Isolation power supply chip based on dual resonance topology and control method thereof

Abstract

The present disclosure provides an isolated power supply chip based on a dual-resonance topology and a control method thereof. The isolated power supply chip includes a first oscillator, a transformer, a second oscillator, a control circuit, and a detection circuit; the transformer includes a primary coil connected to the first oscillator and a secondary coil connected to the second oscillator, wherein: the first oscillator is used to invert a DC input voltage into a high-frequency oscillation power signal, so that the first oscillator operates in a first oscillation state; the second oscillator operates in a second oscillation state after receiving the high-frequency oscillation power signal coupled and transmitted from the primary coil to the secondary coil, and obtains a DC output voltage; the control circuit is used to detect the DC output voltage and regulate the second oscillation state; the detection circuit is used to detect the first oscillation state to determine the influence of the second oscillation state on the first oscillation state, and to adjust the first oscillation state in real time to achieve stable operation of the isolated power supply.

Description

Technical Field

[0001] The present disclosure relates to the technical field of isolated power supplies, and in particular to an isolated power supply chip based on a dual-resonance topology and a control method thereof. Background Art

[0002] Isolated power supply chips can be used to transmit energy between two electrically isolated systems, effectively eliminating noise and surge current between different voltage domains, protecting devices from damage in the event of circuit failures, and preventing people from electric shock. Therefore, they are more widely used in automotive electronics, biomedicine, electric power and other fields. Traditional isolated power supply chips consist of three parts: the inverter circuit at the transmitting end, the power transmission isolation barrier using a transformer, and the rectifier circuit at the receiving end.

[0003] Conversion efficiency is one of the key technical indicators of a power supply. Improving conversion efficiency can reduce energy loss and electricity costs, ease the design burden of the cooling system, extend the life of the equipment, and reduce maintenance requirements due to overheating. The AC-DC rectifier circuit at the receiving end of a traditional isolated power supply chip can be divided into active rectifiers and passive rectifiers. Active rectifiers suffer from excessive gate capacitance switching losses at high frequencies, resulting in low efficiency and making them unsuitable for use in small, low-cost isolated power supply chips. The passive components used in passive rectifiers have a high forward voltage drop and large conduction losses, which limits the conversion efficiency of the isolated power supply chip. Traditional isolated power supply chips require an additional digital isolator as a feedback circuit to regulate the output voltage, which increases the size and cost of the isolated power supply chip. Summary of the Invention

[0004] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present disclosure provides an isolated power supply chip based on a dual-resonance topology and a control method thereof.

[0005] In order to achieve the above objectives, the technical solutions disclosed in this disclosure are as follows:

[0006] According to an embodiment of one aspect of the present disclosure, an isolated power supply chip based on a dual-resonance topology is provided, including a first oscillator, a transformer, a second oscillator, a control circuit, and a detection circuit; the transformer includes a primary coil connected to the first oscillator and a secondary coil connected to the second oscillator, wherein: the first oscillator is used to invert a DC input voltage into a high-frequency oscillation power signal, so that the first oscillator operates in a first oscillation state; the second oscillator operates in a second oscillation state after receiving the high-frequency oscillation power signal coupled and transmitted from the primary coil to the secondary coil, and obtains a DC output voltage; the control circuit is used to detect the DC output voltage and regulate the second oscillation state; the detection circuit is used to detect the first oscillation state to determine the influence of the second oscillation state on the first oscillation state, and to adjust the first oscillation state in real time to achieve stable operation of the isolated power supply.

[0007] According to an embodiment of the present disclosure, the control circuit is also used to control the second oscillator to be turned on or short-circuited, and the detection circuit is also used to control the first oscillator to be turned on or off, thereby realizing the turning on or off of the isolated power supply through the cooperation between the control circuit and the detection circuit.

[0008] According to an embodiment of the present disclosure, when the isolated power supply chip switches from an on state to an off state, the control circuit controls the second oscillator to short-circuit, and the detection circuit controls the first oscillator to shut down by detecting a change in the oscillation frequency of the first oscillator, thereby realizing the shutdown of the isolated power supply.

[0009] According to an embodiment of the present disclosure, when the isolated power supply chip switches from an off state to an on state, the control circuit controls the second oscillator to operate, and the detection circuit controls the first oscillator to turn on by detecting that the first oscillator is affected by the second oscillator and generates oscillations, thereby realizing the turning on of the isolated power supply.

[0010] According to an embodiment of the present disclosure, the second oscillator is provided with a second switch; the control circuit includes a feedback network, a non-overlapping circuit, and a short-circuit switch, wherein: the feedback network is configured to detect the DC output voltage and generate a control signal; the non-overlapping circuit receives the control signal and controls the conduction and disconnection of the short-circuit switch and the second switch.

