CN216699832U

CN216699832U - Multiplexed output switching power supply and electronic device

Info

Publication number: CN216699832U
Application number: CN202121477930.8U
Authority: CN
Inventors: 李林凯; 张程龙
Original assignee: Huayuan Zhixin Semiconductor Shenzhen Co ltd
Current assignee: Huayuan Zhixin Semiconductor Shenzhen Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2022-06-07
Anticipated expiration: 2031-06-30

Abstract

The utility model provides a multi-output switch power supply and electronic equipment, wherein the switch power supply comprises N output modules, a transformer, a secondary rectifier tube and an output control module; each output module comprises an output capacitor, an output switch and an output node, wherein the first end of the output switch is connected with the first end of the secondary coil of the transformer, the second end of the output switch is connected with the first end of the output capacitor, the first end of the output capacitor is connected with the output node, the second end of the output capacitor is connected with the second end of the secondary coil, and the second end of the secondary coil is grounded; the first end of the secondary rectifier tube is connected with the second end of the secondary coil, and the second end of the secondary rectifier tube is grounded; the output control module is connected with the first end of the output capacitor, and the output control module is connected with the control end of the output switch.

Description

Multiplexed output switching power supply and electronic device

Technical Field

The utility model relates to the technical field of switching power supplies, in particular to a multi-output switching power supply and electronic equipment.

Background

The switch power supply converts direct current into high-frequency alternating current to be supplied to the transformer for transformation, so that one or more groups of required voltages are generated, and the switch power supply can be applied to various electronic fields according to different sizes and designs.

In the prior art, when the switching power supply needs to perform multi-path output, the following two methods are generally adopted:

(1) a plurality of secondary windings are adopted, each winding corresponds to one output path, such as the circuit in fig. 1, but the plurality of windings in this way can make the transformer quite complicated and high in cost, and the voltage precision of the other load path can be influenced by the change of the load of one path, so that the cross regulation rate is poor, and the transformer is suitable for fixed loads;

(2) multiplexing can be achieved by using a single secondary winding and then adding multiple DC-DC conversion circuits (i.e., Buck or Buck circuits) to the secondary winding, such as the circuit of fig. 2, which improves the cross regulation problem, but is complex, costly, and inefficient.

SUMMERY OF THE UTILITY MODEL

The utility model provides a multi-output switching power supply and electronic equipment, which aim to solve the problems of high cost and complex circuit.

According to a first aspect of the present invention, there is provided a multiple output switching power supply comprising: the device comprises N output modules, a transformer, a secondary rectifier tube and an output control module;

each output module comprises an output capacitor, an output switch and an output node, wherein a first end of the output switch is connected with a first end of a secondary coil of the transformer, a second end of the output switch is connected with the first end of the output capacitor, the first end of the output capacitor is connected with the output node, the second end of the output capacitor is connected with a second end of the secondary coil, and the second end of the secondary coil is grounded;

the first end of the secondary rectifier tube is connected with the second end of the secondary coil, and the second end of the secondary rectifier tube is grounded;

the output control module is connected with the first end of the output capacitor, and the output control module is connected with the control end of the output switch;

the output control module is used for:

detecting actual output voltages of the N output nodes;

and when the secondary rectifier tube is in a conducting state, controlling the on-off of the N output switches according to the deviation of the actual output voltages of the N output nodes relative to the corresponding target output voltage.

Optionally, the deviation is matched with a difference obtained by subtracting a corresponding actual output voltage from a corresponding target output voltage, and when the secondary rectifier tube is in the on state, the controlled on output switches are one or more output switches with the largest corresponding difference.

Optionally, N is equal to 2, and the two output control modules are a first output module and a second output module respectively; the first output module comprises a first output node and the second output module comprises a second output node;

when the secondary rectifier tube is in a conducting state, the output control module controls the on-off of the N output switches according to the deviation of the actual output voltages of the N output nodes relative to the corresponding target output voltage, and is specifically used for:

determining a first deviation from a first actual output voltage of the first output node and a corresponding first reference voltage, the first deviation characterizing a deviation of the first reference voltage from the first actual output voltage;

determining a second deviation from a second actual output voltage of the second output node and a corresponding second reference voltage, the second deviation characterizing a deviation of the second reference voltage from the second actual output voltage; the reference voltage matches a corresponding target output voltage;

when the first deviation is higher than the second deviation and the secondary rectifier tube is in the conducting state, controlling a first output switch of the first output module to be conducted and a second output switch of the second output module to be turned off;

when the first deviation is lower than the second deviation and the secondary rectifier tube is in the conducting state, the first output switch of the first output module is controlled to be turned off, and the second output switch of the second output module is controlled to be turned on.

