Circuit adaptive zero voltage switching control method based on switch tube electroluminescence, electroluminescence detection circuit and module structure thereof

Abstract

The present invention discloses a circuit adaptive zero-voltage switching control method based on electroluminescence of a switching tube, an electroluminescence detection circuit and its module structure. The adaptive zero-voltage switching control method uses the electroluminescence effect to detect the switching state and autonomously control the gate switch of the device. The method effectively realizes adaptive zero-voltage switching operation under both steady-state and transient load conditions. The detection circuit uses two signal receiving and amplifying components in a differential mode to improve the signal-to-noise ratio of the electroluminescence detection circuit with ultra-high amplification gain. The first silicon photomultiplier tube of the first signal receiving and amplifying component is placed close to the bare chip of the switching tube to be detected in the embedded printed circuit board power module, and is used to sense the electroluminescence of the bare chip of the switching tube; the second silicon photomultiplier tube of the second signal receiving and amplifying component is located outside the electroluminescence transmission area to eliminate potential noise caused by ambient light and electromagnetic interference.

Description

Technical Field

[0001] The present invention relates to a circuit adaptive zero-voltage switching control method based on switch tube electroluminescence, an electroluminescence detection circuit and a module structure thereof. Background Art

[0002] Zero voltage switching (ZVS) is an effective method for eliminating significant switching losses in converters, especially when operating at high switching frequencies. Traditional critical conduction mode (CRM) and the emerging triangular current conduction mode (TCM) or quadrangular current conduction mode (QCM) can achieve ZVS at the expense of increased current ripple. Ideally, ZVS would switch semiconductor devices at the instant of zero voltage. However, achieving such precise control is nearly impossible, so excessive ripple current is often unavoidable in practical applications, resulting in increased conduction losses.

[0003] The zero voltage switching operation of the silicon carbide (SiC) half-bridge leg using triangle wave conduction mode TCM is shown in Figure 2. Figure 1 (a) A practical way to ensure that the upper switch Q1 achieves zero voltage switching (ZVS) is to over-design the reverse load current. i L , so that it can completely discharge the output capacitance (Coss) of the upper switch Q1 during the transient ②. However, excessive reverse current will cause large current ripple and Current RMS , which leads to a significant increase in conduction losses. This also results in increased conduction losses in the body diode during the longer on-time, i.e., during ③. Theoretically, optimal zero-voltage switching can only be achieved by triggering the high-side switch Q1 within the optimal interval between when the output capacitor is fully discharged (i.e., the drain-source voltage Vds drops to zero) and when the output capacitor is reversely charged to the conduction voltage of its body diode (i.e., the body diode begins to conduct additional reverse current), as shown in the final stage of transient ②.

[0004] However, achieving optimal zero-voltage switching (ZVS) under conditions where the load current is constantly changing is almost impossible because accurately detecting the switching state and correctly calculating the required reverse current remains very difficult. Previous work has used zero-current detection (ZCD) to measure the zero current point and then calculate the delay to determine the zero-voltage moment. However, using electrical signals to implement zero-current detection (ZCD), such as using current sensors, saturated inductors, and drain-source voltage measurements, introduces additional losses and response delays, and these measurements are easily corrupted by electromagnetic noise due to their close proximity to high dv / dt and di / dt noise sources. In addition, due to the nonlinear characteristics of the output capacitor Coss and the dynamically changing system operating conditions, the analysis and programming of the control algorithm used to determine the optimal zero-voltage switching time can be very complex and computationally intensive. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an accurate, stable and universal circuit adaptive zero voltage switching control method.

[0006] To solve the above technical problems, the present invention adopts the following technical solution: a circuit adaptive zero-voltage switching control method, which uses a light sensor to detect whether a switch in the circuit has electroluminescence. If the light sensor does not detect electroluminescence photons from the parasitic body diode or anti-parallel freewheeling diode of the switch to be controlled during the current switching cycle of the circuit, the switching frequency fsw of the circuit is reduced by a variable Δfsw in the next switching cycle to increase the amplitude of the reverse inductor current. At the same time, the circuit continuously detects whether electroluminescence is present. If electroluminescence is still not detected, the switching frequency is continuously reduced by a variable Δfsw in each subsequent switching cycle, and electroluminescence is continuously detected until the light sensor detects electroluminescence, indicating that the circuit has reached a stable operating state.