[0011] According to an embodiment of the present disclosure, the first oscillator is provided with a first switch; the detection circuit includes a level detection circuit, a frequency detection circuit, and a logic circuit, wherein: the level detection circuit is used to detect the level change of the oscillation power signal of the first oscillator and transmit the level detection result to the logic circuit; the frequency detection circuit is used to detect the oscillation frequency of the oscillation power signal of the first oscillator and transmit the frequency detection result to the logic circuit; the logic circuit is configured to control the conduction and disconnection of the first switch according to the level detection result and the frequency detection result, so as to control the opening and closing of the first oscillator.

[0012] According to an embodiment of the present disclosure, the first oscillator and / or the second oscillator adopts a cross-coupled LC oscillator topology structure, or adopts a switch full-bridge driver topology structure.

[0013] According to an embodiment of the present disclosure, the transformer includes one primary coil or multiple primary coils arranged in series, and correspondingly, the transformer includes one secondary coil or multiple secondary coils arranged in series.

[0014] According to an embodiment of the present disclosure, the coupling coefficient of the transformer is greater than 0.75.

[0015] Another embodiment of the present disclosure provides a control method for an isolated power supply chip based on a dual-resonance topology, which controls the isolated power supply chip described in any of the above items. The control method includes: inverting a DC input voltage into a high-frequency oscillation power signal to enable the first oscillator to operate in a first oscillation state; coupling and transmitting the high-frequency oscillation power signal to the secondary coil through the primary coil of the transformer to enable the second oscillator to operate in a second oscillation state and obtain a DC output voltage; detecting the DC output voltage and regulating the second oscillation state; and detecting the first oscillation state to determine the impact of the second oscillation state on the first oscillation state, and adjusting the first oscillation state in real time to achieve stable operation of the isolated power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a system block diagram of a traditional full-bridge rectifier isolated power supply chip.

[0018] Figure 2 Schematic diagram of an isolated power supply chip based on a dual-resonance topology according to an embodiment of the present disclosure.

[0019] Figure 3 FIG2 is a schematic diagram of an isolated power supply chip based on a dual-resonance topology according to another embodiment of the present disclosure.

[0020] Figure 4 This is a schematic diagram of an isolated power supply chip based on a dual-resonance topology according to another embodiment of the present disclosure.

[0021] Figure 5 Schematic diagram of key waveforms of an isolated power supply chip based on a dual-resonance topology according to an embodiment of the present disclosure.

[0022] Figure 6 Schematic diagram of the key waveforms and working principle of the isolated power supply chip based on the dual-resonance topology according to the embodiment of the present disclosure.

[0023] Figure 7This is a flow chart of a control method for an isolated power supply chip based on a dual-resonance topology according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] This disclosure provides an isolated power supply chip based on a dual-resonance topology and its control method. By reusing a power transformer to transmit feedback signals for voltage modulation, this approach eliminates the digital isolator circuits required in traditional isolated power supply chips, reduces chip size, and lowers costs. Furthermore, by introducing a Class D LC oscillator at the receiving end, replacing the traditional rectifier, the conversion efficiency of the isolated power supply system is improved. Compared to traditional rectifiers, Class D LC oscillators achieve higher efficiency because they lack gate capacitance switching losses and have a higher gate voltage when the MOS transistor is turned on, resulting in lower conduction losses.

[0025] Isolation components in isolated power supplies include linear optocouplers, capacitors, and transformers. Linear optocouplers suffer from large size, high cost, and high losses, limiting their application in portable devices and high-speed digital isolators. Traditional capacitive isolators, limited by their dielectric breakdown voltage, struggle to achieve high isolation. Transformers, with their high noise immunity, compact size, and monolithic integration capabilities, have become the mainstream isolation component in isolated power supply ICs.

[0026] In isolated power supplies, AC-DC rectification losses limit the efficiency and cost of isolated power supplies. Losses in MOSFET-based active rectifiers can be divided into conduction losses and gate capacitance switching losses. At low switching frequencies, since MOSFETs can fully conduct at high gate-source voltages, conduction losses can be minimized within a given size. Furthermore, gate capacitance switching losses are low, enabling MOSFET active rectification to achieve higher efficiency. (See [D. Pan et al, "A2.1W 60%-Peak-Efficiency Isolated DC-DC Converter with Complementary Edge-Aligned and Adaptive Over-Compensation Techniques Meeting the CISPR-32 Class-B EMI Standard," IEEE European Solid-State Electronics Research Conference - (ESSERC), Bruges, Belgium, 2024]) However, at higher switching frequencies (generally above 25MHz), excessive gate capacitance switching losses reduce the efficiency of active rectifiers. Therefore, employing active rectification circuits increases the size of the transformer, which in turn increases chip size and cost.

