CN102832650A - Multipurpose power supply management device, charging path control circuit and control method thereof - Google Patents

Abstract

The invention provides a multipurpose power supply management device, a charging path control circuit and a control method thereof. The multipurpose power management device is used for controlling power conversion from input power to output power and charging of a battery from the output power, and comprises: a switching circuit including at least one first power transistor; a switch control circuit for generating a switching signal for controlling the power transistor to control power conversion from input power to output power; a charging management circuit for controlling the charging of the battery by the output power; and a path selection circuit for determining whether to use the charging management circuit to control the charging of the battery.

Description

Multipurpose power management device, charging path control circuit and control method thereof

technical field

The invention relates to a multi-purpose power management device, a power supply path control circuit and its control method, which can automatically determine whether the charging management circuit needs to be started according to the connection mode between the system load and the battery, so it can be flexibly applied to the system load directly or indirectly Different power consumers with connected batteries.

Background technique

FIG. 1 shows a schematic diagram of a power supply system in the prior art. Referring to FIG. 1, a switching power supply 1a is used in the power supply system 10, and the external electric energy is converted from the input terminal Vin to the output terminal Vout, and the output terminal Vout supplies the system load (for example: computer host) and the battery Batt charging. When there is no external power supply at the input terminal, the battery Batt will output power to the output terminal Vout. The feedback circuit 13 includes two serially connected resistors R1 and R2, wherein one end of R1 is coupled to the output voltage Vout, and one end of R2 is coupled to the ground potential. The feedback signal FB1 is obtained from the voltage division on the resistor R2. The error amplifier 11 receives the feedback signal FB1 and compares the reference voltage Vref1 to generate an error signal Comp1 for a pulse width modulation (PWM) signal generator 12 . The PWM signal generator 12 generates switching signals according to the error signal Comp1 to switch the upper bridge transistor Q1 and the lower bridge transistor Q2 respectively, convert the input voltage of the power input terminal Vin into a current through the inductor L, and supply current from the power output terminal Vout to Battery Batt charging. The upper bridge transistor Q1 and the lower bridge transistor Q2 form a switch circuit 14 . In order to control the charging current of the battery Bat, a sensing resistor RS is provided between the output terminal Vout and the battery Bat, and the error amplifier 16 is used to detect the voltage across the sensing resistor RS, and input to the PWM signal generator 12 to control The charging current to the battery Bat is within the specified range. This prior art generally integrates the error amplifier 11, the PWM signal generator 12, the switch circuit 14 and the error amplifier 16 into a chip or a device. However, this chip or device is only suitable for the battery Batt in FIG. The configuration of directly connecting to the output terminal Vout cannot be used in the power supply system shown in Figure 2 below.

Referring to FIG. 2 , the power supply system 20 includes a switching power supply 1 a , a charging management circuit 2 a , a battery Batt and a PMOS transistor 27 . The switching power supply 1a converts the external electric energy from the input terminal Vin to the output terminal Vout, and the output terminal Vout supplies the system load (for example: computer host) and charges the battery Batt. When there is no external power supply at the input terminal, the battery Batt will output power to the output terminal Vout. The power supply system 20 detects whether the battery Batt needs to be charged or stops charging, so as to control the PMOS transistor 27 to turn on or cut off the charging current flowing to the battery Batt.

The feedback circuit 26 includes two serially connected resistors R3 and R4, wherein one end of R3 is coupled to the battery Batt output voltage Vbatt, one end of R4 is coupled to the ground potential, and the feedback signal FB2 is obtained from the voltage divider on the resistor R4. The error amplifier 21 receives the feedback signal FB2 and compares it with the reference voltage Vref2 to generate an error signal Comp2. The error amplifier 24 detects the voltage across the sense resistor RS and outputs an error signal Comp4 , and the error amplifier 23 compares the error signal Comp4 with the reference voltage Vref3 and outputs an error signal Comp3 . The adder 25 sums up the two error signals Comp2 and Comp3 and outputs the summed signal to the charging controller 22 . The charging controller 22 determines whether the battery Batt needs to be charged or is saturated and does not need to be recharged according to the summed signal, and then decides to turn on or turn off the PMOS transistor 27 .

