Five-port isolated error amplifier and its transmitting end circuit and isolated power supply

Abstract

This disclosure provides a five-port isolation error amplifier and its transmitting circuit and isolation power supply, including a detection circuit, a bias current generation circuit, an oscillation circuit, a feedback coupling capacitor, a feedback rectifier circuit, a feedback filter circuit, and a feedback adjustment circuit. The detection circuit detects the input voltage and outputs a detection current. The bias current generation circuit generates a bias current positively correlated with the detection current. The oscillation circuit generates a target oscillation signal with an amplitude positively correlated with the bias current. The feedback coupling capacitor couples and transmits the target oscillation signal. The feedback rectifier circuit rectifies the oscillation-coupled feedback signal to obtain a feedback rectified output voltage. The feedback filter circuit filters out the ripple in the feedback rectified output voltage to obtain a first DC voltage. The feedback adjustment circuit converts the first DC voltage into a feedback current positively correlated with it to shunt the detection current. It can replace the optocoupler in the isolation feedback scenario 1:1 and can also improve the accuracy of signal isolation transmission.

Description

Technical Field

[0001] Embodiments of this disclosure relate to the field of integrated circuit technology, and more particularly to a five-port isolation error amplifier and its transmitting circuit and isolation power supply. Background Technology

[0002] Isolators are widely used in medical, automotive electronics and aerospace fields because they can eliminate noise and protect devices from high voltage damage. Among them, optocouplers have always been the mainstream choice for isolators due to their low price, small size, light weight and simple circuit.

[0003] In isolated power supplies, especially in scenarios requiring stable output voltage and isolated feedback, traditional solutions use optocouplers for isolation feedback. However, optocouplers suffer from problems such as low transmission rate, low transmission signal bandwidth, easy aging, and short lifespan, making them unsuitable for the ever-increasing integration requirements of current electronic systems. Therefore, there is an urgent need to propose a solution that can replace optocouplers for isolation feedback to transmit analog signals. Summary of the Invention

[0004] This disclosure provides a five-port isolation error amplifier, its transmitting circuit, and an isolation power supply, which can replace the optocoupler in an isolation feedback scenario 1:1, thereby avoiding a series of problems caused by the optocoupler and improving the accuracy of signal isolation transmission.

[0005] In a first aspect, this disclosure provides a transmitting circuit for a five-port isolation error amplifier, including a detection circuit, a bias current generating circuit, an oscillation circuit, a feedback coupling capacitor, a feedback rectifier circuit, a feedback filter circuit, and a feedback adjustment circuit. The input terminal of the transmitting circuit is connected to the input terminal of the detection circuit, the output terminal of the detection circuit is connected to the input terminal of the oscillation circuit through the bias current generating circuit, and the output terminal of the oscillation circuit is connected to the output terminal of the detection circuit in sequence through the feedback coupling capacitor, the feedback rectifier circuit, the feedback filter circuit, and the feedback adjustment circuit.

[0006] The detection circuit is used to detect the input voltage and output a detection current. The bias current generation circuit is used to generate a bias current positively correlated with the detection current based on the detection current and provide it to the oscillation circuit. The oscillation circuit is used to generate a target oscillation signal with an amplitude positively correlated with the bias current. The feedback coupling capacitor is used to couple and transmit the target oscillation signal.

[0007] The feedback rectifier circuit is used to receive the oscillating coupled feedback signal output by the feedback coupling capacitor and rectify the oscillating coupled feedback signal to obtain a feedback rectified output voltage. The feedback filter circuit is used to filter out the ripple in the feedback rectified output voltage to obtain a first DC voltage. The feedback adjustment circuit is used to convert the first DC voltage into a feedback current positively correlated with the first DC voltage, so as to shunt the detection current through the first reference ground.

[0008] In some embodiments of this disclosure, the detection circuit includes a voltage-to-current conversion circuit and a first current mirror. The input terminal of the first current mirror is connected to the first input terminal of the transmitting circuit. The first input terminal of the voltage-to-current conversion circuit is connected to the second input terminal of the transmitting circuit. The second input terminal of the voltage-to-current conversion circuit is connected to a reference voltage. The first output terminal of the first current mirror is connected to the first reference ground through the voltage-to-current conversion circuit. The second output terminal of the first current mirror is connected to the input terminal of the bias current generation circuit and the input terminal of the feedback adjustment circuit.

[0009] The voltage-to-current conversion circuit is used to determine the error amplification voltage between the input voltage and the reference voltage, and to convert the error amplification voltage into an error amplification current, wherein the error amplification current is derived from the input current. The first current mirror is used to mirror the error amplification current into the detection current.

[0010] In some embodiments of this disclosure, the feedback adjustment circuit includes an adjustment transistor, the source of which is connected to the first reference ground, the drain of which is connected to the output of the detection circuit, and the gate of which is connected to the output of the feedback filter circuit.

[0011] In some embodiments of this disclosure, the feedback adjustment circuit further includes a second current mirror, the input terminal of which is connected to the output terminal of the detection circuit, the first output terminal of which is connected to the first reference ground through the adjustment tube, and at least one second output terminal of which is connected to the first reference ground.

[0012] The second current mirror is used to mirror the feedback current as at least one branch current to shunt the detection current through the first reference ground.

[0013] In some embodiments of this disclosure, the oscillation circuit includes a first oscillator, a charge pump circuit, and a second oscillator. The input terminal of the first oscillator is connected to the output terminal of the bias current generating circuit. The output terminal of the first oscillator is connected to the input terminal of the second oscillator through the charge pump circuit. The output terminal of the second oscillator is connected to the input terminal of the feedback rectifier circuit through the feedback coupling capacitor.

[0014] The first oscillator is used to convert the bias current into an initial oscillation signal whose amplitude is positively correlated with the bias current. The charge pump circuit is used to rectify and boost the initial oscillation signal to obtain a second DC voltage. The second oscillator is used to convert the second DC voltage into the target oscillation signal, wherein the amplitude of the target oscillation signal is greater than the amplitude of the initial oscillation signal.

[0015] In some embodiments of this disclosure, the oscillation circuit is an LC oscillator, and the feedback rectifier circuit is a rectifier-boost circuit. The rectifier-boost circuit is used to rectify and boost the oscillation-coupled feedback signal to obtain the feedback rectified output voltage.

[0016] In a second aspect, this disclosure provides a five-port isolation error amplifier, including a first input port, a second input port, a first ground port, a second ground port, an output port, a coupling transmission circuit, a receiving circuit, and any of the transmitting circuits provided in the first aspect.

[0017] The first input port is connected to the first input terminal of the transmitting circuit, the second input port is connected to the second input terminal of the transmitting circuit, the first ground port is connected to the first reference ground, the transmitting circuit is connected to the input terminal of the receiving circuit through the coupling transmission circuit, the output terminal of the receiving circuit is connected to the output port, and the second ground port is connected to the second reference ground.

