CN111082496A

CN111082496A - Linear adjustable power converter based on PD (proportion integration) protocol and charging method

Info

Publication number: CN111082496A
Application number: CN202010019196.4A
Authority: CN
Inventors: 殷一; 刘南毅
Original assignee: Shenzhen Julide Electronics Co ltd
Current assignee: Shenzhen Julide Electronics Co ltd
Priority date: 2020-01-08
Filing date: 2020-01-08
Publication date: 2020-04-28

Abstract

The invention discloses a linear adjustable power converter based on a PD protocol and a charging method, wherein the power converter can perform intermediate conversion between a PD power adapter and electric equipment, and can adjust VBUS voltage acquired from the PD power adapter to target voltage required by the electric equipment to supply power to the electric equipment (such as traditional notebook computers, routers, optical modems, LED table lamps and other equipment), so that different electric equipment can use the same PD power adapter, resource sharing can be realized, the application range of the PD power adapter is expanded, and the problem that a common user cannot find a proper power adapter easily if an original charger is damaged can be solved. The charging method establishes communication with the PD power adapter through the PD protocol handshaking module, adopts a PWM voltage regulation and control mode, is simple, and can regulate and output according to a set target voltage value for electric equipment.

Description

Linear adjustable power converter based on PD (proportion integration) protocol and charging method

Technical Field

The invention belongs to the technical field of adapters, and particularly relates to a conversion device for performing intermediate conversion between an adapter and electric equipment and a charging method thereof.

Background

In daily life, the input voltage of electric equipment powered by low-voltage direct current is usually within a range of 5-20V, and the unification is difficult to achieve, so that each product is provided with a special power adapter, but the power adapters of the products cannot be used in a mixed manner, the resource sharing cannot be achieved, the resource waste is easily caused, and sometimes, office equipment or household appliances are often burnt due to wrong connection because the power adapters are not well distinguished. If the original charger is damaged, the ordinary user is difficult to find a proper power adapter.

The existing PD power adapters are limited to supplying power to mobile phones, tablets and notebook computers, and have a narrow application range, and in addition, the required charging voltages of various electric devices cannot be covered by several voltage values specified in 5V, 12V and 20V in PD2.0 and 5V, 9V, 12V and 20V in PD3.0, and the conventional electric devices are difficult to handshake with a PD power adapter protocol except for a dedicated power adapter thereof, cannot effectively communicate with each other, and cannot acquire a specific voltage value required by a target device.

Although there are also some current power adapters in common use, which mainly obtain the required supply voltage and current by manually adjusting the parameters of the electronic components, this control technique has obvious drawbacks: the control is not flexible, the adjusted numerical value cannot be accurately known, the electric equipment is easily burnt out or the power supply is insufficient, the use is unsafe, and the humanization is also lacked.

Patent application CN201610951378.9 discloses a method for controlling output voltage of a USB PD system in a PWM mode, comprising an electronic product system #1 and a system #2 which adopt a USB Type-C interface and support a PD protocol, wherein power supply control systems are arranged in the electronic product system #1 and the system #2, and each power supply control system is composed of a PWM generator, a filter network and a DC/DC chip. In this patent application CN201610951378.9, by controlling the DC/DC chip with the PWM signal, although different voltage outputs can be controlled, and more control signals are not needed, the PCB area can be saved, but the following problems still exist: different electric equipment cannot use the same PD power adapter, and resource sharing cannot be achieved.

Disclosure of Invention

In order to solve the problems, the invention provides a linear adjustable power converter based on a PD protocol and a charging method, wherein the power converter can perform intermediate conversion between a PD power adapter and electric equipment, and can adjust a VBUS voltage acquired from the PD power adapter to a target voltage required by the electric equipment to supply power to the electric equipment (such as a traditional notebook, a router, a light cat, an LED table lamp and other equipment), so that different electric equipment can use the same PD power adapter, the resource sharing can be realized, the application range of the PD power adapter is expanded, and the problem that an ordinary user cannot find a proper power adapter easily if an original charger is damaged can be solved. The charging method establishes communication with the PD power adapter through the PD protocol handshaking module, adopts a PWM voltage regulation and control mode, is simple, and can regulate and output according to a set target voltage value for electric equipment.