[0007] If, during the current switching cycle of the circuit, the set photosensor detects electroluminescent photons from the parasitic body diode or anti-parallel freewheeling diode of the switch tube to be controlled, the switching frequency fsw will be increased by a variable Δfsw in the next switching cycle and the detection of electroluminescence will continue. If electroluminescence is still detected, the switching frequency will continue to increase by the variable Δfsw in each subsequent switching cycle and the detection of electroluminescence will continue until the set photosensor detects no electroluminescence, which means that the operating state has reached a stable state.

[0008] After reaching a stable operating state, the circuit switching frequency maintains a reciprocating increase and decrease variable Δfsw in consecutive switching cycles, that is, electroluminescence is generated at intervals in consecutive switching cycles, thereby achieving an adaptive zero-voltage switching operating state.

[0009] The variable Δfsw is an arbitrary value not greater than the difference between the switching frequency fsw ii and the switching frequency fsw iii. The switching frequency fsw ii is the switching frequency at which the circuit discharges the output capacitance of the switch to be controlled to zero within the dead time, marking the beginning of the optimal zero-voltage switching interval. The switching frequency fsw iii is the switching frequency at which the circuit reversely charges the voltage across the switch to be controlled to the forward voltage of the body diode or anti-parallel diode within the dead time, marking the end of the optimal zero-voltage switching interval.

[0010] The beneficial effects of this program are:

[0011] Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) inherently possess a parasitic body diode in the PN junction between the source and drain. When the depletion layer capacitance is reversely charged to the parasitic body diode's turn-on voltage, the diode emits photons in forward-biased conduction, a phenomenon known as electroluminescence (EL). This EL precisely marks the end of the optimal zero-voltage switching (ZVS) interval and provides an opportunity to detect the ZVS state. This control method utilizes the EL effect to trigger the power semiconductor switch's own gate switching signal, thereby achieving adaptive ZVS operation. This circuit's adaptive ZVS control method enables the device to alternate between switching states at any load current without requiring any electrical parameter measurements or knowledge of the switch's precise parasitic parameters.

[0012] Since Δfsw is set to the difference between the switching frequencies in states ii and iii, the converter is ensured to return directly to the optimal zero-voltage switching region in the next switching cycle, which provides a positive response to changing operating conditions.

[0013] Another technical problem to be solved by the present invention is to provide a detection circuit for detecting the electroluminescence of the above-mentioned circuit switch tube.

[0014] In order to solve the above technical problems, the technical solution adopted by the present invention is: it includes a first signal receiving and amplifying component and a second signal receiving and amplifying component arranged in parallel, both groups of signal receiving and amplifying components are connected to a differential amplifier, the output end of the differential amplifier is connected to a comparator, the output end of the comparator is connected to a digital signal processor, the first signal receiving and amplifying component includes a first silicon photomultiplier tube and a first transimpedance amplifier, the second signal receiving and amplifying component includes a second silicon photomultiplier tube and a second transimpedance amplifier, wherein the first signal receiving and amplifying component is close to the bare chip of the switch tube to be detected in the embedded printed circuit board power module, and is used to sense electroluminescence, and the second signal receiving and amplifying component is located outside the electroluminescence transmission area to eliminate potential noise caused by ambient light and electromagnetic interference EMI.

[0015] As a preferred solution, the comparator needs to set a threshold voltage and a hysteresis trigger level. The threshold voltage should be higher than the sum of noise caused by all sources on the electroluminescent sensor signal; the hysteresis trigger level of the comparator is greater than the amplitude of any fluctuation on the electroluminescent sensor signal during circuit operation, and the value of the threshold voltage plus the hysteresis trigger level is lower than the electroluminescent sensor signal value triggered when the switch tube in the circuit is electroluminescent.

[0016] As a preferred solution, the gain of the transimpedance amplifier is 5×10 4 ; The gain of the differential amplifier is 4.4.

