JP2009268325A - Fly back converter - Google Patents

Fly back converter Download PDF

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Publication number
JP2009268325A
JP2009268325A JP2008118036A JP2008118036A JP2009268325A JP 2009268325 A JP2009268325 A JP 2009268325A JP 2008118036 A JP2008118036 A JP 2008118036A JP 2008118036 A JP2008118036 A JP 2008118036A JP 2009268325 A JP2009268325 A JP 2009268325A
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Japan
Prior art keywords
voltage
synchronous rectification
turned
control circuit
transformer
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Withdrawn
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JP2008118036A
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Japanese (ja)
Inventor
Nobuyuki Inoue
Yasuki Takeda
信之 井上
泰樹 武田
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Noritz Corp
Noritz Electronics Technology Corp
ノーリツエレクトロニクステクノロジー株式会社
株式会社ノーリツ
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Priority to JP2008118036A priority Critical patent/JP2009268325A/en
Publication of JP2009268325A publication Critical patent/JP2009268325A/en
Application status is Withdrawn legal-status Critical

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Abstract

A synchronous rectification type flyback converter with few malfunctions, ideal operation and low loss is provided.
A control circuit 1 for a main switch SW1 is provided with a control circuit for a synchronous rectification switch SW2 so that the synchronous rectification switch SW2 can be controlled, and a voltage detection line 2 for detecting a voltage on the secondary side of a transformer T. Connect. Then, the control circuit 1 controls the synchronous rectification switch SW2 to be turned on / off in a phase opposite to that of the main switch SW1. In the case of the current discontinuous mode, when the synchronous rectification switch SW2 is turned on, the control circuit 1 monitors the voltage V2 of the secondary winding, and when this voltage V2 changes from a positive voltage to a negative voltage, The rectification switch SW2 is turned off, and the state is maintained until the main switch SW1 is turned on next and then turned off again.
[Selection] Figure 1

Description

  The present invention relates to a flyback converter, and more particularly to a control technique for a flyback converter having a synchronous rectification switch on the secondary winding side of a switching transformer.

FIG. 5A is a circuit diagram showing a basic configuration of a conventional flyback converter.
As is well known, this type of flyback converter has a transformer T wound so that the primary winding N1 and the secondary winding N2 have opposite polarities (the direction in which the coil starts to be wound is indicated by “·”). A primary switch N1 is connected to a main switch SW1 (for example, a semiconductor element such as a transistor or FET) capable of high-speed switching by a drive signal P1 from the control circuit 1, and a rectifier diode is connected to the secondary winding N2 side. D1 and the smoothing capacitor C2 are connected, and the output voltage Vout is extracted from both ends of the smoothing capacitor C2. In the figure, C1 indicates a capacitor provided on the input side.

  FIG. 5B is a waveform diagram showing an example of the operation of such a flyback converter. In the figure, P1 is a drive signal for the main switch SW1, Vd1 is a voltage applied to the rectifier diode D1, and In2 is a waveform of a current flowing through the secondary winding N2.

  As shown in the figure, when the drive signal P1 from the control circuit 1 is turned on (see the period Ton in the figure), the main switch SW1 is turned on and the input voltage Vin is applied to the primary winding N1 of the transformer T. A current flows through the next winding N1. At this time, since the secondary winding N2 of the transformer T has a reverse polarity, a reverse voltage is applied to the secondary-side rectifier diode D1, so no current flows, and the energy supplied to the primary winding N1. Is stored in the transformer T.

  When the drive signal P1 is turned off (see the period of Toff in the figure), the main switch SW1 is turned off and the power supply to the primary winding N1 of the transformer T is stopped, and at the same time, the secondary winding N2 is reversed. An electromotive force is generated, a forward voltage is applied to the rectifier diode D1, the rectifier diode D1 is turned on, and the energy accumulated in the transformer T is released to the output side (capacitor C2).

  Here, FIG. 5B shows a state in which the control circuit 1 is operating in a current discontinuous mode (an operation mode in which all energy accumulated in the transformer T is released during the period of Toff). In this case, even if the current In2 flowing through the secondary winding N2 becomes zero, there is a certain period ta until the main switch SW1 is turned on next time. By the way, as the operation mode, in addition to the current discontinuous mode shown in FIG. 5B, a critical mode in which energy release is completed at the end of the Toff period, and all energy is not released during the Toff period. There is a current continuous mode in which the Ton period starts while leaving the residual energy, but which operation mode is adopted is set in the control circuit 1. The present invention to be described later is applied to a flyback converter in which the control circuit 1 has the current discontinuous mode.