Another object of the present invention is to provide a PD protocol-based linear adjustable power converter and a charging method, in which a target voltage is set by a key module, and adjustment is convenient; the preset and adjusted voltage value and the real-time output voltage value and current value are displayed through the digital display module, and the power converter is further provided with overcurrent protection, so that the use safety performance can be improved. In the charging method, the PWM duty ratio (output duty ratio) is controlled by adjusting the on/off duty ratio time of the MOS tube in unit time, the output voltage value can be displayed in real time, and the charging method is convenient and simple for a user to use.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a PD protocol based linearly tunable power converter comprising: the device comprises a main control module, a PWM voltage regulation and control module, an LDO power supply module for supplying power to the main control module, a PD protocol handshaking module for establishing protocol communication with a PD power adapter, an input module connected with the PD power adapter and an output module connected with electric equipment; the PD protocol handshaking module, the PWM voltage regulating module and the LDO power supply module are electrically connected with the input module, and the LDO power supply module is also electrically connected with the main control module; one end of the PWM voltage regulation and control module is connected with the main control module, the other end of the PWM voltage regulation and control module is connected with the output module, and the PWM voltage regulation and control module is controlled by the main control module.

In the invention, the input module is connected with the PD power adapter, the PD protocol handshake module is communicated with the PD power adapter through being connected with the input module to acquire the VBUS voltage of the PD power adapter, the main control module sends out a PWM signal to control the PWM voltage regulation and control module to regulate the VBUS voltage, the regulation range is usually 0-20V, the VBUS voltage is regulated to a target voltage required by electric equipment, and then the VBUS voltage is output to the electric equipment through the output module for use, for example, the electric equipment supplies power to traditional notebooks, routers, optical cats, LED table lamps and the like, so that a larger application scene of PD quick charging is realized. The power converter can perform intermediate conversion between the PD power adapter and the electric equipment, so that different electric equipment can use the same PD power adapter, resource sharing can be realized, the application range of the PD power adapter is expanded, and the problem that an ordinary user is difficult to find a proper power adapter if an original charger is damaged can be solved.

Specifically, the power converter further comprises a key module, a digital display module and an output current detection module for performing overcurrent detection; one end of the output current detection module is electrically connected with the main control module, and the other end of the output current detection module is electrically connected with the output module; the key module and the digital display module are electrically connected with the main control module.

The key module is connected with the main control module, is a user input port and generally comprises a key switch and a plus and a minus used for adjusting the value of the target voltage, and can be set through the key module when the target voltage output to the electric equipment is preset, so that a user can adjust the target voltage by taking 0.1V as a division value between 3.3V and 20V, and the adjustment is convenient.

Specifically, the input module comprises a Type-C female socket electrically connected with an external PD power adapter; the PD protocol handshaking module comprises a PD protocol chip and a first PD resistor, the model of the PD protocol chip is XS-P01, one end of the first PD resistor is connected to a VBUS pin of the Type-C female seat, and the other end of the first PD resistor is connected with a VDD pin of the PD protocol chip; the CC1 pin and the CC2 pin of the PD protocol chip are also respectively connected with the CC1 pin and the CC2 pin of the Type-C female seat to establish protocol communication with the PD power adapter and acquire the VBUS voltage of the PD power adapter; PWM voltage regulation and control module and LDO power module all are connected with the VBUS pin of the female seat of Type-C.

Specifically, the main control module comprises a main control MCU and an output voltage detection unit, and the output voltage detection unit is electrically connected with the main control MCU; the PWM voltage regulation and control module, the LDO power supply module, the output current detection module, the key module and the digital display module are all electrically connected with the main control MCU.

The output voltage detection unit is used for detecting the output voltage, judging the output voltage and the target voltage, and feeding back the judgment result to the main control MCU.

The key module comprises a key, and the key is electrically connected with the main control MCU; the digital DISPLAY module comprises an LED DISPLAY screen and a current-limiting resistor, the LED DISPLAY screen is of a DISPLAY888VA type, is a three-position seven-segment digital tube and can DISPLAY preset and adjusted voltage values and real-time output voltage values and current values, the use safety is improved, and the LED DISPLAY screen is electrically connected with the main control MCU through the current-limiting resistor.