[0018] The coupling transmission circuit is used to couple and transmit the target oscillation signal. The receiving circuit is used to receive the oscillation coupling transmission signal output by the coupling transmission circuit and convert the oscillation coupling transmission signal into an output current that is positively correlated with the detection current.

[0019] In some embodiments of this disclosure, the receiving end circuit includes a transmission rectifier circuit, a transmission filter circuit, and an open-drain (OD) gate. The input terminal of the transmission rectifier circuit is connected to the output terminal of the coupled transmission circuit. The output terminal of the transmission rectifier circuit is connected to the gate of the OD gate through the transmission filter circuit. The source of the OD gate is connected to the second reference ground, and the drain of the OD gate is connected to the output port.

[0020] The transmission rectifier circuit is used to receive the oscillating coupled transmission signal and rectify it to obtain a transmission rectified output voltage. The transmission filter circuit is used to filter out ripple in the transmission rectified output voltage to obtain a third DC voltage, which is equal to the first DC voltage. The OD gate is used to convert the third DC voltage into an output current that is positively correlated with the third DC voltage, and the output current is linearly positively correlated with the detection current.

[0021] In some embodiments of this disclosure, the transmission rectifier circuit and the feedback rectifier circuit are the same, the transmission filter circuit and the feedback filter circuit are the same, the regulating transistor in the OD gate and the feedback regulating circuit is the same type of metal oxide field-effect transistor (MOS), and the OD gate and the regulating transistor operate in the saturation region.

[0022] In some embodiments of this disclosure, the five-port isolation error amplifier further includes a first bare chip and a second bare chip, the first bare chip including the transmitting circuit, the second bare chip including the receiving circuit, and the coupling transmission circuit disposed on the first bare chip and / or the second bare chip.

[0023] Thirdly, this disclosure provides an isolated power supply, including any of the transmitting circuits provided in the first aspect, or any of the five-port isolation error amplifiers provided in the second aspect.

[0024] The technical solution disclosed herein provides a transmitting circuit for a five-port isolation error amplifier, including a detection circuit, a bias current generation circuit, an oscillation circuit, a feedback coupling capacitor, a feedback rectifier circuit, a feedback filter circuit, and a feedback adjustment circuit. The detection circuit detects the input voltage and outputs a detection current. The bias current generation circuit generates a bias current positively correlated with the detection current. The oscillation circuit generates a target oscillation signal with an amplitude positively correlated with the bias current. The feedback coupling capacitor couples and transmits the target oscillation signal. The feedback rectifier circuit receives the oscillation coupling feedback signal output by the feedback coupling capacitor and rectifies the oscillation coupling feedback signal to obtain a feedback rectified output voltage. The feedback filter circuit filters out the ripple in the feedback rectified output voltage to obtain a first DC voltage. The feedback adjustment circuit converts the first DC voltage into a feedback current positively correlated with the first DC voltage to shunt the detection current through a first reference ground. In this way, the power supply output voltage of the isolated power supply can be detected by the detection circuit, and a detection current positively correlated with the power supply output voltage can be obtained. The detection current is shunted by the feedback path composed of the feedback coupling capacitor, feedback rectifier circuit, feedback filter circuit and feedback adjustment circuit, so that the output current of the five-port isolation error amplifier is linearly positively correlated with the detection current. Since the detection current is linearly positively correlated with the input current of the five-port isolation error amplifier, the output current of the five-port isolation error amplifier is linearly positively correlated with the input current. It can replace the optocoupler in the isolation feedback scenario 1:1, thereby avoiding a series of problems caused by the optocoupler, and also improving the accuracy of signal isolation transmission. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. It should be understood that the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure, wherein: Figure 1 This is a schematic diagram of an isolated power supply and its feedback control loop provided in an embodiment of the present disclosure.

[0026] Figure 2 This is a schematic diagram of the structure of a five-port isolation error amplifier provided in an embodiment of the present disclosure.

[0027] Figure 3 This is a schematic diagram of a transmitting circuit provided in an embodiment of the present disclosure.

[0028] Figure 4 This is a circuit diagram of a transmitting end circuit provided in an embodiment of the present disclosure.

[0029] Figure 5 This is a circuit diagram of another transmitting circuit provided in an embodiment of the present disclosure.

[0030] Figure 6 A schematic diagram of the voltage and current waveforms of a key node in a five-port isolation error amplifier provided in this embodiment of the present disclosure.

[0031] Figure 7 This is a schematic diagram of another five-port isolation error amplifier provided in an embodiment of the present disclosure.

[0032] Figure 8 This is a schematic diagram illustrating the relationship between input voltage and input current, provided as an embodiment of this disclosure.

[0033] Figure 9 This is a schematic diagram of another five-port isolation error amplifier provided in an embodiment of the present disclosure.

[0034] Figure 10 This is a schematic diagram of another five-port isolation error amplifier provided in an embodiment of the present disclosure.

[0035] Figure 11 A schematic diagram of the voltage and current waveforms of a key node in another five-port isolation error amplifier provided in an embodiment of this disclosure. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are also within the scope of protection of this disclosure.

[0037] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, the statement “connecting” two or more parts together shall mean that the parts are joined directly together or joined through one or more intermediate components.

[0038] In this disclosure, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this disclosure can be combined with other embodiments.

[0039] Furthermore, the terms "first," "second," etc., in the specification, claims, or the accompanying drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0040] In this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three possibilities: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of this disclosure, unless otherwise stated, "multiple" and "at least two" mean two or more (including two), and similarly, "multiple groups" and "at least two groups" mean two or more (including two groups).

[0042] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0043] Figure 1 This is a schematic diagram of the structure of an isolated power supply and its feedback control loop provided in an embodiment of this disclosure, as shown below. Figure 1 As shown, the isolated power supply includes a power transformer for transmitting power signals, a switching transistor SW connected to the primary coil of the power transformer, and a rectifier diode D and an output capacitor C connected to the secondary coil of the power transformer. The first end of the primary coil is connected to the power input terminal to receive the power input voltage Vin, and the second end of the primary coil is connected to the switching transistor SW. The first end of the secondary coil is connected to the power output terminal through the rectifier diode D to output the power output voltage Vout. The second end of the secondary coil is connected to the first reference ground GND1, and the output capacitor C is connected between the power output terminal and the first reference ground GND1.

