DC-DC boost circuit and driving circuit board

Abstract

The present disclosure belongs to the technical field of display. Provided are a DC-DC boost circuit and a driving circuit board. The DC-DC boost circuit comprises a power MOSFET and a control module electrically connected to a control end of the power MOSFET, wherein the control module is configured to provide a control signal capable of controlling the turning-on and turning-off of the power MOSFET. The voltage value of a high-level signal in the control signal is 0.5-0.8 times the maximum rated value of the gate-source voltage of the power MOSFET. The DC-DC boost circuit can reduce the temperature of a power MOSFET. (Figure 3)

Description

DC-DC boost circuit and driver circuit board

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application number 202310632831.X, filed on May 31, 2023, entitled “DC-DC Boost Circuit and Drive Circuit Board”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a DC-DC boost circuit and a driving circuit board. Background Art

[0004] High-power DC-DC (direct current to direct current) boost circuits are often used in high-brightness display devices such as liquid crystal displays (LCDs) and micro-LED displays. Due to size and cost constraints, these DC-DC boost circuits often use power MOSFETs (metal-oxide semiconductor field-effect transistors) in smaller packages, often without the ability to add heat sinks. This leads to overheating of the MOSFETs.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art and provide a DC-DC boost circuit and a drive circuit board to reduce the temperature of the power MOSFET.

[0008] According to one aspect of the present disclosure, there is provided a DC-DC boost circuit, comprising a power MOSFET and a control module electrically connected to a control terminal of the power MOSFET;

[0009] The control module is configured to provide a control signal capable of controlling the on and off of the power MOSFET; wherein the voltage value of the high-level signal in the control signal is 0.5 to 0.8 times the maximum rated value of the gate-source voltage of the power MOSFET.

[0010] According to an embodiment of the present disclosure, the control module is further configured to, when providing a sink current to the control terminal of the power MOSFET, ensure that the maximum value of the sink current is not less than 0.5A.

[0011] According to an embodiment of the present disclosure, the control module includes a driver chip, a voltage stabilizing unit, an inverter unit, and a driver unit;

[0012] The driving chip is configured to provide an initial control signal;

[0013] The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high-level signal in the control signal;

[0014] The inverter unit includes a second resistor and a second switch, wherein a first end of the second resistor is electrically connected to the output end of the voltage stabilizing unit, a second end of the second resistor and a first end of the second switch are electrically connected to a first node, and a second end of the second switch is used to apply a ground voltage; a control end of the second switch is electrically connected to the output end of the driver chip; and the second switch is configured to be turned on in response to a high-level signal in the initial control signal and turned off in response to a low-level signal in the initial control signal;

[0015] The first end of the driving unit is electrically connected to the output end of the voltage stabilizing unit, and the second end of the driving unit is used to load the ground voltage; the control end of the driving unit is electrically connected to the first node, and the output end of the driving unit is electrically connected to the control end of the power MOSFET; the driving unit is configured to conduct between the first end of the driving unit and the control end of the power MOSFET when the voltage of the first node is at a low level, and to conduct between the second end of the driving unit and the control end of the power MOSFET when the voltage of the first node is at a high level.

[0016] According to an embodiment of the present disclosure, the driving unit includes a third switch and a fourth switch;

[0017] A first end of the third switch is electrically connected to the output end of the voltage stabilizing unit, and a first end of the fourth switch is used to apply the ground voltage; a control end of the third switch and a control end of the fourth switch are electrically connected to the first node, and a second end of the third switch and a second end of the fourth switch are electrically connected to the control end of the power MOSFET;

[0018] The third switch is configured to be turned on when the voltage on the first node is at a low level and to be turned off when the voltage on the first node is at a high level; the fourth switch is configured to be turned on when the voltage on the first node is at a high level and to be turned off when the voltage on the first node is at a low level.

[0019] According to an embodiment of the present disclosure, the control module further includes an EMC suppression resistor, one end of the EMC suppression resistor is electrically connected to the first node, and the other end of the EMC suppression resistor is electrically connected to the control end of the drive unit.

[0020] According to an embodiment of the present disclosure, the second switch is a transistor or a MOSFET.

[0021] According to an embodiment of the present disclosure, the control module includes a driver chip, a voltage stabilizing unit, and a driver unit;

[0022] The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high-level signal in the control signal;

[0023] The driving chip is configured to output an initial control signal according to the driving voltage provided by the voltage stabilizing unit;

[0024] The first end of the driving unit is electrically connected to the output end of the voltage stabilizing unit, and the second end of the driving unit is used to load the ground voltage; the control end of the driving unit is configured to receive the initial control signal, and the output end of the driving unit is electrically connected to the control end of the power MOSFET; the driving unit is configured to electrically conduct between the first end of the driving unit and the power MOSFET in response to a high-level signal in the initial control signal, and to electrically conduct between the second end of the driving unit and the power MOSFET in response to a low-level signal in the initial control signal.