[0027] When the frequency is high, the receiving module of a traditional isolated power supply uses a passive full-bridge rectifier as the AC-DC rectification scheme. Specific implementation schemes include but are not limited to diode full-bridge rectification and MOS transistor full-bridge rectification. Reference [W. Qin et al., "An 800mW Fully Integrated Galvanic Isolated Power Transfer System Meeting CISPR 22 Class-B Emission Levels with 6dB Margin," 2019 IEEE International Solid-State Circuits Conference - (ISSCC), San Francisco, CA, USA, 2019].

[0028] like Figure 1 As shown, when the traditional isolated power supply chip is working, the LC oscillator 100 is connected to the primary inductance L of the transformer 200. P The AC signal is coupled to the secondary inductor L of the transformer 200. S The sinusoidal current I with alternating direction is generated LS . When I LS When the current direction is from a to b, diodes D1 and D4 are turned on. LS When the current direction is from b to a, diodes D2 and D3 are turned on. In this process, the current flowing through capacitor C O The direction of current is always from the output voltage V ISO The output end of the current is directed to GND2, thus providing energy to the load. The two diodes in the current path have V D The voltage drop of the rectifier can be expressed as:

[0029] ;

[0030] Although compared with active rectification, diode full-bridge rectification does not have gate capacitance switching loss, the forward voltage and on-resistance of the on-chip diodes in conventional BCD processes are high, resulting in V D Larger, efficiency η RX Lower. Using a Schottky diode can use a larger area in exchange for a lower voltage drop V D However, it requires special processes and is costly. Due to the threshold voltage of MOS tubes, using diode-connected MOS tubes instead of rectifier diodes cannot significantly improve the efficiency of the passive rectifier.

[0031] On the other hand, since the transmitting end of the traditional isolated power supply chip is a DC-AC inverter circuit, such as an LC oscillator, and the receiving end is an AC-DC rectifier circuit, such as a diode full-bridge rectifier, the circuits of the transmitting and receiving ends are different and need to be designed and manufactured separately, which increases the design and development cost of the isolated power supply.

[0032] As can be seen from the above, the circuits at the transmitting and receiving ends of the traditional isolated power supply chip are different and need to be designed and manufactured separately, which increases the development cost. The traditional isolated power supply chip requires an additional digital isolator circuit to transmit the feedback signal to adjust the output power, which increases the size and cost of the isolated power supply chip. Therefore, the present disclosure proposes an isolated power supply chip based on a dual-resonance topology and a control method thereof, which introduces a Class D LC oscillator into the receiving end to replace the traditional rectifier and improve the conversion efficiency of the isolated power supply system. The transmitting and receiving circuits can be designed to be exactly the same, so the transmitting circuit and the receiving circuit can be reused, reducing the design and development cost of the isolated power supply. By reusing the power control method of the power transformer to transmit the feedback signal, the digital isolator circuit required for the traditional isolated power supply chip is saved, the chip size is reduced, and the cost is reduced.

[0033] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0034] In an embodiment of the present disclosure, an isolated power supply chip based on a dual-resonance topology is provided. Figure 2 As shown, the isolated power supply chip includes a first oscillator 100 arranged at the transmitting end, a transformer 200, a second oscillator 300 arranged at the receiving end, a control circuit, and a detection circuit; the transformer 200 includes a primary coil L connected to the first oscillator P and the secondary coil L connected to the second oscillator S ,in:

[0035] The first oscillator 100 is used to invert the DC input voltage into a high-frequency oscillation power signal, so that the first oscillator operates in a first oscillation state;

[0036] The second oscillator 300 operates in a second oscillation state after receiving the high-frequency oscillation power signal coupled and transmitted from the primary coil to the secondary coil, and obtains a DC output voltage;

[0037] The control circuit 400 is used to detect the DC output voltage and regulate the second oscillation state;

[0038] The detection circuit 500 is used to detect the first oscillation state to determine the influence of the second oscillation state on the first oscillation state, and to adjust the first oscillation state in real time to achieve stable operation of the isolated power supply.

[0039] Specifically, combined Figure 2 As shown, the first oscillator 100 is used to convert the DC input voltage V IN Inverted into a differential high-frequency oscillation power signal V PP and V PN And output to the primary coil L of the transformer 200 P Transformer 200, used as an isolation device for transmitting AC power, consists of a primary coil L P and the secondary coil L S The high frequency oscillation power signal V in the first oscillator 100 is PP and V PN The primary coil L of the transformer 200 is connected to the voltage node P TX at both ends P and TX N The high frequency oscillation power signal V of the second oscillator 300 SP and V SN The secondary winding L of the transformer 200 is connected via a voltage node S RX at both ends P and RX N . The primary coil L P The high frequency oscillation power signal V PP and V PN Coupled to the secondary coil L S , so that the high oscillation power signal V SP and V SN With V PP and V PN Oscillate together, and with V SP and V SN The high frequency oscillation power signal forms a DC common mode point at the center point of the transformer 200, from which a DC output voltage V ISO ; The receiving end control circuit 400 detects the output voltage V ISO , and controls the state of the second oscillator; when the second oscillator oscillates, it affects the oscillation state of the first oscillator. The transmitting end detection circuit 500 detects the working state of the first oscillator, thereby controlling the working state of the first oscillator to achieve voltage modulation.