  When the energy accumulated in the transformer T is thus released, the control circuit 1 turns on the drive signal P1 again, and thereafter, the ON / OFF ratio set according to the target voltage of the output voltage Vout. In response to this, ON / OFF of the drive signal P1 is repeated to supply power to the output side. At that time, in the illustrated flyback converter, the output voltage Vout is monitored by the control circuit 1, and the feedback control of the ON / OFF ratio of the drive signal P1 is performed so that the output voltage Vout is stabilized at the target voltage. It is configured.

By the way, in the flyback converter using the diode D1 in the secondary side rectifier circuit as described above, the forward voltage V F of the rectifier diode D1 is normally about 0.5 V, so the output voltage Vout is low. voltage (e.g., about 3.3V) case, the ratio of the forward voltage V F of the rectifier diode D1 occupying the output voltage is high, it is impossible to obtain a high conversion efficiency.

  Therefore, in order to solve such a problem, a synchronous rectification method using a power MOSFET with low on-loss as the synchronous rectification switch SW2 instead of the rectification diode D1 has been proposed (for example, see Patent Document 1).

  FIG. 6A shows an example of the circuit configuration of a flyback converter that employs such a synchronous rectification method. Here, the power MOSFET has a characteristic that it is turned on when a signal equal to or higher than the threshold voltage is applied between the gate and the source, and both the drain-to-source direction and the source-to-drain direction become conductive. Therefore, when such a power MOSFET is used as the synchronous rectification switch SW2, it is necessary to prevent the reverse current (reverse direction in the rectifier diode D1) from flowing and to control only the forward current to flow. is there. Therefore, in the circuit shown in FIG. 6 (a), the current flowing through the secondary circuit is monitored using a detector (comparator CP) whose output is connected to the gate of the power MOSFET, and the current is inverted. The power MOSFET is configured to be switched on / off.

Japanese Unexamined Patent Publication No. 7-7928

  However, such a circuit configuration shown in FIG. 6 (a) has the following problems, and improvements have been desired.

(1) That is, if the synchronous rectification switch SW2 is an ideal switch (see FIGS. 6B and 6A) having no capacitance component, the energy stored in the transformer T when the main switch SW1 is turned off. Is started, the current (In2) flowing through the secondary circuit gradually decreases to zero, and then remains zero until the main switch SW1 is turned off again to release energy. However, since this type of power MOSFET has a parasitic capacitance a and a parasitic diode b as in the equivalent circuit shown in FIGS. 6B and 6B, in an actual circuit, the inductance component of the transformer T is used. When the current in the secondary circuit is switched from positive to zero due to the parasitic capacitance a of the power MOSFET, voltage oscillation occurs, and at the same time, the current also oscillates (see the waveform during the period tb in FIG. 6C).

  Therefore, in the circuit configuration shown in FIG. 6 (a), the detector detects the vibration of the current and the power MOSFET malfunctions (specifically, as shown in malfunction example 1 in FIG. 6 (c), the power MOSFET In some cases, the drive signal P2 applied to the gate of the first and second gates is repeatedly turned ON / OFF in accordance with voltage oscillation.

(2) In addition, in the circuit configuration of FIG. 6 (a), when detecting the current of the secondary circuit, the detector detects the current by replacing it with a voltage, so the input voltage of the detector is a very small voltage. Therefore, due to detector variation (offset variation), the current is not zero but erroneously determined to be zero (specifically, as shown in Malfunction Example 2 in FIG. 6 (c), the current is not zero). In some cases, however, the drive signal P2 is turned off.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a synchronous rectification type flyback converter with few malfunctions, ideal operation, and low loss. With the goal.

  In order to achieve the above object, a flyback converter according to the present invention is a flyback converter having a synchronous rectifier switch on the secondary side of the transformer, and is provided with voltage monitoring means for monitoring the voltage of the secondary winding of the transformer. The switching control unit maintains the primary switch on the primary side of the transformer in the OFF state and maintains the synchronous rectification switch on the secondary side of the transformer in the ON state. When detecting that the voltage of the secondary winding has changed from a positive voltage to a negative voltage, the synchronous rectification switch is turned off, and the synchronous rectification switch is turned off until the main switch is turned on again after being turned on next time. A control configuration for maintaining the state is provided.