[0025] According to an embodiment of the present disclosure, the driving unit includes a third switch and a fourth switch;

[0026] A first end of the third switch is electrically connected to the output end of the voltage stabilizing unit, and a first end of the fourth switch is used to apply the ground voltage; a control end of the third switch and a control end of the fourth switch are configured to receive the initial control signal, and a second end of the third switch and a second end of the fourth switch are electrically connected to the control end of the power MOSFET;

[0027] The third switch is configured to be turned on in response to a high level signal in the initial control signal, and to be turned off in response to a low level signal in the initial control signal;

[0028] The fourth switch is configured to be turned on in response to a low-level signal in the initial control signal, and to be turned off in response to a high-level signal in the initial control signal.

[0029] According to an embodiment of the present disclosure, the control module further includes an EMC suppression resistor, one end of the EMC suppression resistor is used to load the initial control signal, and the other end is electrically connected to the control end of the drive unit.

[0030] According to an embodiment of the present disclosure, the third switch and the fourth switch are transistors or MOSFETs.

[0031] According to an embodiment of the present disclosure, the control module includes a driver chip and a voltage stabilizing unit;

[0032] The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high-level signal in the control signal;

[0033] The driving chip is configured to output the control signal according to the driving voltage.

[0034] According to one embodiment of the present disclosure, the DC-DC boost circuit further includes a gate resistor and a diode;

[0035] The first end of the gate resistor is electrically connected to the output end of the control module, and the second end of the gate resistor is electrically connected to the control end of the power MOSFET; the anode of the diode is electrically connected to the second end of the gate resistor, and the cathode of the diode is electrically connected to the first end of the gate resistor.

[0036] According to an embodiment of the present disclosure, the voltage stabilizing unit includes a first switch, a voltage stabilizing diode, a first resistor, and a filtering subcircuit;

[0037] The first end of the first switch is used to load the input voltage, and the second end of the first switch is electrically connected to the output end of the voltage stabilizing unit; a first resistor is connected between the control end of the first switch and the first end of the first switch, the control end of the first switch is electrically connected to the cathode of the voltage stabilizing diode, and the anode of the voltage stabilizing diode is used to load the ground voltage; the filtering subcircuit is electrically connected to the output end of the voltage stabilizing unit.

[0038] According to an embodiment of the present disclosure, the DC-DC boost circuit further includes an input-end filter unit, an inductor, a diode, and an output-end filter unit;

[0039] The first end of the inductor is used to load the input voltage and is electrically connected to the input filter unit; the second end of the inductor is connected to the first end of the power MOSFET, and the second end of the power MOSFET is used to load the ground voltage;

[0040] The anode of the diode is electrically connected to the first end of the power MOSFET; the cathode of the diode is electrically connected to the output end of the DC-DC boost circuit and is connected to the output end filter unit.

[0041] According to a second aspect of the present disclosure, a driving circuit board is provided, comprising the above-mentioned DC-DC boost circuit.

[0042] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0044] FIG1 is a schematic structural diagram of a driving circuit board in one embodiment of the present disclosure.

[0045] FIG2 is a schematic diagram showing the principle of a DC-DC boost circuit in one embodiment of the present disclosure.

[0046] FIG3 is a schematic diagram showing the principle of a DC-DC boost circuit in another embodiment of the present disclosure.

[0047] FIG4 is a schematic diagram of the principle of a control module in one embodiment of the present disclosure.

[0048] FIG5 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0049] FIG6 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0050] FIG7 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0051] FIG8 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0052] FIG9 is a schematic diagram of the principle of a control module in one embodiment of the present disclosure.

[0053] FIG10 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0054] FIG11 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure.

[0055] FIG12 is a schematic diagram of the principle of a control module in one embodiment of the present disclosure.

[0056] FIG13 is a schematic diagram of an equivalent circuit of a control module in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0058] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0059] The present disclosure provides a driver circuit board (see FIG1 ). The driver circuit board includes one or more DC-DC (direct current to direct current) boost circuits. The driver circuit board can be used to drive a light board or display panel. For example, the driver circuit board can be used to drive a direct-lit LED (light-emitting diode) backlight board or a direct-lit Micro LED (micro-light-emitting diode) backlight board. Of course, the driver circuit board of the present disclosure can also be used in other devices.

[0060] In the driver circuit board provided in this embodiment, the DC-DC boost circuit can be optimized to reduce the power consumption of the power MOSFET in the DC-DC boost circuit, thereby reducing the temperature of the power MOSFET and improving the performance stability of the driver circuit board.

[0061] Referring to Figure 2 , the DC-DC boost circuit includes a power MOSFET and a control module CTR connected to the control terminal of the power MOSFET. The control module CTR is configured to provide a control signal capable of turning the power MOSFET on and off; the control signal includes a high-level signal and a low-level signal. The voltage value of the high-level signal in the control signal is 0.5 to 0.8 times the maximum rated gate-source voltage of the power MOSFET.

[0062] In this embodiment, the high-level signal of the control signal provided by the control module CTR has a relatively high voltage value, which can enable the power MOSFET to maintain a higher gate-source voltage when it is turned on, thereby reducing the static loss of the power MOSFET, especially significantly reducing the conduction loss of the power MOSFET, thereby significantly reducing the power consumption of the power MOSFET and reducing the heat release of the power MOSFET, thereby preventing the power MOSFET and the DC-DC boost circuit from overheating. In this embodiment, when the high-level signal of the control signal is applied to the control terminal of the power MOSFET, the gate-source voltage of the power MOSFET is substantially equal to the voltage value of the high-level signal (without considering voltage drop); so that the voltage value of the high-level signal of the control signal is 0.5 to 0.8 times the maximum rated value of the gate-source voltage of the power MOSFET, it can ensure the safety of the power MOSFET and maximize the gate-source voltage of the power MOSFET when it is turned on. In this way, the DC-DC boost circuit can reduce the loss and heat generation of the power MOSFET while ensuring the safety of the power MOSFET.