Optionally, the output control module comprises a detection unit and a switch control unit,

the detection unit is connected with the first end of the output capacitor, the detection unit is connected with the switch control unit, and the detection unit determines corresponding deviation according to the detected actual output voltages of the N output nodes and corresponding reference voltages and feeds N paths of deviation back to the switch control unit;

the switch control unit is connected with the control end of the output switch and used for:

comparing the N paths of deviations to obtain a comparison result;

and when the secondary rectifier tube is in the conducting state, controlling the on-off of the N output switches according to the comparison result.

Optionally, the switch control unit includes a logic processing circuit, a switch trigger circuit, N driving circuits,

the first side of the logic processing circuit is connected with the detection unit, and the second side of the logic processing circuit is connected with the switch trigger circuit so as to compare the received N paths of deviations, output the comparison result and feed the comparison result back to the switch trigger circuit;

the switch trigger circuit is connected with the N drive circuits so as to generate at least one driver control signal according to the comparison result when the secondary rectifier tube is in the conducting state and feed back the at least one driver control signal to the corresponding drive circuit;

the drive circuit is connected with the control end of the corresponding switch, and the drive circuit is used for driving the corresponding output switch to be conducted if the drive circuit receives the drive control signal.

Optionally, the secondary rectifier tube is a rectifier diode, a cathode of the rectifier diode is connected to the second end of the secondary coil, and an anode of the rectifier diode is grounded.

Optionally, when N is equal to 2, the two output control modules are respectively a first output module and a second output module; the first output module comprises a first output node and the second output module comprises a second output node;

the logic processing circuit comprises a comparator, and the switch trigger circuit comprises a buffer and an inverter;

the first input end and the second input end of the comparator are respectively connected with the detection unit;

the input end of the buffer is connected with the output end of the comparator, and the output end of the buffer is connected with the first driving circuit;

the input end of the phase inverter is connected with the output end of the comparator, and the output end of the phase inverter is connected with the second driving circuit;

when the first deviation of the first output node is higher than the second deviation of the second output node and the rectifier diode is in the conducting state, the output end of the buffer outputs a first level, the output end of the inverter outputs a second level, and the first level can control the driving circuit to generate an output control signal;

when the first deviation is lower than the second deviation and the rectifier diode is in the conducting state, the output end of the buffer outputs a second level, and the output end of the inverter outputs a first level.

Optionally, the secondary rectifier tube is a rectifier field effect tube, and the output control module includes a rectifier tube detection unit;

the first pole of the rectification field effect transistor is connected with the second end of the secondary coil, the second pole of the rectification field effect transistor is grounded, and the first pole of the rectification field effect transistor is connected with the output control module so as to detect whether the on-off state of the rectification field effect transistor is a conducting state or a turning-off state;

the rectifier tube detecting unit is connected with a first pole of the rectifier field effect tube, the rectifier tube detecting unit is connected with the switch trigger circuit, and the rectifier tube detecting unit is used for detecting the on-off state, obtaining a corresponding state signal and feeding the state signal back to the switch trigger circuit.

the logic processing circuit comprises a comparator, and the switch trigger circuit comprises a D trigger;

the output end of the comparator is connected with the first side of the D trigger, and the rectifier tube detection unit is connected with the enabling end of the D trigger;

the first end of the second side of the D trigger is connected with the first driving circuit, and the second end of the second side of the D trigger is connected with the second driving circuit; the D flip-flop is used for:

when the first deviation of the first output node is higher than the second deviation of the second output node and the on-off state of the rectifying field effect transistor is changed from the off state to the on state, the first end of the second side of the D trigger outputs a first level, the second end of the second side of the D trigger outputs a second level, and the first level can control the driving circuit to generate an output control signal;

and after the deviation is lower than the second deviation, when the on-off state of the rectifying field effect transistor is changed from the off state to the on state, the first end of the second side of the D trigger outputs a second level, and the second end of the second side of the D trigger outputs a first level.

