CN113381626B

CN113381626B - Load power supply system suitable for dimming driving and dimming driving system

Info

Publication number: CN113381626B
Application number: CN202110501035.3A
Authority: CN
Inventors: 刘白仁
Original assignee: Shenzhen Biyi Microelectronics Co ltd
Current assignee: Shenzhen Biyi Microelectronics Co ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2023-02-17
Anticipated expiration: 2041-05-08
Also published as: CN113381626A

Abstract

The invention provides a load power supply system and a dimming driving system for a light emitting diode. The load power supply system comprises a first switch circuit, a second switch circuit and a control circuit, wherein the first switch circuit is used for converting an input power supply signal into an output signal to supply power to a load, and the input power supply signal is provided with a first reference ground; a first control circuit to control the first switch based on the adjustment signal, the first control circuit having a floating ground reference that is not common with the first reference ground; and a signal generating circuit that generates the adjustment signal based on the input signal, wherein the signal generating circuit and a reference ground of the first control circuit are common ground. The system is used for realizing accurate sampling of current and realizing a flexible output current regulation function.

Description

Load power supply system suitable for dimming driving and dimming driving system

Technical Field

The present invention relates to the field of electronics, and in particular, but not exclusively, to a load power supply system, a dimming driving system for a light emitting diode, and a load power supply method.

Background

Driving schemes for Light Emitting Diodes (LEDs) include isolated driving architectures and non-isolated driving architectures, which are less costly and bulky because they do not require the use of transformer devices. Meanwhile, in many applications of the light emitting diode, the brightness of the light emitting diode needs to be adjusted. Existing non-isolated dimming schemes for leds basically use a framework that shares the same reference ground, usually ground, with the input power source. The LED dimming circuit has the advantages of simple structure, and convenience in dimming an LED because the power switch is driven based on the ground.

However, in such an architecture, feedback to the output current is often incomplete or inaccurate, current sampling accuracy is poor, and control consistency between chips is poor.

In view of the above, it is desirable to provide a new structure or control method to solve at least some of the above problems.

Disclosure of Invention

The invention provides a load power supply system, a dimming driving system for a light emitting diode and a load power supply method, which aim at one or more problems in the prior art.

According to one aspect of the invention, a load power supply system comprises: the first switch circuit comprises a first switch, wherein the input end of the first switch circuit is coupled with an input power signal, the output end of the first switch circuit is coupled with a load and used for supplying power to the load, and the input power signal is provided with a first reference ground; the signal input end of the first control circuit receives the adjusting signal, the output end of the first control circuit is coupled with the control end of the first switch, the first control circuit is provided with a floating ground reference ground, and the floating ground reference ground is not common with the first reference ground; and the signal generating circuit receives the input signal, generates an adjusting signal to the signal input end of the first control circuit based on the input signal and is used for controlling the output signal of the first switch circuit, wherein the reference ground of the signal generating circuit and the reference ground of the first control circuit are in common ground.

In one embodiment, the first switch circuit comprises a Buck circuit, a first terminal of the first switch is coupled to the input power signal, and a second terminal of the first switch is coupled to the rectifier and coupled to a ground reference of the first control circuit as a floating ground reference.

In one embodiment, the first switch circuit includes a Buck circuit, a first terminal of the first switch is coupled to the input power signal, a second terminal of the first switch is coupled to the rectifier and a first terminal of the current sampling resistor, and a second terminal of the current sampling resistor is coupled to the inductor and to a ground reference of the first control circuit as a floating ground reference.

In one embodiment, the first control circuit controls the load based on the adjustment signal and a voltage difference between the first terminal of the current sampling resistor and a floating ground reference for adjusting the current flowing through the load.

In one embodiment, the first switch comprises a MOSFET transistor, a drain of the MOSFET transistor is coupled to the input power signal, a source of the MOSFET transistor is coupled to the floating ground reference through a current sampling resistor, and a gate of the MOSFET transistor is coupled to the output terminal of the first control circuit.