[0044] For example, such as Figure 1 As shown, the feedback control loop of the isolated power supply includes a feedback network and a five-port isolation error amplifier 100. The feedback network includes a first resistor R1, a second resistor R2, and a third resistor R3. The first resistor R1 and the second resistor R2 are connected in series between the power supply output terminal and the first reference ground GND1. The first end of the third resistor R3 is connected to the power supply output terminal, and the second end of the third resistor R3 is the first feedback output terminal of the isolated power supply. The connection point of the first resistor R1 and the second resistor R2 is the second feedback output terminal of the isolated power supply. The current output by the first feedback output terminal is Iin, and the voltage output by the second feedback output terminal is Vfb, and the voltage Vfb is linearly positively correlated with the power supply output voltage Vout.

[0045] The feedback control loop also includes a pulse width modulation (PWM) comparator CMP and a fourth resistor R4. The non-inverting input of the PWM comparator CMP is connected to the first terminal of the fourth resistor R4, the second terminal of the fourth resistor R4 is connected to the fixed voltage VC, the inverting input of the PWM comparator CMP is connected to the ramp voltage Vramp, and the output of the PWM comparator CMP is connected to the control terminal of the switching transistor SW.

[0046] Figure 2 This is a schematic diagram of the structure of a five-port isolation error amplifier provided in an embodiment of the present disclosure, as shown below. Figure 2 As shown, the five-port isolation error amplifier 100 includes a first input port Pin1, a second input port Pin2, a first ground port Pin3, an output port Pin4, a second ground port Pin5, a transmitting circuit 200, a coupling transmission circuit 300, and a receiving circuit 400.

[0047] Specifically, the first input port Pin1 is connected to the first feedback output terminal of the isolated power supply and the first input terminal of the transmitting circuit 200; the second input port Pin2 is connected to the second feedback output terminal of the isolated power supply and the second input terminal of the transmitting circuit 200; the first ground port Pin3 is connected to the first reference ground GND1; the transmitting circuit 200 is connected to the input terminal of the receiving circuit 400 through the coupling transmission circuit 300; the output terminal of the receiving circuit 400 is connected to the output port Pin4; and the second ground port Pin5 is connected to the second reference ground GND2.

[0048] The transmitting circuit 200 receives the current Iin output from the first feedback output terminal and the voltage Vfb output from the second feedback output terminal. Using Vfb as the input voltage and Iin as the input current, it detects the input voltage Vfb to obtain the detection current Idet. Based on the detection current Idet, it determines the target oscillation signal VT and shunts the detection current Idet based on the target oscillation signal VT. The detection current Idet is linearly positively correlated with the input current Iin and positively correlated with the input voltage Vfb.

[0049] The coupling transmission circuit 300 is used to couple and transmit the target oscillation signal VT. The receiving circuit 400 is used to receive the oscillation coupling transmission signal VR output by the coupling transmission circuit 300 and convert the oscillation coupling transmission signal VR into an output current Iout that is positively correlated with the detection current Idet.

[0050] For example, Figure 3 This is a schematic diagram of the structure of a transmitting circuit provided in an embodiment of the present disclosure, such as... Figure 3As shown, the transmitting circuit 200 includes a detection circuit 210, a bias current generating circuit 220, an oscillation circuit 230, a feedback coupling capacitor 240, a feedback rectifier circuit 250, a feedback filter circuit 260, and a feedback adjustment circuit 270.

[0051] The input terminal of the transmitting circuit 200 is connected to the input terminal of the detection circuit 210. The output terminal of the detection circuit 210 is connected to the input terminal of the oscillation circuit 230 through the bias current generating circuit 220. The output terminal of the oscillation circuit 230 is connected to the output terminal of the detection circuit 210 in sequence through the feedback coupling capacitor 240, the feedback rectifier circuit 250, the feedback filter circuit 260 and the feedback adjustment circuit 270.

[0052] The detection circuit 210 is used to detect the input voltage Vfb and output a detection current Idet that is positively correlated with the input voltage Vfb.

[0053] The bias current generating circuit 220 is used to generate a bias current Ibias that is positively correlated with the detection current Idet based on the detection current Idet, and to provide it to the oscillation circuit 230.

[0054] The oscillation circuit 230 is used to generate target oscillation signals VT (positive phase target oscillation signal VTP and negative phase target oscillation signal VTN) whose amplitude is positively correlated with the bias current Ibias.

[0055] Feedback coupling capacitor 240 is used to couple and transmit the target oscillation signal VT (positive phase target oscillation signal VTP and negative phase target oscillation signal VTN).

[0056] The feedback rectifier circuit 250 is used to receive the oscillation coupling feedback signal VFB (positive oscillation coupling feedback signal VFBP and negative oscillation coupling feedback signal VFBN) output by the feedback coupling capacitor 240, and to rectify the oscillation coupling feedback signal VFB (positive oscillation coupling feedback signal VFBP and negative oscillation coupling feedback signal VFBN) to obtain the feedback rectified output voltage VFB_DC.

[0057] The feedback filter circuit 260 is used to filter out the ripple in the feedback rectified output voltage VFB_DC to obtain the first DC voltage VDC1.

[0058] The feedback adjustment circuit 270 is used to convert the first DC voltage VDC1 into a feedback current Ifb that is positively correlated with the first DC voltage VDC1, so as to shunt the detection current Idet through the first reference ground GND1.

[0059] For example, Figure 4 This is a circuit diagram of a transmitting end circuit provided in an embodiment of the present disclosure, such as... Figure 4As shown, the detection circuit 210 includes a voltage-to-current conversion circuit 211 and a first current mirror 212. The input terminal of the first current mirror 212 is connected to the first input terminal of the transmitting circuit 200. The first input terminal of the voltage-to-current conversion circuit 211 is connected to the second input terminal of the transmitting circuit 200. The second input terminal of the voltage-to-current conversion circuit 211 is connected to the reference voltage Vref. The first output terminal of the first current mirror 212 is connected to the first reference ground GND1 through the voltage-to-current conversion circuit 211. The second output terminal of the first current mirror 212 is connected to the input terminal of the bias current generation circuit 220 and the input terminal of the feedback adjustment circuit 270.

[0060] The voltage-to-current conversion circuit 211 includes an error amplifier EA and a first transistor M1. The first input terminal of the error amplifier EA is connected to the input voltage Vfb, the second input terminal of the error amplifier EA is connected to the reference voltage Vref, the output terminal of the error amplifier EA is connected to the control terminal of the first transistor M1, the input terminal of the first transistor M1 is connected to the first output terminal of the first current mirror 212, and the output terminal of the first transistor M1 is connected to the first reference ground GND1. The first transistor M1 is an N-type metal-oxide-semiconductor field-effect transistor (NMOS).

[0061] For example, the reference voltage Vref can be generated by a reference module in the voltage-to-current conversion circuit 211. The first terminal of the reference module is connected to the first reference ground, and the second terminal of the reference module is connected to the second input terminal of the error amplifier EA to provide the reference voltage Vref.

