Resonant power converter and conversion control circuit and conversion control method thereof

Abstract

The invention provides a resonant power converter and a conversion control circuit and a conversion control method thereof. The resonant power converter comprises a first transistor and a second transistor which are used for forming a half-bridge circuit; the resonance circuit comprises a resonance inductor, a primary side winding of the transformer and a resonance capacitor which are coupled in series, and the first transistor and the second transistor are used for switching the resonance circuit to generate resonance current so as to convert input voltage to generate output voltage; and the conversion control circuit is used for generating a ramp signal according to the resonance current and generating a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage. The first driving signal and the second driving signal are respectively used for controlling the first transistor and the second transistor. In a signal period of the ramp signal, the ramp signal is monotonically increased or monotonically decreased.

Description

Technical Field

[0001] The present invention relates to a resonant power converter, and particularly to a resonant power converter with high efficiency and low power consumption, and the resonant power converter of the present invention has better transient response ability. The present invention also relates to a conversion control circuit and method for controlling a resonant power converter. Background Art

[0002] Prior art related to this application includes: US 8085558 B2 and US 9065350 B2.

[0003] Figure 1 Schematic diagram showing a prior art resonant power converter. As Figure 1 shown, in a prior art resonant power converter 900, resistors R1 and R2 sense the voltage across the resonant capacitor Cr to generate a divided voltage k*VCr. The divided voltage k*VCr has a k-fold proportional relationship with the voltage across the resonant capacitor Cr, where k is greater than 0 and less than 1. The divided voltage k*VCr is added to the bias voltage Vdm to generate a first bias signal VCrh, and the divided voltage k*VCr is subtracted from the bias voltage Vdm to generate a second bias signal VCrl, where the level of the first bias signal VCrh is higher than the level of the second bias signal VCrl. The control circuit 90 generates an upper bridge drive signal SH and a lower bridge drive signal SL based on the first bias signal VCrh, the second bias signal VCrl, and a feedback signal Vfb related to the output voltage Vout, and controls the upper bridge transistor QH and the lower bridge transistor SL respectively.

[0004] One of the disadvantages of the above prior art is that using resistors R1 and R2 for voltage division will cause additional power loss. Moreover, in the prior art, it is necessary to bias the divided voltage k*VCr to generate a higher bias signal and a lower bias signal, and then process the higher bias signal and the lower bias signal, which will increase the complexity of the circuit and result in poor transient response ability.

[0005] In view of this, the present invention aims at the deficiencies of the above prior art and provides a resonant power converter with high efficiency and low power consumption. The resonant power converter of the present invention full-wave rectifies the resonant-related signal of the resonant current, and processes the full-wave rectified signal by integration or differentiation to generate a ramp signal, and then generates a drive signal based on the ramp signal and a compensation signal related to the output voltage, thereby controlling the switching of the upper bridge transistor and the lower bridge transistor. The present invention solves the power consumption caused by the voltage division circuit in the prior art, and through the full-wave rectification method, the upper bridge transistor and the lower bridge transistor can be independently controlled in the same cycle, thereby improving the transient response ability of the resonant power converter. Summary of the Invention

[0006] In one aspect, the present invention provides a resonant power converter, comprising: a first transistor and a second transistor for forming a half-bridge circuit; a resonant circuit including a resonant inductor, a primary winding of a transformer, and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer, and the resonant capacitor are serially coupled to each other, and wherein the first transistor and the second transistor are used to switch the resonant circuit to generate a resonant current for converting an input voltage to generate an output voltage; and a conversion control circuit for generating a ramp signal according to the resonant current, and generating a first drive signal and a second drive signal according to the ramp signal and a compensation signal related to the output voltage, wherein the first drive signal and the second drive signal are respectively used to control the first transistor and the second transistor; wherein within a signal period of the ramp signal, the ramp signal monotonically increases or decreases.

[0007] In one embodiment, within a switching period of the first drive signal or the second drive signal, the on-time of the first drive signal and the on-time of the second drive signal are optionally equal or unequal, thereby improving the transient response ability of the resonant power converter.

[0008] In one embodiment, the signal period of the ramp signal is less than the switching period of the first drive signal or the second drive signal.

[0009] In one embodiment, the conversion control circuit further adjusts the switching period of the first drive signal and / or the second drive signal according to the comparison between the ramp signal and the compensation signal to adjust the phase of the resonant current, thereby regulating an output power related to the output voltage.

[0010] In one embodiment, the ramp signal is further generated according to the differentiation or integration of a resonant related signal related to the resonant current.

[0011] In one embodiment, the conversion control circuit includes a rectifying circuit for full-wave rectifying a sensing signal related to the resonant current to generate a resonant related signal related to the resonant current.