In one embodiment, the first switch and the first control circuit are located in a first electronic package, the signal generating circuit is located in a second electronic package, the first electronic package having: the input end is externally coupled with the rectifying and filtering circuit and used for receiving an input power supply signal, and the input end is internally coupled with the drain electrode of the first switch; the signal input end is externally coupled with the signal generating circuit and used for receiving the adjusting signal, and is internally coupled with the signal input end of the first control circuit; the current sampling end is externally coupled with the current sampling resistor and internally coupled with the source electrode of the first switch; the reference ground end is externally coupled with the second end of the current sampling resistor and the first end of the inductor and internally used as a floating ground reference ground of the first control circuit; and the feedback end is externally coupled with the second end of the inductor through the divider resistor, is used for receiving the output voltage feedback signal, and is internally coupled with the feedback input end of the first control circuit.

In one embodiment, the power supply system further comprises a second switch circuit, the second switch circuit comprises a second switch, an input end of the second switch circuit is coupled with the input power signal, and an output end of the second switch circuit is used for supplying power for the signal generating circuit, wherein a reference ground of the second switch circuit is common with a reference ground of the first control circuit.

In one embodiment, the second switching circuit comprises a second Buck circuit and a second control circuit, an output of the second Buck circuit providing power to the second control circuit through a diode and providing the feedback signal.

In one embodiment, the second switching circuit further comprises a diode, wherein an anode of the diode is coupled to the input power signal, and a cathode of the diode is coupled to the input terminal of the second Buck circuit.

In one embodiment, the signal generating circuit comprises a wireless signal transmission unit, and the signal generating circuit generates the adjusting signal based on a wireless input signal received by the wireless signal transmission unit, wherein the adjusting signal is a Pulse Width Modulation (PWM) signal.

In one embodiment, the load includes a light emitting diode, and the adjustment signal is used to adjust the brightness of the light emitting diode.

According to another aspect of the present invention, a dimming driving system for a light emitting diode includes: a first switching circuit for converting an input power signal into an output signal for driving the light emitting diode based on a switching action of the first switch, wherein the input power signal has a first reference ground; the first control circuit is used for receiving the adjusting signal and controlling the first switch to dim the light-emitting diode based on the adjusting signal, wherein the reference ground of the first control circuit is a floating ground reference ground which is not common with the first reference ground; a signal generating circuit providing a regulating signal; the second switch circuit is used for converting an input power supply signal into a power supply source based on the switching action of the second switch and supplying power to the signal generation circuit and/or the first control circuit; wherein the first control circuit, the signal generating circuit and the second switching circuit are commonly grounded.

According to still another aspect of the present invention, a load power supply method includes: controlling on/off of a first switch by a first control circuit for converting an input power signal to an output signal for powering a load, wherein the first control circuit receives an adjustment signal and generates a control signal based on the adjustment signal to adjust the output signal, wherein a reference ground of the input power signal is not common with a reference ground of the control signal; and generating an adjustment signal based on the wireless signal, wherein a reference ground of the adjustment signal is common to a reference ground of the control signal.

In one embodiment, the method further comprises: a second switching circuit is employed for converting the input power to the supply power, wherein a reference ground of the second switching circuit is common to the first control circuit.

According to the load power supply system, the dimming driving system for the light emitting diode and the load power supply method, floating control which is not grounded with the ground is adopted in the control circuit and the signal generating circuit, so that accurate sampling of current can be realized, and a flexible output current adjusting function can be realized.

Drawings

FIG. 1 shows a block diagram schematic of a load powering system according to an embodiment of the invention;

FIG. 2 shows a block diagram schematic of a load powering system according to another embodiment of the invention;

FIG. 3 is a circuit diagram of a dimming driving system for an LED according to an embodiment of the present invention;

fig. 4 is a schematic flow chart of a load power supply method according to an embodiment of the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

The description in this section is for several exemplary embodiments only and the invention is not to be limited in scope by the embodiments described. Combinations of the various embodiments, and substitutions of features from different embodiments, or similar prior art means, may be made to or replace some of the features of the embodiments with others, are also within the scope of the invention as described and claimed.

