter capacitor and the second filter capacitor is connected between a battery of the battery-type device and an input pin of the DC-DC power supply module, and a second end of the parallel circuit is electrically connected to a first end of the third filter capacitor and a first end of a second voltage divider resistor and then grounded; The voltage divider circuit includes a first voltage divider resistor and a second voltage divider resistor, wherein a first end of the first voltage divider resistor is connected to the power supply pin of the charging port, and a second end of the first voltage divider resistor is electrically connected to the second end of the second voltage divider resistor, the second end of the third filter capacitor, one end of the switch, and the enable pin; When the switch of the switch circuit is pressed, the battery voltage is added to the enable pin of the DC-DC power module, the DC-DC power module has a voltage output, and then fed back to the enable pin of the DC-DC power module through the first voltage divider resistor.

2. The charging port power supply control circuit for a battery device according to claim 1, wherein: The current sampling detection circuit includes a sampling resistor, and the sampling resistor is connected to the status detection pin of the charging port and the comparison amplifier circuit.

3. The charging port power supply control circuit for a battery device according to claim 2, wherein: The comparison amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a first capacitor. The first resistor is connected to the positive input terminal of the operational amplifier, the second resistor is connected to the negative input terminal of the operational amplifier, the third resistor is connected between the output terminal and the negative input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the fourth resistor, the fourth resistor is connected to the high and low level control circuit, the sampling resistor is connected between the first resistor and the second resistor, one end of the fifth resistor and one end of the first capacitor are both connected between the fourth resistor and the high and low level control circuit, and the other end of the fifth resistor and the other end of the first capacitor are both grounded.

4. The charging port power supply control circuit for a battery device according to claim 3, wherein: The high and low level control circuit includes a first transistor, a sixth resistor, a seventh resistor, a second transistor, an eighth resistor, and a second capacitor. The fourth resistor is connected to the base of the first transistor, the emitter of the first transistor is grounded, one end of the sixth resistor is connected to the power supply pin of the charging port, the other end of the sixth resistor is connected to the collector of the first transistor, one end of the seventh resistor, and one end of the second capacitor, the other end of the second capacitor is grounded, the other end of the seventh resistor is connected to one end of the eighth resistor and the base of the second transistor, the other end of the eighth resistor is grounded, the emitter of the second transistor is grounded, and the collector of the second transistor is connected to the voltage divider circuit and the enable pin of the DC-DC power supply module.

5. The charging port power supply control circuit for a battery device according to claim 1, wherein: It also includes a self-starting circuit, which includes a self-starting capacitor. The self-starting capacitor is connected between the self-boosting pin of the DC-DC power supply module and the inductor connection feedback input pin.

6. The charging port power supply control circuit for a battery device according to claim 1, wherein: It also includes an RC absorption circuit, which includes a ninth resistor and a third capacitor. The ninth resistor is connected in series with the third capacitor, the third capacitor is grounded, and the ninth resistor is connected to the inductor connection feedback input pin of the DC-DC power supply module.

7. The charging port power supply control circuit for a battery device according to claim 1, wherein: The device further includes an LC filter circuit, the LC filter circuit including a filter capacitor and a filter inductor, the filter capacitor being connected to the filter inductor, the filter capacitor being connected to the inductor connection feedback input pin of the DC-DC power supply module, the power supply pin of the charging port being connected between the filter capacitor and the filter inductor, and the filter capacitor being grounded; The system further includes a feedback circuit, which includes a first feedback resistor, a second feedback resistor, and a third feedback resistor. The first feedback resistor, the second feedback resistor, and the third feedback resistor are connected in series in sequence. The first feedback resistor is connected between the filter inductor and the filter capacitor, and the third feedback resistor is grounded. The voltage feedback input terminal of the DC-DC power supply module is connected between the first feedback resistor and the second feedback resistor.

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