[0012] In one embodiment, the conversion control circuit includes: a trans-conductance amplification circuit for generating a trans-conductance amplification current according to the resonant related signal; and an integration circuit including an integration capacitor for integrating an integration current to generate the ramp signal, wherein the integration current includes the trans-conductance amplification current; and wherein the first drive signal and the second drive signal are further generated according to the comparison between the ramp signal and the compensation signal.

[0013] In one embodiment, the rectifying circuit includes: a plurality of switches, including a first group of switches and a second group of switches connected in parallel with each other, wherein the first group of switches is used to switch according to the first driving signal, and the second group of switches is used to switch according to the second driving signal, thereby performing full-wave rectification on the sensing signal to generate the resonance-related signal.

[0014] In one embodiment, the conversion control circuit further includes a sensing circuit for generating the sensing signal according to the resonance current.

[0015] In one embodiment, the integral current further includes a ramp compensation current for compensating the slope of the transconductance amplified current.

[0016] In one embodiment, the ramp compensation current is related to the input voltage to achieve feedforward control.

[0017] In one embodiment, the conversion control circuit includes: a differentiating circuit for differentiating the resonance-related signal to generate the ramp signal; wherein the first driving signal and the second driving signal are further generated according to the comparison between the ramp signal and the compensation signal.

[0018] In another aspect, the present invention provides a conversion control circuit for controlling a resonant power converter, wherein the resonant power converter includes a first transistor, a second transistor, and a resonant circuit, wherein the first transistor and the second transistor are used to form a half-bridge circuit, wherein the resonant circuit includes a resonant inductor, a primary winding of a transformer, and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer, and the resonant capacitor are connected in series with each other, wherein the first transistor and the second transistor are used to switch the resonant circuit to generate a resonance current to convert an input voltage to generate an output voltage; the conversion control circuit includes: a sensing circuit for generating a sensing signal according to the resonance current; and a signal processing circuit for generating a ramp signal according to the sensing signal; wherein the conversion control circuit is used to generate a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage, wherein the first driving signal and the second driving signal are respectively used to control the first transistor and the second transistor; wherein within a signal period of the ramp signal, the ramp signal increases monotonically or decreases monotonically.

[0019] In another aspect, the present invention provides a conversion control method for controlling a resonant power converter, where the resonant power converter includes a first transistor, a second transistor, and a resonant circuit. The first transistor and the second transistor are used to form a half-bridge circuit. The resonant circuit includes a resonant inductor, a primary winding of a transformer, and a resonant capacitor. The resonant inductor, the primary winding of the transformer, and the resonant capacitor are serially coupled to each other. The first transistor and the second transistor are used to switch the resonant circuit to generate a resonant current to convert an input voltage to generate an output voltage. The conversion control method includes: generating a sensing signal according to the resonant current; generating a ramp signal according to the sensing signal; and generating a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage, where the first driving signal and the second driving signal are respectively used to control the first transistor and the second transistor; and during a signal period of the ramp signal, the ramp signal monotonically increases or monotonically decreases.

[0020] The following will be described in detail through specific embodiments to more easily understand the purpose, technical content, features, and achieved effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram showing a resonant power converter of the prior art.

[0022] Figure 2 Block diagram showing an embodiment of the resonant power converter of the present invention.

[0023] Figure 3 Operation waveform diagram showing an embodiment of the resonant power converter of the present invention.

[0024] Figure 4 Block diagram showing an embodiment of the resonant power converter of the present invention.

[0025] Figure 5 Block diagram showing an embodiment of the resonant power converter of the present invention.

[0026] Figure 6 Showing the resonant power converter of the present invention corresponding to Figure 4 a schematic diagram of an embodiment.

[0027] Figure 7 Showing the resonant power converter of the present invention corresponding to Figure 4 a schematic diagram of a specific embodiment.

[0028] Figure 8 Schematic diagram showing a specific embodiment of the resonant power converter of the present invention.

[0029] Figure 9 Schematic diagram showing a specific embodiment of the resonant power converter of the present invention corresponding to Figure 4 .

[0030] Figure 10 Schematic diagram showing a specific embodiment of the resonant power converter of the present invention corresponding to Figure 5 .