Optionally, the detection unit includes N error amplifiers, a first input end of each error amplifier is connected to the first end of the output capacitor, a second input end of each error amplifier is connected to a corresponding reference voltage, and an output end of each error amplifier is connected to the output switch control unit.

Optionally, the system further comprises a control module and a primary side switch;

the control module is in communication with a control terminal of the primary side switch, the primary side switch being connected between a first terminal of a primary winding of the transformer and ground;

the output control module is directly or indirectly connected with the control module to send a feedback signal related to the actual output voltage to the control module.

Optionally, the output control module includes a feedback signal generating unit;

the detection unit is connected with the feedback signal generation unit to receive the N paths of deviations and generate a feedback signal according to the N paths of deviations;

the feedback signal generating unit is directly or indirectly communicated with the control module so as to feed the feedback signal back to the control module.

Optionally, the feedback signal generating unit includes N feedback resistors, a first optocoupler transistor, and a detection resistor;

the first end of the feedback resistor is connected with the output end of the error amplifier, the second end of the feedback resistor is connected with the first end of the first optocoupler transistor, the first end of the detection resistor is connected with the second end of the first optocoupler transistor, and the second end of the detection resistor is connected with the power supply;

the first optocoupler transistor generates the feedback signal according to the applied first voltage and feeds the feedback signal back to the control module.

Optionally, the control module includes a controller and a second optocoupler transistor;

a second end of the second optocoupler transistor is grounded, and a control end of the second optocoupler transistor detects the feedback signal;

the controller is connected with a first end of the second optical coupling transistor, and the controller is connected with a control electrode of the primary side switch so as to generate a primary control signal according to a second voltage of the first end of the second optical coupling transistor to drive the primary side switch to be switched on.

According to a second aspect of the present invention there is provided an electronic device comprising a multiple output switching power supply according to the first aspect of the present invention and its alternatives.

According to the multi-output switch power supply and the electronic equipment, the output control modules are arranged to control the N output switches of the output modules, and further, when the load of at least one output module is the highest, the corresponding output switch is controlled to be conducted.

In an alternative scheme of the utility model, a rectification field effect transistor, such as a MOSFET or a GaN FET, is arranged, a state signal is obtained by detecting the on-off state of the rectification field effect transistor, and the switch control unit receives the state signal to realize the synchronous switching of the N output switches.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a first schematic circuit diagram of a prior art multiple output switching power supply;

FIG. 2 is a first schematic circuit diagram of a prior art multiple output switching power supply;

FIG. 3 is a first schematic circuit diagram of a multiple-output switching power supply according to an embodiment of the present invention;

FIG. 4 is a second schematic circuit diagram of the multiple output switching power supply according to an embodiment of the present invention;

FIG. 5 is a third schematic circuit diagram of a multiple-output switching power supply according to an embodiment of the present invention;

fig. 6 is a fourth schematic circuit diagram of the multiple-output switching power supply according to an embodiment of the present invention;

fig. 7 is a fifth schematic circuit diagram of the multiple-output switching power supply according to an embodiment of the utility model;

fig. 8 is a sixth schematic circuit diagram of a multiple-output switching power supply according to an embodiment of the present invention;

fig. 9 is a seventh schematic circuit diagram of a multiple-output switching power supply according to an embodiment of the utility model;

fig. 10 is a circuit diagram eight of the multiple-output switching power supply according to an embodiment of the present invention;

fig. 11 is a circuit diagram of a multiple-output switching power supply according to an embodiment of the present invention;

fig. 12 is a circuit schematic diagram of a multiple-output switching power supply according to an embodiment of the utility model;

FIG. 13 is a waveform diagram of a portion of nodes in an embodiment of the utility model.

