TWM340660U - Half-bridge llc resonant conver with self-driven synchronous rectifier - Google Patents

Abstract

This invention discloses a half-bridge LLC resonant converter with self-driven synchronous rectifiers, which utilizes a DC shifter, a DC restorer and/or a differential transformer to drive the synchronous rectifiers in the secondary power loop. The drive voltage of the synchronous rectifiers can be either bipolar or unipolar. Under the valid operation mode, this half-bridge LLC resonant converter with self-driven synchronous rectifiers can decrease the rectifier conduction loss to increase the converter efficiency.

Description

M340660 VIII. New Description: [New Technology Field] This work reveals a half-bridge LLC spectrum converter with self-driven synchronous rectifier. - [Prior Art] The circuit diagram of the prior art is shown in FIG. 1 , in which the first switching transistor ^^ and the second switching transistor M2 are connected to the input voltage source Vin in a half-bridge configuration. Between the resonant tanks; the LLC resonant circuit includes a magnetizing inductance, the resonant inductor 4 and the resonant capacitor transformer comprise a set of primary side coils and two sets of secondary side coils I; a first rectifying diode. The second rectifying diode D2 is connected to the secondary side coil slave output capacitor C in a center-tapped fUll-wave rectifier configuration. between. For convenience of explanation, the following circuit parameters are defined: 乂 is the switching frequency of % and • %; is the resonant frequency of 4 and Cr; “=| is the ratio of the primary side to the secondary side turns of Tl; K is the output Voltage; l = voltage for reflection, in terms of circuit variation, circuit variables, and gate-source voltage ]) and c (〇, spectrum, capacitor voltage % (0, primary side) The reference polarity of the voltage vj/) and the secondary side voltage and the reference direction of the resonant inductor current 乂(7), magnetizing inductor current, (〇, primary current /〆/) and secondary side current 7 are also indicated in Figure 1. According to 乂</,乂=乂 and 乂>, the waveforms of C(0, e(/), /j), and 4) are shown in Fig. 2a, Fig. 2b, and 2c, respectively. Since there is symmetry between the first half cycle and the second half cycle M340660, only the equivalent circuit and key waveforms of the first half cycle are explained. First, the physical meanings of /=/, and &~ are as follows: The moment of restarting; the moment from a negative value to a positive value; ^ is, ♦ (the time when 〇 falls to 0; 〇) falls to 〇 engraved.

Regardless of 乂<乂 or 乂 >乂, during this period, M^M2 is turned off. Because 匕(〖) is smaller than 〇 and larger than ◦, the body diode flowing through the ground; 0)> turbulent flow into the black point end; α〇> 〇 outflow of the black point end; D! But D2 is cut off. 4 was clamped by 匕; failed to participate in the resonance of 4 and cr. /jL W and 7; (〇 are all sine waves;, (the rising slope of 〇 is 匕. 〇1 at

Aw / two /. The time is switched by zero current (zen>current_switche(j,zcs) to conduction); Ml can be zero-voltage-switched (ZVS) during the period and/or zero at the moment of Μ The current is switched to the _ state to reduce the switching loss (switdiingbss). In the case of 乂$乂, /〆/) drops to 〇 before the ground is closed (ie 丨. During this period, Μ〗 is turned on but Μ: 赖. During the period, because (10) is greater than 〇 and greater than 々 (,), therefore, (0 flows through M] channel; />(〇> 〇flow into 黑^ black point end; curry outflow ^ black point end; Α conduction but D2 cutoff. 4 is clamped; unable to participate in the spectrum., (4) and (6) white is a sine wave, the rising slope of J is ^ ^ & κ zero current is switched to the off state. ~ During the period, because the coffee is 〇 and equals W, the miscellaneous Μ H ' /» GL ; Di and D2 are both worn and not clamped by L; can participate in the 振 and ^• white vibration 'J') The rising slope is less than the zero current cut m to the conducting state at the time of the call.