[0017] As a preferred solution, the transimpedance amplifier and the differential amplifier are both TI OPA818 with a high bandwidth of 2.7 GHz.

[0018] The beneficial effects of this program are:

[0019] This solution utilizes two signal receiving and amplifying components in differential mode to improve the signal-to-noise ratio (SNR) of an ultra-high-gain EL detection circuit. The first silicon photomultiplier (SPM) in the first SPM is placed close to the switch die to be detected, embedded in a printed circuit board power module, to sense the EL (electroluminescence) emitted by the switch die. The second SPM is located outside the EL transmission area to eliminate potential noise caused by ambient light and electromagnetic interference (EMI). Each SPM is connected to a transimpedance amplifier (TIA), forming the first and second SPMs, respectively. These components convert the current excitation from the SPMs into voltage signals. A differential amplifier (diff-amp) then eliminates background noise and further increases signal strength.

[0020] Through two amplification stages, the electroluminescence of the switch die under test is converted into an analog signal Vsense in the range of several volts. A comparator digitizes the analog signal Vsense and outputs a digital signal Vst. The digital signal Vst has two levels, "high" or "low," indicating whether the converter is operating in state iv or state iii, respectively. Using digital signal Vst, the digital signal processor adjusts the switching frequency for the next switching cycle according to an algorithm.

[0021] Silicon photomultipliers have an inherent noise source: dark counts caused by their self-activation mechanism, which generates dark current noise. Increasing the bias voltage can improve the sensitivity of detecting photons, but it also increases the intensity of dark current noise.

[0022] The comparator has a 25 mV hysteresis trigger function to eliminate false triggering, making the overall trigger scheme robust and fast response.

[0023] To achieve fast response, the transimpedance amplifier and differential amplifier in the circuit are both TI OPA818 with a high bandwidth of 2.7 GHz.

[0024] Another technical problem to be solved by the present invention is to provide an embedded printed circuit board power module structure for detecting the electroluminescence of the switch tube of the controlled circuit in conjunction with the circuit adaptive zero voltage switching control method.

[0025] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0026] An embedded printed circuit board power module structure for detecting the electroluminescence of a switch tube in a controlled circuit in conjunction with a circuit adaptive zero-voltage switching control method includes a top printed circuit board and a bottom printed circuit board. The bare die of the switch tube to be detected in the circuit to be controlled using the adaptive zero-voltage switching method is arranged between the top printed circuit board and the bottom printed circuit board. Notches are respectively provided on the top printed circuit board and the bottom printed circuit board at positions close to the bare die of the switch tube to be detected. The printed circuit board for the electroluminescence detection circuit is inserted into the notches so that a first silicon photomultiplier tube in a first signal receiving and amplifying component faces the bare die of the switch tube to be detected.

[0027] As a preferred solution, the switching tube bare chip and the first silicon photomultiplier tube in the electroluminescent detection circuit are both encapsulated in the same power module; if the switching tube bare chip is a vertical device, the first silicon photomultiplier tube is placed vertically on a certain side of the switching tube bare chip; if the switching tube bare chip is a planar device, the first silicon photomultiplier tube is placed parallel to above the switching tube bare chip.

[0028] The beneficial effects of this solution are: the embedded printed circuit board power module structure can quickly install and position the sensor printed circuit board of the electroluminescence detection circuit, and the bare chip of the switch tube to be detected that requires the adaptive zero voltage switching (ZVS) control circuit is arranged between the top printed circuit board and the bottom printed circuit board, so that the electroluminescence emitted by the bare chip of the switch tube to be detected can be collected more accurately, thereby ensuring the reliable operation of the adaptive zero voltage switching (ZVS) control circuit.

[0029] By packaging the bare chip of the switch tube and the first silicon photomultiplier tube in the electroluminescent detection circuit in the same power module, the luminous state of the power semiconductor can be further accurately detected, thereby more precisely controlling the reverse valley current required for soft switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1. (a) Typical TCM zero-voltage switching (ZVS) switching transient waveforms for a half-bridge, and (b) four transients during reverse inductor current.