The term "coupled" or "connected" in this specification includes both direct and indirect connections. An indirect connection is a connection made through an intermediate medium, such as a conductor, wherein the electrically conductive medium may contain parasitic inductance or parasitic capacitance, or through an intermediate circuit or component as described in the embodiments in the specification; indirect connections may also include connections through other active or passive devices that perform the same or similar function, such as connections through switches, signal amplification circuits, follower circuits, and so on. "plurality" or "plurality" means two or more.

Fig. 1 shows a schematic diagram of a load power supply system according to an embodiment of the invention. The load power supply system includes a first switch circuit 11, a first control circuit 12, and a signal generation circuit 13. The first switch circuit 11 includes a first switch Q1, an input terminal of the first switch circuit 11 is coupled to an input power signal Vin, and an output terminal of the first switch circuit 11 is coupled to a load RL for enabling the output signal Vout to supply power to the load RL, wherein the input power signal Vin has a first reference ground. In one embodiment, the load power supply system further includes a rectifying and filtering circuit 14, and the input power signal Vin is a dc voltage signal obtained by rectifying and filtering the commercial power alternating current Vac through the rectifying and filtering circuit 14. Preferably, the rectifying-filtering circuit 14 comprises a full-bridge type rectifying circuit. The rectifying and filtering circuit 14 may include an input capacitor for preliminary filtering of the rectified signal. In the illustrated embodiment, the ground reference of the rectifying-filtering circuit 14 is the first ground reference GND1, so that the input power signal Vin is a voltage signal based on the first ground reference GND1. In one embodiment, the first ground reference GND1 is coupled to a ground through a socket. In one embodiment, the first switch circuit 11 includes a Buck circuit (voltage-reducing circuit) for converting an input power signal Vin into a lower-voltage output voltage Vout for driving the load RL, wherein a first terminal of the first switch Q1 is coupled to the input power signal Vin, a second terminal of the first switch Q1 is coupled to the rectifying tube D1 of the first switch circuit 11 and is coupled to the ground reference GND2 of the first control circuit 12 as a floating ground reference, or a second terminal of the first switch Q1 is coupled to the ground reference of the first control circuit 12 through a current sampling resistor and is coupled to the floating ground reference GND2, and a control terminal of the first switch Q1 receives a control signal CT, wherein the control signal CT is a voltage signal based on the floating ground reference GND2. The floating ground GND2 is not common to the first ground GND1, and preferably, the floating ground GND1 is not electrically coupled to the ground, and thus is referred to as a floating ground. In other embodiments, the first switch circuit is not limited to a Buck circuit, but may be in other topologies, such as a Boost circuit. The first switching circuit 11 and the ground reference of the load RL may be the first ground reference GND1.

The first control circuit 12 has a signal input terminal and a signal output terminal, wherein the signal input terminal of the first control circuit 12 receives the adjustment signal PWM, the output terminal of the first control circuit 12 is coupled to the control terminal of the first switch Q1, and the first control circuit 12 generates a control signal CT to control the switch Q1 based on the adjustment signal PWM, so as to adjust the on-duty ratio of the switch Q1 or adjust the reference signal of the output current, thereby adjusting the output voltage Vout or the output current. The first control circuit 12 has a floating ground GND2, and the floating ground GND2 is not common to the first ground GND1, so that the ground reference of the control signal CT is also the floating ground GND2 which is not common to the first ground GND1. In one embodiment, the floating ground reference GND2 is electrically coupled to an output terminal of the first switch Q1, such as a source of a MOSFET. The floating control of the first control circuit 12 is beneficial to realize the full current sampling of the inductive current and the accurate sampling, thereby realizing the accurate control of the output signal.