[0063] In the relevant technology, the loss of power MOSFET mainly includes static loss and dynamic loss. Among them, static loss includes conduction loss (also known as power conduction loss) and cutoff loss (also known as turn-off loss). Dynamic loss mainly includes switching loss, gate drive loss, built-in diode forward loss (also known as freewheeling loss), internal diode reverse loss, etc. The zero gate voltage leakage current of power MOSFET is small, so the cutoff loss is not the main loss factor of power MOSFET. The total gate charge of power MOSFET and the reverse recovery charge of the PN junction of the internal diode are also very small, so the gate drive loss and the internal diode reverse loss are not the main loss factors of power MOSFET.

[0064] In related technologies, the largest share of power MOSFET losses comes from conduction losses. Switching losses primarily consist of on-state losses and off-state losses. In the disclosed embodiments, the control module CTR can increase the gate-source voltage of the power MOSFET when it is on, thereby reducing the static impedance of the power MOSFET when it is on, thereby lowering the conduction losses of the power MOSFET. Furthermore, increasing the gate-source voltage of the power MOSFET when it is on can also reduce the on-state losses of the power MOSFET. Thus, the DC-DC boost circuit of the disclosed embodiments can reduce power MOSFET losses and lower the temperature of the power MOSFET.

[0065] In one example, the voltage value of the high-level signal in the control signal is 0.6 to 0.7 times the maximum rated value of the gate-source voltage of the power MOSFET. For example, when the maximum rated value of the gate-source voltage of the power MOSFET is 20V, the voltage value of the high-level signal in the control signal can be set to 12 to 14V, thereby ensuring that the gate-source voltage of the power MOSFET is within the range of 12 to 14V when it is turned on.

[0066] In some related technologies, a chip can be used to directly control a power MOSFET. The voltage value of the high-level signal of the control signal output by the chip is often relatively low, for example, generally between 4 and 8V. Although this high-level signal is sufficient to turn on the power MOSFET, the gate-source voltage of the power MOSFET is not high enough, which causes the power MOSFET to have a large on-resistance, resulting in large conduction losses and severe heat generation, and the temperature of the power MOSFET is high. In the embodiments of the present disclosure, the gate-source voltage of the power MOSFET when it is turned on can be increased as much as possible while ensuring the safety of the power MOSFET. For example, the gate-source voltage of the power MOSFET when it is turned on can be increased to 12 to 14V, thereby achieving the purpose of reducing the conduction losses of the power MOSFET, reducing the heat generation of the power MOSFET, and lowering the temperature of the power MOSFET.

[0067] It will be appreciated that the above embodiment merely uses the maximum gate-source voltage rating of the power MOSFET as 20V as an example to illustrate the gate-source voltage when the power MOSFET is turned on. In other embodiments of the present disclosure, the maximum gate-source voltage rating of the power MOSFET may not be 20V, for example, it may be 25V, 30V, etc. Furthermore, the maximum gate-source voltage rating of the power MOSFET can be obtained by consulting the power MOSFET's parameter manual.

[0068] In one embodiment of the present disclosure, the control module CTR is further configured such that, when providing a sink current to the control terminal of the power MOSFET, the maximum value of the sink current is no less than 0.5A, for example, between 1A and 2A. In this way, the control module CTR can provide a large sink current to the power MOSFET, thereby further reducing the on-state loss of the power MOSFET and facilitating lowering the temperature of the power MOSFET. It will be understood that when the control module CTR provides a sink current to the control terminal of the power MOSFET, the magnitude of the sink current is dynamically changing rather than being a constant current.

[0069] In one embodiment of the present disclosure, see 2, the DC-DC boost circuit may further include a gate resistor Rg. A first end of the gate resistor Rg is electrically connected to the output terminal of the control module CTR, and a second end of the gate resistor Rg is electrically connected to the control terminal of the power MOSFET. In this manner, when the control module CTR applies a high-level signal to the control terminal of the power MOSFET, the gate resistor Rg can also control the current flow, preventing damage to the power MOSFET caused by transiently excessive current flow.

[0070] In one embodiment of the present disclosure, referring to FIG3 , the DC-DC boost circuit may further include a diode D2. The anode of diode D2 is electrically connected to the second end of gate resistor Rg, and the cathode of diode D2 is electrically connected to the first end of gate resistor Rg. When the control signal output by control module CTR is low, the control terminal of the power MOSFET can discharge through diode D2 and gate resistor Rg. At this time, diode D2 is turned on, thereby enabling the power MOSFET to have a large current draw, which can reduce the power MOSFET's off-state loss.