Description of reference numerals:

11-an output module; 12-an output control module; 121-a detection unit; 122-a switch control unit; 1221-a logic processing circuit; 1222-a switch trigger circuit; 1223-a driver circuit; 123-rectifier tube detection unit; 13-a secondary rectifier tube; 14-a control module;

CP 1-comparator; CP 2-comparator; u1-buffer; u2-inverter; U3-D flip-flop;

s1 — a first output switch; c1 — first output capacitance; out1 — first output port; OP 1-first error amplifier; r1 — first feedback resistance; s2 — a second output switch; c2 — second output capacitance; out2 — second output port; OP 2-second error amplifier; r2 — second feedback resistance; sn-nth output switch; cn-nth output capacitance; outn-nth output port; an OPn-nth error amplifier; rn-nth feedback resistance;

r0 — sense resistance; vdd-supply; a T-transformer; t1-primary coil; t2-secondary coil; q1-primary side switch; q2-rectifying field effect transistor; a D-rectifier diode; u4-controller; d1 — a first optocoupler transistor; d2-second optocoupler transistor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "upper surface", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the description of the present invention, "a plurality" means a plurality, e.g., two, three, four, etc., unless specifically limited otherwise.

In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected" and the like are to be construed broadly, e.g., as meaning fixedly attached, detachably attached, or integrally formed; can be mechanically connected, electrically connected or can communicate with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Referring to fig. 3, an embodiment of the utility model provides a multiple-output switching power supply, including: the transformer T comprises N output modules 11, a transformer T, a secondary rectifier tube 13 and an output control module 12; the transformer comprises a secondary winding, namely a secondary coil T2;

each output module 11 comprises an output capacitor, an output switch and an output node, wherein a first end of the output switch is connected with a first end of a secondary coil T2 of the transformer, a second end of the output switch is connected with a first end of the output capacitor, a first end of the output capacitor is connected with the output node, a second end of the output capacitor is connected with a second end of the secondary coil T2, and a second end of the secondary coil T2 is grounded; the output node is used for connecting a load and transmitting the energy received by the output module to the load, and the load can be applied to high-power-density multi-output PDs, household appliances, intelligent lighting systems and the like;

a first end of the secondary rectifier tube 13 is connected with a second end of the secondary coil T2, and a second end of the secondary rectifier tube 13 is grounded;

the output control module 12 is connected to a first end of the output capacitor, and the output control module 12 is connected to a control end of the output switch;

the output control module 12 is configured to:

detecting actual output voltages of the N output nodes;

when the secondary rectifier tube 13 is in a conducting state, the on-off of the N output switches is controlled according to the deviation of the actual output voltages of the N output nodes relative to the corresponding target output voltage.

In one example, the output switch is a bidirectional switch, and a path of the bidirectional switch may connect the first end of the secondary winding to the output node, and the output control module may control the path to be turned on or off;

in another example, the output switch is a transistor switch, two poles (such as a source and a drain, a collector and an emitter) of the transistor switch are respectively connected to the first end of the secondary coil and the output node, and the output control module controls the transistor switch to be turned on or off by controlling a voltage of a control pole (such as a gate and a base).

In the above embodiment, one transformer and one secondary coil are adopted, and the output control modules are arranged to control the N output switches of the output modules, so that when the load of at least one output module is the highest, the corresponding output switches are controlled to be turned on.

In one embodiment, the deviation is matched to a difference value obtained by subtracting a corresponding actual output voltage from a corresponding target output voltage, and the output switches controlled to be turned on when the secondary rectifier tube is in the on state are one or more output switches with the largest corresponding difference values.

In an example, the deviation may be obtained by calculating a difference between the target output voltage and the actual output voltage, and in another example, the deviation may be obtained by calculating a difference between the actual output voltage and the target output voltage and then taking an absolute value, so long as when the secondary rectifier tube is in the on state, the output switches controlled to be turned on are one or more output switches having the largest difference between the corresponding target output voltage and the actual output voltage.