[0031] Figure 2. Flowchart of the circuit adaptive zero-voltage switching control method.

[0032] Figure 3. Typical triangle-wave conduction mode (TCM) switching states of a buck converter.

[0033] Figure 4. Schematic diagram of electroluminescence detection circuit.

[0034] Figure 5. Cross-sectional view of the signal acquisition circuit inserted into the slot of the embedded printed circuit board power module.

[0035] Figure 6. Waveform of the adaptive zero voltage switching (ZVS) result in steady state.

[0036] Figure 7. Waveform during a load step from 10% to 50%.

[0037] Figure 8. Waveform during a load step from 50% to 10%.

[0038] In the figure: 1 differential amplifier, 2 comparator, 3 digital signal processor, 4 first silicon photomultiplier tube, 5 first transimpedance amplifier, 6 second silicon photomultiplier tube, 7 second transimpedance amplifier, 8 bare chip of switch tube to be detected;

[0039] 9 top printed circuit board, 10 bottom printed circuit board, 11 notch, 12 sensor printed circuit board. DETAILED DESCRIPTION

[0040] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] Figures 2 and 3 illustrate a circuit-adaptive zero-voltage switching control method. A light sensor is provided to detect whether a switch in the circuit emits electroluminescence. If, during the current switching cycle of the circuit, the light sensor does not detect electroluminescence photons from the parasitic body diode of the switch to be controlled, the switching frequency fsw of the circuit is reduced by a variable Δfsw in the next switching cycle to increase the amplitude of the reverse inductor current. At the same time, the circuit continuously detects electroluminescence. If electroluminescence is still not detected, the switching frequency is continuously reduced by a variable Δfsw in each subsequent switching cycle, and electroluminescence is continuously detected until the light sensor detects electroluminescence, indicating that the circuit has reached a stable operating state.

[0042] If, during the current switching cycle of the circuit, the set photosensor detects electroluminescence photons from the parasitic body diode of the switch to be controlled, the switching frequency fsw will be increased by a variable Δfsw in the next switching cycle and the detection of electroluminescence will continue. If electroluminescence is still detected, the switching frequency will continue to increase by the variable Δfsw in each subsequent switching cycle and the detection of electroluminescence will continue until the set photosensor detects no electroluminescence, which means that the circuit has reached a stable operating state.

[0043] After reaching a stable operating state, the circuit switching frequency maintains a reciprocating increase and decrease variable Δfsw in consecutive switching cycles, that is, electroluminescence is generated at intervals in consecutive switching cycles, thereby achieving an adaptive zero-voltage switching operating state.

[0044] The variable Δfsw is an arbitrary value not greater than the difference between the switching frequency fsw ii and the switching frequency fsw iii. The switching frequency fsw ii is the switching frequency at which the circuit discharges the output capacitance of the switch to be controlled to zero within the dead time, marking the beginning of the optimal zero-voltage switching interval. The switching frequency fsw iii is the switching frequency at which the circuit reversely charges the voltage across the switch to be controlled to the forward voltage of the body diode or anti-parallel diode within the dead time, marking the end of the optimal zero-voltage switching interval.

[0045] This adaptive zero-voltage switching (ZVS) control algorithm can be extended to other circuits, such as boost, totem-pole PFC, interleaved parallel converters, etc. In addition, by adopting different optical sensors with different detection wavelength ranges, this method can also be applied to Si MOSFETs, Si IGBTs / FRDs, and GaN HEMTs, because the electroluminescence (EL) effect still exists in these devices, albeit with different spectra due to their different bandwidths.

[0046] As shown in Figure 4, a detection circuit for detecting the electroluminescence of the switch tube of the above-mentioned controlled circuit includes a first signal receiving and amplifying component and a second signal receiving and amplifying component arranged in parallel. Both groups of signal receiving and amplifying components are connected to a differential amplifier. The output end of the differential amplifier is connected to a comparator, and the output end of the comparator is connected to a digital signal processor. The first signal receiving and amplifying component includes a first silicon photomultiplier tube and a first transimpedance amplifier, and the second signal receiving and amplifying component includes a second silicon photomultiplier tube and a second transimpedance amplifier. The first signal receiving and amplifying component is close to the bare chip of the switch tube to be detected in the embedded printed circuit board power module for sensing the electroluminescence, and the second signal receiving and amplifying component is located outside the electroluminescence transmission area to eliminate potential noise caused by ambient light and electromagnetic interference EMI.