[0071] In one embodiment of the present disclosure, referring to FIG2 , the DC-DC boost circuit further includes an input filter unit Cin, an inductor L, a diode DD, and an output filter unit Cout; the first end of the inductor L is used to apply the input voltage Vin and is electrically connected to the input filter unit Cin. The second end of the inductor L is electrically connected to the first end of the power MOSFET, and the second end of the power MOSFET is used to apply the ground voltage GND. The anode of the diode DD is electrically connected to the first end of the power MOSFET; the cathode of the diode DD is electrically connected to the output end of the DC-DC boost circuit and to the output filter unit Cout. In this way, the control module CTR can make the output voltage Vout of the boost circuit higher than the input voltage Vin by controlling the conduction and cutoff of the power MOSFET.

[0072] In one embodiment of the present disclosure, referring to Figures 4 to 13 , a control module CTR may include a voltage stabilizing unit U1 configured to provide a driving voltage that is no less than the voltage of the high-level signal in the control signal. The control module CTR can utilize this driving voltage to ensure that the high-level signal of the output control signal has a higher voltage value, thereby increasing the gate-source voltage of the power MOSFET when it is turned on. This overcomes the problem of low voltage values ​​of the high-level signal of the control signal directly output by the control chip in related art.

[0073] Optionally, the voltage stabilizing unit U1 can output a driving voltage based on the input voltage Vin. In this way, the power supply on the driver circuit board can simultaneously power the inductor L and the voltage stabilizing unit U1, which helps simplify the driver circuit board and reduce the cost of the driver circuit board. Of course, in other embodiments of the present disclosure, the voltage stabilizing unit U1 can also use other power supply voltages to generate the driving voltage.

[0074] In one example, the voltage stabilizing unit U1 includes a first switch Q1, a Zener diode ZD1, a first resistor R1, and a filter subcircuit C1. The first end of the first switch Q1 is used to apply the input voltage Vin, and the second end of the first switch Q1 is electrically connected to the output end of the voltage stabilizing unit U1. A first resistor R1 is connected between the control end of the first switch Q1 and the first end of the first switch Q1. The control end of the first switch Q1 is electrically connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is used to apply the ground voltage GND. The filter subcircuit C1 is electrically connected to the output end of the voltage stabilizing unit U1. In this example, the first switch Q1, the Zener diode ZD1, and the first resistor R1 form a voltage regulator. The filter subcircuit C1 can filter the output of the voltage regulator to remove the AC component. The appropriate Zener diode ZD1 can be selected based on the required drive voltage. For example, when the maximum gate-source voltage rating of the power MOSFET is 20V and the derating factor used is 0.6-0.7, the Zener diode ZD1 can have a stable voltage range of 12V-14V. It is understood that when selecting the first switch Q1, the first resistor R1, and the Zener diode ZD1, the specifications (e.g., current specifications, power specifications, voltage specifications, etc.) of the first switch Q1, the first resistor R1, and the Zener diode ZD1 can also be verified to avoid damage to the first switch Q1, the first resistor R1, and the Zener diode ZD1 during operation due to non-compliant specifications.

[0075] In the embodiment of the present disclosure, a variety of different strategies can be adopted to utilize the voltage stabilizing unit U1 to generate a control signal and make the voltage value of the high-level signal of the control signal higher, and even enable the control module CTR to provide a large current injection for the control terminal of the power MOSFET.

[0076] In one embodiment of the present disclosure, referring to Figures 4 to 8, the control module CTR includes a driver chip DIC, a voltage stabilizing unit U1, an inverter unit U2, and a driver unit U3. The driver chip DIC is configured to provide an initial control signal, which includes a high-level signal and a low-level signal. The voltage stabilizing unit U1 is configured to provide a driving voltage, which is not less than the voltage of the high-level signal in the control signal. The inverter unit U2 includes a second resistor R2 and a second switch Q2, wherein the first end of the second resistor R2 is electrically connected to the output end of the voltage stabilizing unit U1, the second end of the second resistor R2 and the first end of the second switch Q2 are electrically connected to the first node N1, and the second end of the second switch Q2 is used to load the ground voltage GND.

[0077] The driver chip DIC has an output terminal GATE for outputting an initial control signal. The control terminal of the second switch Q2 is electrically connected to the output terminal of the driver chip. Thus, the control terminal of the second switch Q2 can receive the initial control signal from the driver chip DIC. The second switch Q2 is configured to turn on in response to a high-level signal in the initial control signal and to turn off in response to a low-level signal in the initial control signal. When the second switch Q2 is turned on, the voltage at the first node N1 is pulled down to the ground voltage GND, reaching a low level. When the second switch Q2 is turned off, the voltage at the first node N1 is pulled up to a high level by the voltage stabilization unit U1.

[0078] The first end of the driving unit U3 is electrically connected to the output end of the voltage stabilizing unit U1, and the second end of the driving unit U3 is used to apply the ground voltage GND. The control end of the driving unit U3 is electrically connected to the first node N1, and the output end of the driving unit U3 is electrically connected to the control end of the power MOSFET. The driving unit U3 is configured to conduct electricity between the first end of the driving unit U3 and the control end of the power MOSFET when the voltage at the first node N1 is low (the driving unit U3 outputs a high-level control signal at this time), and to conduct electricity between the second end of the driving unit U3 and the control end of the power MOSFET when the voltage at the first node N1 is high (the driving unit U3 outputs a low-level control signal at this time).