[0062] Error amplifier EA amplifies the voltage difference Vfb-Vref between the input voltage Vfb and the reference voltage Vref to obtain the error amplification voltage Vea. That is, the error amplification voltage Vea is positively correlated with the input voltage Vfb. The first transistor M1 can convert the error amplification voltage Vea into a voltage-to-current converter to obtain the error amplification current Iea. The error amplification current Iea is positively correlated with the error amplification voltage Vea, that is, the error amplification current Iea is positively correlated with the input voltage Vfb.

[0063] Thus, the voltage-to-current conversion circuit 210 can determine the error amplification voltage Vea of ​​the input voltage Vfb and the reference voltage Vref, and convert the error amplification voltage Vea into the error amplification current Iea, which comes from the input current Iin.

[0064] The first current mirror 212 includes a second transistor M2 and a third transistor M3, both of which are PMOS transistors. The source of the second transistor M2 and the source of the third transistor M3 are connected to the first input terminal of the transmitting circuit 200. The gate of the second transistor M2 is connected to the drain of the second transistor M2, the input terminal of the first transistor M1, and the gate of the third transistor M3. The drain of the third transistor M3 is connected to the output terminal of the detection circuit 210.

[0065] The third transistor M3 can mirror the current flowing through the second transistor M2. The current flowing through the second transistor M2 is the error amplification current Iea. Therefore, the third transistor M3 can mirror the error amplification current Iea into a detection current Idet. This means the detection current Idet is linearly and positively correlated with the error amplification current Iea, and thus, the detection current Idet is positively correlated with the input voltage Vfb. The sum of the detection current Idet and the error amplification current Iea is the input current Iin. Therefore, the detection current Idet is linearly and positively correlated with the input current Iin, and the input current Iin is positively correlated with the input voltage Vfb.

[0066] Thus, the first current mirror 212 can mirror the error amplification current Iea into the detection current Idet.

[0067] See also Figure 4 The bias current generating circuit 220 includes a fourth transistor M4 connected in diode configuration, a fifth transistor M5 connected in diode configuration, and a sixth transistor M6 connected in diode configuration. The fourth transistor M4 and the fifth transistor M5 are connected in series between the output terminal of the detection circuit 210 and the first reference ground GND1. The fourth transistor M4 and the sixth transistor M6 constitute a current mirror.

[0068] For example, the fourth transistor M4 and the sixth transistor M6 are PMOS, the fifth transistor M5 is NMOS, the source of the fourth transistor M4 and the source of the sixth transistor M6 are connected to the output of the detection circuit 210, the gate of the fourth transistor M4 is connected to the drain of the fourth transistor M4, the gate of the sixth transistor M6, the drain of the fifth transistor M5 and the gate of the fifth transistor M5, the source of the fifth transistor M5 is connected to the first reference ground GND1, and the drain of the sixth transistor M6 is connected to the input of the oscillation circuit 230.

[0069] When there is a deviation between the input voltage Vfb and the reference voltage Vref, a current positively correlated with the detection current Idet is generated, which is the branch current of the branch where the fourth transistor M4 is located. The sixth transistor M6 mirrors the branch current of the branch where the fourth transistor M4 is located as the bias current Ibias. That is, the bias current Ibias is positively correlated with the detection current Idet. Therefore, the bias current Ibias is positively correlated with the input current Iin (input voltage Vfb), and the bias current Ibias is provided to the oscillation circuit 230.

[0070] The oscillator circuit 230 can be Figure 4 The LC oscillator shown can be any of the following: a ring oscillator or other types of oscillators. Figure 5 The diagram shows an oscillator with a boost function, comprising a low-voltage oscillator, a low-voltage charge pump, and a high-voltage oscillator. Figure 5 This is a circuit diagram of another transmitting circuit provided in an embodiment of the present disclosure. The present disclosure does not specifically limit the types of low-voltage and high-voltage oscillators; LC oscillators or ring oscillators, etc., can be used. The present disclosure also does not specifically limit the type of low-voltage charge pump; a Dickson charge pump, etc., can be used.

[0071] After oscillation starts, the oscillation circuit 230 can output a positive-phase target oscillation signal VTP and an anti-phase target oscillation signal VTN, the oscillation amplitude of which is positively correlated with the bias current Ibias. Figure 6 As shown, Figure 6 A schematic diagram of the voltage and current waveforms of a key node in a five-port isolation error amplifier provided in this embodiment of the present disclosure.

[0072] See also Figure 4 and Figure 5 The feedback coupling capacitor 240 includes a first coupling capacitor and a second coupling capacitor. The first end of the first coupling capacitor is connected to the non-inverting output terminal of the oscillation circuit 230, the first end of the second coupling capacitor is connected to the inverting output terminal of the oscillation circuit 230, the second end of the first coupling capacitor is connected to the first input terminal of the feedback rectifier circuit 250, and the second end of the second coupling capacitor is connected to the second input terminal of the feedback rectifier circuit 250.

[0073] Feedback coupling capacitor 240 is used to couple the positive-phase target oscillation signal VTP to the feedback rectifier circuit 250 and filter out the DC signal in the positive-phase target oscillation signal VTP to obtain the AC form of the positive-phase oscillation coupling feedback signal VFBP. It also couples the negative-phase target oscillation signal VTN to the feedback rectifier circuit 250 and filters out the DC signal in the negative-phase target oscillation signal VTN to obtain the AC form of the negative-phase oscillation coupling feedback signal VFBN. Finally, it outputs the positive-phase oscillation coupling feedback signal VFBP and the negative-phase oscillation coupling feedback signal VFBN to the feedback rectifier circuit 250.

[0074] The feedback rectifier circuit 250 can be Figure 5 The full-bridge rectifier circuit shown can be any of the charge pump circuits and other types of rectifier circuits; alternatively, it can be a rectifier-boost circuit with a boost function, for example, the rectifier-boost circuit can be adopted... Figure 4 The charge pump circuit shown can be implemented using a Dixon charge pump. The feedback rectifier circuit 250 can rectify the positive-phase oscillation coupled feedback signal VFBP and the negative-phase oscillation coupled feedback signal VFBN into a feedback rectified output voltage VFB_DC, which is then provided to the feedback filter circuit 260.

[0075] The feedback filter circuit 260 can be an RC filter or other types of low-pass filter, for example, Figure 4 and Figure 5 As shown, the feedback filter circuit 260 includes a first capacitor C1 and a fifth resistor R5. The first end of the fifth resistor R5 is connected to the output terminal of the feedback rectifier circuit 250, and the second end of the fifth resistor R5 is connected to the first plate of the capacitor C1 and the output terminal of the feedback filter circuit 260. The second plate of the capacitor C1 is connected to the first reference ground GND1.

[0076] The feedback filter circuit 260 performs a low-pass filter on the feedback rectified output voltage VFB_DC to remove the ripple in VFB_DC, resulting in a smoother first DC voltage VDC1. Figure 6 As shown, the first DC voltage VDC1 is provided to the feedback adjustment circuit 270.