Specifically, the PWM voltage regulation and control module includes a first triode, a second triode, a third triode, a first resistor, a second resistor, a third resistor, an MOS transistor, and a schottky diode; the model of the master control MCU is GD32F150G4U 6; the MOS tube can be NCE30P 15S; one end of the first resistor is connected with a PB4 pin of the main control MCU, the other end of the first resistor is connected with a base electrode of the first triode, an emitting electrode of the first triode is grounded, and a collecting electrode of the first triode is connected with a grid electrode of the MOS tube; one end of the second resistor is also connected with a PB4 pin of the main control MCU, the other end of the second resistor is connected with an emitting electrode of a third triode, a base electrode of the third triode is connected with a 3.3V voltage source, and a collector electrode of the third triode is connected with a base electrode of the second triode; one end of the third resistor is connected with the base electrode of the second triode, the other end of the third resistor is connected with the emitting electrode of the second triode, the emitting electrode of the second triode is also connected with the source electrode of the MOS tube, and the collector electrode of the second triode is also connected with the collector electrode of the first triode; the drain electrode of the MOS tube is connected with one end of the Schottky diode, the other end of the Schottky diode is grounded, and one end of the Schottky diode is further connected with the output module.

When the PWM signal is at a low level, the first triode is turned off, the second triode and the third triode are turned on, and at the moment, the grid electrode of the MOS tube is at a high level, and the MOS tube is turned off; when the PWM signal is the high level, first triode switches on, and second triode and third triode turn-off, the grid of MOS pipe are the low level, and the MOS pipe switches on, and the electric current flows in from the VBUS pin of female seat of Type-C, exports for consumer through output module. The main control MCU controls the PWM voltage regulation module to regulate the output ratio of the VBUS voltage to regulate the output voltage, and the main control MCU regulates the on-off ratio time of the MOS tube in unit time to control the output ratio.

After the PD protocol chip establishes protocol communication with the PD power adapter, the VBUS voltage of the PD power adapter is 20V, the output duty ratio (PWM duty ratio) is 100%, 20V is directly output, and if the output duty ratio is 50%, the output voltage is about 10V. The PWM voltage regulation and control module can regulate the output voltage by 0-20V, so that the requirements of different electric equipment are met.

Specifically, the output module comprises a filter unit and an output port, wherein one end of the filter unit is connected with the Schottky diode, and the other end of the filter unit is electrically connected with the output port; the output current detection module comprises an overcurrent detection resistor, one end of the overcurrent detection resistor is electrically connected with the output port, and the other end of the overcurrent detection resistor is grounded; one end of the over-current detection resistor is also connected with a PA0 pin of the main control MCU.

The output voltage regulated by the PWM voltage regulation module is output to electric equipment through an output port by a filtering unit, the output port can be a DC terminal lead, and the DC terminal can comprise any one of the following specifications: 3.5X1.1, 3.5X1.35, 3.5X1.5, 3.5X1.7,5.5X1.7, 5.5X2.1, 5.5X2.5, 3.4X1.0, 3.5X1.1, 3.5X1.35, 3.5X1.4, 3.5X1.7, 3.8X1.0, 3.8X1.4, etc., and when the user selects, different DC terminals can be replaced according to actual requirements.

The output current detection module comprises an overcurrent detection resistor, the output current can be calculated by detecting the voltages at the two ends of the overcurrent detection resistor, the main control MCU calculates the output current by detecting the voltages at the two ends of the overcurrent detection resistor, and then judges whether the output current value exceeds a set current value to judge whether the current is overcurrent or not, when overcurrent occurs, the main control MCU controls and reduces the PWM duty ratio to reduce the output voltage and the output current, so that the aim of overcurrent protection is fulfilled. The set current value may be set by a key module, which is displayed on the display module, and is generally the maximum current value allowed to pass through.

Specifically, the output voltage detection unit comprises a first voltage-dividing resistor, a second voltage-dividing resistor, a controllable voltage-stabilizing source, a VOUT end and a VDDA end; the controllable voltage-stabilizing source is TL431A in model number, one end of the controllable voltage-stabilizing source is connected with the VDDA end, the other end of the controllable voltage-stabilizing source is connected with a first voltage-dividing resistor, the other end of the first voltage-dividing resistor is connected with a PA1 pin of the main control MCU, a second voltage-dividing resistor is connected with the other end of the first voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected with the VOUT end; and the VDDA end is also connected with a VDDA pin of the master control MCU.

In the output voltage detection unit, after voltage division is performed on the first voltage division resistor and the second voltage division resistor, the output voltage detection unit is connected to a PA1 pin of a main control MCU, and when the output voltage is smaller than a set target voltage, the main control MCU sends a PWM signal to control a PWM voltage regulation module so as to increase the PWM duty ratio; when the output voltage is greater than the target voltage, the main control MCU receives the signal and controls the PWM duty ratio to be reduced. The output voltage generally refers to the voltage regulated by the PWM voltage regulation module.