[0040] According to an embodiment of the present disclosure, the first oscillator and / or the second oscillator may adopt a cross-coupled LC oscillator topology or a switch full-bridge driver topology. It should be noted that the two oscillators may also adopt other topologies such as a Class D oscillator or other types of oscillators, as long as the oscillator function can be realized.

[0041] According to an embodiment of the present disclosure, the control circuit 400 is also used to control the second oscillator 300 to be turned on or short-circuited, and the detection circuit 500 is also used to control the first oscillator 100 to be turned on or off, thereby realizing the turning on or off of the isolated power supply through the cooperation between the control circuit and the detection circuit.

[0042] For example, when switching from the on state to the off state, the control circuit short-circuits the second oscillator, and the detection circuit detects changes in the first oscillator's oscillation frequency and controls the first oscillator to shut down, effectively shutting down the isolated power supply. Specifically, after the receiving-end control circuit 400 detects the output voltage and generates a shutdown signal, it short-circuits the second oscillator 300. This short-circuit changes the oscillation frequency of the first oscillator 100. At this point, the transmitting-end detection circuit 500 detects the change in the first oscillator's oscillation frequency and controls the first oscillator 100 to shut down, effectively shutting down the entire isolated power supply system.

[0043] From the off state to the on state, the control circuit controls the second oscillator to work, and the detection circuit controls the first oscillator to start by detecting that the first oscillator is affected by the second oscillator to oscillate, thereby realizing the start of the isolated power supply. Specifically, when the receiving end control circuit 400 detects the DC output voltage and generates a start signal, the second oscillator 300 starts to oscillate, and the secondary coil L S The high frequency oscillation power signal V SP and V SN Will be coupled to the primary coil L P , so that the high oscillation power signal V PP and V PN With V SP and V SN The oscillating voltage signal is detected by the control circuit 500, which turns on the first oscillator 100 and turns on the entire isolated power supply system.

[0044] According to the embodiment of the present disclosure, Figure 2 、 Figure 3 、 Figure 4 As shown, the transformer may include one primary coil or multiple primary coils arranged in series, and correspondingly, the transformer may include one secondary coil or multiple secondary coils arranged in series.

[0045] According to the embodiment of the present disclosure, Figure 3As shown, transformer 200 includes two primary coils and two secondary coils connected in series, forming a transformer group comprising two transformers. The first oscillator 100 and the second oscillator 300 employ a cross-coupled LC oscillator topology. The second oscillator is provided with a second switch 301. The control circuit 400 includes a feedback network 401, a non-overlapping circuit 402, and a short-circuit switch 403. The feedback network 401 is configured to detect the DC output voltage and generate a control signal. The non-overlapping circuit 402 is configured to receive the control signal and control the on / off switching of the short-circuit switch 403 and the second switch 301.

[0046] Specifically, if Figure 3 As shown, the first oscillator 100 converts the DC input voltage V IN Inverted into a differential high-frequency oscillation power signal V PP and V PN And output to the primary coil L of the transformer group 200 P1 and L P2 The transformer group 200 with symmetrical primary and secondary windings is used as an isolation device for transmitting AC power. The primary and secondary windings are composed of two identical windings. The identical windings are for the convenience of analysis and are not limited to this. The coupling coefficient of the transformer is greater than 0.75. P1 and the secondary coil L S1 In this example, L P1 With L S1 The same is for the convenience of analysis, but is not limited to this. The second transformer consists of a primary coil L P2 and the secondary coil L S2 In this example, L P2 With L S2 The same is for the convenience of analysis, but is not limited to this. P1 The high frequency oscillation power signal V PP Coupled to the secondary coil L S1 , so that V SP Follow V PP Oscillation, the second transformer will convert the primary coil L P2 The high frequency oscillation power signal V PN Coupled to the secondary coil L S2 , so that V SN Follow V PN Oscillation, so that the second oscillator 300 has a high oscillation power signal V SP and V SN With V PP and V PN oscillates together, and by virtue of port V SP and V SNThe high-frequency oscillation power signal forms a DC common mode point at the center of the transformer group 200, from which a DC output voltage is output. It should be noted that the second oscillator 300 is the same as the first oscillator circuit. The second oscillator 300 is made the same as the first oscillator 100 for ease of analysis and is not limited to being the same as the transmitter circuit 100. The receiver control circuit 400 detects the output voltage V ISO , and controls the state of the second oscillator; when the second oscillator oscillates, it affects the oscillation state of the first oscillator, and the transmitting end detection circuit 500 detects the working state of the first oscillator, thereby controlling the working state of the first oscillator to achieve voltage modulation.