  That is, the flyback converter of the present invention performs ON / OFF control of the synchronous rectification switch using the switching control unit that performs ON / OFF control of the main switch on the primary side of the transformer. In controlling the synchronous rectification switch, the switching control unit turns off the main switch and simultaneously turns on the synchronous rectification switch. In this state, that is, when the main switch is maintained in the OFF state and the synchronous rectification switch is maintained in the ON state, the voltage of the secondary winding detected by the voltage monitoring means is positive. When the voltage changes to a negative voltage, the synchronous rectification switch is switched from ON to OFF at that timing. Then, the synchronous rectification switch is kept off until the main switch is turned on and then turned off again.

  As described above, the flyback converter of the present invention maintains this state until the synchronous rectification switch is turned off when the voltage of the secondary winding of the transformer changes from the positive voltage to the negative voltage and then the main switch is turned off again. Therefore, even if voltage oscillation occurs in the current discontinuous period, the synchronous rectification switch is prevented from being repeatedly turned ON / OFF by the voltage oscillation.

  As a preferred embodiment of the present invention, an auxiliary winding may be provided in the transformer, and the voltage monitoring unit may be configured to monitor the voltage of the auxiliary winding.

  That is, since a voltage proportional to the voltage of the secondary winding appears in the auxiliary winding provided in the transformer, the voltage of the auxiliary winding is monitored without directly detecting the voltage of the secondary winding, The synchronous rectification switch can be switched from ON to OFF at a timing when the voltage changes from a positive voltage to a negative voltage. Also in this case, after the synchronous rectification switch is turned off, the synchronous rectification switch is kept off until the main switch is turned on and then turned off again.

  In this embodiment, since the voltage of the secondary winding is indirectly detected through the auxiliary winding, the switching control unit can be provided on the primary side of the transformer.

  Furthermore, as another preferred embodiment of the present invention, the switching control unit can be configured to perform ON / OFF control of the main switch by a pseudo resonance method.

  That is, according to this embodiment, since the main switch is ON / OFF controlled by the pseudo resonance method, it is possible to provide a flyback converter with little switching loss.

  According to the present invention, the switching control unit detects that the voltage of the secondary winding or auxiliary winding of the transformer has changed from a positive voltage to a negative voltage, turns off the synchronous rectification switch, and then turns on the main switch. Since the synchronous rectification switch remains off until it is turned off again, even if voltage oscillation occurs during the current discontinuity period, the synchronous rectification switch does not malfunction, allowing ideal operation and loss. Thus, it is possible to provide a synchronous rectification type flyback converter with less power consumption.

  Hereinafter, a switching power supply device to which a flyback converter according to the present invention is applied will be described in detail with reference to the drawings. FIG. 1 shows a first embodiment of a flyback converter according to the present invention, FIG. 1 (a) is a circuit diagram showing a schematic configuration of the flyback converter, and FIG. 1 (b) shows its waveform. The figure is shown.

  The flyback converter shown in FIG. 1 applies ON / OFF control of the main switch SW1 to the control circuit (switching control unit) 1 based on the voltage of the secondary winding N2 of the transformer T. A function for performing OFF control is provided, and accordingly, a configuration for detecting the voltage of the secondary winding N2 of the transformer T and a synchronous rectification switch SW2 based on the detected voltage are provided. And a configuration for performing ON / OFF control. Since the other points are the same as those of the flyback converter shown in FIG. 6 described above, the parts having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  In the flyback converter according to the first embodiment, since the synchronous rectification switch SW2 is connected to the negative pole side of the secondary winding N2 of the transformer T, the secondary winding is connected to the negative pole side of the secondary winding N2. One end of the voltage detection line 2 for detecting the voltage of the winding N2 is connected and the other end is connected to the control circuit 1 so that the voltage signal of the secondary winding N2 can be taken into the control circuit 1. The That is, in this embodiment, voltage monitoring means for monitoring the voltage of the secondary winding N2 of the transformer T is configured by the voltage detection line 2 and a part of the control circuit 1.

  Then, the control circuit 1 supplies the drive signal P2 to the gate of the synchronous rectification switch SW2 based on the voltage V2 of the secondary winding N2 detected via the voltage detection line 2, thereby turning on the synchronous rectification switch SW2. / OFF control is performed. In the figure, reference numeral 3 denotes a signal line for supplying the drive signal P2 to the synchronous rectification switch SW2.

  The operation of the flyback converter thus configured (the control configuration of the control circuit 1) will be described below with reference to the waveform diagram of FIG.