Specifically, LDO power module includes LDO power supply chip and fourth resistance, and the model of LDO power supply chip is AMS1117-3.3V, and the one end of fourth resistance and the VIN pin connection of LDO power supply chip, the other end and the VBUS pin connection of the female seat of Type-C of fourth resistance, the VOUT pin and the VDD pin connection of master control MCU of LDO power supply chip. The working voltage of the main control MCU is 3.3V, and the LDO power supply module converts the VBUS voltage in the range of 5-20V into 3.3V by utilizing the LDO power supply chip to ensure that the main control MCU works stably, safely and efficiently so as to supply power for the main control MCU.

The invention also provides a charging method of the linear adjustable power converter based on the PD protocol, which comprises the following steps:

s1: after the input module establishes TYPE-C connection with the PD power adapter, the PD protocol handshaking module establishes protocol communication with the PD power adapter to acquire VBUS voltage;

s2: the target voltage value and the set current value required by the electric equipment are set through the key module, and the preset adjusted target voltage value is displayed through the digital display module;

s3: the main control module reads a set target voltage value, outputs a PWM signal to the PWM voltage regulation and control module to control the PWM voltage regulation and control module to regulate the VBUS voltage, finally obtains an output voltage equal to the target voltage, and the digital display module displays the output voltage value and the output current value in real time;

s4: the output module receives the output voltage output from the PWM voltage regulation module and outputs the output voltage to the electric equipment so as to supply power to the electric equipment. The output module comprises an output port, and after the output port of the power converter is connected, an led display screen in the digital display module can alternately display the current output voltage value and the current value in real time.

In the charging method of the power converter, the communication is established with the PD power adapter through the PD protocol handshaking module, a PWM voltage regulation and control mode is adopted, the method is simple, and the output can be regulated according to the set target voltage value for the use of electric equipment.

Specifically, in step S3, the method specifically includes the following steps:

s31: the main control MCU reads a set target voltage value and outputs a PWM signal to the PWM voltage regulation module so as to control the PWM voltage regulation module to regulate the VBUS voltage to obtain an output voltage;

s32: judging the magnitude of the output voltage value and the target voltage value: the output voltage detection unit compares the output voltage value with a target voltage value, then feeds back a comparison result to the main control MCU, and the main control MCU judges and makes the following reactions according to the comparison result:

s33: judging whether the output voltage value is equal to the target voltage value, if so, skipping S310; if not, jumping to S34;

s34: judging whether the output voltage value is smaller than the target voltage value, if so, skipping to S35, and if not, skipping to S36;

s35: the main control MCU controls the PWM voltage regulation module to increase the PWM duty ratio, and then S32 is skipped;

s36: judging whether the output voltage value is larger than the target voltage value, if so, skipping to S37, and if not, skipping to S38;

s37: the main control MCU controls the PWM voltage regulation module to reduce the PWM duty ratio, and then S32 is skipped;

s38: judging whether the output current value is larger than the set current value, if so, jumping to S39, and if not, jumping to S32;

s39: adjusting the PWM duty ratio to be reduced, and jumping to S36;

the PWM duty ratio is adjusted by adjusting the on/off duty ratio time of the MOS tube in unit time;

s310: whether the user switches the set target voltage value or not, if not, the output is kept, and S4 is skipped; if so, go to S31.

In the charging method, the PWM duty ratio (output duty ratio) is controlled by adjusting the on/off duty ratio time of the MOS tube in unit time, the output voltage value can be displayed in real time, and the charging method is convenient and simple for a user to use.

The invention has the advantages that:

compared with the prior art, the linear adjustable power converter based on the PD protocol and the charging method have the advantages that the power converter can perform intermediate conversion between the PD power adapter and the electric equipment, can adjust the VBUS voltage acquired from the PD power adapter to the target voltage required by the electric equipment, and supplies power to the electric equipment (such as traditional notebooks, routers, optical cats, LED table lamps and other equipment), so that different electric equipment can use the same PD power adapter, resource sharing can be realized, the application range of the PD power adapter is expanded, and the problem that an ordinary user cannot find a proper power adapter easily if an original charger is damaged can be solved. The charging method establishes communication with the PD power adapter through the PD protocol handshaking module, adopts a PWM voltage regulation and control mode, is simple, and can regulate and output according to a set target voltage value for electric equipment.

In the power converter, the target voltage is set through the key module, so that the regulation is convenient; the preset and adjusted voltage value and the real-time output voltage value and current value are displayed through the digital display module, and the power converter is further provided with overcurrent protection, so that the use safety performance can be improved. In the charging method, the PWM duty ratio (output duty ratio) is controlled by adjusting the on/off duty ratio time of the MOS tube in unit time, the output voltage value can be displayed in real time, and the charging method is convenient and simple for a user to use.