[0077] See also Figure 4 and Figure 5 The feedback adjustment circuit 270 includes an adjustment transistor M0, for example, an NMOS transistor M0. The source of the adjustment transistor M0 is connected to the first reference ground GND1, the drain of the adjustment transistor M0 is connected to the output of the detection circuit 210, and the gate of the adjustment transistor M0 is connected to the output of the feedback filter circuit 260 to receive the first DC voltage VDC1.

[0078] The regulating transistor M0 converts the first DC voltage VDC1 into a feedback current Ifb. This feedback current Ifb flows through the regulating transistor M0 and then to the first reference ground GND1. Therefore, the regulating transistor M0 can shunt the detection current Idet output by the detection circuit 210, thereby reducing the sum of the currents flowing into the bias current generation circuit 220 and the oscillation circuit 230. Since the sum of the currents flowing into the bias current generation circuit 220 and the oscillation circuit 230 is much smaller than the feedback current Ifb, most of the current in the detection current Idet flows into the feedback regulating circuit 270, making the detection current Idet approximately equal to the feedback current Ifb flowing into the feedback regulating circuit 270.

[0079] The coupling transmission circuit 300 can be a transformer or a coupling capacitor. The coupling transmission circuit 300 and the feedback coupling capacitor 240 perform the same function, namely, coupling and transmitting the positive-phase target oscillation signal VTP and the negative-phase target oscillation signal VTN. The difference is that the coupling transmission circuit 300 needs to ensure the isolation withstand voltage required by the overall circuit, while the feedback coupling capacitor 240 does not need to have an isolation withstand voltage.

[0080] The coupling transmission circuit 300 can couple the positive-phase target oscillation signal VTP to obtain the positive-phase oscillation coupled transmission signal VRP, such as... Figure 6 As shown, the inverted target oscillation signal VTN is coupled to obtain the inverted oscillation coupled transmission signal VRN, and the oscillation coupled transmission signal VR (the positive oscillation coupled transmission signal VRP and the inverted oscillation coupled transmission signal VRN) is provided to the receiving circuit 400.

[0081] For example, Figure 7 A schematic diagram of another five-port isolation error amplifier provided in this disclosure embodiment is shown below. Figure 7 As shown, the receiver circuit 400 includes a transmission rectifier circuit 410, a transmission filter circuit 420, and an open-drain (OD) gate 430.

[0082] The input terminal of the transmission rectifier circuit 410 is connected to the output terminal of the coupling transmission circuit 300. The output terminal of the transmission rectifier circuit 410 is connected to the gate of the OD gate 430 through the transmission filter circuit 420. The source of the OD gate 430 is connected to the second reference ground GND2, and the drain of the OD gate 430 is connected to the output port Pin4.

[0083] The transmission rectifier circuit 410 is used to receive the oscillating coupled transmission signal VR (positive oscillating coupled transmission signal VRP and negative oscillating coupled transmission signal VRN), and rectify the oscillating coupled transmission signal VR (positive oscillating coupled transmission signal VRP and negative oscillating coupled transmission signal VRN) to obtain the transmission rectified output voltage VR_DC.

[0084] The transmission filter circuit 420 is used to filter out the ripple in the transmission rectified output voltage VR_DC to obtain the third DC voltage VDC3, which is equal to the first DC voltage VDC1.

[0085] The OD gate 430 is used to convert the third DC voltage VDC3 into an output current Iout that is positively correlated with the third DC voltage VDC3. The output current Iout is linearly positively correlated with the detection current Idet.

[0086] The transmission rectifier circuit 410 and the feedback rectifier circuit 250 are the same; that is, if the feedback rectifier circuit 250 is... Figure 5The full-bridge rectifier circuit shown is a transmission rectifier circuit 410; if the feedback rectifier circuit 250 is a charge pump circuit, then the transmission rectifier circuit 410 is a charge pump circuit; if the feedback rectifier circuit 250 is a charge pump circuit, then the transmission rectifier circuit 410 is a charge pump circuit. Figure 4 The rectifier-boost circuit shown has a boost function, and the transmission rectifier circuit 410 is a rectifier-boost circuit with a boost function.

[0087] The transmission rectifier circuit 410 can rectify the positive-phase oscillating coupled transmission signal VRP and the negative-phase oscillating coupled transmission signal VRN into a transmission rectified output voltage VR_DC, and provide it to the transmission filter circuit 420.

[0088] The transmission filter circuit 420 is the same as the feedback filter circuit 260; that is, the transmission filter circuit 420 is an RC filter or other type of low-pass filter. It can perform low-pass filtering on the transmission rectified output voltage VR_DC to filter out the ripple in the transmission rectified output voltage VR_DC, resulting in a smoother third DC voltage VDC3. Figure 6 As shown.

[0089] Thus, by using the detection circuit 210, bias current generation circuit 220, oscillation circuit 230, feedback coupling capacitor 240, coupling transmission circuit 300, the same feedback rectifier circuit 250 and transmission rectifier circuit 410, as well as the same feedback filter circuit 260 and transmission filter circuit 420, equal first DC voltage VDC1 and third DC voltage VDC3 can be obtained.

[0090] The OD gate 430 and the regulating transistor M0 are of the same type of MOS, for example, both OD gate 430 and the regulating transistor M0 are high-voltage NMOS. The gate voltage of OD gate 430 is the third DC voltage VDC3, and the gate voltage of regulating transistor M0 is the first DC voltage VDC1. Therefore, the gate voltages of OD gate 430 and regulating transistor M0 are equal. Furthermore, the source voltages of both OD gate 430 and regulating transistor M0 are at ground potential. Therefore, the gate-source voltages of OD gate 430 and regulating transistor M0 are equal. Since OD gate 430 and regulating transistor M0 operate in the saturation region, they are mirror images of each other.

[0091] Therefore, the drain current of OD gate 430 is a mirror image of the drain current of regulating transistor M0, and the output current Iout is a mirror image of the feedback current Ifb. That is, the output current Iout and the feedback current Ifb are linearly positively correlated. As can be seen from the above embodiment analysis, the detection current Idet is approximately equal to the feedback current Ifb, so the output current Iout is linearly positively correlated with the detection current Idet, and the detection current Idet is linearly positively correlated with the input current Iin. Figure 6As shown, this ensures a high current transfer ratio (CTR) characteristic, thereby guaranteeing the accuracy of signal isolation transmission in isolated feedback scenarios.