This prior art usually integrates the error amplifier 11, the PWM signal generator 12, the switch circuit 14, the error amplifier (21, 23, 24), the charge controller 22 and the adder 25 into one chip or a power management device 2d However, this power management device is only suitable for the configuration in which the battery Batt is connected to the output terminal Vout through the resistor RS and the PMOS transistor 27 in FIG. 2, and cannot be used in the power supply system without the PMOS transistor 27 in FIG. 1.

In view of this, the present invention aims at the deficiencies of the above-mentioned prior art, and proposes a multi-purpose power management device, a power supply path control circuit and its control method, which can automatically determine whether the charging management circuit is connected according to the connection mode between the system load and the battery. Startup is required, so it can be flexibly applied in different power consumers where the system load is directly or indirectly connected to the battery through a switch.

Contents of the invention

One of the objectives of the present invention is to overcome the deficiencies and defects of the prior art and provide a multi-purpose power management device.

Another object of the present invention is to provide a charging path control circuit.

Another object of the present invention is to provide a charging path control method.

In order to achieve the above object, from one point of view, the present invention provides a multipurpose power management device for controlling the power conversion from input power to output power and charging the battery from output power, the multipurpose power management device The device includes: a switch circuit, including at least one first power transistor; a switch control circuit, which generates a switch signal for controlling the power transistor, so as to control the power conversion from input power to output power; a charging management circuit, used to control the power transistor The output power is used to charge the battery; and a path selection circuit is used to determine whether to use the charging management circuit to control the charging of the battery.

In the above multipurpose power management device, when the output power and the battery are connected through a second power transistor, the path selection circuit selects the charging management circuit to operate the second power transistor to control the charging of the battery; when the output power And the battery is not connected through a second power transistor, the path selection circuit will not select the charging management circuit to control the charging of the battery.

In one of the implementation types, the path selection circuit includes a multiplexer, which determines whether to use the charging management circuit to control the charging of the battery according to an external setting signal.

In another implementation mode, the charging management circuit generates an output signal, which is output from a pin, and wherein the path selection circuit includes: a detection signal generator, and the detection signal generator generates a detection signal output from the pin to generate a detection voltage; a comparator to compare the detection voltage with a reference voltage; and a multiplexer to determine whether to use the charge management circuit to control the battery according to the output of the comparator Charge.

In one of the implementation forms, the charging management circuit includes a first error amplifier, the first error amplifier generates a first error signal according to the information about the charging current of the battery, and the path selection circuit determines the first error signal The signal is sent to the switch control circuit or the charging management circuit.

From another point of view, the present invention provides a charging path control circuit, at least one control loop is selected according to an output power and a connection relationship between batteries, the charging path control circuit includes: a charging management circuit for controlling the charging the battery with the output power; and a path selection circuit, according to whether there is a power transistor between the output power and the battery, decides whether to use the charging management circuit to control the charging of the battery.

From yet another point of view, the present invention provides a charging path control method, including: converting an input power into an output power; charging a battery from the output power through a charging path; detecting whether the charging path is set There is a power transistor; when the charging path is provided with a power transistor, the power transistor is controlled to control the charging of the battery; and when the charging path is not provided with a power transistor, the conversion of the input power and the output power is controlled to control charge the battery.

Preferably, the charging path control method further includes: detecting the current on the charging path to generate information about the charging current of the battery; when there is a power transistor on the charging path, using the information feedback to control the power transistor; And when there is no power transistor on the charging path, the information feedback is used to control the conversion of the input power and output power.