[0047] The comparator needs to set a threshold voltage and a hysteresis trigger level. The threshold voltage should be higher than the sum of the noise caused by all sources on the electroluminescent sensor signal; the hysteresis trigger level of the comparator is greater than the amplitude of any fluctuation on the electroluminescent sensor signal during circuit operation, and the value of the threshold voltage plus the hysteresis trigger level is lower than the electroluminescent sensor signal value triggered when the switch tube in the circuit is electroluminescent.

[0048] Both the transimpedance amplifier and the differential amplifier are TI OPA818s with a high bandwidth of 2.7 GHz. The gain of the transimpedance amplifier is 5×104, and the gain of the differential amplifier is 4.4.

[0049] Considering this trade-off in the converter and the available auxiliary power supplies, this paper uses 34V as the bias voltage Vbias, providing a 5V overvoltage above the breakdown voltage of the SiPM tube, which results in a relatively low dark current noise of 50mV observed in a dark room.

[0050] Therefore, this paper conservatively presets a threshold voltage Vth of 0.4V for the comparator, corresponding to a diode conduction current of 1.5A, to eliminate the influence of all noise sources, improve the signal-to-noise ratio, maintain high sensitivity of EL detection, and avoid excessive conduction current.

[0051] As shown in FIG5 , an embedded printed circuit board power module structure for detecting the electroluminescence of the switch tube of the controlled circuit in conjunction with the above-mentioned circuit adaptive zero-voltage switching control method includes a top printed circuit board and a bottom printed circuit board. The bare die of the switch tube to be detected in the circuit to be controlled using the adaptive zero-voltage switching method is arranged between the top printed circuit board and the bottom printed circuit board. Notches are respectively provided on the top printed circuit board and the bottom printed circuit board at positions close to the bare die of the switch tube to be detected. The printed circuit board for the electroluminescence detection circuit is inserted into the notches so that the first silicon photomultiplier tube in the first signal receiving and amplifying component faces the bare die of the switch tube to be detected.

[0052] The switching tube die and the first silicon photomultiplier tube in the electroluminescent detection circuit are both encapsulated in the same power module; if the switching tube die is a vertical device, the first silicon photomultiplier tube is placed vertically on a certain side of the switching tube die; if the switching tube die is a planar device, the first silicon photomultiplier tube is placed parallel to and above the switching tube die.

[0053] The proximity of the current conduction paths between the top and bottom PCBs provides tightly coupled magnetic flux, which enables very low power loop stray inductance for fast switching of the SiC MOSFETs.

[0054] To demonstrate the proposed adaptive zero-voltage switching (ZVS) method, a 5kW-rated synchronous buck converter was constructed using two SiC MOSFET die (rated voltage 750V; Rds,on 14.4mΩ) and a custom printed circuit board (PCB) embedded power module. The converter operates with a 400V input voltage, a 200V output voltage, and a 25µH inductor. An electroluminescence (EL) detection circuit was inserted into a slot near the high-side MOSFET Q1 to detect the EL of the high-side MOSFET Q1 and determine its switching state. A TMS320F28379D controller was used to adjust the switching frequency fsw in the next switching cycle based on the detected switching state in the current cycle. Since the sensing circuit and PCB embedded module were not packaged in this experiment, the entire test setup was placed in a darkroom to eliminate ambient light noise.

[0055] Figure 6 shows the drain-source voltage Vds of switch Q1, the inductor current iL, the analog signal Vsense, the digital signal Vst, and the gate-source voltage Vgs1 of the high-side MOSFET Q1 and the gate-source voltage Vgs2 of the low-side MOSFET Q2 during steady-state operation at 50% of rated power with adaptive zero-voltage switching (ZVS) control enabled. It can be seen that the analog signal Vsense pulses every other cycle, while the digital signal Vst provides a low-noise signal, indicating the switching state. The results show that the switching frequency fsw automatically adjusts to ensure that the high-side MOSFET Q1 turns on at or just before the body diode conduction moment, that is, at the boundary between states iii and iv, achieving optimal zero-voltage switching (ZVS) operation.