[0047] According to an embodiment of the present disclosure, the first oscillator 100 includes a pair of NMOS transistors, the NMOS transistors including a first NMOS transistor M and a second NMOS transistor M. N1 and the second NMOS tube M N2 The first NMOS tube M N1 The gate of the second NMOS tube M N2 The drain stage of the second NMOS tube M N2 Connected to the first NMOS tube M N1 The drain stage of the first NMOS tube M N1 and the second NMOS tube M N2 The source of the first NMOS transistor M is connected to one end of the switch, and the other end of the switch is grounded. N1 The drain of the transformer group 200 is connected to the TX port P , the second NMOS tube M N2 The drain of the transformer group 200 is connected to the TX port N .

[0048] According to an embodiment of the present disclosure, the second oscillator 300 includes a pair of NMOS transistors, the NMOS transistor group including a third NMOS transistor M N3 and the fourth NMOS tube M N4 The third NMOS tube M N3 The gate of the fourth NMOS tube M N4 The drain stage, the fourth NMOS tube M N4 The gate of the third NMOS tube M N3 The drain of the third NMOS tube M N3 and the fourth NMOS tube M N4 The source of the third NMOS transistor M is connected to one end of the switch, and the other end of the switch is grounded. N3 The drain of the transformer bank 200 is connected to the RX port. P , the fourth NMOS tube M N4 The drain of the transformer bank 200 is connected to the RX port. N .

[0049] According to the embodiment of the present disclosure, the receiving end control circuit 400 is composed of a feedback network 401, a non-overlapping circuit 402 and an oscillator short-circuit switch 403. The feedback network is used to detect the output voltage V ISO And generate a control signal and transmit the control signal to the non-overlapping circuit 402. The function of the non-overlapping circuit 402 is to control the conduction and disconnection of the second switch 301 and the short-circuit switch 403, and to prevent the second switch 301 and the short-circuit switch 403 from being turned on at the same time and causing a power short circuit.

[0050] According to an embodiment of the present disclosure, the first oscillator is provided with a first switch 101; the detection circuit 500 includes a level detection circuit 501, a frequency detection circuit 502, and a logic circuit 503, wherein: the level detection circuit 501 is used to detect the level change of the oscillation power signal of the first oscillator and transmit the level detection result to the logic circuit 503; the frequency detection circuit 502 is used to detect the oscillation frequency of the oscillation power signal of the first oscillator and transmit the frequency detection result to the logic circuit 503; the logic circuit 503 is configured to control the conduction and disconnection of the first switch 101 according to the level detection result and the frequency detection result, so as to control the opening and closing of the first oscillator 100.

[0051] According to the embodiment of the present disclosure, the level detection result is a high-level or low-level signal transmitted to the logic circuit 503; the frequency detection result is a high-level or low-level signal transmitted to the logic circuit 503. The level detection circuit 501 and the frequency detection circuit 502 can selectively detect the V PP or V PN You can choose to detect one of them or both at the same time.

[0052] According to the embodiment of the present disclosure, Figure 3 As shown, the transformer group 200 is composed of two transformers, wherein the primary coil L of the first transformer P1 The first port, TX P Connected to the first NMOS transistor M in the first oscillator 100 N1 The drain of the first transformer secondary coil L S1 The first port, RX P The third NMOS transistor M connected to the second oscillator 300 N3 The drain of the first transformer primary coil L P1 The second port is connected to the primary of the second transformer L P2 The first port is connected to the DC common mode point port TX of the transformer group primary. M , and the DC input voltage V of the isolated power chip IN The secondary winding L of the first transformer is connected. S1 The second port is connected to the second transformer secondary coil LS2 The first port is connected to the DC common mode point port RX of the secondary side of the transformer group. M , and the DC output voltage V of the isolated power chip ISO The second transformer primary coil L P2 The second port TX N The second NMOS transistor M connected to the first oscillator 100 N2 The drain of the second transformer secondary coil L S2 The second port RX N The fourth NMOS transistor M connected to the second oscillator 300 N4 The drain level.

[0053] Further, such as Figure 4 As shown, the first NMOS transistor M of the first oscillator 100 N1 The gate can be coupled to the first capacitor C C1 Connected to the second NMOS tube M N2 The drain stage of the second NMOS tube M N2 The gate can be coupled through the second coupling capacitor C C2 Connected to the first NMOS tube M N1 The drain bias voltage V BN1 The first bias resistor R B1 Connected to the first NMOS tube M N1 The gate of the B2 Connected to the second NMOS tube M N2 The first coupling capacitor C C1 and the second coupling capacitor C C2 The two coupling capacitors respectively convert the differential signal V generated by the oscillator into PP and V PN Coupled to the second NMOS tube M N2 , the first NMOS tube M N1 The gate of the MOS tube, where the coupling capacitance value is equal to the parasitic capacitance C of the gate to ground of the MOS tube GG The ratio of determines the swing of the MOS tube gate voltage signal. Bias DC voltage V BN1 Through the feedback resistor R B1 、R B2 Set the gate common mode voltage of NMOS in the oscillator to V BN1 .