In the above charging path control method, the step of detecting whether a power transistor is provided on the charging path preferably includes: providing a pin connected to the gate of the power transistor or grounded; generating a detection signal , output from the pin to generate a detection voltage; and compare the detection voltage with a reference voltage to determine whether the power transistor is provided.

The following will be described in detail through specific embodiments, so that it is easier to understand the purpose, technical content, characteristics and effects of the present invention.

Description of drawings

FIG. 1 shows a schematic diagram of a power supply system in the prior art;

FIG. 2 shows a schematic diagram of another prior art power supply system;

FIG. 3 shows a schematic diagram of a multi-purpose power management device applied to a power supply system according to an embodiment of the present invention;

FIG. 4 shows a schematic diagram of the application of the multipurpose power management device of the present invention to a power supply system;

Fig. 5 marks another embodiment of path selection circuit 3c;

6A-6B illustrate two embodiments of the detection signal generator 33;

7A-7B illustrate another two embodiments of the detection signal generator 33;

FIG. 8 shows a schematic diagram of a multi-purpose power management device applied to a power supply system according to another embodiment of the present invention;

FIG. 9 shows a schematic diagram of applying the multipurpose power management device of the present invention to a power supply system.

Explanation of symbols in the figure

1a, 3a, 5a Switching Mode Power Supplies

2a, 3b, 5b charging management circuit

2d Power management device

3c Path selection circuit

3d, 5d multi-purpose power management device

10, 20 Power supply system

11 Error Amplifier

12 PWM signal generator

13 Feedback circuit

14 switch circuit

15, 15' switch control circuit

16 Error Amplifier

21, 22, 23, 24, 31 Error amplifier

25 Adder

26 Feedback circuit

27 PMOS transistor

30, 40, 50, 60 Power supply system

31 Comparator

32 Multi-tasker

33 Detection signal generator

34 Adder

55, 56 Error amplifier

Batt Battery

Comp1～Comp6 Error signal

FB 1, FB2 Feedback signal

L Inductance

P Pin

PPCTRL Signal

Q1 High Bridge Transistor

Q2 Lower Bridge Transistor

R1～R4 Resistance

RS sense resistor

SW Switch

Vin Input Voltage

Vout output voltage

Vbatt Voltage

Vref1～Vref6 Reference voltage

Detailed ways

The drawings in the present invention are all schematic, mainly intended to show the functions of each component and the signal relationship between each component, and the dimensions, distances, etc. are not drawn to scale.

Please refer to FIG. 3 and FIG. 4, which show that the multi-purpose power management device 3d of the present invention can be used with different circuit board configurations, that is, it can be applied to the configuration in which the battery Batt is directly connected to the output terminal Vout through the resistor RS in FIG. 1, It is also applicable to the configuration in which the battery Batt is connected to the output terminal Vout through the resistor RS and the PMOS transistor 27 in FIG. 2 , as shown in FIGS. 3 and 4 respectively. How the multi-purpose power management device 3d recognizes which configuration it is connected to can be artificially set by means of external signals, and in one embodiment, it can be further connected with the transistor 27 according to the multi-purpose power management device 3d (or not connected with the transistor 27). Transistor 27 connection) pin potential to automatically judge.

Please refer to FIG. 3 , the power supply system 30 includes a switching power supply 3a, a charging management circuit 3b, a battery Batt, a transistor 27 (the transistor 27 shown is a PMOS transistor, but of course it can also be an NMOS transistor) and a path selection circuit 3c. The switching power supply 3a controls the power conversion between the input terminal Vin and the output terminal Vout, the charging management circuit 3b controls the charging of the battery Batt, and the path selection circuit 3c is based on whether there is a transistor 27 between the output terminal Vout and the battery Batt , and choose to feed back the charging current information of the battery Batt to the switching power supply 3a or the charging management circuit 3b.