[0079] In this way, when the voltage at the first node N1 is low, the driving voltage can be written to the control terminal of the power MOSFET (i.e., providing a sink current to charge the control terminal of the power MOSFET), turning on the power MOSFET and ensuring a high gate-source voltage when the power MOSFET is on. Furthermore, because the driving voltage has a large voltage value, the driver unit U3 can provide a large sink current to the control terminal of the power MOSFET. Overall, when the initial control signal output by the driver chip DIC is a high-level signal, the control signal output by the driver unit U3 is a high-level signal. Conversely, when the voltage at the first node N1 is high, the ground voltage GND can be written to the control terminal of the power MOSFET via the driver unit U3 (i.e., providing a drain current to discharge the control terminal of the power MOSFET), thereby turning off the power MOSFET. In this process, the control terminal of the power MOSFET discharges, which is equivalent to the driver unit U3 providing a drain current to the control terminal of the power MOSFET. Overall, when the initial control signal output by the driver chip DIC is a low-level signal, the control signal output by the driver unit U3 is a low-level signal. In this way, the control signal output by the driving unit U3 is synchronized with the initial control signal output by the driving chip DIC.

[0080] In this embodiment, the inverter unit U2 and the driver unit U3 together constitute a level conversion sub-circuit, which converts the high-level voltage of the initial control signal output by the driver chip DIC into the gate drive voltage required by the power MOSFET; the driver unit U1 provides the sink current of the gate drive current required by the power MOSFET, and the gate drive current also includes the draw current (also called the leakage current)."

[0081] Optionally, the voltage value of the high-level signal output by the driver unit U3 is greater than the voltage value of the high-level signal of the initial control signal output by the driver chip DIC. In this way, the control module CTR can convert the low-voltage high-level signal output by the driver chip DIC into a high-voltage high-level signal, thereby increasing the gate-source voltage of the power MOSFET when it is turned on and reducing the power MOSFET's losses.

[0082] Optionally, the sink current output by the driving unit U3 is greater than the sink current output by the driving chip DIC, so as to further reduce the on-state loss of the power MOSFET.

[0083] In some examples of this embodiment, the second switch Q2 may be a MOSFET, such as an N-type MOSFET. This allows the second switch Q2 to have a wide range of applications, particularly in high-power DC-DC boost circuits. For example, when the power of the DC-DC boost circuit is greater than 100W, such as when the power of the DC-DC boost circuit is 150W, the second switch Q2 may be a MOSFET.

[0084] In other examples of this embodiment, the second switch Q2 can be a transistor. Thus, the second switch Q2 can be used in low- to medium-power DC-DC boost circuits. For example, when the power of the DC-DC boost circuit is no greater than 100W, such as 80W, the second switch Q2 can be a transistor.

[0085] In some examples of this embodiment, the driving unit U3 includes a third switch Q3 and a fourth switch Q4; a first end of the third switch Q3 is connected to the output end of the voltage stabilizing unit U1, and a first end of the fourth switch Q4 is used to apply the ground voltage GND; a control end of the third switch Q3 and a control end of the fourth switch Q4 are electrically connected to the first node N1, and a second end of the third switch Q3 and a second end of the fourth switch Q4 are electrically connected to a second node N2, which is electrically connected to the control end of the power MOSFET, for example, via a gate resistor Rg. The third switch Q3 is configured to be turned on when the voltage at the first node N1 is low and to be turned off when the voltage at the first node N1 is high; and the fourth switch Q4 is configured to be turned on when the voltage at the first node N1 is high and to be turned off when the voltage at the first node N1 is low.

[0086] In one example, the third switch Q3 and the fourth switch Q4 can be MOSFETs. For example, the third switch Q3 can be a P-type MOSFET and the fourth switch Q4 can be an N-type MOSFET. This drive unit U3 has a wide range of applications, particularly in high-power DC-DC boost circuits. For example, when the power of the DC-DC boost circuit is greater than 100W, such as when the power of the DC-DC boost circuit is 150W, the third switch Q3 and the fourth switch Q4 can be MOSFETs.

[0087] In another example, the third switch Q3 and the fourth switch Q4 may be transistors. In this case, the drive unit U3 may be used in a low- to medium-power DC-DC boost circuit. For example, when the power of the DC-DC boost circuit is no greater than 100W, such as 80W, the third switch Q3 and the fourth switch Q4 may be transistors.

[0088] In one exemplary embodiment, the second switch Q2, the third switch Q3, and the fourth switch Q4 are MOSFETs. The disclosed embodiments also tested this DC-DC boost circuit. Three DC-DC boost circuits were provided on the verification driver circuit board, each of which used the control module of this example to control the power MOSFETs. Three DC-DC boost circuits were provided on the control driver circuit board; the three DC-DC boost circuits on the verification driver circuit board corresponded one-to-one with the three DC-DC boost circuits on the control driver circuit board. The three DC-DC boost circuits on the verification driver circuit board all employed conventional technology, using a driver chip to directly control the power MOSFETs. The driver chip on the verification driver circuit board was identical to the driver chip on the control driver circuit board. The verification driver circuit board and the control driver circuit board were each operated for 2.5 hours, and then the temperature of the power MOSFETs in each DC-DC boost circuit was measured. The temperatures of the three power MOSFETs on the verification driver circuit board were 80.0°C, 83.5°C, and 67.2°C, respectively; the temperatures of the corresponding three power MOSFETs on the control driver circuit board were 96.0°C, 92.8°C, and 89.8°C, respectively. It can be seen from this that after adopting the solution of this implementation, the temperatures of the three power MOSFETs on the driver circuit board all dropped significantly (the first power MOSFET dropped from 96.0°C to 80.0°C, the second power MOSFET dropped from 92.8°C to 83.5°C, and the third power MOSFET dropped from 89.8°C to 67.2°C).