Drawings

Fig. 1 is a schematic structural diagram of a PD protocol-based linear adjustable power converter implemented in the present invention.

Fig. 2 is a circuit schematic diagram of a PD protocol based linearly adjustable power converter implemented by the present invention.

Fig. 3 is an enlarged view of a portion a in fig. 2.

Fig. 4 is an enlarged view of a portion B in fig. 2.

Fig. 5 is an enlarged view of a portion C in fig. 2.

Fig. 6 is an enlarged view of a portion D in fig. 2.

Fig. 7 is an enlarged view of a portion E in fig. 2.

Fig. 8 is an enlarged view of a portion F in fig. 2.

Fig. 9 is an enlarged view of a portion G in fig. 2.

Fig. 10 is a flowchart of a charging method of a PD protocol-based linearly tunable power converter implemented by the present invention.

Fig. 11 is a PWM voltage regulation flow chart of a charging method of a PD protocol-based linear adjustable power converter implemented by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The technical scheme of the invention is as follows:

referring to fig. 1-11, a PD protocol based linear adjustable power converter implemented by the present invention includes: the device comprises a main control module, a PWM voltage regulation and control module, an LDO power supply module for supplying power to the main control module, a PD protocol handshaking module for establishing protocol communication with a PD power adapter, an input module connected with the PD power adapter and an output module connected with electric equipment; the PD protocol handshaking module, the PWM voltage regulating module and the LDO power supply module are electrically connected with the input module, and the LDO power supply module is also electrically connected with the main control module; one end of the PWM voltage regulation and control module is connected with the main control module, the other end of the PWM voltage regulation and control module is connected with the output module, and the PWM voltage regulation and control module is controlled by the main control module.

In this embodiment, the power converter further includes a key module, a digital display module, and an output current detection module for performing overcurrent detection; one end of the output current detection module is electrically connected with the main control module, and the other end of the output current detection module is electrically connected with the output module; the key module and the digital display module are electrically connected with the main control module.

In the present embodiment, the input module includes a Type-C female socket J1 electrically connected to the external PD power adapter; the PD protocol handshaking module comprises a PD protocol chip U1 and a first PD resistor R1, the model of the PD protocol chip U1 is XS-P01, one end of the first PD resistor R1 is connected to a VBUS pin of the Type-C female seat J1, and the other end of the first PD resistor R1 is connected with a VDD pin of the PD protocol chip U1; the CC1 pin and the CC2 pin of the PD protocol chip U1 are also connected with the CC1 pin and the CC2 pin of the Type-C female seat J1 respectively to establish protocol communication with the PD power adapter and acquire the VBUS voltage of the PD power adapter; the PWM voltage regulation and control module and the LDO power supply module are connected with a VBUS pin of a Type-C female socket J1.

In this embodiment, the main control module includes a main control MCU U7 and an output voltage detection unit, and the output voltage detection unit is electrically connected to the main control MCU; the PWM voltage regulation and control module, the LDO power supply module, the output current detection module, the key module and the digital display module are all electrically connected with the main control MCU.

The key module comprises a key S1, a key S2 and a key S3 which are electrically connected with the main control MCU U7; the digital DISPLAY module comprises an LED DISPLAY screen LED1 and a current-limiting resistor, the LED DISPLAY screen LED1 is of a DISPLAY888VA type, is a three-position seven-segment digital tube and can DISPLAY preset and adjusted voltage values and real-time output voltage values and current values, the use safety is improved, and the LED DISPLAY screen LED1 is electrically connected with the master control MCU U7 through the current-limiting resistor.

In this embodiment, the PWM voltage regulation and control module includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a first resistor R10, a second resistor R18, a third resistor R9, a MOS transistor U2, and a schottky diode D1; the model of the master control MCU U7 is GD32F150G4U 6; the MOS tube U2 can be NCE30P 15S; one end of a first resistor R10 is connected with a PB4 pin of the main control MCU U7, the other end of the first resistor R10 is connected with a base electrode of a first triode Q1, an emitting electrode of the first triode Q1 is grounded, and a collector electrode of the first triode Q1 is connected with a grid electrode of the MOS tube U2; one end of a second resistor R18 is also connected with a PB4 pin of the main control MCU U7, the other end of the second resistor R18 is connected with an emitter of a third triode Q3, a base of the third triode Q3 is connected with a 3.3V voltage source, and a collector of the third triode Q3 is connected with a base of the second triode Q2; one end of the third resistor R9 is connected with the base electrode of the second triode Q3, the other end of the third resistor R9 is connected with the emitter electrode of the second triode Q2, the emitter electrode of the second triode Q2 is also connected with the source electrode of the MOS tube U2, and the collector electrode of the second triode Q2 is also connected with the collector electrode of the first triode Q1; the drain of the MOS transistor U2 is connected to one end of the schottky diode D1, the other end of the schottky diode D1 is grounded, and one end of the schottky diode D1 is further connected to the output block.