In one embodiment, where N is equal to 2, the two output control modules 11 are a first output module and a second output module, respectively; the first output module comprises a first output node (e.g., the first output node Out1 in FIG. 6), the second output module comprises a second output node (e.g., the second output node Out2 in FIG. 6);

when the secondary rectifier tube 13 is in a conducting state, the output control module controls on/off of the N output switches according to a deviation of actual output voltages of the N output nodes relative to corresponding target output voltages, and is specifically configured to:

when the first deviation is higher than the second deviation and the secondary rectifier tube 13 is in the on state, controlling a first output switch of the first output module to be on and a second output switch of the second output module to be off;

and when the first deviation is lower than the second deviation and the secondary rectifier tube 13 is in the conducting state, controlling the first output switch of the first output module to be turned off and the second output switch of the second output module to be turned on.

Referring to fig. 4, in one embodiment, the output control module 12 includes a detection unit 121 and a switch control unit 122,

the detection unit 121 is connected to a first end of the output capacitor, the detection unit 121 is connected to the switch control unit 122, and the detection unit 121 determines a corresponding deviation according to the detected actual output voltages of the N output nodes and corresponding reference voltages, and feeds back the N deviations to the switch control unit 122;

the switch control unit 122 is connected to the control end of the output switch, and is configured to:

comparing the N paths of deviations to obtain a comparison result;

and when the secondary rectifier tube 13 is in the conducting state, controlling the on-off of the N output switches according to the comparison result.

Referring to fig. 5, in one embodiment, the switch control unit includes a logic processing circuit 1221, a switch trigger circuit 1222, N driving circuits 1223,

the first side of the logic processing circuit 1221 is connected to the detection unit 121, and the second side of the logic processing circuit 1221 is connected to the switch trigger circuit 1222, so as to compare the received N-way deviations, output the comparison result, and feed back the comparison result to the switch trigger circuit 1222;

the switch trigger circuit 1222 is connected to the N driving circuits 1223, so as to generate at least one driver control signal according to the comparison result when the secondary rectifier 13 is in the conducting state, and feed back the at least one driver control signal to the corresponding driving circuit 1223;

the driving circuit 1223 is connected to the control end of the corresponding switch, and the driving circuit 1223 is configured to drive the corresponding output switch to be turned on if the driver control signal is received.

Referring to fig. 6, in an embodiment, the secondary rectifier 13 is a rectifier diode D, a cathode of the rectifier diode D is connected to the second end of the secondary winding T2, and an anode of the rectifier diode D is grounded.

In one embodiment, when N is equal to 2, the two output control modules are respectively a first output module and a second output module; the first output module comprises a first output node and the second output module comprises a second output node;

the logic processing circuit 1221 comprises a comparator CP1, the switch trigger circuit 1222 comprises a buffer U1 and an inverter U2;

a first input end and a second input end of the comparator CP1 are respectively connected with the detection unit 121;

the input end of the buffer U1 is connected to the output end of the comparator CP1, and the output end of the buffer U1 is connected to a first driving circuit (i.e. the driving circuit 1233 connected to the output switch S1 in FIG. 6);

the input end of the inverter U2 is connected with the output end of the comparator CP1, and the output end of the inverter U2 is connected with a second driving circuit (i.e. the driving circuit 1233 connected with the output switch S2 in FIG. 6);

when the rectifier diode D is in the conducting state after the first deviation of the first output node is higher than the second deviation of the second output node, the output end of the buffer U1 outputs a first level, the output end of the inverter U2 outputs a second level, and the first level can control the driving circuit to generate an output control signal;

when the rectifying diode D is in the on state after the first deviation of the first output node is lower than the second deviation of the second output node, the output terminal of the buffer U1 outputs a second level and the output terminal of the inverter U2 outputs a first level.

Referring to fig. 7, in one embodiment, the secondary rectifier 13 is a rectifier fet Q2, and the output control module 12 includes a rectifier detection unit 123; the rectifying field effect transistor Q2 may be a MOSFET, such as an NMOS, a PMOS, or a wide bandgap semiconductor device, such as a GaN FET;

a first pole of the rectifying field-effect transistor Q2 is connected with a second end of the secondary coil T2, and a second pole of the rectifying field-effect transistor Q2 is grounded;

the rectifier tube detection unit 123 is connected to a first electrode of the rectifier field-effect tube Q2 to detect whether the on-off state of the rectifier field-effect tube Q2 is an on-state or an off-state;

the rectifier tube detecting unit 123 is connected to the switch trigger circuit 1222, and the rectifier tube detecting unit 123 is configured to detect the on-off state, obtain a corresponding state signal, and feed the state signal back to the switch trigger circuit.