[0089] In another example, the second switch Q2 , the third switch Q3 , and the fourth switch Q4 are transistors.

[0090] In an example, the on-resistances of the third switch Q3 and the fourth switch Q4 are both relatively small, for example, both are less than 2 ohms.

[0091] In one embodiment of the present disclosure, the second resistor R2 may be selected to have an appropriate resistance value so that the current passing through the second resistor R2 when it is turned on is between 50 mA and 300 mA. In this way, the steepness of the waveform at the first node N1 can be improved.

[0092] In one example of this embodiment, the control module CTR further includes an EMC suppression resistor Rx (electromagnetic interference suppression resistor). A first end of the EMC suppression resistor Rx is electrically connected to the first node N1, and a second end of the EMC suppression resistor Rx is electrically connected to a control terminal of the drive unit U3 (e.g., to a control terminal of the third switch Q3 and a control terminal of the fourth switch Q4). Electromagnetic interference can be reduced by properly setting the resistance value of the EMC suppression resistor Rx.

[0093] In this embodiment, the driving voltage provided by the voltage stabilizing unit U1 does not need to be applied to the driver chip DIC. The final sink current output by the control module CTR is also provided by the voltage stabilizing unit U1, not by the driver chip DIC. Therefore, this embodiment is applicable to various types of driver chips DIC, as long as the driver chip DIC can provide the initial control signal. For example, the driver chip DIC can be either one that can utilize an external sink voltage or one that cannot. This greatly expands the selection range of driver chips DIC, avoiding the high material costs and low chip versatility caused by a narrow selection range, thereby helping to reduce costs.

[0094] For example, when the driver chip DIC is not capable of utilizing an external voltage sink, the voltage value of the high-level signal of the initial control signal output by the driver chip DIC is determined by the voltage within the chip, which is a fixed and generally low voltage, and the output current sink is generally small. The disclosed embodiment can utilize this initial control signal to control the second switch Q2, and thus the driver unit U3, generating a high-level control signal and a current sink using the drive voltage provided by the driver unit U3 and the voltage stabilization unit U1.

[0095] For another example, when the driver chip DIC is a chip capable of utilizing an external voltage input, it is also possible not to set an external voltage input for the driver chip DIC. In this way, the voltage value of the high-level signal of the initial control signal output by the driver chip DIC is determined by the voltage within the chip, which is a fixed voltage that is generally low, and the output current input is generally small. The disclosed embodiment can utilize this initial control signal to control the second switch Q2, and thus control the driver unit U3, generating the high-level signal of the control signal and the current input using the drive voltage provided by the driver unit U3 and the voltage stabilization unit U1.

[0096] In other embodiments of the present disclosure, the driver chip DIC is a chip that can utilize an external input voltage. In this case, the driver chip DIC can utilize the driving voltage provided by the voltage stabilizing unit U1 so that the high-level signal of the output initial control signal has a larger voltage value. In the prior art, control chips that can output high levels are often expensive and have fewer types and specifications; directly using these control chips to configure the DC-DC boost circuit will greatly increase the cost of the DC-DC boost circuit and reduce the flexibility of the DC-DC boost circuit in configuration. In this embodiment, the driving voltage provided by the voltage stabilizing unit U1 can be loaded onto the driver chip DIC and used as the external input voltage of the driver chip DIC; the driver chip DIC outputs a high-level signal of the initial control signal based on the driving voltage, which can greatly improve the flexibility of the control chip selection and reduce costs.

[0097] In one embodiment of the present disclosure, referring to Figures 9 to 11 , the control module CTR includes a driver chip DIC, a voltage regulator unit U1, and a driver unit U3. The voltage regulator unit U1 is configured to provide a driving voltage that is no less than the voltage of the high-level signal in the control signal. The driver chip DIC is a control chip capable of utilizing an external voltage input and is configured to output an initial control signal based on the driving voltage provided by the voltage regulator unit U1. A first terminal of the driver unit U3 is electrically connected to the output terminal of the voltage regulator unit U1, and a second terminal of the driver unit U3 is used to apply the ground voltage GND. A control terminal of the driver unit U3 is configured to receive the initial control signal, and an output terminal of the driver unit U3 is electrically connected to the gate of the power MOSFET. The driver unit U3 is configured to electrically connect the first terminal of the driver unit U3 to the power MOSFET in response to a high-level signal in the initial control signal, and to electrically connect the second terminal of the driver unit U3 to the power MOSFET in response to a low-level signal in the initial control signal.