In detail, the switching power supply 3 a converts the external power from the input terminal Vin to the output terminal Vout, and the output terminal Vout supplies the system load and charges the battery Batt. When there is no external power supply at the input terminal, the battery Batt will output power to the output terminal Vout. The power supply system 30 detects whether the battery Batt needs to be charged or stops charging, so as to control the PMOS transistor 27 to turn on or cut off the charging current flowing to the battery Batt.

The feedback circuit 13 includes two serially connected resistors R1 and R2, wherein one end of R1 is coupled to the output voltage Vout, and one end of R2 is coupled to the ground potential. The feedback signal FB1 is obtained from the voltage division on the resistor R2. In the switching power supply 3 a , the error amplifier 11 receives the feedback signal FB1 and compares the reference voltage Vref1 to generate an error signal Comp1 for the PWM controller 12 . The PWM signal generator 12 generates switching signals according to the error signal Comp1 to switch the upper bridge transistor Q1 and the lower bridge transistor Q2 respectively, convert the input voltage of the power input terminal Vin into a current through the inductor L, and supply the output current from the power output terminal Vout to the Battery Batt charging. The upper bridge transistor Q1 and the lower bridge transistor Q2 form a switch circuit 14 . In Fig. 3, since a PMOS transistor 27 is arranged between the output terminal Vout and the battery Batt, the multiplexer (multiplexer) 32 in the path selection circuit 3c selects the path output to the adder 25 and does not select the path output to the adder 34. path (details of the path selection circuit 3c will be described later); therefore, in the switching power supply 3a, the adder (adder) 34 only receives the error signal Comp1. Furthermore, the error amplifier 11 , the adder 34 , and the PWM signal generator 12 form a switch control circuit 15 .

The feedback circuit 26 includes two serially connected resistors R3 and R4, wherein one end of R3 is coupled to the battery Batt output voltage Vbatt, one end of R4 is coupled to the ground potential, and the feedback signal FB2 is obtained from the voltage divider on the resistor R4. In the charging management circuit 3b, the error amplifier 21 receives the feedback signal FB2 and compares it with the reference voltage Vref2 to generate the error signal Comp2. The error amplifier 24 detects the voltage across the sense resistor RS and outputs an error signal Comp4 , and the error amplifier 23 compares the error signal Comp4 with the reference voltage Vref3 and outputs an error signal Comp3 . Because the multiplexer 32 in the path selection circuit 3c selects the path output to the adder 25, the adder 25 will add up the two error signals Comp2 and Comp3, and output the summed signal to the charge controller 22, the summed signal represents Information about the battery voltage and charging current for the battery Batt. The charging controller 22 determines whether the battery Batt needs to be charged or is saturated and does not need to be recharged according to the summed signal, and outputs a signal PPCTRL (Power Path Control) to turn on or turn off the PMOS transistor 27.

In this embodiment, the path selection circuit 3 c includes a comparator 31 , a multiplexer 32 and a detection signal generator 33 . The detection signal generator 33 generates a detection signal to detect the external connection status of the pin P through the output node PPCTRL of the charge controller 22 and the pin P. In FIG. 3 , since the pin P is connected to the PMOS transistor 27 , the detection signal generated by the detection signal generator 33 will generate a higher voltage at the node PPCTRL. The negative input terminal of the comparator 31 receives the voltage generated by the detection signal, compares it with the reference voltage Vref4 at the positive input terminal, and outputs a control signal to the multiplexer 32 to select the transmission path of the error signal Comp3. The path selection circuit 3c should only set the path selection when the system is started or reset, so as to avoid the influence of the output signal PPCTRL of the charging controller 22 on the path selection circuit 3c when the system enters a normal working state. In one embodiment, when the power supply system 30 is turned on to supply power, the power-on reset (Power-On Reset; POR) signal can be used as an enable signal to control the comparator 31 and/or detect the signal Whether generator 33 works. When the start-up phase is completed, the comparator 31 and/or the detection signal generator 33 are disabled, so that the multiplexer 32 is determined to be on the selected path without being disturbed by the change of the signal PPCTRL.