  The configuration related to ON / OFF control of the main switch SW1 in the control circuit 1 is the same as that of a conventionally known control circuit. That is, the control circuit 1 gives the drive signal P1 to the main switch via the signal line 4 connected to the control terminal of the main switch SW1 (the FET is used as the main switch SW1 in the illustrated example). It is configured as follows. The drive signal P1 is generated by a PWM controller (not shown) provided in the control circuit 1.

  Here, since the configuration of the PWM controller and the ON / OFF ratio of the drive signal P1 are well known, the description thereof will be omitted. A controller having a current discontinuous mode in which a winding is provided and a PWM controller detects that the primary side voltage has been reduced by this auxiliary winding (not shown) is used. FIG. 1 (b) shows a state of operating in this current discontinuous mode. In the present embodiment, the PWM controller is configured to monitor the output voltage Vout and perform feedback control so that the output voltage becomes the target voltage when setting the ON / OFF ratio of the drive signal P1. Yes. In the figure, reference numeral 5 indicates a voltage detection line for feedback control.

  When the drive signal P1 for the main switch SW1 shown in FIG. 1B is output from the control circuit 1, an input current flows through the primary winding N1 of the transformer T during the period Ton when the drive signal P1 is ON. When energy is accumulated in the transformer T and the drive signal P1 is turned OFF, the energy accumulated in the transformer T during the Toff is released to the secondary side.

  At this time, in the ON / OFF control of the synchronous rectification switch SW2, the control circuit 1 basically generates and synchronizes the drive signal P2 so that the synchronous rectification switch SW2 is turned ON / OFF in the opposite phase to the main switch SW1. Although given to the gate of the rectifying switch SW2, when operating in the current discontinuous mode as shown in the present embodiment, the following control is executed in the current discontinuous period.

  That is, when the control circuit 1 outputs the drive signal P1 for turning off the main switch SW1 described above, the control circuit 1 turns on the drive signal P2 of the synchronous rectification switch SW2 in synchronization with this. As a result, the synchronous rectification switch SW2 becomes conductive, and the current In2 due to the counter electromotive force flows through the secondary winding N2 of the transformer T. As shown in FIG. 1 (b), the current In2 is gradually reduced as energy is released, and eventually becomes zero. As described above, when the current In2 becomes zero, voltage oscillation occurs in the secondary circuit, and the current In2 also causes minute current oscillation.

  When the control circuit 1 is in such a state, that is, in a state where the drive signal P1 of the main switch SW1 is maintained OFF and the drive signal P2 of the synchronous rectification switch SW2 is maintained ON, the voltage detection line 2 is used to monitor the voltage of the secondary winding N2 and detect when the voltage of the secondary winding N2 changes from a positive voltage to a negative voltage. Specifically, in this embodiment, control is performed to detect when the voltage V2 of the secondary winding N2 is inverted from a positive voltage to a negative voltage, and to switch the synchronous rectification switch SW2 from ON to OFF at the timing when this inversion is detected. The signal P2 is output.

  Here, the reason why the voltage of the secondary winding N2 is monitored as the timing of turning off the synchronous rectification switch SW2 is that the voltage oscillation has a larger fluctuation than the current oscillation and is easy to detect (see FIG. This is because the release of the energy of the transformer T can be reliably captured (see the vibration waveform of In2 and V2 in 1 (b)).

  When the control circuit 1 turns off the synchronous rectification switch SW2, the control circuit 1 maintains the OFF state of the synchronous rectification switch SW2 until the main switch SW1 is turned on and then turned off again. That is, the control circuit 1 is configured to maintain the drive signal P2 for the synchronous rectification switch SW2 in the OFF state at least until the drive signal P1 for the main switch SW1 is turned from OFF to ON.

  As described above, the control circuit 1 has a control configuration in which the drive signal P2 is generated and applied to the synchronous rectification switch SW2 so that the synchronous rectification switch SW2 is turned on / off in the opposite phase to the main switch SW1. If the drive signal P2 of the synchronous rectification switch SW2 is maintained in the OFF state until the drive signal P1 for the SW1 is turned from OFF to ON, the drive signal for the synchronous rectification switch SW2 is maintained during the subsequent period of the main switch SW1 being ON. Since P2 is also maintained in the OFF state, as a result, the OFF state of the synchronous rectification switch SW2 is maintained until the main switch SW1 is turned from OFF to ON and then turned off again. When outputting the drive signal P1 for turning off the main switch SW1 again, the control circuit 1 outputs the drive signal P2 for turning on the synchronous rectification switch SW2 as described above, and thereafter turning on / off the main switch SW1. The above-described operation is repeated according to the above.