The signal generating circuit 13 receives an input signal and generates a regulating signal PWM based on the input signal to a signal input terminal of the first control circuit 12 for controlling an output signal of the first switch circuit 11, wherein the signal generating circuit 13 and the reference ground of the first control circuit 12 are both the floating ground reference ground GND2. In one embodiment, the output signal comprises an output voltage. In another embodiment, the output signal comprises an output current, and the first control circuit 12 controls the current flowing in the load based on the adjustment signal PWM. In one embodiment, the adjustment signal output by the signal generation circuit 13 is a dimming PWM wave, the duty cycle of which indicates the brightness. The first control circuit 12 may generate a current reference signal based on a duty ratio of the adjustment signal PWM and adjust a current value of the load or a brightness of the LED load according to the current reference signal. The regulating signal of the type has stronger signal transmission error tolerance, the logic error of a certain logic signal cannot cause the damage of the first switch Q1, and the reliability is higher.

Through the topology, the first control circuit 12 and the floating ground reference ground GND2 of the signal generating circuit 13 in the system are grounded, so that the voltage of the control end of the first switch Q1 can be accurately and flexibly controlled by the adjusting signal PWM, further signal conversion is not needed, and the system structure is simple.

In one embodiment, the load RL includes a Light Emitting Diode (LED), the power supply system is an LED dimming system, the first control circuit 12 performs dimming on the LED based on the adjustment signal PWM, and the floating-ground reference ground GND2 performs common-ground control, so that full-time sampling of the output current is facilitated, the control accuracy is improved, and the dimming signal can be flexibly controlled, thereby realizing precise dimming on the LED.

In order to achieve an efficient output of the dimming signal PWM for the signal generation circuit, in one embodiment, the power supply of the signal generation circuit 13 is a power supply generated based on the floating ground reference GND2.

Fig. 2 shows a block diagram of a load powering system according to another embodiment of the invention. Compared to fig. 1, the load supply system in fig. 2 further comprises a second switching circuit 21. The second switch circuit 21 includes a second switch, an input terminal of the second switch circuit 12 is coupled to the input power signal Vin, an output terminal of the second switch circuit 21 provides a power supply VDD for supplying power to the signal generation circuit 13, wherein the second switch circuit 21 is common to the signal generation circuit 13 and the first control circuit 12, and is all floating ground GND2, so that the power supply VDD can directly drive the signal generation circuit 13, and the adjustment signal PWM based on the floating ground GND2 for controlling the first control circuit can be generated without additional conversion. By controlling the first control circuit, the signal generating circuit and the second switch circuit to be grounded and to be a floating ground reference, the accurate dimming of the LED load can be flexibly realized.