[0031] Description of symbols in the figure

[0032] 100, 108: Resonant circuit

[0033] 1002, 1004, 1005, 1006, 1007, 1008, 1009, 1010: Resonant power converter

[0034] 200, 204, 205, 2041, 2042, 2043, 2044, 2051: Conversion control circuit

[0035] 2040, 2050: Signal processing circuit

[0036] 210: Transduction amplification circuit

[0037] 216: Transduction amplifier

[0038] 220, 226: Integral circuit

[0039] 230, 236, 237, 238: Sensing circuit

[0040] 240, 245, 246: Rectifying circuit

[0041] 250, 251: Differentiating circuit

[0042] 270: Comparator

[0043] 280: Driving circuit

[0044] 290: Inverting amplifier

[0045] 30: Buffer

[0046] 40: Transformer

[0047] 50: Optocoupler

[0048] Cd: Differentiating capacitor

[0049] Cin: Integrating capacitor

[0050] Comp: Compensation signal

[0051] Cr: Resonant capacitor

[0052] Cs, Cx: Sensing capacitor

[0053] G1: The first group of switches

[0054] G2: The second group of switches

[0055] HG: The first transistor

[0056] HS: The first drive signal

[0057] Iin: Integral current

[0058] ILm: The current of the primary winding

[0059] Iof: Bias current source

[0060] Iota: Transduction amplification current

[0061] Ir: Resonant current

[0062] Islope: Ramp compensation current

[0063] LG: The second transistor

[0064] Lm: Primary winding

[0065] Lr: Resonant inductor

[0066] LS: The second drive signal

[0067] LX: Switching node

[0068] Nr: Node

[0069] Rd: Differential resistance

[0070] Rof: Bias resistor

[0071] Rs, Rx: Sense resistors

[0072] Sa1, Sa2: Signals

[0073] Sdt: Hysteresis time signal

[0074] Sw1 - Sw5: Switches

[0075] t1 - t3: Time points

[0076] Ta: Signal period

[0077] Td: Hysteresis time

[0078] Tp: Switching period

[0079] Vbias: Bias voltage

[0080] Vco: Comparison result

[0081] VCr: Cross voltage of the resonant capacitor

[0082] VCS: Sensing signal

[0083] VCSa: Resonance-related signal

[0084] VCSa’: Amplified signal

[0085] VCSd: Differential signal

[0086] Vd: Differential signal

[0087] Vdc: Pre-sensing signal

[0088] Vin: Input voltage

[0089] Vof: Bias voltage

[0090] Vout: Output voltage

[0091] Vramp: Ramp signal Detailed implementation manners

[0092] The drawings in the present invention are all schematic, mainly intended to show the coupling relationships between circuits and the relationships between various signal waveforms. As for circuits, signal waveforms and frequencies, they are not drawn to scale.

[0093] Figure 2 A block diagram showing an embodiment of the resonant power converter of the present invention is shown. In one embodiment, the resonant power converter 1002 includes: a first transistor HG, a second transistor LG, a resonant circuit 100, and a conversion control circuit 200. In this embodiment, the first transistor HG is an upper-bridge transistor, and the second transistor LG is a lower-bridge transistor. The first transistor HG and the second transistor LG are used to form a half-bridge circuit. In one embodiment, the resonant circuit 100 includes a resonant inductor Lr and a resonant capacitor Cr. In this embodiment, the resonant circuit 100 further includes a primary winding Lm of a transformer 40. The resonant inductor Lr, the primary winding Lm, and the resonant capacitor Cr are sequentially connected in series to a switching node LX between the first transistor HG and the second transistor LG. In this embodiment, the first transistor HG and the second transistor LG are used to switch the resonant circuit 100 to generate a resonant current Ir to convert the input voltage Vin to generate the output voltage Vout. The conversion control circuit 200 is used to generate a ramp signal Vramp according to the resonant current Ir, and generate a first drive signal HS and a second drive signal LS according to the ramp signal Vramp and a compensation signal Comp related to the output voltage Vout. The first drive signal HS and the second drive signal LS are respectively used to control the first transistor HG and the second transistor LG. In one embodiment, the output voltage Vout generates the compensation signal Comp via an isolation element (such as Figure 2 the optical coupler 50 shown).

[0094] Please also refer to Figure 2 and Figure 3 . Figure 3 Fig. shows an operating waveform diagram of an embodiment of the resonant power converter of the present invention. In one embodiment, as Figure 3 shown, within a signal period Ta of the ramp signal Vramp, the ramp signal Vramp monotonically increases or decreases. For example, in the embodiment of Figure 3 , from time point t1 to t2, the ramp signal Vramp monotonically increases. In one embodiment, the ramp signal Vramp is related to the integral or differential of a sine wave, particularly the integral or differential of the positive half-cycle of a sine wave. Therefore, it can be, for example, a partial waveform with a monotonically increasing characteristic in the positive or negative half-cycle of a cosine wave. In one embodiment, within a switching period Tp of the first drive signal HS or the second drive signal LS, the on-time of the first drive signal HS and the on-time of the second drive signal LS are optionally equal or unequal, thereby enhancing the transient response ability of the resonant power converter 1002, and its operation details will be described in detail in subsequent embodiments.