[0092] Furthermore, the values ​​of the output current Iout and the feedback current Ifb depend on the width-to-length ratio of the OD gate 430 and the width-to-length ratio of the regulating transistor M0, as well as the number of OD gates 430 and the number of regulating transistors M0. Therefore, by adjusting the ratio of the width-to-length ratio of the OD gate 430 to the width-to-length ratio of the regulating transistor M0 and / or the ratio of the number of OD gates 430 to the number of regulating transistors M0, the linear proportional relationship between the output current Iout and the feedback current Ifb can be adjusted to obtain different CTRs.

[0093] Figure 8 A schematic diagram illustrating the relationship between input voltage and input current provided in an embodiment of this disclosure is shown below. Figure 8 As shown, under the same input current Iin, for an isolation error amplifier without a feedback path (feedback coupling capacitor 240, feedback rectifier circuit 250, feedback filter circuit 260 and feedback adjustment circuit 270), the input voltage Vfb varies significantly, which will affect the operation of the transmitting circuit 100 and result in poor linearity.

[0094] For the five-port isolation error amplifier 100 with a feedback path, most of the detected current Idet flows into the feedback adjustment circuit 270 in the feedback path and is discharged to ground through the feedback adjustment circuit 270. When the input current Iin is large, the detected current Idet is large, and the feedback adjustment circuit 270 discharges a large current to ground. The sum of the currents flowing into the bias current generation circuit 220 and the oscillation circuit 230 increases less, causing the generated voltage, i.e., the power supply voltage of the oscillation circuit 230, to increase slowly. When the input current Iin is small, the detected current Idet is small, and the feedback adjustment circuit 270 discharges a small current to ground.

[0095] Therefore, the feedback path ensures that the output of the five-port isolation error amplifier 100 can maintain good linearity within a large input current Iin range. Even in high current scenarios, it can still ensure that the power supply voltage amplitude of the oscillation circuit 230 will not change too much due to excessive input current Iin, thus avoiding the problem of reduced circuit linearity caused by excessive changes in the circuit operating point, and ensuring the accuracy of signal isolation transmission.

[0096] The feedback control loop works as follows: When the power supply output voltage Vout increases, the input voltage Vfb increases, the input current Iin increases, the output current Iout increases accordingly, and the voltage at the output port Pin4 decreases. The PWM comparator CMP compares the ramp voltage Vramp with the voltage at the output port Pin4. The duty cycle of the PWM signal output by the PWM comparator CMP decreases, and the on-time of the drive switch SW decreases accordingly, thereby causing the power supply output voltage Vout to drop.

[0097] Conversely, when the power supply output voltage Vout decreases, the input voltage Vfb decreases, the input current Iin decreases, the output current Iout decreases accordingly, the voltage at the output port Pin4 increases, the duty cycle of the PWM signal increases, and the conduction time of the driving switch SW increases accordingly, thereby causing the power supply output voltage Vout to rise. Therefore, through the above negative feedback control, the power supply output voltage Vout of the isolated power supply can be stabilized.

[0098] In summary, the transmitting circuit provided in this disclosure includes a feedback path consisting of a feedback coupling capacitor, a feedback rectifier circuit, a feedback filter circuit, and a feedback adjustment circuit, as well as a detection circuit. The detection circuit detects the power supply output voltage of the isolation power supply to obtain a detection current positively correlated with the power supply output voltage. The detection current is shunted through the feedback path, so that the output current of the five-port isolation error amplifier is linearly positively correlated with the detection current. Since the detection current is linearly positively correlated with the input current of the five-port isolation error amplifier, the output current of the five-port isolation error amplifier is linearly positively correlated with the input current. This allows for a 1:1 replacement of the optocoupler in the isolation feedback scenario, thereby avoiding a series of problems caused by the optocoupler and improving the accuracy of signal isolation transmission.

[0099] In some embodiments, such as Figure 4 and Figure 5 As shown, the feedback adjustment circuit 270 also includes a second current mirror. The input terminal of the second current mirror is connected to the output terminal of the detection circuit 210. The first output terminal of the second current mirror is connected to the first reference ground GND1 through the adjustment tube M0. At least one second output terminal of the second current mirror is connected to the first reference ground GND1.

[0100] The second current mirror is used to mirror the feedback current Ifb into at least one branch current so as to shunt the detection current Idet through the first reference ground GND1.

[0101] For example, such as Figure 4 and Figure 5As shown, the second current mirror includes a seventh transistor M7, an eighth transistor M8, and a ninth transistor M9. The seventh transistor M7 and the eighth transistor M8 are PMOS transistors, and the ninth transistor M9 is an NMOS transistor. The source of the seventh transistor M7 and the source of the eighth transistor M8 are connected to the output of the detection circuit 210. The gate of the seventh transistor M7 is connected to the drain of the seventh transistor M7, the gate of the eighth transistor M8, and the drain of the regulating transistor M0. The drain of the eighth transistor M8 is connected to the drain of the ninth transistor M9 and the gate of the ninth transistor M9. The source of the ninth transistor M9 is connected to the first reference ground GND1.

[0102] The current in the branch containing the regulating transistor M0 and the seventh transistor M7 is the feedback current Ifb. The eighth transistor M8 can mirror the feedback current Ifb into the branch current. This branch current is discharged to the first reference ground GND1 through the ninth transistor M9 to shunt the detection current Idet. This can further reduce the sum of the currents flowing into the bias current generation circuit 220 and the oscillation circuit 230, while increasing the current discharge path to ground and reducing the current capability and size requirements of the regulating transistor M0.

[0103] It should be noted that, Figure 4 and Figure 5 This example only illustrates the second current mirror including one branch and the main path where the regulating transistor M0 is located. In practical applications, the second current mirror can also include multiple branches, mirroring the feedback current Ifb into multiple branch currents. The second current mirror shunts the detection current Idet through multiple branches to further reduce the sum of the currents flowing into the bias current generation circuit 220 and the oscillation circuit 230, while increasing the current discharge path to ground and reducing the current capability and size requirements of the regulating transistor M0.

[0104] In some embodiments, Figure 9 A schematic diagram of another five-port isolation error amplifier provided in this disclosure embodiment is shown below. Figure 9 As shown, the oscillation circuit 230 is an LC oscillator, the feedback rectifier circuit 250 is a first rectifier boost circuit, and the transmission rectifier circuit 410 is a second rectifier boost circuit.

[0105] The first rectifier boost circuit is used to rectify and boost the oscillation coupling feedback signal VFB (positive oscillation coupling feedback signal VFBP and negative oscillation coupling feedback signal VFBN) to obtain the feedback rectified output voltage VFB_DC.

[0106] For example, such as Figure 9 As shown, the coupling transmission circuit 300 is implemented using an on-chip transformer, and the oscillation circuit 230 is a low-voltage oscillator that does not have a boost function. For example, the oscillation circuit 230 can be implemented using... Figure 4This can be implemented using any one of the following: a complementary cross-coupled oscillator with a tail current source, an NMOS cross-coupled oscillator with a tail current source, and a PMOS cross-coupled oscillator with a tail current source. An on-chip transformer is used to implement the coupling transmission circuit 300, which has the advantage of strong signal coupling capability.