[0098] In this embodiment, the high level signal of the initial control signal output by the driver chip DIC has a sufficiently high voltage value, and is therefore sufficient to directly drive the driver unit U3. Therefore, the control module CTR of this embodiment does not need to be provided with an inverter unit U2, thereby reducing the cost of the control module CTR.

[0099] In one example of this embodiment, the drive unit U3 includes a third switch Q3 and a fourth switch Q4. A first end of the third switch Q3 is electrically connected to the output end of the voltage stabilizing unit U1, and a first end of the fourth switch Q4 is used to apply the ground voltage GND. Control ends of the third switch Q3 and the fourth switch Q4 are configured to receive the initial control signal. Second ends of the third switch Q3 and the fourth switch Q4 are electrically connected to a second node N2, which is electrically connected to the control end of the power MOSFET, for example, via a gate resistor Rg. The third switch Q3 is configured to turn on in response to a high-level signal in the initial control signal and to turn off in response to a low-level signal in the initial control signal. The fourth switch Q4 is configured to turn on in response to a low-level signal in the initial control signal and to turn off in response to a high-level signal in the initial control signal.

[0100] Optionally, the third switch Q3 can be an N-type MOSFET and the fourth switch Q4 can be a P-type MOSFET. In this way, the drive unit U3 has greater applicability, for example, it can also be used under high power. For example, in a DC-DC boost circuit with a power greater than 100W, the third switch Q3 and the fourth switch Q4 in the drive unit U3 can be MOSFETs. Of course, in other examples of the present disclosure, the third switch Q3 and the fourth switch Q4 can also be transistors of opposite types; in this case, the drive unit U3 can be applicable to small and medium power DC-DC boost circuits, for example, in a DC-DC boost circuit with a power not greater than 100W, the third switch Q3 and the fourth switch Q4 in the drive unit U3 can be transistors.

[0101] In one example of this embodiment, the control module CTR further includes an EMC suppression resistor Rx. A first end of the EMC suppression resistor Rx is electrically connected to the output end of the driver chip, and a second end of the EMC suppression resistor Rx is electrically connected to the control end of the driver unit U3 (for example, to the control end of the third switch Q3 and the control end of the fourth switch Q4). Electromagnetic interference can be reduced by properly setting the resistance value of the EMC suppression resistor Rx.

[0102] In another embodiment of the present disclosure, referring to Figures 12 and 13 , the control module CTR includes a driver chip DIC and a voltage regulator unit U1. The voltage regulator unit U1 is configured to provide a driving voltage that is no less than the voltage of the high-level signal in the control signal. The driver chip DIC is a control chip capable of utilizing an external voltage input and is configured to output the control signal based on the driving voltage. In this embodiment, the initial control signal output by the driver chip DIC can be directly applied to the control terminal of the power MOSFET as a control signal, without the need for voltage or current adjustment by the driver unit U3.

[0103] For example, referring to FIG13 , the driver chip DIC has an external voltage input terminal VCC for loading an external voltage input, and an output terminal GATE for outputting a control signal. The output terminal of the voltage stabilizing unit U1 can be electrically connected to the external voltage input terminal VCC, thereby allowing the driving voltage to be loaded onto the driver chip DIC as an external voltage input. The driver chip DIC can output a control signal from the output terminal GATE based on the external voltage input, rather than outputting the control signal based on an internal constant voltage, which enables the high-level signal of the control signal to have a high voltage value. The output terminal GATE can be electrically connected to the control terminal of the power MOSFET, for example, through a gate resistor Rg.

[0104] In this embodiment, the driver chip DIC can generate a control signal based on the external input voltage (driving voltage) provided by the voltage stabilizing unit U1. The high-level signal of this control signal has a relatively high voltage value, thereby significantly reducing the conduction loss of the control terminal of the power MOSFET. In particular, when the DC-DC boost circuit does not have strict requirements for controlling temperature rise, the control module CTR of this embodiment can omit the inverter unit U2 and the driver unit U3, thereby reducing the cost of the control module CTR.

[0105] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A DC-DC boost circuit, comprising a power MOSFET and a control module electrically connected to a control terminal of the power MOSFET; The control module is configured to provide a control signal capable of controlling the on and off of the power MOSFET; wherein, The voltage value of the high-level signal in the control signal is 0.5 to 0.8 times the maximum rated value of the gate-source voltage of the power MOSFET.

2. The DC-DC boost circuit according to claim 1, wherein: The control module is further configured such that, when providing a current injection to the control terminal of the power MOSFET, the maximum value of the current injection is not less than 0.5A.

3. The DC-DC boost circuit according to claim 1, wherein: The control module includes a driving chip, a voltage stabilizing unit, an inverter unit and a driving unit; The driving chip is configured to provide an initial control signal; The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high level signal in the control signal; The inverting unit includes a second resistor and a second switch, wherein a first end of the second resistor is electrically connected to an output end of the voltage stabilizing unit, a second end of the second resistor and a first end of the second switch are electrically connected to a first node, and a second end of the second switch is used to load a ground voltage; a control end of the second switch is electrically connected to an output end of the driving chip; and the second switch is used to be turned on in response to a high level signal in the initial control signal, and turned off in response to a low level signal in the initial control signal; The first end of the driving unit is electrically connected to the output end of the voltage stabilizing unit, and the second end of the driving unit is used to load the ground voltage; the control end of the driving unit is electrically connected to the first node, and the output end of the driving unit is electrically connected to the control end of the power MOSFET; the driving unit is configured to conduct between the first end of the driving unit and the control end of the power MOSFET when the voltage of the first node is at a low level, and to conduct between the second end of the driving unit and the control end of the power MOSFET when the voltage of the first node is at a high level.

