Power converter with multi-stage upper bridge drive mechanism

Abstract

A power converter with a multi-stage upper bridge driving mechanism is disclosed. A control circuit outputs a first upper bridge control signal. An upper bridge driving circuit outputs a first stage upper bridge driving signal to a control terminal of an upper bridge switch according to the first upper bridge control signal and a first input voltage signal, to pull up a voltage of the control terminal of the upper bridge switch from zero to a first stage voltage. Then, the control circuit outputs a second upper bridge control signal. A charge pump outputs a charge signal. The upper bridge driving circuit outputs a second stage upper bridge driving signal to the control terminal of the upper bridge switch according to the second upper bridge control signal and the charge signal, to pull up the voltage of the control terminal of the upper bridge switch from the first stage voltage to a target voltage.

Description

Technical Field

[0001] This invention relates to a power converter, and more particularly to a power converter having a multi-stage overbridge drive mechanism. Background Technology

[0002] A power converter is used to convert input voltage and provide the converted input voltage as the output voltage to other electronic devices, enabling them to obtain the power required for operation. The on-time of the upper bridge switch in a power converter affects the magnitude of the output voltage. A charge pump is typically included within the power converter to provide charging voltage to the upper bridge switch.

[0003] However, the voltage supplied by the charge pump to the control terminal of the upper bridge switch may drop too much when the upper bridge switch is turned on, preventing the switch from opening smoothly. To avoid this, conventional power converters incorporate a large capacitor within the charge pump to provide a higher charging voltage to the control terminal of the upper bridge switch, enabling it to open smoothly and operate normally. However, this large capacitor occupies considerable space within the conventional power converter. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a power converter with a multi-stage upper-bridge drive mechanism, addressing the shortcomings of existing technologies. The converter includes an upper-bridge switch, a lower-bridge switch, a charge pump, a control circuit, a lower-bridge drive circuit, and an upper-bridge drive circuit. A first terminal of the upper-bridge switch is connected to an input power source to receive a first input voltage signal. A first terminal of the lower-bridge switch is connected to a second terminal of the upper-bridge switch. The second terminal of the lower-bridge switch is grounded. The charge pump is configured to output a charging signal. The control circuit is configured to output a first upper-bridge control signal and a second upper-bridge control signal, and to output a lower-bridge control signal. The lower-bridge drive circuit is connected to the control terminal of the lower-bridge switch and the control circuit. The lower-bridge drive circuit is configured to output a lower-bridge drive signal to the control terminal of the lower-bridge switch based on the lower-bridge control signal. The upper-bridge drive circuit is connected to the control terminal of the upper-bridge switch, the charge pump, and the control circuit. The upper-bridge drive circuit is configured to output a first-stage upper-bridge drive signal to the control terminal of the upper-bridge switch based on the first upper-bridge control signal, thereby boosting the voltage at the control terminal of the upper-bridge switch to the first-stage voltage. After the voltage at the control terminal of the upper bridge switch is raised to the first stage voltage, the upper bridge drive circuit is configured to output a second stage upper bridge drive signal to the control terminal of the upper bridge switch according to the second upper bridge control signal and the charging signal, so as to raise the voltage at the control terminal of the upper bridge switch from the first stage voltage to the target voltage.

[0005] In this embodiment, the upper bridge drive circuit includes a first upper bridge driver and a second upper bridge driver. The first upper bridge driver is connected to the control terminal of the upper bridge switch and the control circuit. The first upper bridge driver is configured to output a first-stage upper bridge drive signal to the control terminal of the upper bridge switch according to a first upper bridge control signal, so as to pull up the voltage of the control terminal of the upper bridge switch to the first-stage voltage. The second upper bridge driver is connected to the control terminal of the upper bridge switch, the charge pump, and the control circuit. After the voltage of the control terminal of the upper bridge switch is pulled up to the first-stage voltage, the second upper bridge driver is configured to output a second-stage upper bridge drive signal to the control terminal of the upper bridge switch according to a second upper bridge control signal and a charging signal, so as to pull up the voltage of the control terminal of the upper bridge switch from the first-stage voltage to the target voltage.

[0006] In this embodiment, the upper bridge drive circuit further includes a third upper bridge driver. The third upper bridge driver is connected to the control terminal and the second terminal of the upper bridge switch, and is also connected to the control circuit. The third upper bridge driver is configured to output a third upper bridge drive signal to the control terminal and the second terminal of the upper bridge switch based on a third upper bridge control signal received from the control circuit, so as to close the upper bridge switch.