Compared with FIG. 3 , the system load of the power supply system 40 in FIG. 4 is only connected to the battery Batt through the sense resistor RS, without the PMOS transistor 27 therebetween, so the pin P of the output signal PPCTRL of the charging controller 22 is grounded. The negative input terminal of the comparator 31 is also connected to the ground terminal, and after comparing with the reference voltage Vref4 at the positive input terminal, the control signal is output to the multiplexer 32 to select the error signal Comp3 to be sent to the adder 34 . The adder 34 sums Comp1 and Comp3 and outputs to the PWM signal generator 12 . In one embodiment, the switch control circuit 15, the switch circuit 14, the error amplifier (11, 21, 23, 24), the charging controller 22, the adder (25, 34) and the path selection circuit 3c can be integrated into one chip or In a multi-purpose power management device 3d, this chip or device can be suitable for the application example in which the battery Batt is connected to the output terminal Vout through the PMOS transistor 27 and the sensing resistor RS in FIG. An application example in which the sensing resistor RS is connected to the output terminal Vout. However, the circuits and components included in the multipurpose power management device of the present invention are not limited thereto. For example, when the operating power of the power transistor in the switch circuit 14 is too high, the switch circuit 14 may not be integrated in the multipurpose power management device 3d. .

The above embodiments illustrate that the path selection circuit 3c can automatically detect whether the transistor 27 is set in the path for charging the battery Batt, so as to decide to feed back the charging current information of the battery Batt to the switching power supply 3a or the charging management circuit 3b. Of course, as shown in FIG. 5 , the feedback path of the battery Batt charging current information can also be set by a setting signal from the chip or outside the device. In this case, the path selection circuit 3c only needs to have a multiplexer 32 at a minimum, that is, Can.

6A-6B illustrate two embodiments of the detection signal generator 33, the detection signal generator 33 can be, for example, a weak current source or a resistor, and the upper end is connected to a suitable voltage (such as but not limited to the chip operating voltage VDD ), the lower end is coupled to the output node PPCTRL (pin P) of the charging controller 22, when the system is started or reset, if the pin P is coupled to the PMOS transistor 27, the detection signal generator 33 can pull the node high On the other hand, if the pin P is grounded, the voltage of the node PPCTRL cannot be pulled up. When the system is working normally, the voltage of the node PPCTRL is controlled by the output of the charge controller 22 and is not affected by the detection signal generator 33 .

7A-7B illustrate another two embodiments of the detection signal generator 33. In these two embodiments, the detection signal generator 33 also includes a switch SW, which is controlled by the power-on reset signal POR and turned on. When the system enters the normal working state after the start-up phase is completed, the switch SW is turned off to reduce power consumption.

Please refer to FIG. 8 and FIG. 9 , which show that another embodiment of the present invention is applicable to the application of different connection modes between the system load and the battery. Compared with FIG. 3 and FIG. 4 , the present embodiment adds error amplifiers 55 and 56 to accurately control the switching power supply 5 a and the charging management circuit 5 b respectively. Other similarities with the embodiments shown in FIG. 3 and FIG. 4 will not be described repeatedly.

As shown in FIG. 8 , the power supply system 50 includes a switching power supply 5 a, a charge management circuit 5 b, a battery Batt, a PMOS transistor 27 and a path selection circuit 3 c. The multiplexer 32 in the path selection circuit 3 c selects to transmit the error signal Comp3 to the error amplifier 55 or 56 . The error amplifier 55 compares the error signal Comp3 and the reference voltage Vref5 to output an error signal Comp5 , and the adder 34 sums the error signals Comp1 and Comp5 and outputs it to the PWM signal generator 12 . Similarly, the error amplifier 56 compares the error signal Comp3 and the reference voltage Vref6 to output an error signal Comp6 , and the adder 25 sums up the error signals Comp2 and Comp6 and outputs it to the charge controller 22 . The difference between the circuit in FIG. 8 and the circuit in FIG. 3 is that the information Comp3 representing the charging current of the battery Batt is not input into the adder 25 or 34 with the same value, but is compared with the reference voltage Vref5 or the reference voltage Vref6 to generate an error signal Comp5 or Comp6 is input to the adder 25 or 34, so that the switching circuit 14 or the PMOS transistor 27 can be controlled more precisely.