[0095] Figure 4 Fig. shows a block diagram of an embodiment of the resonant power converter of the present invention. As Figure 4 shown, in one embodiment, the conversion control circuit 204 in the resonant power converter 1004 includes a sensing circuit 230 and a signal processing circuit 2040. In this embodiment, the signal processing circuit 2040 includes a rectifying circuit 240, a transduction amplification circuit 210, and an integrating circuit 220. In one embodiment, the sensing circuit 230 is used to generate a sensing signal VCS according to the resonant current Ir, and the rectifying circuit 240 is used to perform full-wave rectification on the sensing signal VCS to generate a resonant-related signal VCSa related to the resonant current Ir. The transduction amplification circuit 210 is used to generate a transduction amplification current Iota according to the resonant-related signal VCSa, and the integrating circuit 220 is used to integrate the integration current Iin to generate a ramp signal Vramp. In this embodiment, the integration current Iin includes the transduction amplification current Iota. In one embodiment, the first drive signal HS and the second drive signal LS are also generated according to the comparison between the ramp signal Vramp and the compensation signal Comp.

[0096] Figure 5 Fig. shows a block diagram of an embodiment of the resonant power converter of the present invention. As Figure 5As shown, in one embodiment, the conversion control circuit 205 in the resonant power converter 1005 includes a sensing circuit 230 and a signal processing circuit 2050. In this embodiment, the signal processing circuit 2050 includes a rectifying circuit 240 and a differentiating circuit 250. In one embodiment, the sensing circuit 230 is configured to generate a sensing signal VCS according to the resonant current Ir, and the rectifying circuit 240 is configured to perform full-wave rectification on the sensing signal VCS to generate a resonant-related signal VCSa related to the resonant current Ir. In this embodiment, the differentiating circuit 250 is configured to generate a ramp signal Vramp according to the differentiation of the resonant-related signal VCSa. Similar to Figure 4 the embodiment of, in this embodiment, the first driving signal HS and the second driving signal LS are also generated according to the comparison between the ramp signal Vramp and the compensation signal Comp.

[0097] Figure 6 showing a schematic diagram of a specific embodiment of the resonant power converter of the present invention corresponding to Figure 4 a specific embodiment. Figure 6 The resonant power converter 1006 of is Figure 4 a specific embodiment of the resonant power converter 1004 of. In Figure 6 the embodiment of, the conversion control circuit 2041 further includes a comparator 270 and a driving circuit 280. In this embodiment, the transduction amplification circuit is configured as a transduction amplifier 216, the sensing circuit 236 includes a sensing capacitor Cs, a sensing resistor Rs, a bias current source Iof, and a bias resistor Rof, and the integrating circuit 226 includes an integrating capacitor Cin and a switch Sw5. In one embodiment, the sensing circuit 236 is coupled to a node Nr between the primary winding Lm and the resonant capacitor Cr. Specifically, the sensing capacitor Cs is coupled between the node Nr and the sensing resistor Rs, and the sensing resistor Rs is coupled between the sensing capacitor Cs and the ground potential. The sensing capacitor Cs and the sensing resistor Rs are configured to differentiate the voltage across the resonant capacitor Cr to generate a differential signal Vd indicative of the resonant current Ir. The bias current source Iof and the bias resistor Rof are configured to generate a bias voltage Vof to bias the DC voltage value of the differential signal Vd, thereby generating the sensing signal VCS.

[0098] In one embodiment, the rectifying circuit 246 includes a plurality of switches, which include a first group of switches G1 and a second group of switches G2 that are coupled in parallel with each other. The first group of switches G1 is used to switch according to a first driving signal HS, and the second group of switches G2 is used to switch according to a second driving signal LS, thereby performing full-wave rectification on the sensing signal VCS to generate a resonance-related signal VCSa. In this embodiment, the resonance-related signal VCSa includes a signal Sa1 and a signal Sa2. In one embodiment, the first group of switches G1 includes a switch Sw1 and a switch Sw3, and the second group of switches G2 includes a switch Sw2 and a switch Sw4. In this embodiment, the switch Sw1 is coupled between the sensing signal VCS and the positive input terminal of the transduction amplifier 216, the switch Sw2 is coupled between the sensing signal VCS and the negative input terminal of the transduction amplifier 216, the switch Sw3 is coupled between the bias voltage Vof and the negative input terminal of the transduction amplifier 216, and the switch Sw4 is coupled between the bias voltage Vof and the positive input terminal of the transduction amplifier 216.