4. The DC-DC boost circuit according to claim 3, wherein: The driving unit includes a third switch and a fourth switch; The first end of the third switch is electrically connected to the output end of the voltage stabilizing unit, and the first end of the fourth switch is used to load the ground voltage; the control end of the third switch and the control end of the fourth switch are electrically connected to the first node, and the second end of the third switch and the second end of the fourth switch are electrically connected to the control end of the power MOSFET; The third switch is configured to be turned on when the voltage on the first node is at a low level and to be turned off when the voltage on the first node is at a high level; the fourth switch is configured to be turned on when the voltage on the first node is at a high level and to be turned off when the voltage on the first node is at a low level.

5. The DC-DC boost circuit according to claim 3, wherein: The control module further includes an EMC suppression resistor, one end of which is electrically connected to the first node, and the other end of which is electrically connected to the control end of the driving unit.

6. The DC-DC boost circuit according to claim 3, wherein: The second switch is a transistor or a MOSFET.

7. The DC-DC boost circuit according to claim 1, wherein: The control module includes a driving chip, a voltage stabilizing unit and a driving unit; The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high level signal in the control signal; The driving chip is configured to output an initial control signal according to the driving voltage provided by the voltage stabilizing unit; The first end of the driving unit is electrically connected to the output end of the voltage stabilizing unit, and the second end of the driving unit is used to load the ground voltage; the control end of the driving unit is configured to receive the initial control signal, and the output end of the driving unit is electrically connected to the control end of the power MOSFET; the driving unit is configured to respond to a high-level signal in the initial control signal to electrically conduct between the first end of the driving unit and the power MOSFET, and respond to a low-level signal in the initial control signal to electrically conduct between the second end of the driving unit and the power MOSFET.

8. The DC-DC boost circuit according to claim 7, wherein: The driving unit includes a third switch and a fourth switch; The first end of the third switch is electrically connected to the output end of the voltage stabilizing unit, and the first end of the fourth switch is used to load the ground voltage; the control end of the third switch and the control end of the fourth switch are configured to receive the initial control signal, and the second end of the third switch and the second end of the fourth switch are electrically connected to the control end of the power MOSFET; The third switch is configured to be turned on in response to a high level signal in the initial control signal, and to be turned off in response to a low level signal in the initial control signal; The fourth switch is configured to be turned on in response to a low level signal in the initial control signal, and to be turned off in response to a high level signal in the initial control signal.

9. The DC-DC boost circuit according to claim 7, wherein: The control module further includes an EMC suppression resistor, one end of which is used to load the initial control signal, and the other end of which is electrically connected to the control end of the driving unit.

10. The DC-DC boost circuit according to claim 4 or 8, wherein: The third switch and the fourth switch are triodes or MOSFETs.

11. The DC-DC boost circuit according to claim 1, wherein: The control module includes a driving chip and a voltage stabilizing unit; The voltage stabilizing unit is configured to provide a driving voltage, wherein the driving voltage is not less than a voltage of a high level signal in the control signal; The driving chip is configured to output the control signal according to the driving voltage.

12. The DC-DC boost circuit according to any one of claims 1 to 11, wherein: The DC-DC boost circuit also includes a gate resistor and a diode; The first end of the gate resistor is electrically connected to the output end of the control module, and the second end of the gate resistor is electrically connected to the control end of the power MOSFET; the anode of the diode is electrically connected to the second end of the gate resistor, and the cathode of the diode is electrically connected to the first end of the gate resistor.

13. The DC-DC boost circuit according to any one of claims 3 to 11, wherein: The voltage stabilizing unit includes a first switch, a voltage stabilizing diode, a first resistor and a filtering subcircuit; The first end of the first switch is used to load the input voltage, and the second end of the first switch is electrically connected to the output end of the voltage stabilizing unit; a first resistor is connected between the control end of the first switch and the first end of the first switch, the control end of the first switch is electrically connected to the cathode of the voltage stabilizing diode, and the anode of the voltage stabilizing diode is used to load the ground voltage; the filtering subcircuit is electrically connected to the output end of the voltage stabilizing unit.

14. The DC-DC boost circuit according to any one of claim 13, wherein: The DC-DC boost circuit also includes an input filter unit, an inductor, a diode and an output filter unit; The first end of the inductor is used to load the input voltage and is electrically connected to the input filter unit; the second end of the inductor is connected to the first end of the power MOSFET, and the second end of the power MOSFET is used to load the ground voltage; The anode of the diode is electrically connected to the first end of the power MOSFET; the cathode of the diode is electrically connected to the output end of the DC-DC boost circuit and is connected to the output end filter unit.

15. A driving circuit board, comprising the DC-DC boost circuit according to any one of claims 1 to 14.

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