[0054] According to the embodiment of the present disclosure, Figure 4 As shown, the third NMOS transistor M of the second oscillator 300 N3 The gate can be coupled through the third coupling capacitor C C3 Connected to the fourth NMOS tube M N4The drain stage, the fourth NMOS tube M N4 The gate can be coupled through the fourth coupling capacitor C C4 Connected to the third NMOS tube M N3 The drain bias voltage V BN2 The third bias resistor R B3 Connected to the third NMOS tube M N3 The gate of the B4 Connected to the fourth NMOS tube M N4 The third coupling capacitor C C3 and the fourth coupling capacitor C C4 The differential signal V generated by the oscillator is SP and V SN Coupled to the fourth NMOS tube M N4 , the third NMOS tube M N3 The gate of the MOS tube, where the coupling capacitance value is equal to the parasitic capacitance C of the gate to ground of the MOS tube GG The ratio of determines the swing of the MOS tube gate voltage signal. Bias DC voltage V BN2 Through the feedback resistor R B3 、R B4 Set the gate common mode voltage of NMOS in the oscillator to V BN2 .

[0055] According to the embodiment of the present disclosure, Figure 5 As shown in the figure, when the isolated power supply chip starts working, the working principle of the isolated power supply system is divided into two phases for description, and each phase includes 5 states:

[0056] In the first phase:

[0057] State ①: First NMOS tube M N1 And the third NMOS tube M N3 The first transformer primary L is turned on. P1 Current I LP1 is a positive value, that is, V IN Flows to GND1 and gradually increases; the secondary of the first transformer L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO And gradually becomes smaller. The second NMOS tube M N2 With the fourth NMOS tube M N4 Turn off, the second transformer primary L P2 Current I LP2 is a positive value, that is, V IN Flows to GND1 and gradually increases, V PN Less than V IN And gradually increases. The second transformer secondary L S2Current I LS2 is a positive value, that is, V ISO Flows to GND2 and gradually increases, V SN Less than V ISO And gradually increase.

[0058] State ②: First NMOS tube M N1 And the third NMOS tube M N3 The first transformer primary L is turned on. P1 Current I LP1 is a positive value, that is, V IN Flows to GND1 and gradually increases; the secondary of the first transformer L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO And gradually becomes smaller. The second NMOS tube M N2 With the fourth NMOS tube M N4 Turn off, the second transformer primary L P2 Current I LP2 is a positive value, that is, V IN flows to GND1 and gradually decreases, V PN Greater than V IN And gradually increases. The second transformer secondary L S2 Current I LS2 is a positive value, that is, V ISO Flows to GND2 and decreases first and then increases, V SN Greater than V ISO And gradually increase.

[0059] State ③: First NMOS tube M N1 And the third NMOS tube M N3 The first transformer primary L is turned on. P1 Current I LP1 is a positive value, that is, V IN Flows to GND1 and gradually increases; the secondary of the first transformer L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO And gradually becomes smaller. The second NMOS tube M N2 With the fourth NMOS tube M N4 Turn off, the second transformer primary L P2 Current I LP2 is a positive value, that is, V IN flows to GND1 and gradually decreases, V PN Greater than V IN And gradually increases. The second transformer secondary L S2 Current I LS2 is negative, that is, it flows from GND2 to V ISO And gradually increases, VSN Greater than V ISO And gradually decreases.

[0060] State ④: First NMOS tube M N1 And the third NMOS tube M N3 The first transformer primary L is turned on. P1 Current I LP1 is a positive value, that is, V IN Flows to GND1 and gradually increases; the secondary of the first transformer L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO And gradually becomes smaller. The second NMOS tube M N2 With the fourth NMOS tube M N4 Turn off, the second transformer primary L P2 Current I LP2 is negative, that is, it flows from GND1 to V IN And gradually increases, V PN Greater than V IN And gradually decreases. The second transformer secondary L S2 Current I LS2 is negative, that is, it flows from GND2 to V ISO And it increases first and then decreases, V SN Greater than V ISO And gradually decreases.

[0061] State ⑤: First NMOS tube M N1 And the third NMOS tube M N3 The first transformer primary L is turned on. P1 Current I LP1 is a positive value, that is, V IN Flows to GND1 and gradually increases; the secondary of the first transformer L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO And gradually becomes smaller. The second NMOS tube M N2 With the fourth NMOS tube M N4 Turn off, the second transformer primary L P2 Current I LP2 is negative, that is, it flows from GND1 to V IN And gradually increases, V PN Less than V IN And gradually decreases. The second transformer secondary L S2 Current I LS2 is negative, that is, it flows from GND2 to V ISO And gradually increases, V SN Less than V ISO And gradually decreases.