[0107] The feedback rectifier circuit 250 adopts, for example Figure 4 The first rectifier-boost circuit is implemented using a rectifier-boost circuit with boost function, as shown. Since the transmission rectifier circuit 410 is the same as the feedback rectifier circuit 250, the transmission rectifier circuit 410 is also implemented using a rectifier-boost circuit with boost function, which is the second rectifier-boost circuit. For example, the first and second rectifier-boost circuits can be implemented using a charge pump rectifier-boost circuit.

[0108] The feedback rectifier circuit 250 can rectify and boost the oscillation coupling feedback signal VFB (positive oscillation coupling feedback signal VFBP and negative oscillation coupling feedback signal VFBN) to obtain the feedback rectified output voltage VFB_DC, thereby improving the amplitude and driving capability of the gate voltage signal of the regulating transistor M0, and can better drive the regulating transistor M0.

[0109] The transmission rectifier circuit 410 can rectify and boost the oscillating coupled transmission signal VR (positive oscillating coupled transmission signal VRP and negative oscillating coupled transmission signal VRN) to obtain the transmission rectified output voltage VR_DC, thereby improving the amplitude and driving capability of the gate voltage signal of the OD gate 430 and enabling better driving of the OD gate 430.

[0110] In some embodiments, Figure 10 A schematic diagram of another five-port isolation error amplifier provided in this disclosure embodiment is shown below. Figure 10 As shown, the oscillation circuit 230 includes a first oscillator 231, a charge pump circuit 232, and a second oscillator 233. The input terminal of the first oscillator 231 is connected to the output terminal of the bias current generating circuit 220, the output terminal of the first oscillator 231 is connected to the input terminal of the second oscillator 233 through the charge pump circuit 232, and the output terminal of the second oscillator 233 is connected to the input terminal of the feedback rectifier circuit 250 through the feedback coupling capacitor 240.

[0111] The first oscillator 231 is used to convert the bias current Ibias into an initial oscillation signal VO (positive phase initial oscillation signal VOP and negative phase initial oscillation signal VON) whose amplitude is positively correlated with the bias current Ibias.

[0112] The charge pump circuit 232 is used to rectify and boost the initial oscillation signal VO (positive initial oscillation signal VOP and negative initial oscillation signal VON) to obtain the second DC voltage VDC2.

[0113] The second oscillator 233 is used to convert the second DC voltage VDC2 into a target oscillation signal VT (positive target oscillation signal VTP and negative target oscillation signal VTN), wherein the amplitude of the target oscillation signal VT is greater than the amplitude of the initial oscillation signal VO.

[0114] For example, such as Figure 10 As shown, the coupling transmission circuit 300 is implemented using on-chip coupling capacitors. The coupling transmission circuit 300 includes a third coupling capacitor and a fourth coupling capacitor. The first end of the third coupling capacitor is connected to the non-inverting output terminal of the oscillation circuit 230, the first end of the fourth coupling capacitor is connected to the inverting output terminal of the oscillation circuit 230, the second end of the third coupling capacitor is connected to the first input terminal of the transmission rectifier circuit 410, and the second end of the fourth coupling capacitor is connected to the second input terminal of the transmission rectifier circuit 410.

[0115] The capacitance values ​​of the third and fourth coupling capacitors may be equal to or different from those of the first and second coupling capacitors; this disclosure does not impose specific limitations on this. Since capacitors have a small area, using on-chip coupling capacitors to implement the coupling transmission circuit 300 can reduce the area of ​​the five-port isolation error amplifier 100.

[0116] The oscillation circuit 230 is implemented using a boost oscillator, including a low-voltage oscillator (first oscillator 231), a low-voltage charge pump circuit (charge pump circuit 232), and a high-voltage oscillator (second oscillator 233). This disclosure does not specifically limit the types of the first oscillator 231 and the second oscillator 233; for example, an LC oscillator or a ring oscillator can be used. The charge pump circuit 232 can be... Figure 5 The Dickson charge pump shown is used to achieve this.

[0117] The first oscillator 231 can generate an initial oscillation signal VO (positive-phase initial oscillation signal VOP and negative-phase initial oscillation signal VON) whose amplitude is positively correlated with the bias current Ibias, such as Figure 11 As shown, Figure 11 The voltage and current waveform diagram of a key node of another five-port isolation error amplifier provided in this embodiment of the present disclosure is shown. The initial oscillation signal VO (positive initial oscillation signal VOP and negative initial oscillation signal VON) can be used as the clock signal of the charge pump circuit 232.

[0118] After rectification and boosting, the charge pump circuit 232 outputs a second DC voltage VDC2 that is positively correlated with the amplitude of the clock signal and has a higher amplitude, such as... Figure 11As shown, the second DC voltage VDC2 provides power supply voltage for the second oscillator 233. The second oscillator 233 outputs a target oscillation signal VT (positive phase target oscillation signal VTP and negative phase target oscillation signal VTN) with an amplitude that is positively correlated with the second DC voltage VDC2 and has a higher amplitude, so as to improve the amplitude and driving capability of the target oscillation signal VT and better drive the OD gate 430 and the regulating tube M0.

[0119] The feedback rectifier circuit 250 and the transmission rectifier circuit 410 do not need to boost the voltage; they only need to perform the rectification function. For example, the feedback rectifier circuit 250 and the transmission rectifier circuit 410 can be full-bridge rectifier circuits, such as... Figure 10 As shown, the feedback rectifier circuit 250 is the first full-bridge rectifier circuit, and the transmission rectifier circuit 410 is the second full-bridge rectifier circuit.

[0120] In some embodiments, such as Figure 9 and Figure 10 As shown, the five-port isolation error amplifier 100 includes a first bare chip 110 and a second bare chip 120. The first bare chip 110 includes a transmitting circuit 200, and the second bare chip 120 includes a receiving circuit 400. A coupling transmission circuit 300 is disposed on the second bare chip 120.

[0121] For example, the first bare chip 110 and the second bare chip 120 are packaged in the same housing by bonding wire or other connection methods. The pins of the first bare chip 110 are the first input port Pin1, the second input port Pin2 and the first ground port Pin3, and the pins of the second bare chip 120 are the output port Pin4 and the second ground port Pin5.

[0122] In some other embodiments, the coupling transmission circuit 300 is disposed on the first bare chip 110, or on the first bare chip 110 and the second bare chip 120, and this disclosure does not impose any specific limitations on this.

[0123] Unless otherwise expressly indicated by the context, the singular form of words used herein and in the appended claims includes the plural form, and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Similarly, the terms “comprising” and “including” are to be interpreted as including rather than exclusively. Likewise, the terms “including” and “or” should be interpreted as including unless such interpretation is expressly prohibited herein. Where the term “example” is used herein, the “example” is merely exemplary and illustrative, and should not be considered exclusive or extensive.