[0099] It should be noted that when the first driving signal HS controls the switches Sw1 and Sw3 to conduct, the signal Sa1 corresponds to the sensing signal VCS, and the signal Sa2 corresponds to the bias voltage Vof, such that the resonance-related signal VCSa is positively correlated with the sensing signal VCS. When the second driving signal LS controls the switches Sw2 and Sw4 to conduct, the signal Sa2 corresponds to the sensing signal VCS, and the signal Sa1 corresponds to the bias voltage Vof, such that the resonance-related signal VCSa is negatively correlated with the sensing signal VCS. Through the operations of the above-mentioned first group of switches G1 and second group of switches G2, and the coupling relationship between the first group of switches G1, the second group of switches G2 and the transduction amplifier 216, the resonance-related signal VCSa can correspond to the sensing signal VCS after full-wave rectification. In other words, the resonance-related signal VCSa corresponds to the difference between the signal Sa1 and the signal Sa2.

[0100] In one embodiment, as Figure 6As shown, the transduction amplifier 216 is powered by a bias voltage Vbias to convert the resonance-related signal VCSa to generate a transduced amplified current Iota. In this embodiment, the positive input terminal and the negative input terminal of the transduction amplifier 216 respectively generate a transduced amplified current Iota linearly related to the resonance-related signal VCSa according to the signal Sa1 and the signal Sa2. In one embodiment, the integrating capacitor Cin is used to integrate the transduced amplified current Iota, and the switch Sw5 is used to reset the voltage of the integrating capacitor Cin according to the dead time signal Sdt, thereby generating a ramp signal Vramp. In one embodiment, the comparator 270 is used to compare the ramp signal Vramp with the compensation signal Comp to generate a comparison result Vco, and the drive circuit 280 is used to generate a first drive signal HS and a second drive signal LS according to the comparison result Vco, thereby controlling the first transistor HG and the second transistor LG respectively.

[0101] Please also refer to Figure 3 and Figure 6 . As Figure 3 shown, in one embodiment, the waveform of the resonance current Ir has resonance characteristics, and the excitation current ILm is a triangular wave. In one embodiment, the waveform of the sensing signal VCS corresponds to the waveform of the resonance current Ir, and the waveform of the resonance-related signal VCSa corresponds to the waveform of the sensing signal VCS after full-wave rectification. In one embodiment, the DC voltage value of the sensing signal VCS is the bias voltage Vof, and the valley value of the resonance-related signal VCSa is the bias voltage Vof, thereby ensuring that the voltage value of the resonance-related signal VCSa is greater than 0, for example. In Figure 6 the embodiment of Figure 3At time point t1, the ramp signal Vramp is generated by integrating the transduction amplified current Iota generated according to the resonance-related signal VCSa, and at time point t2, the integration value is reset according to the dead time signal Sdt. In one embodiment, the signal period Ta of the ramp signal Vramp is less than the switching period Tp of either the first driving signal HS or the second driving signal LS. In this embodiment, the conversion control circuit 2041 also adjusts the switching period Tp of the first driving signal HS or the second driving signal LS according to the compensation signal Comp. Specifically, in one embodiment, the switching time points of the first driving signal HS and the second driving signal LS are determined according to the intersection time point of the ramp signal Vramp and the compensation signal Comp (for example, time points t1 or t2, which is also the aforementioned reset time point of the ramp signal Vramp), so as to adjust the phase of the resonance current Ir, thereby adjusting an output power related to the output voltage Vout. Specifically, in this embodiment, the intersection time point of the ramp signal Vramp and the compensation signal Comp determines the rising edge of the dead time signal Sdt, and the conversion control circuit 2041 is also used to determine the dead time Td, that is, the time when neither the first driving signal HS nor the second driving signal LS is turned on.

[0102] It should be noted that according to the present invention, the intersection time point of the ramp signal Vramp and the compensation signal Comp is determined by the level of the compensation signal Comp to determine the switching phase of the first driving signal HS and the second driving signal LS, and then determine its switching frequency, thereby adjusting the phase of the resonance current Ir (that is, adjusting the resonance degree), thereby adjusting the output power. Compared with the complex circuits of the prior art, the present invention processes the ramp signal Vramp, so that the conduction time of the first driving signal HS and the conduction time of the second driving signal LS may not be equal, that is, the output power can be adjusted at each switching time point of the first driving signal HS and the second driving signal LS (for example, time points t1, t2 or t3), thereby improving the transient response ability of the resonant power converter, and the circuit configuration of the present invention is simpler, so the efficiency can be improved.