Compared with FIG. 8 , the system load in the power supply system 60 in FIG. 9 is connected to the battery Batt through the sense resistor RS, and the PMOS transistor 27 is not provided therebetween, so the pin P of the output signal PPCTRL of the charge controller 22 is grounded, and The detection signal output by the detection signal generator 33 generates different voltages at the output node PPCTRL of the charging controller 22 depending on whether the PMOS transistor 27 is provided, so after the judgment of the comparator 31, the multiplexer 32 can select an appropriate voltage. path of. And error amplifier (11,55), adder 34, PWM signal generator 12 constitute a switch control circuit 15 '.

In one embodiment, the switch control circuit 15', the switch circuit 14, the error amplifier (11, 21, 23, 24, 55, 56), the charging controller 22, the adder (25, 34) and the path selection circuit 3c can be Integrate into a chip or a multi-purpose power management device 5d, and this chip or device can be suitable for the application example in which the battery Batt is connected to the output terminal Vout through the PMOS transistor 27 and the sense resistor RS in FIG. 8, and can also be suitable for An application example in which the battery Batt is connected to the output terminal Vout through the sensing resistor RS in FIG. 9 .

The present invention has been described above with reference to preferred embodiments, but the above description is only for those skilled in the art to easily understand the content of the present invention, and is not intended to limit the scope of rights of the present invention. Under the same spirit of the present invention, various equivalent changes can be conceived by those skilled in the art. For example, if there is no resistor RS between the output terminal Vout and the battery Batt to sense the charging current to Batt (the output terminal Vout is directly connected to the battery Batt), this configuration method can still apply the multi-purpose power management of the present invention For device 3d or 5d, it is only necessary to ground or float the input of the error amplifier 24 . Accordingly, the scope of the invention should encompass the above and all other equivalent variations.

Claims (16)