When the PWM signal is at a low level, the first transistor Q1 is turned off, the second transistor Q2 and the third transistor Q3 are turned on, and at this time, the gate of the MOS transistor U2 is at a high level, and the MOS transistor U2 is turned off; when the PWM signal is at a high level, the first transistor Q1 is turned on, the second transistor Q2 and the third transistor Q3 are turned off, the gate of the MOS transistor U2 is at a low level, the MOS transistor U2 is turned on, and a current flows from the VBUS pin of the Type-C female socket J1 and is output to the electric device through the output module. The master control MCU U7 controls the PWM voltage regulation module to regulate the output ratio of the VBUS voltage to regulate the output voltage, and the master control MCU U7 regulates the on/off ratio time of the MOS tube U2 in unit time to control the output ratio.

After the PD protocol chip U1 establishes protocol communication with the PD power adapter, the VBUS voltage of the PD power adapter is 20V, and the output duty ratio (PWM duty ratio) is 100%, then 20V is directly output, and if the output duty ratio is 50%, then the output voltage is about 10V. The PWM voltage regulation and control module can regulate the output voltage by 0-20V, so that the requirements of different electric equipment are met.

In this embodiment, the output module includes a filter unit and an output port J2, where one end of the filter unit is connected to the schottky diode D1, and the other end is electrically connected to the output port J2; the output current detection module comprises an overcurrent detection resistor R22, one end of the overcurrent detection resistor R22 is electrically connected with the output port J2, and the other end of the overcurrent detection resistor R22 is grounded; one end of the over-current detection resistor R22 is also connected with the PA0 pin of the main control MCU U7.

The output voltage regulated by the PWM voltage regulation and control module is output to the electric device through the filtering unit via the output port J2, the output port J2 may be a DC terminal lead, wherein the DC terminal may include any one of the following specifications: 3.5X1.1, 3.5X1.35, 3.5X1.5, 3.5X1.7,5.5X1.7, 5.5X2.1, 5.5X2.5, 3.4X1.0, 3.5X1.1, 3.5X1.35, 3.5X1.4, 3.5X1.7, 3.8X1.0, 3.8X1.4, etc., and when the user selects, different DC terminals can be replaced according to actual requirements.

The output current detection module comprises an overcurrent detection resistor R22, the output current can be calculated by detecting the voltages at two ends of the overcurrent detection resistor R22, the main control MCU U7 judges whether the output current value exceeds a set current value to judge whether the current is overcurrent or not by detecting the voltages at two ends of the overcurrent detection resistor R22, when the overcurrent occurs, the main control MCU U7 controls and reduces the PWM duty ratio, the output voltage is reduced, the output current is reduced, the purpose of overcurrent protection is achieved, and the use safety performance is improved. The set current value may be set by the key module, which is displayed on the display module, and is generally the maximum current value allowed to pass by the electric device.

In the present embodiment, the output voltage detection unit includes a first voltage-dividing resistor R24, a second voltage-dividing resistor R23, a controllable voltage-stabilizing source D3, a terminal VOUT, and a terminal VDDA; the model of the controllable voltage-stabilizing source D3 is TL431A, one end of a controllable voltage-stabilizing source D3 is connected with a VDDA end, the other end of the controllable voltage-stabilizing source D3 is connected with a first voltage-dividing resistor R24, the other end of the first voltage-dividing resistor R24 is connected with a PA1 pin of a main control MCU U7, a second voltage-dividing resistor R23 is connected with the other end of the first voltage-dividing resistor R24, and the other end of the second voltage-dividing resistor R24 is connected with a VOUT end; the VDDA terminal is also connected to the VDDA pin of the master MCU U7.

In the output voltage detection unit, after voltage division is performed through a first voltage division resistor R24 and a second voltage division resistor R23, the output voltage detection unit is connected to a PA1 pin of a main control MCU U7, and when the output voltage is smaller than a set target voltage, the main control MCU U7 sends a PWM signal to control a PWM voltage regulation module so as to increase the PWM duty ratio; when the output voltage is greater than the target voltage, the master MCU U7 receives the signal and controls the PWM duty cycle to decrease. The output voltage generally refers to the voltage regulated by the PWM voltage regulation module.