[0007] In this embodiment, the first upper-bridge driver is connected to the input power supply to receive a first input voltage signal from the input power supply. When the first upper-bridge driver receives the first upper-bridge control signal, it pulls up the voltage at the control terminal of the upper-bridge switch to the first stage voltage according to the first input voltage signal.

[0008] In this embodiment, the charging pump is connected to the input power supply to receive a first input voltage signal from the input power supply.

[0009] In this embodiment, the first stage voltage is equal to the voltage of the first input voltage signal.

[0010] In this embodiment, the charging pump includes a first capacitor. A first terminal of the first capacitor is connected to an input power source to receive a first input voltage signal from the input power source. The first terminal of the first capacitor is also connected to an upper bridge drive circuit. The second terminal of the first capacitor is grounded.

[0011] In this embodiment, the charging pump further includes a second capacitor. A first terminal of the second capacitor is connected to an input power source to receive a first input voltage signal from the input power source. A second terminal of the second capacitor is connected to the first terminal of the first capacitor.

[0012] In this embodiment, the charging pump further includes a first switching assembly. A first terminal of the first switching assembly is connected to an input power source to receive a first input voltage signal from the input power source. A second terminal of the first switching assembly is connected to a first terminal of a second capacitor.

[0013] In this embodiment, the charging pump further includes a second switching assembly. A first terminal of the second switching assembly is connected to a second terminal of the second capacitor. The second terminal of the second switching assembly is connected to a first terminal of the first capacitor.

[0014] In this embodiment, the charging pump further includes a third switching assembly. A first terminal of the third switching assembly is connected to an input power source to receive a first input voltage signal from the input power source. A second terminal of the third switching assembly is connected to a second terminal of a second capacitor.

[0015] In this embodiment, the charging pump further includes a fourth switching component. A first terminal of the fourth switching component is connected to a first terminal of the second capacitor. A second terminal of the fourth switching component is coupled to a reference voltage.

[0016] In this embodiment, the difference between the first-stage voltage and the target voltage is a boost voltage. The reference voltage is equal to the voltage of the first input voltage signal minus the boost voltage.

[0017] As described above, this invention provides a power converter with a multi-stage bridge drive mechanism. The bridge drive circuit first raises the voltage at the control terminal of the bridge switch from zero to a first-stage voltage based on the input voltage signal. Then, a charge pump raises the voltage at the control terminal of the bridge switch from the first-stage voltage to the target voltage, thereby enabling the bridge switch to turn on and operate normally. That is, the charge pump does not need to directly and significantly raise the voltage at the control terminal of the bridge switch from zero to the target voltage. Therefore, only a small capacitor needs to be included in the charge pump, thus saving space occupied by the capacitor in the power converter.

[0018] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0019] Figure 1 This is a block diagram of a power converter with a multi-stage bridge driving mechanism according to the first embodiment of the present invention.

[0020] Figure 2 This is a block diagram of a power converter with a multi-stage bridge driving mechanism according to a second embodiment of the present invention.

[0021] Figure 3 The waveform diagram shows the signal of the power converter with a multi-stage bridge drive mechanism according to the second embodiment of the present invention.

[0022] Figure 4 This is a waveform diagram of the signal from a traditional power converter. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" as used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0024] Please see Figure 1 This is a block diagram of a power converter with a multi-stage bridge driving mechanism according to the first embodiment of the present invention.

[0025] The power converter in this embodiment of the invention may include an upper bridge switch HS, a lower bridge switch LS, a charge pump CHP, a control circuit COT, a lower bridge drive circuit LDR, and an upper bridge drive circuit HDR.

[0026] The first terminal of the upper bridge switch HS is connected to the input power supply to receive the first input voltage signal VM. The first terminal of the lower bridge switch LS is connected to the second terminal of the upper bridge switch HS. The second terminal of the lower bridge switch LS is grounded. The upper bridge drive circuit HDR is connected to the control terminal of the upper bridge switch HS, the charge pump CHP, and the control circuit COT. The lower bridge drive circuit LDR is connected to the control terminal of the lower bridge switch LS and the control circuit COT.

[0027] First, the control circuit COT can output a first upper bridge control signal HON1 to the upper bridge drive circuit HDR based on an upper bridge enable signal HSEN received from the external enable circuit.

[0028] The upper bridge drive circuit HDR can output a first-stage upper bridge drive signal to the control terminal of the upper bridge switch HS based on (the first input voltage signal VM received from the input power supply and) the first upper bridge control signal HON1 received from the control circuit COT, so as to pull up the voltage at the control terminal of the upper bridge switch HS (from zero value) to the first-stage voltage. The first-stage voltage is greater than zero. For example, this first-stage voltage is equal to the voltage of the first input voltage signal VM.