M340660 In the case of Λ>Λ, (8) After Η is closed, it will drop to 0 (ie ^#〇00, |. In the same call =, Ml _Μ2 is closed. Because (10) is large (four) and greater than w, so by Ml, ~ ( ,) ~ black point of the righteousness; u') > 0 out of the black point end; & conduction but test °; do add ice, (Peach is sinusoidal; U0 rise slope is less than [ _, Μι and M2 axis. Called greater than Ό) Therefore 'j') flowing through the body of the body of the diode, (,) > 〇流 into the # black point end; curry flow "the black point end; Dl Conducted but 〇2 was closed by the system of membership; failed to participate in the

Cancer of Cr. , (/) and coffee are sine waves; (,) the rising slope is 匕. ",) at, ii, s, s, s, s, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y Since the switching transistor and the rectifying diode can be switched by zero voltage or switched by zero current, this conventional converter has low switching loss. However, this converter _ diode is a rectifier, which leads to a lower rectifier conduction loss (four) ^ also (10)! (4). This creation replaces the rectifier rectifier with a synchronous rectifier to reduce the rectification II conduction losses and reveals a cheap and efficient gate driver. The 'primary side switching transistor and the secondary side synchronous rectifier can be driven by the primary side integrated circuit control Jay or the secondary side integrated circuit controller. In practice, the primary side integrated circuit controller has three advantages over the secondary side integrated circuit controller: (1) easier to obtain (2) easier to cooperate with the primary side power factor corrector (3) easier to implement the converter Protection function. Therefore, the present invention proposes a method of driving a secondary side synchronous rectifier with a primary side integrated circuit controller. M340660 [Creation Contents] & Solve the above problems' This work reveals a half-bridge LLC resonant converter with self-driven synchronous rectifier, which uses the _ secondary side integrated circuit controller and the question mark driver with __ secondary side switch Transistor and secondary side synchronous rectifier. The idler driver is composed of an IC-based or transformer-based driver (DC), or a DC shifter (DC sinking) and a DC resetter ( Dc restorer) is composed of a differential transformer. The driving voltage of the primary side switching transistor is unipolar; the driving voltage of the secondary side synchronous rectifier can be bipolar or unipolar. [Embodiment] First, the analysis of Figs. 2a to 2c will explain the influence of the relationship between the switching frequency and the resonance frequency on the operation of the converter. In the case of 乂, during the period of /, the Μι is turned on but the M2 is turned off. Because of diL (/) V τ di 〇). Therefore, Di is closed. If D! is replaced by the first synchronous rectifier SR!, then SR is synchronized with Μ. The voltage difference between the output voltage & and the secondary side voltage v) divided by the small on-resistance of SR (con(jucti〇n resistance) will result in a large shoot-through current and burn the first synchronous rectifier SR! In the case of 乂> ,, during the period of /g, it is turned off with M2. Since M340660 diLm (/) v T diT ί/) _ a == K, D is turned on. If d! is replaced by the first synchronous rectifier, then SR is closed synchronously with Μ. 4) The body diode will flow through the si^ and the converter will still operate safely. Therefore, the half-bridge LLC resonant converter with self-driven synchronous rectifier disclosed in the present application is only applicable to the case of Λ >/. The first switch and the second switch on the primary side may be a p-channel metal oxide semiconductor field effect transistor (PMOS), an N-channel metal oxide semiconductor field effect transistor (NM0S), and a p-type connection. The p_type junction field effect transistor (p-JFET) and the N-type junction field effect transistor (n-JFET) are implemented, but attention should be paid to the polarity of the transistor electrode. By the same principle, the first synchronous rectifier and the second synchronous rectifier on the secondary side can be implemented by PMOS, NMOS, p-JFET or n-JFET', but attention should be paid to the polarity of the transistor electrode. For convenience of explanation, the first switch and the second switch on the primary side and the first synchronous rectifier and the second synchronous rectifier on the secondary side are implemented by NMOS, and are denoted as M2, SR!, SR2, respectively. The circuit diagram and the driving voltage waveform diagram of the first embodiment are shown in FIGS. 3a and 3b, respectively, wherein the primary side integrated circuit controller U! outputs two ground-referenced driving voltage % (〇) And the first switching transistor Μι and the second switching transistor M2 are connected in a half-bridge configuration between the input voltage source Vin and the resonant tank, and the connection point between Μι and M2 Recorded as p, its voltage is recorded as Vp; LLC resonant circuit includes magnetizing inductance 4, resonant inductor 々 and resonant capacitor, Mai Yaoding 2 contains 'a set of ^ primary side coil A and two sets ^ primary side coil <; ^ A synchronous rectifier SR! and a second synchronous rectifier SR2 are connected in a common source structure (c〇mm〇n_ M340660 configuration) between the secondary side coil % and the secondary side ground end, and the two sets of secondary side coil turns are connected At the voltage output terminal V., the voltage output terminal V. Connects to the wave capacitor at the secondary side ground terminal. When turned on but Μ: when turned off, the source potential is %; when Μ 〗 is turned off but % is turned on, Μ The source potential is 〇. Therefore, the source potential Vp of μ! is one. Fluctuating potential 〇! The opening of the Μ! The voltage difference between the gate and the source is higher than the gate-source threshold voltage, so an integrated circuit basic type (K&gt ;based) or a transformer-based driver module must be used to convert % (〇 and ~ (〇 into Μ: unipolar gate · source voltage heart and heart. :1:1 The ratio of the primary side to the secondary side turns ratio of the differential transformer D3 is reduced by ~(/), (/) to generate the bipolar gate and source voltage of 81^ and SR2, The voltage of the gate of the secondary synchronous rectifier is shown in Table 1: ^3 (0 y〇f(〇y〇?(〇K Kc ~Kc 0 0 0 _Kc Kc Table 1