In this embodiment, the LDO power supply module includes LDO power supply chip U8 and fourth resistor R25, the model of LDO power supply chip U8 is AMS1117-3.3V, the one end of fourth resistor R25 is connected with the VI N pin of LDO power supply chip U8, the other end of fourth resistor R25 is connected with the VBUS pin of Type-C female seat J1, the VOUT pin of LDO power supply chip U8 is connected with the VDD pin of main control MCU U7. The working voltage of the master control MCU U7 is 3.3V, the LDO power supply module enables the master control MCU U7 to work stably, safely and efficiently, and the VBUS voltage in the range of 5-20V is converted into 3.3V by the aid of the LDO power supply chip U8 to supply power for the master control MCU.

s4: the output module receives the output voltage output from the PWM voltage regulation module and outputs the output voltage to the electric equipment so as to supply power to the electric equipment. The output module comprises an output port, and after the output port of the power converter is connected, the LED display screen LED1 in the digital display module can alternately display the current output voltage value and current value in real time.

In the present embodiment, the step S3 specifically includes the following steps:

s31: the main control MCU U7 reads the set target voltage value and outputs a PWM signal to the PWM voltage regulation module to control the PWM voltage regulation module to regulate the VBUS voltage to obtain an output voltage;

s39: adjusting the PWM duty ratio to be reduced, and jumping to S36;

In the charging method, the PWM duty ratio (output duty ratio) is controlled by adjusting the on/off duty ratio time of the MOS tube U2 in unit time, so that the output voltage value can be displayed in real time, and the charging method is convenient and simple for users to use.

The invention has the advantages that:

compared with the prior art, the linear adjustable power converter based on the PD protocol and the charging method have the advantages that the power converter can perform intermediate conversion between the PD power adapter and the electric equipment, can adjust the VBUS voltage acquired from the PD power adapter to the target voltage required by the electric equipment, and supplies power to the electric equipment (such as traditional notebooks, routers, optical cats, LED table lamps and other equipment), so that different electric equipment can use the same PD power adapter, the resource sharing can be realized, the application range of the PD power adapter is expanded, and the problem that a common user cannot find a proper power adapter easily if an original charger is damaged can be solved. The charging method establishes communication with the PD power adapter through the PD protocol handshaking module, adopts a PWM voltage regulation and control mode, is simple, and can regulate and output according to a set target voltage value for electric equipment.

In the power converter, the target voltage is set through the key module, so that the regulation is convenient; the preset and adjusted voltage value and the real-time output voltage value and current value are displayed through the digital display module, and the power converter is further provided with overcurrent protection, so that the use safety performance can be improved. In the charging method, the PWM duty ratio (output duty ratio) is controlled by adjusting the on/off duty ratio time of the MOS tube U2 in unit time, the output voltage value can be displayed in real time, and the charging method is convenient and simple for users to use.

The above description is illustrative of the preferred embodiment of the present invention and is not to be construed as limiting the invention, but rather as encompassing all the modifications, equivalents, and improvements made within the spirit and principles of the invention.

Claims

1. A PD protocol based linearly tunable power converter, comprising: the device comprises a main control module, a PWM voltage regulation and control module, an LDO power supply module for supplying power to the main control module, a PD protocol handshaking module for establishing protocol communication with a PD power adapter, an input module connected with the PD power adapter and an output module connected with electric equipment;

the PD protocol handshaking module, the PWM voltage regulating and controlling module and the LDO power supply module are all electrically connected with the input module, and the LDO power supply module is also electrically connected with the main control module; one end of the PWM voltage regulation and control module is connected with the main control module, the other end of the PWM voltage regulation and control module is connected with the output module, and the PWM voltage regulation and control module is controlled by the main control module.

2. The PD protocol based linear adjustable power converter as recited in claim 1, further comprising a key module, a digital display module and an output current detection module for detecting over-current; one end of the output current detection module is electrically connected with the main control module, and the other end of the output current detection module is electrically connected with the output module; the key module and the digital display module are electrically connected with the main control module.