Fig. 3 is a circuit diagram of a dimming driving system for dimming driving a light emitting diode according to an embodiment of the present invention. The dimming driving system includes a first switching circuit, a first control circuit controlling a first switch Q1 in the first switching circuit, a signal generating circuit 32, and a second switching circuit 33. Wherein the first switch Q1 and the first control circuit are located in the first electronic package 31, the signal generating circuit 32 is located in the second electronic package, and the second switch Q2 in the second switch circuit 33 and the second control circuit controlling the second switch Q2 are located in the third electronic package 331. In this power supply system, the load is a light emitting diode LED, and the brightness of the light emitting diode LED is controlled by adjusting the adjustment signal PWM. The dimming driving system may further include a rectifying and filtering circuit 34 for rectifying and filtering the ac mains Vac into an input power signal Vin for providing input power to the first and second switching circuits 33. In the illustrated embodiment, the first switching circuit includes a Buck circuit, which specifically includes a first switch Q1, a rectifier D1, and an inductor L. The output capacitor C1 may also be considered as part of the first switching circuit. The first end of the first switch Q1 receives an input power signal Vin, the second end of the first switch Q1 is coupled to the cathode of the rectifying tube D1 and the first end of the inductor L, and the second end of the inductor L is coupled to the output capacitor C1 and serves as an output end of the Buck circuit for supplying power to the light emitting diode. In a first state, the first switch Q1 is turned on, current flows from the output end of the rectifying and filtering circuit 34 to the inductor L and the output capacitor C1, a current loop is formed through the first ground GND1, and the output capacitor C1 is charged; in the second state, the first switch Q1 is turned off, the current forms a current loop through the inductor L, the light emitting diode LED and/or the output capacitor C1, the first reference ground GND1 and the rectifier tube D1, the current in the inductor L gradually decreases, the output capacitor C1 is switched from charging to discharging, and energy begins to be released to the light emitting diode. In the illustrated embodiment, the first switch Q1 includes a MOSFET transistor (metal oxide semiconductor field effect transistor), the first terminal of the MOSFET is the drain thereof, the second terminal of the MOSFET is the source thereof, and the control terminal of the MOSFET is the gate thereof. Of course the first switch may also be another type of transistor. In one embodiment, the first switch Q1 is fabricated on a first semiconductor substrate, the first control circuit is fabricated on a second semiconductor substrate, and the first switch Q1 and the first control circuit are packaged in the same electronic package 31 by a multi-chip packaging technique.

As shown, the first electronic package 31 has an input terminal D, a signal input terminal PWM, a current sampling terminal CS, a ground reference terminal GND, and a feedback terminal FB. The input terminal D is externally coupled to the rectifying and filtering circuit 34 for receiving the input power signal Vin, the input terminal D is internally coupled to the drain of the first switch Q1, and the input terminal D serves as the input terminal of the first switch circuit for receiving the input power signal Vin. The signal input terminal PWM is coupled to the signal generating circuit 32 for receiving the adjusting signal PWM, and coupled to the signal input terminal of the first control circuit. In one embodiment, the first control circuit controls the current flowing through the light emitting diode based on the adjustment signal PWM to achieve dimming of the light emitting diode. The current sampling terminal CS is externally coupled to the current sampling resistor Rcs and the cathode of the rectifier tube D1, and internally coupled to the source of the first switch Q1. The reference ground GND is coupled to the second terminal of the current sampling resistor Rcs and the first terminal of the inductor L, and is used as a floating ground of the first control circuit or the first electronic package 31. The feedback terminal FB is externally coupled to the second terminal of the inductor L through the voltage dividing resistor for receiving a feedback signal of the output voltage Vout, and is internally coupled to a feedback input terminal of the first control circuit. Through the structure, the floating control of the first switch Q1 is realized, the source electrode of the first switch Q1 is coupled with the current sampling resistor Rcs, and the voltage of the source electrode end of the first switch Q1 is directly collected, the voltage of the source electrode end, namely the voltage of the current sampling end CS, is equal to the voltage difference of the first end of the current sampling resistor Rcs relative to the floating reference ground GND2, therefore, no matter in the on stage of the first switch Q1 or the off stage of the first switch Q1, the current flowing through the inductor L simultaneously flows through the current sampling resistor Rcs, the voltage difference of the first end of the current sampling resistor Rcs relative to the floating reference ground GND2 can accurately reflect the current flowing through the inductor L, and therefore, the average current flowing through the inductor L can be accurately obtained, and the average current flowing through the LED is equal to the current flowing through the light emitting diode. The first control circuit in the first electronic package 31 controls the first switch Q1 based on the adjustment signal PWM and the voltage of the current sampling terminal CS, thereby adjusting the current flowing through the load. Through the arrangement, accurate control of the current in the light emitting diode LED can be realized. In one embodiment, the adjusting signal PWM is a pulse modulation signal, the first control circuit generates a current reference signal proportional to a duty ratio of the adjusting signal PWM based on the adjusting signal PWM, compares or error-amplifies the current sampling terminal CS voltage signal with the current reference signal, and controls the current of the light emitting diode based on the comparison result or the error-amplified signal. Because the voltage signal of the current sampling end CS and the adjusting signal PWM are common ground and are signals based on the floating ground reference ground GND2, the accurate and flexible dimming of the light-emitting diode can be realized. The first control circuit may drive and control the output current based on the regulation signal PWM, the current sampling signal at the CS terminal, based on any applicable inner loop. In one embodiment, the first control circuit generates a loop compensation signal based on the current sampling signal and the adjustment signal, compares the loop compensation signal with the periodic variation signal to generate a signal for controlling the first switch Q1 to be turned on, and turns off the first switch Q1 when the inductor current decreases to a zero value.