'(〇,,^/), v^), heart illusion and illusion voltage waveform as shown in the first figure. The circuit diagram and the driving voltage waveform diagram of the second embodiment are shown in FIGS. 4a and 4c, respectively, wherein the combination of the diode Da and the resistor Rs, the combination of the diode D62 and the resistor & the second M340660 polar body 0^ The combination with the PNP bipolar transistor Qs and the combination of the diode d61 and the PNP bipolar transistor Q6 constitute a haif_wave rectifier and a fast tum-off circuit of SRi and SR2, respectively. When 4 (0=匕, D52, D51, Q6 are turned on but Q5, d62, D61 are turned off; SR] is turned on • But SR2 is turned off. When &(/)= 〇, D52, D51, D62, D61 are cut off but Q5 Q6 is turned on; SR! and SR2 are both turned off. When &(/)=', D62, D61, and Q5 are turned on but Q6, D52, and D51 are turned off; SR2 is turned on but SR is turned off. Corresponding to Ts bipolar drive Voltage, SR1 and Sr2 unipolar driving voltage are listed in Table 2: Factory r3 (') KHt) ν〇7 (0 Kc Kc 0 0 0 0 -匕0 ------- Kc Table 2

The circuit diagram and the driving voltage waveform diagram of the second embodiment are respectively shown in the first diagram and the figure, wherein the transformer T5 includes a set of primary side coils and a set of secondary side coils; the diode D7 and the diodes 〇 The combination of 8 _ Gong and shame signal distributor (s (four) distnb_). Tian 0) 乂 守 守 〇 导 8 conduction but D7 cutoff; SRi open but Sr2 closed. When (10) = ,, both D7 and d8 are cut off; both SR1 and SR2 are turned off. When it is again, D7 turns on but the U is turned off but SR] is turned off. Corresponding to the bipolar driving voltage of D5, the unipolar driving voltage of the eye and % is listed in Table 3: M340660 匕5 (') nxt) y〇s2(〇vcc 〇0 〇〇-匕〇Kc Table 3 Fourth Implementation The circuit diagram and driving voltage waveform diagrams of the example are shown in Figures 5a and 5b, respectively, wherein the primary side integrated circuit controller recognizes that the first switching transistor can be directly driven by the combination circuit of the DC shifter and the value resetter. A DC shifter is formed from the second switching transistor Μ/capacitor c4 and a pulse transformer I; the capacitor C3 and the diode D3 constitute a DC restorer. The source potential Vp is a fluctuating potential, but the source potential of Μ2 is a grounding potential, so the differential transformer cannot directly compare the gate of the Μι and the source voltage ☆(/) and Μ:gate _ The source voltage is illusory. Therefore, the continual shifter and the dc reset state must be used to convert vyG) to the reference drive voltage 对). The voltage across Q can be derived from the volt-seconds product equilibrium equation (v〇lt_sec〇nds equilibrium equation): [Kc-vC4)d^vC4(id)^vC4=dvcc where 'is the duty cycle ratio of Ml ( Dutyratio). Since /) «0.5 outside 4 = /) heart 0.5 匕, FC4 can be regarded as a fixed voltage source in one switching cycle. - The crossover voltage of the secondary side coil of the A side to the secondary side turns ratio A can be expressed as 12 X&-M340660 \Vcc-VC4 M, on and A off \-Vc , Mx off and D3 on when A is turned on When C3 is charged to ^. Therefore, C3 can also be considered as a fixed voltage source within a 'switching cycle. Voltage; 0.54 The voltage difference between the ant point B and the primary side ground can be expressed as: vB(thVc +v (t)-VJ^-^^〇nandA〇ff = onand A off 3 Λ) °4 \- Vc4 ? μ off and A on |〇, Mx off and D3 on