[0056] In the zoomed-in diagram of state iii, we can observe perfect zero-voltage switching (ZVS). Further zooming in on the drain-source voltage Vds, we see that during the dead time, as the output capacitor Coss reverse charges, the drain-source voltage Vds drops to zero, but does not reach the body diode's conduction voltage. Therefore, the algorithm accurately controls the switch to enter the optimal ZVS region. Furthermore, as shown in the zoomed-in diagram of state iv, ZVS is still achieved in this state, with the analog signal Vsense and the digital signal Vst responding accordingly. In the further zoomed-in diagram, the output capacitor Coss is reverse-charged to the body diode's conduction voltage, and then the body diode conducts for 24 ns, during which the drain-source voltage Vds exhibits a small negative bottom. This 24 ns conduction time is very short, so the increase in the inductor current iL is negligible. Therefore, this solution can control the valley current to a consistent 2 A, the precise value required for optimal ZVS.

[0057] The high bandwidth of the silicon photomultiplier (SiPM) and operational amplifier (op amp) provides a 3 ns delay from turn-on to the start of the analog signal Vsense's response. Furthermore, primarily due to the conservatively set comparator threshold voltage (Vth), the delay from the analog signal Vsense's response to the triggering of the digital signal (Vst) is 18 ns, which also accounts for the 2.5 ns comparator propagation delay. Therefore, considering that the switching frequency (fsw) of most power electronics devices does not exceed 10 MHz, the overall response speed is sufficient for the DSP to adjust fsw in the next cycle.

[0058] Adaptive zero voltage switching (ZVS) results during transient loads:

[0059] Figures 7 and 8 show the transient process when the load changes from 10% to 50% and from 50% to 10% of the rated power, respectively. The proposed method can automatically adapt to the new load current and adjust the switching frequency fsw to achieve optimal zero voltage switching.

[0060] Zoomed-in waveforms with the same time scale demonstrate that the proposed control method adaptively updates the switching frequency fsw for optimal zero-voltage switching (ZVS) during load changes. During load ramp-up and ramp-down cycles, the controller adjusts the switching frequency fsw to 180 kHz and 336 kHz at 50% and 10% loads, respectively. This adjustment is performed automatically, without requiring any preconditions such as table lookup or calculations. Optimal ZVS (ZVS) is consistently achieved and can be verified by observing a constant 2 A valley current at both high and low loads, as the valley current required for ZVS is independent of the load and determined solely by the power device.

[0061] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some embodiments of its application, and are not intended to limit the present invention. It should be noted that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A circuit adaptive zero-voltage switching control method employs a light sensor to detect electroluminescence (EL) from a switching transistor in the circuit. If, during the current switching cycle of the circuit, the light sensor fails to detect EL photons from the parasitic body diode or anti-parallel freewheeling diode of the switching transistor to be controlled, the switching frequency fsw of the circuit is reduced by a variable Δfsw in the next switching cycle to increase the amplitude of the reverse inductor current while continuously detecting EL. If EL is still not detected, the switching frequency is continuously decreased by a variable Δfsw in each subsequent switching cycle while continuously detecting EL until the light sensor detects EL, indicating that the circuit has reached a stable operating state. If, during the current switching cycle of the circuit, the set photosensor detects electroluminescent photons from the parasitic body diode or anti-parallel freewheeling diode of the switch tube to be controlled, the switching frequency fsw will be increased by a variable Δfsw in the next switching cycle and the detection of electroluminescence will continue. If electroluminescence is still detected, the switching frequency will continue to increase by the variable Δfsw in each subsequent switching cycle and the detection of electroluminescence will continue until the set photosensor detects no electroluminescence, which means that the operating state has reached a stable state. After reaching a stable operating state, the circuit switching frequency maintains a reciprocating increase and decrease variable Δfsw in consecutive switching cycles, that is, electroluminescence is generated at intervals in consecutive switching cycles, thereby achieving an adaptive zero-voltage switching operating state. The variable Δfsw is an arbitrary value not greater than the difference between the switching frequency fsw ii and the switching frequency fsw iii. The switching frequency fsw ii is the switching frequency at which the circuit discharges the output capacitance of the switch to be controlled to zero within the dead time, marking the beginning of the optimal zero-voltage switching interval. The switching frequency fsw iii is the switching frequency at which the circuit reversely charges the voltage across the switch to be controlled to the forward voltage of the body diode or anti-parallel diode within the dead time, marking the end of the optimal zero-voltage switching interval.