[0103] Figure 7 Show a schematic diagram of a specific embodiment of the resonant power converter of the present invention corresponding to Figure 4 of. Figure 7 The resonant power converter 1007 is similar to Figure 6 The resonant power converter 1006. The difference is that in Figure 7In an embodiment, the sensing circuit 237 in the conversion control circuit 2042 is coupled to the resonant capacitor Cr. Specifically, in the sensing circuit 237, a sensing resistor Rs is coupled between the resonant capacitor Cr and the ground potential. The voltage across the sensing resistor Rs is proportional to the resonant current Ir. A sensing capacitor Cs is coupled between the resonant capacitor Cr and a bias resistor Rof to block the DC component of the voltage across the sensing resistor Rs. The sensing circuit 237 is used to sense and bias the AC component of the voltage across the sensing resistor Rs to generate a sensing signal VCS. Figure 7 For other details, please refer to Figure 6 the description of

[0104] Figure 8 FIG. shows a schematic diagram of a specific embodiment of the resonant power converter of the present invention. Figure 8 The resonant power converter 1008 is similar to Figure 6 the resonant power converter 1006. Compared with Figure 6 the embodiment of Figure 8 in the resonant circuit 108 of Figure 8 as shown in FIG., the sensing circuit 238 in the conversion control circuit 2043 includes a sensing resistor Rx and a sensing capacitor Cx. The sensing resistor Rx and the sensing capacitor Cx are coupled in parallel to the resonant inductor Lr to perform DC resistance sensing (DCR sensing) on the resonant inductor Lr to generate a pre-sensing signal Vdc. The time constant of the sensing resistor Rx and the sensing capacitor Cx matches the time constant of the resonant inductor Lr and its DC resistance. Thus, the voltage across the sensing capacitor Cx is proportional to the resonant current Ir. The pre-sensing signal Vdc then generates a sensing signal VCS via a DC determination circuit. Figure 8 For other details, please refer to Figure 6 the description of

[0105] Figure 9 FIG. shows a schematic diagram of a specific embodiment of the resonant power converter of the present invention corresponding to Figure 4 a specific embodiment. Figure 9 The resonant power converter 1009 is similar to Figure 6 the resonant power converter 1006. The difference is that, in Figure 9 the embodiment of Figure 9 the integral current Iin of the conversion control circuit 2044 further includes a slope compensation current Islope to compensate for the slope of the transconductance amplification current Iota. In this embodiment, the slope compensation current Islope is related to the input voltage Vin to achieve feedforward control. Figure 9 For other details, please refer to Figure 6 the description of

[0106] Figure 10Showing a schematic diagram of a specific embodiment of the resonant power converter of the present invention corresponding to Figure 5 The resonant power converter 1010 of Figure 10 is a specific embodiment of the resonant power converter 1005 of Figure 5 In the embodiment of Figure 10 the conversion control circuit 2051 further includes a buffer 30, a comparator 270, and a drive circuit 280. The configuration and operation of the sensing circuit 236 are the same as those of Figure 6 , and the details can be referred to the description of Figure 6 The rectifier circuit 245 includes a plurality of switches. The plurality of switches include a first group of switches G1 (switches Sw1, Sw3) and a second group of switches G2 (switches Sw2, Sw4). In this embodiment, the switch Sw1 and the switch Sw4 are coupled to the positive input terminal of the buffer 30, and the switch Sw2 and the switch Sw3 are coupled to the negative input terminal of the buffer 30. For other operation details of the plurality of switches, please refer to the description of Figure 6 In one embodiment, the rectifier circuit 245 is used to full-wave rectify the sensing signal VCS to generate a resonance-related signal VCSa. In this embodiment, the resonance-related signal VCSa is also differentially amplified by the buffer 30 to generate an amplified signal VCSa'. The amplified signal VCSa' is positively correlated with the resonance-related signal VCSa. In this embodiment, the differentiating circuit 251 includes a differentiating capacitor Cd, a differentiating resistor Rd, and an inverting amplifier 290. The differentiating capacitor Cd and the differentiating resistor Rd are used to differentiate the amplified signal VCSa' to generate a differentiating signal VCSd, and the differentiating signal VCSd is generated by the inverting amplifier 290 to generate a ramp signal Vramp. For the operation details not mentioned above, please refer to the description of Figure 6

[0107] Please also refer to Figure 3 and Figure 10 . As shown in Figure 3 , in the embodiment of Figure 10 the ramp signal Vramp is related to the differentiation of the resonance-related signal VCSa. For example, at time point t1, a differentiating signal VCSd is generated according to the differentiation of the resonance-related signal VCSa, and the differentiating signal VCSd is inverted to generate a ramp signal Vramp. It should be noted that when the present invention is configured as the related embodiments of Figure 4 ( Figure 4 , Figures 6 to 9 ), Figure 3 the ramp signal Vramp is generated according to the integration of the resonance-related signal VCSa. When the present invention is configured as the related embodiments of Figure 5 ( Figure 5 and Figure 10 ), Figure 3 ​The ramp signal Vramp is generated based on the differentiation of the resonance-related signal VCSa. For other waveform details other than the above-mentioned differentiation, please refer to the foregoing Figure 3 description.

[0108] In addition, in an embodiment, the differential signal VCSd can also correspond to a ramp signal, which is compared with the compensation signal Comp to determine the switching phases of the first driving signal HS and the second driving signal LS.