[0062] In the first phase, the first transformer secondary winding L S1 Current I LS1 is negative, that is, it flows from GND2 to V ISO , so it can be V ISO Transmit energy.

[0063] In the second phase, the first NMOS transistor M N1 And the third NMOS tube M N3 Turn off, the second NMOS tube M N2 and the fourth NMOS tube M N4 The working states ①-⑤ are similar to those of the first phase. In the second phase, the second transformer secondary coil L S2 Current I LS2 is negative, that is, it flows from GND2 to V ISO , so it can be V ISO Transmit energy.

[0064] The working principle of the receiving end control circuit 400 and the transmitting end detection circuit 500 is as follows: Figure 6 As shown:

[0065] The isolated power system switches from on to off: When the feedback network 401 detects the voltage and generates a shutdown signal, the non-overlapping circuit 402 receives the shutdown signal and first turns on the signal EN. RX From high to low, the second switch 301 is disconnected, and then the short-circuit switch 403 is turned on, so that the second oscillator 300 is short-circuited, which will change the oscillation frequency of the first oscillator 100. At this time, the transmitter frequency detection circuit 502 detects the change in the oscillation frequency of the first oscillator 100 and outputs the signal EN of the logic circuit 503. TX Changing from high to low, the first switch 301 of the first oscillator is disconnected, thereby shutting down the entire isolated power supply chip.

[0066] The isolated power supply system switches from off to on: When the receiving end control circuit 400 detects the voltage and generates an on signal, the non-overlapping circuit 402 first opens the short-circuit switch 403 after receiving the on signal, and then turns on the signal EN. RX From low to high, the second switch 301 is turned on, and the second oscillator 300 starts to oscillate. S The high frequency oscillation power signal V SP and V SN Coupled to the primary coil L P , so that V PP and V PN Oscillation, the oscillating voltage signal is detected by the level detection circuit 501, and the output signal EN of the logic circuit 503 is TX The signal changes from low to high, turning on the first switch 301 of the first oscillator, thereby turning on the entire isolated power supply chip.

[0067] Another embodiment of the present disclosure further provides a control method for an isolated power supply chip based on a dual-resonance topology, which controls the above-mentioned isolated power supply chip, such as Figure 7 As shown, the control method includes:

[0068] Operation S1: Inverting the DC input voltage into a high-frequency oscillation power signal to enable the first oscillator to operate in a first oscillation state;

[0069] Operation S2: coupling and transmitting the high-frequency oscillation power signal to the secondary coil through the primary coil of the transformer, so that the second oscillator operates in a second oscillation state and obtains a DC output voltage;

[0070] Operation S3: detecting the DC output voltage and regulating the second oscillation state;

[0071] Operation S4: detecting the first oscillation state to determine the influence of the second oscillation state on the first oscillation state, and adjusting the first oscillation state in real time to achieve stable operation of the isolated power supply.

[0072] The embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that any implementations not depicted or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the above definitions of the various elements and methods are not limited to the various specific structures, shapes, or methods described in the embodiments, and can be easily modified or replaced by those skilled in the art.

[0073] Based on the above description, those skilled in the art should have a clear understanding of the isolated power supply chip based on the dual-resonance topology and the control method thereof disclosed in the present invention.

[0074] In summary, the present disclosure provides an isolated power supply chip based on a dual-resonance topology and a control method thereof, which effectively improves the conversion efficiency of the isolated power supply system by introducing a more efficient Class D oscillator at the receiving end to replace the traditional low-efficiency AC-DC rectifier to receive energy. Moreover, compared with the traditional isolated power supply chip in which the transmitting and receiving circuits need to be developed separately, the transmitting and receiving circuits of the isolated power supply chip based on this architecture can be reused, reducing the design and development cost of the isolated power supply. In combination with the power control method proposed by reusing power transformers to transmit feedback signals based on the isolated power supply chip system architecture based on the dual-resonance topology, compared with the traditional isolated power supply chip, the digital isolator circuit is saved, the chip size is reduced, and the cost is reduced.

[0075] It should be noted that, herein, unless otherwise specified, “a” element is not limited to a single element, but may include one or more elements.

[0076] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" are used herein solely to distinguish multiple components with the same name and do not imply a hierarchy, level, execution order, or process sequence between them. A "first" component and a "second" component may appear together in the same component or in different components. The presence of a component with a higher ordinal number does not necessarily imply the presence of the other component with a lower ordinal number.

[0077] In this document, unless otherwise specified, the so-called feature A "or" or "and / or" feature B means that A exists alone, B exists alone, or A and B exist at the same time; the so-called feature A "and" or "and" or "and" feature B means that A and B exist at the same time; the so-called "include", "comprise", "have" and "contain" mean including but not limited to these.