  Therefore, according to the configuration of the present embodiment, the control circuit 1 can reliably detect that the current In2 of the secondary circuit has become zero and can turn off the synchronous rectification switch SW2, and the current can be reduced. It is possible to maintain the OFF state of the synchronous rectification switch SW2 without causing the synchronous rectification switch SW2 to malfunction due to voltage oscillation in the continuous period. Therefore, according to the present embodiment, it is possible to provide a synchronous rectification type flyback converter that is free from malfunction of the synchronous rectification switch SW2, can perform ideal operation, and has little loss.

  In the flyback converter shown in the first embodiment, as shown in FIG. 2, the synchronous rectification switch SW2 can be provided on the positive pole side of the secondary winding N2. In this case, the secondary winding The voltage detection line 2 for detecting the voltage of the line N2 is also connected to the + side line of the secondary winding N2.

  Next, a second embodiment of the present invention will be described with reference to FIG. The flyback converter shown in FIG. 3 is obtained by modifying the configuration of the voltage monitoring means in the first embodiment described above.

  That is, in the flyback converter shown in the second embodiment, the voltage monitoring means directly monitors the voltage V2 of the secondary winding N2 in the above-described first embodiment. An auxiliary winding N3 is provided at T, and the voltage V3 of the auxiliary winding N3 is monitored by voltage monitoring means, so that the voltage of the secondary winding N2 is indirectly monitored.

  Specifically, an auxiliary winding N3 having the same polarity as the secondary winding N2 is wound on the secondary side of the transformer T, and a voltage detection line 6 for detecting the voltage of the auxiliary winding N3 is provided on the auxiliary winding N3. By connecting, the voltage of the auxiliary winding N3 can be taken into the control circuit 1.

  That is, according to this configuration, since the voltage V3 proportional to the voltage V2 of the secondary winding N2 is generated in the auxiliary winding 3, the control circuit 1 varies the voltage of the secondary winding N2 based on this voltage V3. Configured to monitor.

  Specifically, also in the present embodiment, the configuration related to the ON / OFF control of the main switch SW1 in the control circuit 1 is the same as that of a conventionally known control circuit. On the other hand, in the ON / OFF control of the synchronous rectification switch SW2, the control circuit 1 basically generates and synchronizes the drive signal P2 so that the synchronous rectification switch SW2 is turned on / off in the opposite phase to the main switch SW1. The rectifier switch SW2 is configured to be supplied. In the current discontinuous period, the following control is particularly executed.

  That is, when outputting the drive signal P1 for turning off the main switch SW1, the control circuit 1 outputs the drive signal P2 for turning on the synchronous rectification switch SW2 in synchronization with this.

  In this state, that is, when the drive signal P1 of the main switch SW1 is maintained OFF and the drive signal P2 of the synchronous rectification switch SW2 is maintained ON, the control circuit 1 6 is used to monitor the voltage of the auxiliary winding N3. That is, since the voltage V3 proportional to the voltage V2 of the secondary winding N2 appears in the auxiliary winding N3, the voltage of the auxiliary winding N3 is a positive voltage as in the monitoring of the voltage V2 of the secondary winding N2. The time point when the voltage changes from negative to negative is detected. Specifically, also in this embodiment, the time point when the voltage V3 of the auxiliary winding N3 is inverted from the positive voltage to the negative voltage is detected, and when this inversion is detected, the control signal P2 for switching the synchronous rectification switch SW2 from ON to OFF is output. To do.

  Then, after turning off the synchronous rectification switch SW2, the control circuit 1 maintains the synchronous rectification switch SW2 in the OFF state until the main switch SW1 is turned on next time and then turned off again, as in the first embodiment.

  Thus, even with the configuration of the present embodiment, the control circuit 1 can reliably detect that the current In2 of the secondary circuit has become zero and can turn off the synchronous rectification switch SW2, and the current It is possible to maintain the OFF state of the synchronous rectification switch SW2 without causing the synchronous rectification switch SW2 to malfunction due to voltage oscillation in the discontinuous period. In addition, in the present embodiment, since the voltage fluctuation of the secondary winding N2 is detected through the auxiliary winding N3, the control circuit 1 can be provided on the primary side. IC) on the premise that it is arranged on the primary side of the circuit can be improved and the manufacturing cost can be reduced.

  In the flyback converter shown in the second embodiment as well, as shown in FIG. 4, it is possible to provide the synchronous rectification switch SW2 on the positive pole side of the secondary winding N2.

  Note that the above-described embodiments merely show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope thereof.