[0109] The present invention has been described with reference to the preferred embodiments. However, the above description is only for making those skilled in the art easily understand the content of the present invention, and is not used to limit the scope of the rights of the present invention. Each of the described embodiments is not limited to being applied alone, and can also be applied in combination. For example, two or more embodiments can be combined, and some components in one embodiment can also be used to replace the corresponding components in another embodiment. In addition, in the same spirit of the present invention, those skilled in the art can think of various equivalent changes and various combinations. For example, the so-called "processing or operating or generating a certain output result according to a certain signal" in the present invention is not limited to the signal itself, and also includes, when necessary, performing voltage-current conversion, current-voltage conversion, and / or proportional conversion on the signal, and then processing or operating according to the converted signal to generate a certain output result. It can be seen that in the same spirit of the present invention, those skilled in the art can think of various equivalent changes and various combinations, and there are many combination methods, which are not listed one by one here. Therefore, the scope of the present invention should cover the above and all other equivalent changes.

Claims

1. A resonant power converter, comprising: A first transistor and a second transistor, used to form a half bridge circuit; A resonant circuit, comprising a resonant inductor, a primary winding of a transformer and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer and the resonant capacitor are coupled in series with each other, wherein the first transistor and the second transistor are used to switch the resonant circuit to generate a resonant current to convert an input voltage to generate an output voltage; as well as a conversion control circuit, for generating a ramp signal according to the resonant current, and generating a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage, wherein the first driving signal and the second driving signal are used to control the first transistor and the second transistor respectively; In a signal cycle of the ramp signal, the ramp signal increases monotonically or decreases monotonically.

2. The resonant power converter according to claim 1, wherein: In a switching cycle of the first driving signal or the second driving signal, an on-time of the first driving signal and an on-time of the second driving signal may be equal or unequal, thereby improving the transient response capability of the resonant power converter.

3. The resonant power converter according to claim 1, wherein: The signal period of the ramp signal is smaller than a switching period of the first driving signal or the second driving signal.

4. The resonant power converter according to claim 1, wherein: The conversion control circuit also adjusts a switching period of the first driving signal and / or the second driving signal according to the comparison between the ramp signal and the compensation signal to adjust the phase of the resonant current, thereby regulating an output power related to the output voltage.

5. The resonant power converter according to claim 1, wherein: The ramp signal is also generated according to a differentiation or integration of a resonance-related signal related to the resonance current.

6. The resonant power converter of claim 1, wherein: The conversion control circuit includes a rectifier circuit for full-wave rectifying a sensing signal related to the resonant current to generate a resonance-related signal related to the resonant current.

7. The resonant power converter as claimed in claim 6, wherein: The conversion control circuit comprises: a transconductance amplifier circuit for generating a transconductance amplifier current according to the resonance-related signal; and an integrating circuit, comprising an integrating capacitor, for integrating an integrating current to generate the ramp signal, wherein the integrating current comprises the transconductance amplified current; The first driving signal and the second driving signal are further generated according to the comparison between the ramp signal and the compensation signal.

8. The resonant power converter as claimed in claim 6, wherein: The rectifier circuit includes: a plurality of switches, including a first group of switches and a second group of switches coupled in parallel with each other, wherein the first group of switches is used to switch according to the first drive signal, and the second group of switches is used to switch according to the second drive signal, thereby full-wave rectifying the sensing signal to generate the resonance-related signal.

9. The resonant power converter as claimed in claim 6, wherein: The conversion control circuit also includes a sensing circuit for generating the sensing signal according to the resonant current.

10. The resonant power converter of claim 7, wherein: The integrated current also includes a slope compensation current for compensating the slope of the transconductance amplification current.

11. The resonant power converter of claim 10, wherein: The slope compensation current is related to the input voltage to achieve feed-forward control.

12. The resonant power converter of claim 6, wherein: The conversion control circuit includes: a differential circuit for differentiating the resonance-related signal to generate the ramp signal; The first driving signal and the second driving signal are further generated according to the comparison between the ramp signal and the compensation signal.

13. A conversion control circuit for controlling a resonant power converter, wherein the resonant power converter comprises a first transistor, a second transistor and a resonant circuit, wherein the first transistor and the second transistor are used to form a half-bridge circuit, wherein the resonant circuit comprises a resonant inductor, a primary winding of a transformer and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer and the resonant capacitor are coupled in series with each other, wherein the first transistor and the second transistor are used to switch the resonant circuit to generate a resonant current to convert an input voltage to generate an output voltage; the conversion control circuit comprises: a sensing circuit for generating a sensing signal according to the resonant current; and a signal processing circuit for generating a ramp signal according to the sensing signal; wherein the conversion control circuit is used to generate a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage, wherein the first driving signal and the second driving signal are used to control the first transistor and the second transistor respectively; In a signal cycle of the ramp signal, the ramp signal increases monotonically or decreases monotonically.