In one example, the rectifier tube detection unit includes a voltage comparator, where the voltage comparator compares an input voltage with a preset voltage threshold, if the input voltage is higher than the voltage threshold, the rectifier field-effect tube is turned on, a high level is output, and if the input voltage is lower than the voltage threshold, the rectifier field-effect tube is turned off, a low level is output, and then the high and low levels output by the comparator are transmitted to the switch trigger circuit 1222 to trigger switching of the output switch.

Referring to fig. 8, in an embodiment, when N is equal to 2, the two output control modules are a first output module and a second output module respectively; the first output module includes a first output node (e.g., output node Out1 in FIG. 8), the second output module includes a second output node (e.g., output node Out2 in FIG. 8);

the logic processing circuit 1221 includes a comparator CP2, the switch trigger circuit 1222 includes a D flip-flop U3;

a first input end and a second input end of the comparator CP2 are respectively connected to the detection unit 121;

the output end of the comparator CP2 is connected with the first side of the D flip-flop U3, and the rectifier tube detection unit 123 is connected with the enabling end of the D flip-flop U3;

a first end of a second side of the D flip-flop U3 is connected with a first driving circuit, and a second end of a second side of the D flip-flop U3 is connected with a second driving circuit; the D flip-flop is used for:

when the on-off state of the rectifying field effect transistor Q2 changes from the off state to the on state after the first deviation of the first output node is higher than the second deviation of the second output node, the first end of the second side of the D flip-flop U3 outputs a first level, the second end of the second side of the D flip-flop U3 outputs a second level, and the first level can control the driving circuit to generate an output control signal;

when the on-off state of the rectifying fet Q2 changes from the off state to the on state after the first deviation of the first output node is lower than the second deviation of the second output node, the first terminal of the second side of the D flip-flop U3 outputs the second level, and the second terminal of the second side of the D flip-flop U3 outputs the first level.

In an example, when N is equal to 3, the logic processing circuit 1221 may include a plurality of comparators and logic gates, and further, output results of the plurality of comparators are processed by the logic gates (e.g., and or gates), which output node with a higher load is determined, so as to obtain a corresponding comparison result, the switch trigger circuit includes a chip with multiple input and output ports, the chip triggers the corresponding port to output a first level to the corresponding driving circuit according to the comparison result, and the driving circuit drives the corresponding output switch to be turned on after receiving the first level;

in another example, when N is equal to 3, the logic processing circuit 1231 may include a plurality of logic gates, and further, the plurality of logic gates (e.g., and or gate) perform logic processing on the three-way deviation, which output node with a higher load is determined, and a corresponding comparison result is obtained, the switch trigger circuit includes a chip with multiple input and output ports, the chip triggers the corresponding port to output the first level to the corresponding driving circuit according to the comparison result, and the driving circuit drives the corresponding output switch to be turned on after receiving the first level.

Therefore, the logic processing circuit and the switch trigger circuit can adopt proper devices to design related circuits according to the number of output nodes in the multi-output switch power supply, so as to realize the control of the output switch.

Referring to fig. 9, in one embodiment, the detecting unit 121 includes N error amplifiers, a first input terminal of each error amplifier is connected to a first end of the output capacitor, a second input terminal of each error amplifier is connected to a corresponding reference voltage, and an output terminal of each error amplifier is connected to the output switch control unit 1222;

the reference voltage accessed by each error amplifier is determined according to the load connected with the output node, and whether the load connected with the corresponding output node is overweight can be determined according to the magnitude of the actual output voltage of the output node and the reference voltage;

in one example, the first input terminal of the error amplifier is a negative input terminal, and the second input terminal of the error amplifier is a positive input terminal.

Referring to fig. 10, in one embodiment, the multiple-output switching power supply further includes a control module 14, a primary side switch Q1;

the control module 14 is connected with a control terminal of the primary side switch Q1, and the primary side switch Q1 is connected between a first terminal of a primary coil T1 of the transformer and the ground;

the output control module 12 communicates directly or indirectly with the control module 14 to send a feedback signal associated with the actual output voltage to the control module 14;

the control module is used for generating a primary control signal so as to transmit energy of the primary side to the secondary side when the primary control signal drives the switch-off of the primary side switch.