1. A multipurpose power management device for controlling power conversion from input power to output power and charging of batteries from output power, characterized in that the multipurpose power management device includes: a switching circuit including at least one first power transistor; A switch control circuit, which generates a switch signal for controlling the power transistor, so as to control the power conversion from input power to output power; a charging management circuit, used to control the charging of the battery by the output power; and A path selection circuit is used to decide whether to use the charging management circuit to control the charging of the battery. 2. The multipurpose power management device as claimed in claim 1, wherein when the output power and the battery are connected through a second power transistor, the path selection circuit selects the charge management circuit to operate the second power transistor to control Charging of the battery: when the output power and the battery are not connected through a second power transistor, the path selection circuit will not select the charging management circuit to control the charging of the battery. 3. The multipurpose power management device as claimed in claim 2, wherein when the output power and the battery are not connected through a second power transistor, the path selection circuit selects to feed back the information about the charging current of the battery to This switch controls the circuit. 4. The multipurpose power management device as claimed in claim 1, wherein the path selection circuit comprises a multiplexer for determining whether to use the charge management circuit to control the charging of the battery according to an external setting signal. 5. The multipurpose power management device as claimed in claim 1, wherein the charge management circuit generates an output signal output from a pin, and wherein the path selection circuit comprises: a detection signal generator, the detection signal generator generates a detection signal output from the pin to generate a detection voltage; a comparator, comparing the detection voltage with a reference voltage; and A multiplexer determines whether to use the charging management circuit to control the charging of the battery according to the output of the comparator. 6. The multipurpose power management device as claimed in claim 2, wherein the charging management circuit comprises a first error amplifier, the first error amplifier generates a first error signal according to the information about the charging current of the battery, and the path The selection circuit decides to send the first error signal to the switch control circuit or the charging management circuit. 7. The multipurpose power management device as claimed in claim 6, wherein the switch control circuit comprises: A second error amplifier, which compares the feedback signal related to the output power with a second reference voltage to generate a second error signal; An adder, receiving the second error signal, summing the second error signal and the first error signal when the path selection circuit decides to send the first error signal to the switch control circuit, otherwise not summing the second error signal and the first error signal; and The pulse width modulation controller generates a switching signal for controlling the first power transistor according to the output of the adder. 8. The multipurpose power management device as claimed in claim 6, wherein the switch control circuit comprises: A second error amplifier, which compares the feedback signal related to the output power with a second reference voltage to generate a second error signal; A third error amplifier, when the path selection circuit decides to transmit the first error signal to the switch control circuit, compares the first error signal with a third reference voltage to generate a third error signal; an adder sums the second error signal and the output of the third error amplifier; and The pulse width modulation controller generates a switching signal for controlling the first power transistor according to the output of the adder. 9. The multipurpose power management device as claimed in claim 6, wherein the charging management circuit comprises: a second error amplifier, which compares the feedback signal related to the battery voltage with a second reference voltage to generate a second error signal; An adder, receiving the second error signal, summing the second error signal and the first error signal when the path selection circuit decides to send the first error signal to the charge management circuit, otherwise not summing the second error signal and the first error signal; and The charging controller generates a signal for controlling the second power transistor according to the output of the adder. 10. The multipurpose power management device as claimed in claim 6, wherein the switch control circuit comprises: a second error amplifier, which compares the feedback signal related to the battery voltage with a second reference voltage to generate a second error signal; a third error amplifier, when the path selection circuit decides to transmit the first error signal to the charge management circuit, compares the first error signal with a third reference voltage to generate a third error signal; an adder sums the second error signal and the output of the third error amplifier; and The charging controller generates a signal for controlling the second power transistor according to the output of the adder. 11. A charging path control circuit, selecting at least one control loop according to an output power and a connection relationship between batteries, characterized in that the charging path control circuit includes: a charge management circuit for controlling the charging of the battery by the output power; and A path selection circuit determines whether to use the charging management circuit to control the charging of the battery according to the output power and whether there is a power transistor between the batteries. 12. The charging path control circuit according to claim 11, wherein the output power is converted from an input power through a switching power supply, and when a power transistor is provided between the output power and the battery, the The path selection circuit feeds back information about the battery charging current to the charge management circuit, and when there is no power transistor between the output power and the battery, the path selection circuit feeds back information about the battery charging current to the switch type power supply. 13. The charging path control circuit as claimed in claim 11, wherein the charging management circuit generates an output signal output from a pin, and wherein the path selection circuit comprises: a detection signal generator, the detection signal generator generates a detection signal output from the pin to generate a detection voltage; a comparator, comparing the detection voltage with a reference voltage; and A multiplexer determines whether to use the charging management circuit to control the charging of the battery according to the output of the comparator. 14. A charging path control method, characterized in that it comprises: converting an input power into an output power; charging a battery from the output power through a charging path; Detecting whether a power transistor is provided on the charging path; When a power transistor is provided on the charging path, controlling the power transistor to control the charging of the battery; and When there is no power transistor on the charging path, the conversion of the input power and output power is controlled to control the charging of the battery. 15. The charging path control method according to claim 14, further comprising: Detect the current on the charging path to generate information about the charging current of the battery; When a power transistor is provided on the charging path, using the information feedback to control the power transistor; and When there is no power transistor on the charging path, the information feedback is used to control the conversion of the input power and output power. 16. The charging path control method as claimed in claim 14, wherein the step of detecting whether a power transistor is provided on the charging path comprises: providing a pin connected to the gate of the power transistor or grounded; generating a detection signal and outputting it from the pin to generate a detection voltage; and The detection voltage is compared with a reference voltage to determine whether the power transistor is provided.

Images