[0029] Next, the control circuit COT outputs a second upper-bridge control signal HON2 to the upper-bridge drive circuit HDR. The charge pump CHP outputs a charging signal to the upper-bridge drive circuit HDR.

[0030] When the upper bridge drive circuit HDR receives the second upper bridge control signal HON2 from the control circuit COT, it obtains a charging signal from the charge pump CHP. Based on this charging signal, it outputs a second-stage upper bridge drive signal to the control terminal of the upper bridge switch HS, thereby raising the voltage at the control terminal of the upper bridge switch HS from the first-stage voltage to the target voltage. The target voltage is greater than the first-stage voltage. For example, the target voltage is as follows: Figure 1 The target voltage signal VCP shown is a target voltage.

[0031] The charge pump CHP may contain one or more capacitors, such as, but not limited to, those that are not limited to, Figure 1 The first capacitor C1 and the second capacitor C2 are shown. If necessary, the charge pump CHP may further include one or more switching components, such as, but not limited to, [other components]. Figure 1 The first switch assembly SW1, the second switch assembly SW2, the third switch assembly SW3, and the fourth switch assembly SW4 are shown.

[0032] A first terminal of the first switching assembly SW1 can be connected to an input power source to receive a first input voltage signal VM from the input power source. A second terminal of the first switching assembly SW1 can be connected to a first terminal of a second capacitor C2. A second terminal of the second capacitor C2 can be connected to a first terminal of the second switching assembly SW2.

[0033] The second terminal of the second switching assembly SW2 can be connected to the first terminal of the first capacitor C1. The second terminal of the first capacitor C1 can be grounded. The first terminal of the first capacitor C1 and the second terminal of the second switching assembly SW2 can be connected to the input terminal of the upper bridge drive circuit HDR.

[0034] The first terminal of the third switching assembly SW3 can be connected to an input power supply to receive a first input voltage signal VM from the input power supply. The second terminal of the third switching assembly SW3 is connected to the second terminal of the second capacitor C2. The first terminal of the second capacitor C2 is connected to the first terminal of the fourth switching assembly SW4. The second terminal of the fourth switching assembly SW4 is coupled to a reference voltage Vref.

[0035] For example, the first-stage voltage (e.g., the voltage of the first input voltage signal VM) and the target voltage (e.g., the voltage of the first input voltage signal VM) mentioned above. Figure 1 The difference between the target voltage signal VCP shown and the target voltage is a boost voltage (e.g., a target voltage). Figure 1 The voltage of the pull-up voltage signal VP shown is given. The reference voltage Vref can be equal to the voltage of the first input voltage signal VM minus the pull-up voltage, for example, 5V. This is only an example and is not intended to limit the invention.

[0036] It should be understood that in the charge pump CHP, the switching of the first switching component SW1, the second switching component SW2, the third switching component SW3, and the fourth switching component SW4 will affect the voltage of the first capacitor C1, and thus affect the voltage of the charging signal output by the charge pump CHP to the upper bridge drive circuit HDR.

[0037] It is worth noting that in the power converter of the present invention, the upper bridge drive circuit HDR first raises the voltage of the control terminal of the upper bridge switch HS (from zero) to the first stage voltage according to the first upper bridge control signal HON1 (and the first input voltage signal VM). Then, the charging signal output by the charge pump CHP only needs to raise the voltage of the control terminal of the upper bridge switch HS from the first stage voltage (greater than zero) to the target voltage (e.g., from the voltage of the first input voltage signal VM to a target voltage of the target voltage signal VCP), rather than from zero. Therefore, the charge pump CHP of the present invention only needs to have capacitors with small capacitance (e.g., the first capacitor C1 and the second capacitor C2), effectively reducing the space occupied by the capacitors of the charge pump CHP within the power converter.

[0038] When the control circuit COT drives the upper bridge drive circuit HDR to turn the upper bridge switch HS on or off, the control circuit COT can also output a lower bridge control signal LSCT based on the lower bridge enable signal LSEN received from the external enable circuit. The lower bridge drive circuit LDR can output a lower bridge drive signal to the control terminal of the lower bridge switch LS based on the lower bridge control signal LSCT to turn the lower bridge switch LS on or off.

[0039] Please see Figure 2 This is a block diagram of a power converter with a multi-stage bridge drive mechanism according to the second embodiment of the present invention. The similarities between the second embodiment and the first embodiment will not be repeated here.

[0040] like Figure 2 As shown, in this embodiment, the upper bridge driver circuit HDR may include a first upper bridge driver HDR1 and a second upper bridge driver HDR2. If necessary, the upper bridge driver circuit HDR may further include, for example... Figure 2 The third upper bridge driver shown is HDR3.