[0124] Several embodiments of this disclosure have been described in detail above. However, it is obvious that those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of this disclosure. The scope of protection of this disclosure is defined by the appended claims.

Claims

1. A transmitting circuit for a five-port isolation error amplifier, characterized in that, It includes a detection circuit, a bias current generation circuit, an oscillation circuit, a feedback coupling capacitor, a feedback rectifier circuit, a feedback filter circuit, and a feedback adjustment circuit; The input terminal of the transmitting circuit is connected to the input terminal of the detection circuit, the output terminal of the detection circuit is connected to the input terminal of the oscillation circuit through the bias current generating circuit, and the output terminal of the oscillation circuit is connected to the output terminal of the detection circuit in sequence through the feedback coupling capacitor, the feedback rectifier circuit, the feedback filter circuit and the feedback adjustment circuit. The detection circuit is used to detect the input voltage and output the detection current. The bias current generating circuit is used to generate a bias current positively correlated with the detected current based on the detected current, and provide it to the oscillation circuit; The oscillation circuit is used to generate a target oscillation signal whose amplitude is positively correlated with the bias current; The feedback coupling capacitor is used to couple and transmit the target oscillation signal; The feedback rectifier circuit is used to receive the oscillating coupling feedback signal output by the feedback coupling capacitor, and to rectify the oscillating coupling feedback signal to obtain the feedback rectified output voltage. The feedback filter circuit is used to filter out the ripple in the feedback rectified output voltage to obtain the first DC voltage; The feedback adjustment circuit is used to convert the first DC voltage into a feedback current that is positively correlated with the first DC voltage, so as to shunt the detection current through the first reference ground.

2. The transmitting circuit according to claim 1, characterized in that, The detection circuit includes a voltage-to-current conversion circuit and a first current mirror; The input terminal of the first current mirror is connected to the first input terminal of the transmitting circuit, the first input terminal of the voltage-to-current conversion circuit is connected to the second input terminal of the transmitting circuit, the second input terminal of the voltage-to-current conversion circuit is connected to the reference voltage, the first output terminal of the first current mirror is connected to the first reference ground through the voltage-to-current conversion circuit, and the second output terminal of the first current mirror is connected to the input terminal of the bias current generation circuit and the input terminal of the feedback adjustment circuit. The voltage-to-current conversion circuit is used to determine the error amplification voltage between the input voltage and the reference voltage, and to convert the error amplification voltage into an error amplification current, wherein the error amplification current is derived from the input current; The first current mirror is used to mirror the error amplification current into the detection current.

3. The transmitting circuit according to claim 1, characterized in that, The feedback adjustment circuit includes an adjustment transistor; The source of the adjustment transistor is connected to the first reference ground, the drain of the adjustment transistor is connected to the output terminal of the detection circuit, and the gate of the adjustment transistor is connected to the output terminal of the feedback filter circuit.

4. The transmitting circuit according to claim 3, characterized in that, The feedback adjustment circuit also includes a second current mirror; The input terminal of the second current mirror is connected to the output terminal of the detection circuit, the first output terminal of the second current mirror is connected to the first reference ground through the adjustment tube, and at least one second output terminal of the second current mirror is connected to the first reference ground. The second current mirror is used to mirror the feedback current as at least one branch current to shunt the detection current through the first reference ground.

5. The transmitting circuit according to claim 1, characterized in that, The oscillation circuit includes a first oscillator, a charge pump circuit, and a second oscillator; The input terminal of the first oscillator is connected to the output terminal of the bias current generating circuit, the output terminal of the first oscillator is connected to the input terminal of the second oscillator through the charge pump circuit, and the output terminal of the second oscillator is connected to the input terminal of the feedback rectifier circuit through the feedback coupling capacitor. The first oscillator is used to convert the bias current into an initial oscillation signal whose amplitude is positively correlated with the bias current; The charge pump circuit is used to rectify and boost the initial oscillation signal to obtain a second DC voltage. The second oscillator is used to convert the second DC voltage into the target oscillation signal, wherein the amplitude of the target oscillation signal is greater than the amplitude of the initial oscillation signal.

6. The transmitting circuit according to claim 1, characterized in that, The oscillation circuit is an LC oscillator, and the feedback rectifier circuit is a rectifier boost circuit; The rectifier-boost circuit is used to rectify and boost the oscillating coupled feedback signal to obtain the feedback rectified output voltage.

7. A five-port isolation error amplifier, characterized in that, It includes a first input port, a second input port, a first ground port, a second ground port, an output port, a coupling transmission circuit, a receiving end circuit, and a transmitting end circuit as described in any one of claims 1-6; The first input port is connected to the first input terminal of the transmitting circuit, the second input port is connected to the second input terminal of the transmitting circuit, the first ground port is connected to the first reference ground, the transmitting circuit is connected to the input terminal of the receiving circuit through the coupling transmission circuit, the output terminal of the receiving circuit is connected to the output port, and the second ground port is connected to the second reference ground. The coupling transmission circuit is used to couple and transmit the target oscillation signal; The receiving circuit is used to receive the oscillating coupled transmission signal output by the coupled transmission circuit and convert the oscillating coupled transmission signal into an output current that is positively correlated with the detection current.

8. The five-port isolation error amplifier according to claim 7, characterized in that, The receiving end circuit includes a transmission rectifier circuit, a transmission filter circuit, and an open-drain (OD) gate; The input terminal of the transmission rectifier circuit is connected to the output terminal of the coupling transmission circuit, the output terminal of the transmission rectifier circuit is connected to the gate of the OD gate through the transmission filter circuit, the source of the OD gate is connected to the second reference ground, and the drain of the OD gate is connected to the output port. The transmission rectifier circuit is used to receive the oscillating coupled transmission signal and rectify the oscillating coupled transmission signal to obtain the transmission rectified output voltage. The transmission filter circuit is used to filter out the ripple in the transmission rectified output voltage to obtain a third DC voltage, which is equal to the first DC voltage. The OD gate is used to convert the third DC voltage into an output current that is positively correlated with the third DC voltage, and the output current is linearly positively correlated with the detection current.

9. The five-port isolation error amplifier according to claim 8, characterized in that, The transmission rectifier circuit and the feedback rectifier circuit are the same, the transmission filter circuit and the feedback filter circuit are the same, the regulating transistors in the OD gate and the feedback regulating circuit are the same type of metal oxide field-effect transistor (MOS), and the OD gate and the regulating transistor operate in the saturation region.

10. An isolated power supply, characterized in that, Includes the transmitting circuit as described in any one of claims 1-6, or the five-port isolation error amplifier as described in claim 7.

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