The secondary side circuit of the fourth embodiment is the same as the secondary side circuit of the first embodiment, and has the same voltage waveform as ^2 (0). The circuit diagram and the driving voltage waveform diagrams of the fifth embodiment and the sixth embodiment are respectively shown in 6a to 6c, the circuit on the primary side is the same as the fourth embodiment, and the circuit on the secondary side is the same as the second embodiment and the third embodiment, respectively, and can be activated by the foregoing embodiment, and no longer Re-narrative.

The embodiments described above are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement them according to the scope of the patent. That is, the equivalent changes or modifications made by the people in accordance with the spirit revealed by this creation should still be covered by the scope of the patent of this creation. 13 M340660 [Simple diagram of the diagram] The circuit diagram of the conventional half-bridge LLC resonant converter of the first figure. Waveforms of voltages and currents of patterns 2a, 2b, and 2c; respectively, corresponding to 乂 <乂, 乂 =乂 and 乂 >乂. Circuit diagram and driving voltage waveform diagrams of the first embodiment of Figs. 3a and 3b. Circuit diagram and driving voltage waveform diagrams of the second embodiment of Figs. 4a and 4c. Circuit diagram and driving voltage waveform diagram of the third embodiment of Fig. 4b and Fig. 4c. Circuit diagram and driving voltage waveform diagram of the fourth embodiment of Fig. 5a and Fig. 5b. Circuit diagram and driving voltage waveform diagram of the fifth embodiment of Fig. 6a and Fig. 6c. FIG. 6b and FIG. 6c are diagrams showing a circuit diagram and a driving voltage waveform of the sixth embodiment. [Main component symbol description] Μι, Μ〗 SR4, SR2 Q5, Q6 switching transistor Synchronous rectification transistor PNP bipolar transistor

Di, D2, D4, D51, D52, D61, D62, diode D7, Ds

Lr ' Lm cr, Co, c3, c4

Vin, V〇, Vp, Vb, VA C(〇Λ v〇s2(0 ' C(〇' C2(〇nn nn nn nn 丄1, 12, 丄3, JU, 丄5 inductor-capacitor voltage gate drive voltage) Transformer 14 M340660 A, B, P, G node lLr (1), iLm (〇, Ip (1), dip) Current t, t〇, t!, ts, tr time

Ui primary side integrated circuit controller u2 drive module resistor R5, R6

15

Claims (1)