The primary side switch can be a MOSFET or a GaN FET.

In one embodiment, the output control module 12 includes a feedback signal generation unit 124;

the detecting unit 121 is connected to the feedback signal generating unit 124 to receive the N-path voltage detection signals and generate feedback signals according to the N-path deviations;

the feedback signal generating unit 124 communicates directly or indirectly with the control module 14 to feed the feedback signal back to the control module 14.

In one example, the magnitude of the feedback signal may be determined by the output module that distributes the secondary energy, such that the magnitude of the primary energy is determined by the magnitude of the load to which the output module is connected.

Referring to fig. 10, in one embodiment, the feedback signal generating unit 124 includes N feedback resistors, a first optocoupler transistor D1, and a detection resistor R0;

a first end of the feedback resistor is connected with an output end of the error amplifier, a second end of the feedback resistor is connected with a first end of the first optocoupler transistor D1, a first end of the detection resistor R0 is connected with a second end of the first optocoupler transistor D1, and a second end of the detection resistor R0 is connected with a power supply Vdd;

the first optical coupling transistor D1 generates the feedback signal according to the applied first voltage, and feeds the feedback signal back to the control module 14;

the first optocoupler transistor includes a light emitter that generates an optical signal based on an electrical signal, such as a light emitting diode.

In one embodiment, the control module 14 includes a controller U4, a second optocoupler transistor D2;

a second end of the second optical coupler transistor D2 is grounded, and a control end of the second optical coupler transistor D2 detects the feedback signal;

the controller U4 is connected to a first end of the second optocoupler transistor D2, and the controller U4 is connected to a control electrode of the primary side switch Q1, so as to generate a primary control signal according to a second voltage at the first end of the second optocoupler transistor D2, so as to drive the primary side switch Q1 to be turned on;

the second optocoupler transistor comprises a light receiver which generates an electrical signal according to the optical signal, such as a photodiode or a phototriode.

In one example, the controller U4 is a PWM controller, and the controller is further connected to a power supply, and the controller controls the power supply to output primary energy.

The following describes a specific working principle in an embodiment of the present invention with reference to fig. 11 and 12:

in fig. 11 and 12, taking N equal to 2 as an example, the first error amplifier OP1 and the second error amplifier OP2 in fig. 11 correspond to the detection unit 121, the D flip-flop U3 corresponds to the switch trigger circuit 1222, the comparator CP2 corresponds to the logic processing circuit 1221, in fig. 12, the waveform corresponding to Vo1 is the waveform of the voltage detection signal output by the first error amplifier OP1, the waveform corresponding to Vo2 is the waveform of the voltage detection signal output by the second error amplifier OP2, the waveform corresponding to Vo3 is the waveform corresponding to the comparison result output by the comparator CP2, the waveform corresponding to Vo4 is the waveform of the state signal output by the rectifying tube detecting unit 122, the waveform corresponding to D1 is the waveform of the signal output by the first driving circuit (i.e., the driving circuit 1223 connected to the output switch S1 in fig. 11), and the waveform corresponding to D2 is the waveform of the signal output by the second driving circuit (i.e., the driving circuit 1223 connected to the output switch S2 in fig. 11);

the first error amplifier OP1 and the second error amplifier OP2 determine the deviation of the corresponding output node according to the detected actual output voltage of the corresponding output node and the corresponding reference voltage, output a first deviation Vo1 and a second deviation Vo2, the comparator CP2 compares the magnitude of the first deviation Vo1 and the second deviation Vo2, and feeds back the comparison result Vo3 to the D port of the D flip-flop, and the D flip-flop is based on the comparison result and the state signal Vo4, and performs Q and Q operations