3. The PD protocol-based linearly tunable power converter of claim 2, wherein the input module includes a Type-C female socket electrically connected to an external PD power adapter;

the PD protocol handshaking module comprises a PD protocol chip and a first PD resistor, the model of the PD protocol chip is XS-P01, one end of the first PD resistor is connected to a VBUS pin of the Type-C female socket, and the other end of the first PD resistor is connected with a VDD pin of the PD protocol chip;

the CC1 pin and the CC2 pin of the PD protocol chip are also respectively connected with the CC1 pin and the CC2 pin of the Type-C female seat to establish protocol communication with the PD power adapter;

and the PWM voltage regulation and control module and the LDO power supply module are connected with a VBUS pin of a Type-C female seat.

4. The PD protocol-based linearly tunable power converter of claim 3, wherein the master control module includes a master MCU and an output voltage detection unit, and the output voltage detection unit is electrically connected to the master MCU; the PWM voltage regulation and control module, the LDO power supply module, the output current detection module, the key module and the digital display module are all electrically connected with the main control MCU.

5. The PD protocol-based linearly tunable power converter according to claim 4, wherein the PWM voltage regulation module includes a first transistor, a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, a MOS transistor, and a schottky diode;

the model of the master control MCU is GD32F150G4U 6;

one end of the first resistor is connected with a PB4 pin of the main control MCU, the other end of the first resistor is connected with a base electrode of the first triode, an emitting electrode of the first triode is grounded, and a collector electrode of the first triode is connected with a grid electrode of the MOS tube;

one end of the second resistor is also connected with a PB4 pin of the main control MCU, the other end of the second resistor is connected with an emitting electrode of the third triode, a base electrode of the third triode is connected with a 3.3V voltage source, and a collector electrode of the third triode is connected with a base electrode of the second triode;

one end of the third resistor is connected with the base electrode of the second triode, the other end of the third resistor is connected with the emitting electrode of the second triode, the emitting electrode of the second triode is also connected with the source electrode of the MOS tube, and the collector electrode of the second triode is also connected with the collector electrode of the first triode;

the drain electrode of the MOS tube is connected with one end of the Schottky diode, the other end of the Schottky diode is grounded, and one end of the Schottky diode is further connected with the output module.

6. The PD protocol based linear tunable power converter as claimed in claim 5, wherein the output module includes a filter unit and an output port, the filter unit having one end connected to the schottky diode and another end electrically connected to the output port;

the output current detection module comprises an overcurrent detection resistor, one end of the overcurrent detection resistor is electrically connected with the output port, and the other end of the overcurrent detection resistor is grounded; and one end of the over-current detection resistor is also connected with a PA0 pin of the main control MCU.

7. The PD protocol-based linearly tunable power converter of claim 6, wherein the output voltage detection unit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a controllable regulated voltage source, a VOUT terminal and a VDDA terminal; the model of the controllable voltage-stabilizing source is TL431A, one end of the controllable voltage-stabilizing source is connected with the VDDA end, the other end of the controllable voltage-stabilizing source is connected with the first voltage-dividing resistor, the other end of the first voltage-dividing resistor is connected with the PA1 pin of the main control MCU, the second voltage-dividing resistor is connected with the other end of the first voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected with the VOUT end; and the VDDA end is also connected with a VDDA pin of the master control MCU.

8. The linear adjustable power converter based on the PD protocol of claim 7, characterized in that the LDO power supply module includes an LDO power supply chip and a fourth resistor, the model of the LDO power supply chip is AMS1117-3.3V, one end of the fourth resistor is connected with VIN pin of the LDO power supply chip, the other end of the fourth resistor is connected with VBUS pin of the Type-C socket, VOUT pin of the LDO power supply chip is connected with VDD pin of the main control MCU;

the digital DISPLAY module comprises an LED DISPLAY screen and a current-limiting resistor, the model of the LED DISPLAY screen is DISPLAY888VA, and the LED DISPLAY screen is electrically connected with the master control MCU through the current-limiting resistor;

the key module comprises a key, and the key is electrically connected with the master control MCU.

9. A charging method of a linear adjustable power converter based on a PD protocol is characterized by comprising the following steps:

s4: the output module receives the output voltage output from the PWM voltage regulation module and outputs the output voltage to the electric equipment so as to supply power to the electric equipment.

10. The charging method of the PD protocol-based linear tunable power converter according to claim 9, wherein in step S3, the method specifically includes the following steps:

s31: the main control MCU reads a set target voltage value and outputs a PWM signal to the PWM voltage regulation module according to the target voltage value so as to control the PWM voltage regulation module to regulate the VBUS voltage to obtain an output voltage;

s39: adjusting the PWM duty ratio to be reduced, and jumping to S36;