In addition, in order to further control the output voltage Vout, such as for over-voltage protection, and/or detect the demagnetization signal, in the illustrated embodiment, the output voltage Vout of the first switch circuit is further fed back to the feedback terminal FB of the first electronic package 31 through a feedback circuit, and the first control circuit further controls the first switch Q1 to be turned on and off based on the output voltage Vout, so as to achieve over-voltage protection of the system. The first control circuit can further obtain the time point when the current in the inductor L is reduced to zero based on the output voltage feedback signal of the feedback terminal FB, and the time point is used for carrying out demagnetization detection. In another embodiment, the power supply system performs stable control on the output voltage based on the output voltage feedback signal of the feedback terminal FB, so as to reduce the led output current ripple.

In another embodiment, the first control circuit controls the first switch Q1 and thus the output voltage based on the regulation signal PWM and a feedback signal based on the output voltage such that the output voltage is constant at a voltage reference characterized by the regulation signal PWM.

In the illustrated embodiment, the signal generating circuit 32 includes a wireless signal transmitting unit, and the signal generating circuit generates the adjustment signal based on a wireless input signal received by the wireless signal transmitting unit. In one embodiment, the adjustment signal is a Pulse Width Modulation (PWM) signal. Of course, the adjustment signal may be other types of signals. The wireless signal transmission unit can receive wireless signals based on a wireless local area network (Wifi) of the IEEE802.11b standard and can also receive wireless signals based on a Bluetooth module. The dimming of the light-emitting diode is realized by adopting a wireless control mode. Through wireless control, the signal generating circuit 32 is more flexible to convert based on the floating ground reference GND2, is more simple to be compatible with a general module, and has higher use safety. In other embodiments, the input signal of the signal generating circuit may be obtained by adjusting an external device.

In order for the signal generation circuit 32 to generate the adjustment signal PWM based on the floating ground reference GND2. The power supply system further includes a second switch circuit 33 common to the signal generation circuit 32, the second switch circuit 33 common to the first electronic package 31 and the signal generation circuit 32, being a floating ground GND2. In the illustrated embodiment, the second switching circuit 33 includes a second Buck circuit and a second control circuit. The second Buck circuit comprises a second switch Q2, a rectifier tube D3, an inductor L2 and an output capacitor C3. The reference ground of the rectifier tube D3 and the output capacitor C3 is the floating ground GND2. The second control circuit is used to control the second switch Q2, wherein the second switch Q2 and the second control circuit can be packaged in the same electronic package 331. The electronic package 331 has a feedback terminal, and the output terminal of the second Buck circuit supplies power to the second control circuit 331 through a feedback diode D4, and simultaneously provides a feedback signal of the power supply VDD for adjusting the power supply VDD. The second switch circuit 33 further includes a diode D2 at an input terminal of the second switch circuit 33, wherein an anode of the diode D2 is coupled to the input power signal Vin, and a cathode of the diode D2 is coupled to the input terminal of the second Buck circuit. The power supply VDD provided by the second switch circuit 33 is used to supply power to the signal generation circuit 32.