14. The conversion control circuit according to claim 13, wherein: The device also comprises a rectifier circuit for performing full-wave rectification on the sensing signal to generate a resonance-related signal related to the resonance current.

15. The conversion control circuit according to claim 14, wherein: The signal processing circuit comprises: a transconductance amplifier circuit for generating a transconductance amplifier current according to the resonance-related signal; and an integrating circuit, comprising an integrating capacitor, for integrating an integrating current to generate the ramp signal, wherein the integrating current comprises the transconductance amplified current; The first driving signal and the second driving signal are further generated according to the comparison between the ramp signal and the compensation signal.

16. The conversion control circuit according to claim 15, wherein: The integrated current also includes a slope compensation current for compensating the slope of the transconductance amplification current.

17. The conversion control circuit according to claim 16, wherein: The slope compensation current is related to the input voltage to achieve feed-forward control.

18. The conversion control circuit according to claim 14, wherein: The rectifier circuit includes: a plurality of switches, including a first group of switches and a second group of switches coupled in parallel with each other, wherein the first group of switches is used to switch according to the first drive signal, and the second group of switches is used to switch according to the second drive signal, thereby full-wave rectifying the sensing signal to generate the resonance-related signal.

19. The conversion control circuit according to claim 14, wherein: The signal processing circuit includes a differentiating circuit for differentiating the resonance-related signal to generate the ramp signal; The first driving signal and the second driving signal are further generated according to the comparison between the ramp signal and the compensation signal.

20. The conversion control circuit according to claim 13, wherein: In a switching cycle of the first driving signal or the second driving signal, an on-time of the first driving signal and an on-time of the second driving signal may be equal or unequal, thereby improving the transient response capability of the resonant power converter.

21. The conversion control circuit according to claim 13, wherein: The signal period of the ramp signal is smaller than a switching period of the first driving signal or the second driving signal.

22. The conversion control circuit according to claim 13, wherein: A switching period of the first driving signal and / or the second driving signal is adjusted according to the comparison between the ramp signal and the compensation signal to adjust the phase of the resonant current, thereby regulating an output power related to the output voltage.

23. The conversion control circuit according to claim 13, wherein: The ramp signal is also generated according to a differentiation or integration of a resonance-related signal related to the resonance current.

24. A conversion control method for controlling a resonant power converter, wherein the resonant power converter comprises a first transistor, a second transistor and a resonant circuit, wherein the first transistor and the second transistor are used to form a half-bridge circuit, wherein the resonant circuit comprises a resonant inductor, a primary winding of a transformer and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer and the resonant capacitor are coupled in series with each other, wherein the first transistor and the second transistor are used to switch the resonant circuit to generate a resonant current to convert an input voltage to generate an output voltage; the conversion control method comprises: generating a sensing signal according to the resonant current; Generate a ramp signal according to the sensing signal; and generating a first driving signal and a second driving signal according to the ramp signal and a compensation signal related to the output voltage, wherein the first driving signal and the second driving signal are used to control the first transistor and the second transistor respectively; In a signal cycle of the ramp signal, the ramp signal increases monotonically or decreases monotonically.

25. The conversion control method according to claim 24, wherein: The step of generating the ramp signal includes: performing full-wave rectification on the sensing signal to generate a resonance-related signal related to the resonance current.

26. The conversion control method according to claim 25, wherein: The step of generating the ramp signal also includes: Generating a transconductance amplified current according to the resonance-related signal; and Integrating an integrated current to generate the ramp signal, wherein the integrated current includes the transconductance amplified current; The step of generating the first driving signal and the second driving signal includes: comparing the ramp signal with the compensation signal.

27. The conversion control method according to claim 26, wherein: The integrated current also includes a slope compensation current for compensating the slope of the transconductance amplification current; The slope compensation current is related to the input voltage to achieve feedforward control.

28. The conversion control method according to claim 25, wherein: The step of generating the ramp signal further includes: differentiating the resonance-related signal to generate the ramp signal; wherein the step of generating the first driving signal and the second driving signal includes: comparing the ramp signal with the compensation signal.

29. The conversion control method according to claim 24, wherein: In a switching cycle of the first driving signal or the second driving signal, an on-time of the first driving signal and an on-time of the second driving signal may be optionally equal or unequal, thereby improving the transient response capability of the resonant power converter; wherein the signal period of the ramp signal is less than a switching cycle of the first driving signal or the second driving signal.

30. The conversion control method according to claim 24, wherein: The step of generating the first driving signal and the second driving signal includes: adjusting a switching period of the first driving signal and / or the second driving signal according to the comparison between the ramp signal and the compensation signal to adjust the phase of the resonant current, thereby adjusting an output power related to the output voltage.

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