M340660 IX. Patent application scope: 1. A half-bridge LLC resonant converter with a self-driven synchronous rectifier, comprising: a first switching transistor and a second switching transistor, wherein the first switching transistor and the first The second switch transistor is connected to the first node, and is connected in series between an external power source and a primary ground terminal; and an LLC resonant circuit comprising a series resonant capacitor, a resonant inductor and a magnetizing inductor Provided by one primary side coil of a power transformer, connected in series between the first node and the primary side ground; a power circuit comprising one of the first secondary coils of the power transformer connected in series, a second synchronous rectifying transistor, a second synchronous rectifying transistor and a second of the power transformer, the coil, the first synchronous rectifying transistor and the second synchronous rectifying transistor are connected to a first-point The second node is connected to the secondary side grounding end, and the second secondary side line and the second secondary side coil are connected to the voltage output end, and a filter is connected between the voltage output end and the secondary side ground end. capacitance a primary side integrated circuit controller; - a gate drive ϋ connected to the gate of the _ switch transistor and the gate of the second switch transistor and the primary side integrated circuit controller; and - differential voltage The device is connected to a Wei-secondary circuit controller, a pole-changer, a gate of the first-synchronous rectifying transistor and a second pole of the second synchronous rectifying transistor. 2. The half bridge of the self-driven synchronous rectifier according to claim 1 is a spectral converter, and the inter-electrode driver is an integrated circuit type or a transformer-based type gate driver. The half-bridge LLC hybrid converter with a self-driven synchronous rectifier according to claim 2, wherein the differential voltage converter comprises a secondary side coil and a second secondary side coil, and the second side of the differential voltage device The end of the coil is connected to the grounding end of the secondary side, and the other ends of the second side ring of the differential voltage device are respectively connected to the second pole of the first synchronous rectifying transistor and the second synchronous trimming crystal a gate, the primary side coil of the differential voltage device is connected to the gate driver. 4. The half-bridge LLC resonant converter with self-driven synchronous rectifier according to the item 3, further comprising a combination circuit , the - the combined circuit is a half-wave rectifier and - fast shut-off circuit of the two 16 M340660: pole: = 1 =: = = = 1 step rectification break 5. 7. (4) Brother—between the idle poles of the synchronous rectifying transistor. The self-driven synchronous rectification as described in Unexamined 4, the half-wave rectifier of the combined circuit comprises a -1 pole body: a resistor self-converter, wherein the half bridge LL__ of any synchronous rectifier, any one of them. The idling circuit of the mouth is closed with a diode and a PNP bipolar electric body. The half-bridge LLC-turn-rotator of the self-driven synchronous rectifier according to claim 2, wherein the 兮 differential voltage device comprises a secondary side coil and a secondary side coil, and the differential voltage device Two signal outputs of the two-connected-signal distributor of the side coil, the input end of the signal splitter is connected to the second node, and the signal output end of the signal splitter is respectively connected to the first-synchronous rectification The gate of the transistor and the gate of the second synchronous rectification transistor, the primary side coil of the differential is connected to the gate driver. %. The half-bridge LLC resonant converter with self-driven synchronous rectifier according to claim 7, wherein the signal distributor comprises a diode and is connected in a common anode manner, wherein the two diodes are negative= For the second round, the common anode of the two diodes is connected to the second node. 9. The half bridge LLC resonant converter of claim 1, wherein the gate driver comprises a DC shifter and a DC current resetter. Λ 10. The half-bridge LLC resonant converter with self-driven synchronous rectifier of claim 9, wherein the DC shifter comprises a capacitor and a pulse transformer. 11. The half-bridge LLC resonant converter of claim 9, wherein the DC reset comprises a capacitor and a diode. 12. The half bridge LLC resonant converter with self-driven synchronous rectifier according to claim 9, wherein the differential voltage converter comprises a primary side coil and a second secondary side coil, and the differential voltage device is The second side of the secondary side coil is connected to the secondary side grounding end, and the other two ends of the secondary side coil are respectively connected to the gate of the first synchronous rectifying transistor and the second synchronous rectifying The gate of the transistor, the primary side coil of the differential voltage transformer is connected to the gate driver. 13. The half-bridge LLC resonant converter with self-driven synchronous rectifier according to claim 12, further comprising a two-integrated circuit, wherein the combined circuit is a combination of a half-wave rectifier and a fast-close circuit, and the combined circuit Connected to the differential voltage device and the 17 M340660 gate of the first synchronous rectification transistor, and between the differential voltage device and the gate of the second synchronous rectification transistor. 14. The half-bridge LLC resonant converter with self-driven synchronous rectifier according to claim 13, wherein the half-wave rectifier of any of the combined circuits comprises a diode and a resistor. The half-bridge LLC resonant converter with self-driven synchronous rectifier according to claim 13, wherein the fast-closing circuit of the combined circuit is a diode and a pNp bipolar transistor. 16. As requested! a half-bridge LLC resonant converter with a self-driven synchronous rectifier, wherein the dynamic voltage includes a secondary side coil and a secondary side coil, and the secondary side coil of the differential voltage device Connecting two signal outputs of a signal distributor between the terminals, one of the signal distributors The second node, the signal output end of the signal distributor is respectively connected to the gate of the 5: / melon electric solar body and the gate of the second synchronous rectifying transistor, the differential electric power is the same A side coil is connected to the gate driver. A half-bridge LLC resonant converter with a self-synchronous rectifier, wherein _ ' is connected in a common anode manner, and t 2 is a cathode of the diode, and a common anode of the diode is connected to the second node. 18