In one embodiment, the first control circuit in the first electronic package 31 is powered by a power supply voltage generated based on the input power signal Vin at the input terminal D, and the first electronic package 31 may further include a power supply terminal for coupling an external capacitor and generating a power supply for the first control circuit based on the voltage Vin. In another embodiment, the first control circuit in the first electronic package 31 may also be powered by the voltage output by the second switch circuit when the output voltage Vout is low.

In the embodiment shown in fig. 3, the first electronic package 31, the signal generating circuit 32 and the second switching circuit 33 in the system are grounded and controlled by using floating ground, and the first ground reference GND1 (usually, ground) is not connected, so that accurate full current sampling can be realized, and meanwhile, the dimming signal based on the floating ground reference GND2 can be conveniently generated based on the wireless signal, so that flexible dimming of the light emitting diode can be realized. And the second switch circuit 33 generates the floating-ground-reference-based power supply VDD for the signal generation circuit 32 directly based on the input power signal Vin. The second switch circuit 33 and the whole power supply system have simple structures and low cost, and can be used for flexibly and conveniently realizing the dimming function of the light emitting diode and realizing accurate dimming.

Fig. 4 is a schematic flow chart of a load power supply method according to an embodiment of the present invention. The load power supply method includes controlling on/off of a first switch Q1 by a first control circuit for converting an input power signal Vin to an output signal Vout for supplying power to a load in step 401, wherein the first control circuit receives a regulation signal PWM and generates a control signal based on the regulation signal to regulate the output signal, wherein a reference ground generating the input power signal is not common with a reference ground generating the control signal. The output signal comprises an output voltage or an output current. Preferably, the load includes a light emitting diode, and the first control circuit adjusts the output current based on the adjustment signal to perform dimming control on the light emitting diode. The load powering method includes generating an adjustment signal based on the wireless signal at step 402, wherein a reference ground of the adjustment signal is common to a reference ground of the control signal. The load powering method may further comprise employing a second switching circuit for converting the input power to the power supply, wherein a reference ground of the second switching circuit is common to the first control circuit. Through the floating control, the full current sampling of the inductance of the Buck circuit can be realized, more accurate dimming can be realized, and the dimming function of the LED can be flexibly, simply and conveniently realized. In one embodiment, the power supply method further includes using a second switch circuit for converting the input power Vin to the power supply VDD, wherein a reference ground of the second switch circuit is common to the first control circuit. In this way, the power supply generated by the second switching circuit can be directly used for supplying power to the signal generating circuit generating the dimming signal, and directly used for generating the dimming signal which is common to the control signal based on the wireless signal. The

above steps

401 and 402 do not indicate that there is a chronological relationship in control, and in a preferred embodiment, the

steps

401 and 402 are performed simultaneously.

Those skilled in the art should understand that the logic controls such as "high" and "low", "set" and "reset", "and gate" and "or gate", "non-inverting input" and "inverting input" in the logic controls referred to in the specification or the drawings may be exchanged or changed, and the subsequent logic controls may be adjusted to achieve the same functions or purposes as the above-mentioned embodiments.

The description and applications of the invention herein are illustrative and are not intended to limit the scope of the invention to the embodiments described above. The descriptions related to the effects or advantages in the specification may not be reflected in practical experimental examples due to uncertainty of specific condition parameters or influence of other factors, and the descriptions related to the effects or advantages are not used for limiting the scope of the invention. Variations and modifications of the embodiments disclosed herein are possible, and alternative and equivalent various components of the embodiments will be apparent to those skilled in the art. It will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, and with other components, materials, and parts, without departing from the spirit or essential characteristics thereof. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.

Claims

1. A load power supply system comprising:

the first switch circuit comprises a first switch, an input end of the first switch circuit is coupled with an input power signal, an output end of the first switch circuit is coupled with a load and used for supplying power to the load, and the input power signal is provided with a first reference ground;

the signal input end of the first control circuit receives the adjusting signal, the output end of the first control circuit is coupled with the control end of the first switch, and the first control circuit is provided with a floating ground reference ground which is different from the first reference ground;

the signal generating circuit receives an input signal, generates an adjusting signal to a signal input end of the first control circuit based on the input signal, and is used for controlling an output signal of the first switching circuit, wherein the reference ground of the signal generating circuit and the reference ground of the first control circuit are in common ground; and

and the input end of the second switch circuit is coupled with the input power signal, and the output end of the second switch circuit is used for supplying power for the signal generating circuit, wherein the reference ground of the second switch circuit is in common with the reference ground of the first control circuit.