[0041] The first upper bridge driver HDR1 is connected to the input power supply to receive the first input voltage signal VM from the input power supply, and is also connected to the control terminal of the upper bridge switch HS and the control circuit COT.

[0042] The second upper bridge driver HDR2 is connected to the control terminal of the upper bridge switch HS, the control circuit COT, and the first terminal of the first capacitor C1 of the charge pump CHP.

[0043] The third upper bridge driver HDR3 is connected to the control terminal and the second terminal of the upper bridge switch HS, and is also connected to the control circuit COT.

[0044] It is worth noting that the first bridge driver HDR1 can output a first-stage bridge drive signal to the control terminal of the bridge switch HS based on the first bridge control signal HON1 (and the first input voltage signal VM) received from the control circuit COT, so as to pull up the voltage at the control terminal of the bridge switch HS from zero to the first-stage voltage. For example, the first-stage voltage is equal to the voltage of the first input voltage signal VM.

[0045] Next, the second upper-bridge driver HDR2 can output a second-stage upper-bridge drive signal to the control terminal of the upper-bridge switch HS based on the second upper-bridge control signal HON2 received from the control circuit COT and a charging signal (e.g., the voltage signal of the first capacitor C1) received from the charge pump CHP, so as to pull up the voltage at the control terminal of the upper-bridge switch HS from the first-stage voltage to the target voltage. For example, the target voltage is equal to the voltage of the target voltage signal VCP.

[0046] When the first bridge driver HDR1 and the second bridge driver HDR2 turn on the bridge switch HS, the third bridge driver HDR3 can output a third bridge drive signal to the control terminal and the second terminal of the bridge switch HS according to the third bridge control signal HOFF received from the control circuit COT, so as to turn off the bridge switch HS.

[0047] Please see Figure 2 , Figure 3 and Figure 4 ,in Figure 3 This is a waveform diagram of the power converter with a multi-stage overbridge drive mechanism according to the second embodiment of the present invention. Figure 4 This is a waveform diagram of the signal from a traditional power converter.

[0048] like Figure 2 and Figure 3 As shown, when the control circuit COT of the power converter of the present invention is enabled by the bridge enable signal HSEN to output a high-level first bridge control signal HON1, the first bridge driver HDR1, according to the high level of the first bridge control signal HON1, pulls the voltage of a bridge control voltage signal VHG at the control terminal of the bridge switch HS from zero to a first stage voltage. For example, this first stage voltage is equal to the voltage of the first input voltage signal VM, i.e., the first input voltage Vvm.

[0049] Next, the second upper bridge driver HDR2 of the power converter of the present invention, based on the high level of the second upper bridge control signal HON2 received from the control circuit COT, pulls the voltage of an upper bridge control voltage signal VHG at the control terminal of the upper bridge switch HS from the first stage voltage (e.g., this first stage voltage is equal to the first input voltage Vvm) to the target voltage Vvcp.

[0050] That is, in the power converter of the present invention, the upper bridge drive circuit HDR first pulls the voltage at the control terminal of the upper bridge switch HS from zero to the first stage voltage according to the first input voltage signal VM of the input power supply. Then, the power converter of the present invention uses the charge pump CHP to pull the voltage at the control terminal of the upper bridge switch HS from this first stage voltage to the target voltage Vvcp. Therefore, the power converter of the present invention only needs to include a small capacitor, which can save the space occupied by the capacitor of the charge pump CHP.

[0051] In comparison, such as Figure 4 As shown, in a conventional power converter, when the control circuit is enabled by the upper bridge enable signal HSEN0 to output a high-level upper bridge control signal HON20, the charge pump directly pulls the voltage of the upper bridge control voltage signal VHG0 at the control terminal of the upper bridge switch from zero to the target voltage Vvcp.

[0052] Because when the upper bridge switch of a traditional power converter is turned on during the high-level time of the upper bridge switch control signal HON20, the voltage at the control terminal of the upper bridge switch will be as follows: Figure 4 The bridge control voltage signal VCP0 drops significantly. A large capacitor is required in the charge pump of a traditional power converter to successfully raise the voltage at the control terminal of the bridge switch from zero to the target voltage Vvcp. However, this large capacitor occupies considerable space within the traditional power converter.