2. A detection circuit for detecting electroluminescence of a switch tube of a controlled circuit in conjunction with the circuit adaptive zero-voltage switching control method according to claim 1, characterized in that: It includes a first signal receiving and amplifying component and a second signal receiving and amplifying component arranged in parallel, both sets of signal receiving and amplifying components are connected to a differential amplifier, the output end of the differential amplifier is connected to a comparator, the output end of the comparator is connected to a digital signal processor, the first signal receiving and amplifying component includes a first silicon photomultiplier tube and a first transimpedance amplifier, the second signal receiving and amplifying component includes a second silicon photomultiplier tube and a second transimpedance amplifier, wherein the first signal receiving and amplifying component is close to the bare chip of the switch tube to be detected in the embedded printed circuit board power module, and is used to sense electroluminescence, and the second signal receiving and amplifying component is located outside the electroluminescence transmission area to eliminate potential noise caused by ambient light and electromagnetic interference EMI.

3. The detection circuit for detecting electroluminescence of a switch tube of a controlled circuit in conjunction with the circuit adaptive zero voltage switching control method according to claim 2, characterized in that: The comparator needs to set a threshold voltage and a hysteresis trigger level. The threshold voltage should be higher than the sum of the noise caused by all sources on the electroluminescent sensor signal; the hysteresis trigger level of the comparator is greater than the amplitude of any fluctuation on the electroluminescent sensor signal during circuit operation, and the value of the threshold voltage plus the hysteresis trigger level is lower than the electroluminescent sensor signal value triggered when the switch tube in the circuit is electroluminescent.

4. The detection circuit for detecting electroluminescence of a switch tube of a controlled circuit in conjunction with the circuit adaptive zero-voltage switching control method according to claim 3, characterized in that: The gain of the transimpedance amplifier is 5×10 4 ; The gain of the differential amplifier is 4.

4.

5. The detection circuit for detecting electroluminescence of a switching tube in a circuit in conjunction with the circuit adaptive zero voltage switching control method according to claim 4, characterized in that: The transimpedance amplifier and the differential amplifier are both TI OPA818 with a high bandwidth of 2.7 GHz.

6. An embedded printed circuit board power module structure for detecting electroluminescence of a switch tube of a controlled circuit in conjunction with a circuit adaptive zero voltage switching control method according to any one of claims 2 to 5, characterized in that: The invention comprises a top printed circuit board and a bottom printed circuit board, wherein the bare chip of the switch tube to be detected in the circuit to be controlled by the adaptive zero-voltage switching method is arranged between the top printed circuit board and the bottom printed circuit board, and notches are respectively provided on the top printed circuit board and the bottom printed circuit board at positions close to the bare chip of the switch tube to be detected, and the printed circuit board in which the electroluminescence detection circuit is arranged is inserted into the notches so that the first silicon photomultiplier tube in the first signal receiving and amplifying component faces the bare chip of the switch tube to be detected.

7. The embedded printed circuit board power module structure of the detection circuit for detecting electroluminescence of the switch tube of the controlled circuit in conjunction with the circuit adaptive zero voltage switching control method according to claim 6, characterized in that: The switching tube die and the first silicon photomultiplier tube in the electroluminescent detection circuit are both encapsulated in the same power module; if the switching tube die is a vertical device, the first silicon photomultiplier tube is placed vertically on a certain side of the switching tube die; if the switching tube die is a planar device, the first silicon photomultiplier tube is placed parallel to and above the switching tube die.

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