2. The load power supply system of claim 1, wherein the first switch circuit comprises a Buck circuit, a first terminal of the first switch is coupled to the input power signal, and a second terminal of the first switch is coupled to the rectifier and to a ground reference of the first control circuit as a floating ground reference.

3. The load power supply system of claim 1, wherein the first switch circuit comprises a Buck circuit, a first terminal of the first switch is coupled to the input power signal, a second terminal of the first switch is coupled to the rectifier and a first terminal of the current sampling resistor, and a second terminal of the current sampling resistor is coupled to the inductor and to a ground reference of the first control circuit as a floating ground reference.

4. The load power supply system of claim 3 wherein the first control circuit controls the load based on the adjustment signal and a voltage difference of the first terminal of the current sampling resistor relative to a floating ground reference for adjusting the current through the load.

5. The load power supply system of claim 1 wherein the first switch comprises a MOSFET transistor having a drain coupled to the input power signal, a source coupled to the floating ground reference through a current sampling resistor, and a gate coupled to the output of the first control circuit.

6. The load power supply system of claim 1 wherein the first switch and the first control circuit are located in a first electronic package and the signal generating circuit is located in a second electronic package, the first electronic package having:

the input end is externally coupled with the rectifying and filtering circuit and used for receiving an input power supply signal, and the input end is internally coupled with the drain electrode of the first switch;

the signal input end is externally coupled with the signal generating circuit and used for receiving the adjusting signal, and is internally coupled with the signal input end of the first control circuit;

the current sampling end is externally coupled with the current sampling resistor and internally coupled with the source electrode of the first switch;

the reference ground end is externally coupled with the second end of the current sampling resistor and the first end of the inductor and internally used as a floating ground reference ground of the first control circuit; and

and the feedback end is externally coupled with the second end of the inductor through the divider resistor for receiving the output voltage feedback signal and internally coupled with the feedback input end of the first control circuit.

7. The load power supply system of claim 1 wherein the second switching circuit comprises a second Buck circuit and a second control circuit, the output of the second Buck circuit powering the second control circuit through a diode and providing the output voltage feedback signal of the second Buck circuit.

8. The load power supply system of claim 1 wherein the second switching circuit further comprises a diode, wherein an anode of the diode is coupled to the input power signal and a cathode of the diode is coupled to the input of the second Buck circuit.

9. The load power supply system of claim 1, wherein the signal generating circuit comprises a wireless signal transmitting unit, the signal generating circuit generating the adjustment signal based on a wireless input signal received by the wireless signal transmitting unit, wherein the adjustment signal is a Pulse Width Modulation (PWM) signal.

10. The load power supply system of claim 1 wherein the load comprises a light emitting diode and the adjustment signal is used to adjust the brightness of the light emitting diode.

11. A dimming driving system for a light emitting diode, comprising:

a first switching circuit for converting an input power signal into an output signal for driving the light emitting diode based on a switching action of the first switch, wherein the input power signal has a first reference ground;

the first control circuit is used for receiving the adjusting signal and controlling the first switch to dim the light-emitting diode based on the adjusting signal, wherein the reference ground of the first control circuit is a floating ground reference ground which is not common with the first reference ground;

a signal generating circuit providing a regulating signal; and

the second switch circuit is used for converting an input power supply signal into a power supply source based on the switching action of the second switch and supplying power to the signal generation circuit and/or the first control circuit;

wherein the first control circuit, the signal generating circuit and the second switching circuit are commonly grounded.