[0078] Furthermore, in this document, terms such as "upper," "lower," "left," "right," "front," "back," or "between" are used solely to describe the relative positions of multiple elements and can be interpreted to include translation, rotation, or mirroring. Furthermore, in this document, unless otherwise specified, "an element is on another element" or similar descriptions do not necessarily mean that the element contacts the other element.

[0079] Furthermore, unless specifically described or required to occur sequentially, the order of the steps is not limited to the order listed above and may be varied or rearranged based on desired design requirements. Furthermore, the above embodiments may be mixed and matched with each other or with other embodiments based on design and reliability considerations. That is, the technical features of different embodiments may be freely combined to form more embodiments.

[0080] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. An isolated power supply chip based on a dual-resonance topology, comprising a first oscillator, a transformer, a second oscillator, a control circuit, and a detection circuit; the transformer comprises a primary coil connected to the first oscillator and a secondary coil connected to the second oscillator, wherein: The first oscillator is used to invert the DC input voltage into a high-frequency oscillation power signal, so that the first oscillator operates in a first oscillation state; The second oscillator operates in a second oscillation state after receiving the high-frequency oscillation power signal coupled and transmitted from the primary coil to the secondary coil, and obtains a DC output voltage; The control circuit is used to detect the DC output voltage and regulate the second oscillation state; The detection circuit is used to detect the first oscillation state to determine the influence of the second oscillation state on the first oscillation state, and to adjust the first oscillation state in real time to achieve stable operation of the isolated power supply.

2. According to the isolated power supply chip based on dual resonance topology according to claim 1, the control circuit is also used to control the second oscillator to be turned on or short-circuited, and the detection circuit is also used to control the first oscillator to be turned on or off, thereby realizing the turning on or off of the isolated power supply through the cooperation between the control circuit and the detection circuit.

3. According to the isolated power supply chip based on the dual-resonance topology of claim 2, from the on state to the off state, the control circuit controls the second oscillator to short-circuit, and the detection circuit controls the first oscillator to shut down by detecting the change in the oscillation frequency of the first oscillator, thereby realizing the shutdown of the isolated power supply.

4. According to the isolated power supply chip based on the dual-resonance topology of claim 2, from the off state to the on state, the control circuit controls the second oscillator to operate, and the detection circuit controls the first oscillator to start by detecting that the first oscillator is affected by the second oscillator to generate oscillation, thereby realizing the start-up of the isolated power supply.

5. The isolated power supply chip based on dual-resonance topology according to any one of claims 1 to 4, wherein the second oscillator is provided with a second switch; the control circuit includes a feedback network, a non-overlapping circuit, and a short-circuit switch, wherein: a feedback network configured to detect a DC output voltage and generate a control signal; The non-overlapping circuit receives the control signal and controls the on and off of the short-circuit switch and the second switch.

6. The isolated power supply chip based on dual-resonance topology according to any one of claims 1 to 4, wherein the first oscillator is provided with a first switch; the detection circuit includes a level detection circuit, a frequency detection circuit, and a logic circuit, wherein: The level detection circuit is used to detect the level change of the oscillation power signal of the first oscillator and transmit the level detection result to the logic circuit; The frequency detection circuit is used to detect the oscillation frequency of the oscillation power signal of the first oscillator and transmit the frequency detection result to the logic circuit; The logic circuit is configured to control the on and off of the first switch according to the level detection result and the frequency detection result, so as to control the on and off of the first oscillator.

7. The isolated power supply chip based on dual-resonance topology according to any one of claims 1 to 4, wherein the first oscillator and / or the second oscillator adopts a cross-coupled LC oscillator topology structure or a switch full-bridge driver topology structure.

8. According to the isolated power supply chip based on dual resonance topology according to any one of claims 1 to 4, the transformer includes a primary coil or multiple primary coils arranged in series, and correspondingly, the transformer includes a secondary coil or multiple secondary coils arranged in series.

9. The isolated power supply chip based on dual resonance topology according to any one of claims 1 to 4, wherein the coupling coefficient of the transformer is greater than 0.

75.

10. A control method for an isolated power supply chip based on a dual-resonance topology, for controlling the isolated power supply chip according to any one of claims 1 to 9, the control method comprising: Inverting the DC input voltage into a high-frequency oscillation power signal to enable the first oscillator to operate in a first oscillation state; The high-frequency oscillation power signal is coupled and transmitted to the secondary coil through the primary coil of the transformer, so that the second oscillator operates in a second oscillation state and obtains a DC output voltage; detecting the DC output voltage and regulating the second oscillation state; as well as The first oscillation state is detected to determine the influence of the second oscillation state on the first oscillation state, and the first oscillation state is adjusted in real time to achieve stable operation of the isolated power supply.

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