  For example, in the above-described embodiment, the control circuit 1 detects the time when the voltage V2 (or V3) of the secondary winding N2 (or auxiliary winding N3) is inverted from the positive voltage to the negative voltage, and sets the synchronous rectification switch SW2. Although the case where it is configured to switch from ON to OFF has been shown, the timing of this switching can be configured to be performed, for example, when the voltage of the secondary winding N2 approaches zero voltage. In short, it is sufficient that the synchronous rectification switch SW2 is not accidentally turned ON when the voltage of the secondary winding N2 is inverted from a negative voltage to a positive voltage due to voltage oscillation.

  Further, the present invention can be applied to a flyback converter having a current discontinuous mode even if it has a critical mode or a current continuous mode. In the above-described embodiment, the case where the control circuit 1 adopts the quasi-resonance method has been shown. However, the present invention is naturally applicable to a flyback converter that controls ON / OFF of the main switch SW1 by other methods. is there.

FIG. 1 shows a first embodiment of a flyback converter according to the present invention. FIG. 1A is a circuit diagram of the flyback converter, and FIG. 1B is a waveform diagram thereof. It is a circuit diagram which shows the modification of the flyback converter shown to the said 1st Embodiment. It is a circuit diagram which shows 2nd Embodiment of the flyback converter which concerns on this invention. It is a circuit diagram which shows the modification of the flyback converter shown to the said 2nd Embodiment. It is explanatory drawing which shows the basic composition of the conventional flyback converter, Fig.5 (a) has shown the circuit diagram, FIG.5 (b) has shown the waveform diagram. FIG. 6A is an explanatory diagram showing an outline of a conventional flyback converter adopting a synchronous rectification method, FIG. 6A is a circuit diagram thereof, FIG. 6B is an equivalent circuit of a synchronous rectification switch, and FIG. Shows a waveform diagram of the circuit.

Explanation of symbols

1 Control circuit (switching control unit)
2,6 Voltage detection lines 3, 4 Drive signal signal line SW1 Main switch SW2 Synchronous rectifier switch P1 Main switch drive signal P2 Synchronous rectifier switch drive signal

Claims (3)

  1. In a flyback converter with a synchronous rectifier switch on the secondary side of the transformer,
    Voltage monitoring means for monitoring the voltage of the secondary winding of the transformer is provided;
    In the state where the primary switch on the primary side of the transformer is maintained in the OFF state and the synchronous rectification switch on the secondary side of the transformer is maintained in the ON state, the switching control unit is When detecting that the voltage of the next winding has changed from a positive voltage to a negative voltage, the synchronous rectification switch is turned off, and the synchronous rectification switch is turned off until the main switch is turned on and then turned off again. A flyback converter comprising a control configuration for maintaining the control.
  2. An auxiliary winding is provided in the transformer,
    The flyback converter according to claim 1, wherein the voltage monitoring means is configured to monitor the voltage of the auxiliary winding.
  3.   3. The flyback converter according to claim 1, wherein the switching control unit performs ON / OFF control of the main switch by a pseudo resonance method. 4.
JP2008118036A 2008-04-30 2008-04-30 Fly back converter Withdrawn JP2009268325A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008118036A JP2009268325A (en) 2008-04-30 2008-04-30 Fly back converter

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JP2008118036A JP2009268325A (en) 2008-04-30 2008-04-30 Fly back converter

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015015811A (en) * 2013-07-04 2015-01-22 富士通テレコムネットワークス株式会社 Synchronous rectification power supply device
CN107251399A (en) * 2015-08-25 2017-10-13 戴洛格半导体公司 Adaptive synchronous commutating device is controlled
CN108471239A (en) * 2013-01-22 2018-08-31 电力集成公司 Controller for synchronous flyback switched mode power converter
WO2019123868A1 (en) * 2017-12-20 2019-06-27 ソニー株式会社 Synchronous rectifier control circuit, control method, power supply system, electronic device, electric vehicle, and power system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108471239A (en) * 2013-01-22 2018-08-31 电力集成公司 Controller for synchronous flyback switched mode power converter
JP2015015811A (en) * 2013-07-04 2015-01-22 富士通テレコムネットワークス株式会社 Synchronous rectification power supply device
CN107251399A (en) * 2015-08-25 2017-10-13 戴洛格半导体公司 Adaptive synchronous commutating device is controlled
WO2019123868A1 (en) * 2017-12-20 2019-06-27 ソニー株式会社 Synchronous rectifier control circuit, control method, power supply system, electronic device, electric vehicle, and power system

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Effective date: 20110705