[0053] In summary, this invention provides a power converter with a multi-stage up-bridge drive mechanism. The up-bridge drive circuit first raises the voltage at the control terminal of the up-bridge switch from zero to a first-stage voltage based on the input voltage signal. Then, the charge pump raises the voltage at the control terminal of the up-bridge switch from the first-stage voltage to the target voltage, thereby enabling the up-bridge switch to turn on and operate normally. That is, the charge pump does not need to directly and significantly raise the voltage at the control terminal of the up-bridge switch from zero to the target voltage. Therefore, only a small capacitor needs to be included in the charge pump, thus saving space occupied by the capacitor in the power converter.

[0054] The above-disclosed content is only a preferred embodiment of the present invention and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A power converter with a multi-stage overbridge drive mechanism, characterized in that, The power converter includes: An upper bridge switch, wherein the first terminal of the upper bridge switch is connected to an input power supply and receives a first input voltage signal from the input power supply; A lower bridge switch, wherein the first terminal of the lower bridge switch is connected to the second terminal of the upper bridge switch, and the second terminal of the lower bridge switch is grounded; A charging pump configured to output a charging signal; The control circuit is configured to output a first upper bridge control signal and a second upper bridge control signal, and to output a lower bridge control signal; A lower bridge drive circuit is connected to the control terminal of the lower bridge switch and the control circuit, and is configured to output a lower bridge drive signal to the control terminal of the lower bridge switch according to the lower bridge control signal. as well as An upper bridge drive circuit is connected to the control terminal of the upper bridge switch and the control circuit. The upper bridge drive circuit is configured to output a first-stage upper bridge drive signal to the control terminal of the upper bridge switch according to the first upper bridge control signal, so as to pull up the voltage of the control terminal of the upper bridge switch to the first-stage voltage. Wherein, after the voltage at the control terminal of the upper bridge switch is pulled up to the first stage voltage, the upper bridge drive circuit is configured to output a second stage upper bridge drive signal to the control terminal of the upper bridge switch according to the second upper bridge control signal and the charging signal, so as to pull up the voltage at the control terminal of the upper bridge switch from the first stage voltage to the target voltage; The charging pump includes a first switching assembly, a second switching assembly, a third switching assembly, a fourth switching assembly, a first capacitor, and a second capacitor. The first terminal of the first switching assembly and the first terminal of the third switching assembly are connected to the input power supply and receive a first input voltage signal from the input power supply. The second terminal of the first switching assembly and the first terminal of the fourth switching assembly are connected to the first terminal of the second capacitor. The first terminal of the second switching assembly and the second terminal of the third switching assembly are connected to the second terminal of the second capacitor. The second terminal of the second switching assembly and the upper bridge drive circuit are connected to the first terminal of the first capacitor. The second terminal of the first capacitor is grounded. The second terminal of the fourth switching assembly is coupled to a reference voltage. Wherein, the reference voltage coupled to the second terminal of the fourth switching component is equal to the voltage of the first input voltage signal minus a pull-up voltage, and the pull-up voltage is equal to the difference between the first stage voltage reached by the control terminal of the upper bridge switch after the first pull-up and the target voltage reached after the second pull-up.

2. The power converter with a multi-stage upper bridge drive mechanism according to claim 1, characterized in that, The upper bridge drive circuit includes: A first bridge driver is connected to the control terminal of the bridge switch and the control circuit, and is configured to output a first-stage bridge drive signal to the control terminal of the bridge switch according to the first bridge control signal, so as to pull up the voltage of the control terminal of the bridge switch to the first-stage voltage. as well as The second bridge driver is connected to the control terminal of the bridge switch, the first terminal of the first capacitor, and the control circuit. It is configured to output a second-stage bridge drive signal to the control terminal of the bridge switch according to the second bridge control signal and the charging signal after the voltage at the control terminal of the bridge switch is pulled up to the first stage voltage, so as to pull up the voltage at the control terminal of the bridge switch from the first stage voltage to the target voltage.

3. The power converter with a multi-stage upper bridge drive mechanism according to claim 2, characterized in that, The upper bridge drive circuit also includes: A third upper bridge driver is connected to the control terminal and the second terminal of the upper bridge switch, and is also connected to the control circuit. It is configured to output a third upper bridge drive signal to the control terminal and the second terminal of the upper bridge switch based on a third upper bridge control signal received from the control circuit, so as to turn off the upper bridge switch.

4. The power converter with a multi-stage upper bridge drive mechanism according to claim 2, characterized in that, The first upper bridge driver is connected to the input power supply to receive the first input voltage signal from the input power supply; Specifically, when the first bridge driver receives the first bridge control signal, the first bridge driver pulls up the voltage at the control terminal of the bridge switch to the first stage voltage according to the first input voltage signal.

5. The power converter with a multi-stage upper bridge drive mechanism according to claim 1, characterized in that, The voltage of the first stage is equal to the voltage of the first input voltage signal.

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