The port respectively outputs a high level and a low level;

specifically, in fig. 12, in a period from t0 to t1, the first deviation Vo1 is greater than the second deviation Vo2, that is, the load connected to the first output node Out1 is high, the output of the first output node Out1 is pulled low, the comparison result Vo3 is at a high level, the first driving circuit receives the high level to drive the first output switch to be turned on, and the first driving circuit receives the low level to turn off the second output switch; after the first deviation Vo1 is smaller than the second deviation Vo2 (namely, the load connected with the second output node Out2 is higher) in the period from t1 to t3, and at a time t2 when the rising edge of the state signal Vo4 approaches, the signal received by the first driving circuit becomes low level, so that the first output switch is turned off, the signal received by the second driving circuit becomes high level, and the second output switch is driven to be turned on; after the first deviation Vo1 is greater than the second deviation Vo2 (i.e., the load connected to the first output node Out1 is high) in the period t3-t5, and at the time t4 when the rising edge of the state signal Vo4 approaches, the signal received by the first driving circuit becomes high level, the first output switch is driven to be turned on, and the signal received by the second driving circuit becomes low level, so that the second output switch is turned off.

An embodiment of the present invention further provides an electronic device, including the multiple-output switching power supply described above.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the utility model has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multiple output switching power supply, comprising: the device comprises N output modules, a transformer, a secondary rectifier tube and an output control module;

the output control module is used for:

detecting actual output voltages of the N output nodes;

2. The multiple-output switching power supply according to claim 1, wherein the deviation is matched to a difference between a target output voltage and an actual output voltage, and the output switches controlled to be turned on when the secondary rectifier is in the on state are the one or more output switches with the largest corresponding difference.

3. The multiple-output switching power supply of claim 1, wherein N is equal to 2, and the two output control modules are respectively a first output module and a second output module; the first output module comprises a first output node and the second output module comprises a second output node;

4. The multiple-output switching power supply according to claim 1, wherein the output control module comprises a detection unit, a switch control unit,

the switch control unit is connected with the control end of the output switch and is used for:

comparing the N paths of deviations to obtain a comparison result;

5. The multiple-output switching power supply according to claim 4, wherein the switch control unit comprises a logic processing circuit, a switch trigger circuit, N driving circuits,

6. The multiple-output switching power supply according to claim 5, wherein the secondary rectifier is a rectifier diode, a cathode of the rectifier diode is connected to the second end of the secondary winding, and an anode of the rectifier diode is grounded.

7. The multiple-output switching power supply according to claim 6, wherein when N is equal to 2, the two output control modules are respectively a first output module and a second output module; the first output module comprises a first output node and the second output module comprises a second output node;

8. The multiple-output switching power supply according to claim 5, wherein the secondary rectifier is a rectifier field effect transistor, and the output control module includes a rectifier detection unit;

9. The multiple-output switching power supply according to claim 8, wherein when N is equal to 2, the two output control modules are respectively a first output module and a second output module; the first output module comprises a first output node and the second output module comprises a second output node;

a first end of a second side of the D trigger is connected with a first driving circuit, and a second end of the second side of the D trigger is connected with a second driving circuit; the D flip-flop is used for:

10. The multiple-output switching power supply according to claim 5, wherein the detection unit includes N error amplifiers, a first input terminal of each error amplifier is connected to the first terminal of the output capacitor, a second input terminal of each error amplifier is connected to a corresponding reference voltage, and an output terminal of each error amplifier is connected to the output switch control unit.

11. The multi-output switching power supply of claim 10, further comprising a control module, a primary side switch;

the control module is connected with a control end of the primary side switch, and the primary side switch is connected between a first end of a primary coil of the transformer and the ground;

the output control module communicates directly or indirectly with the control module to send a feedback signal associated with the actual output voltage to the control module.

12. The multi-output switching power supply according to claim 11, wherein the output control module includes a feedback signal generating unit;

the feedback signal generating unit is directly or indirectly communicated with the control module to feed the feedback signal back to the control module.

13. The multi-output switching power supply according to claim 12, wherein the feedback signal generating unit includes N feedback resistors, a first optocoupler transistor, and a detection resistor;

14. The multi-output switching power supply according to claim 13, wherein the control module comprises a controller, a second optocoupler transistor;

a second end of the second optical coupling transistor is grounded, and a control end of the second optical coupling transistor detects the feedback signal;

15. An electronic device comprising the multiple-output switching power supply of any one of claims 1 to 14.