Electronic circuit
By using SiC or SiC/GaN transistors and a bootstrap mechanism, a negative gate voltage is generated using a second diode and a second capacitor, solving the problems of complex and costly high-side switch negative voltage control in the prior art, and achieving a simplified and low-cost circuit design.
Patent Information
- Application Number
- CN202480017476.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-03-16
- Filing Date
- 2024-03-12
- Publication Date
- 2025-11-11
AI Technical Summary
Existing technologies, particularly the negative voltage control process of the high-side switch in the control circuit for generating load switches, are complex and require a large number of electronic components, leading to increased manufacturing costs.
By employing SiC or SiC/GaN type transistors and combining them with a bootstrap mechanism, a negative gate voltage is generated by positioning a second diode and a second capacitor, utilizing the inherent characteristics of the transistor, thus simplifying the negative voltage generation process.
It enables the simple and low-cost generation of negative voltage control on high-side transistors, reducing the use of electronic components and lowering circuit complexity and manufacturing costs.
Smart Images
Figure CN120937249A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an electronic circuit, such as a control device for a switching structure capable of supplying power to an inductive load. The inductive load may be an actuator.
[0002] The present invention is preferably, but not limited to, applications in the field of motor vehicles.
[0003] This invention can be implemented, for example, in electronic circuits that integrate switching structures such as transistor H-bridges or transistor H-half-bridges. Background Technology
[0004] Those skilled in the art typically control at least one switch, such as a transistor, in the control circuit of the load.
[0005] Figure 1 An example of such a control circuit 10 is illustrated. The control circuit 10 includes a first switch C10 and a second switch C20. Each switch can be a transistor of the MOS (metal-oxide-semiconductor) type or a MOSFET (metal oxide semiconductor field effect transistor) type.
[0006] The first switch C10 includes a first pin C10B1, a second pin C10B2, and a third pin C10B3. Each pin corresponds to the gate, source, or drain of the transistor. The second switch C20 includes a first pin C20B1, a second pin C20B2, and a third pin C20B3.
[0007] In this case and as Figure 1 As shown in the diagram, the first pin C10B1 is coupled to a positive voltage source, such as a 600-volt source. The second pin C10B2 is coupled to the first connection point C100. Finally, the third pin C10B3 is coupled to the second connection point C200.
[0008] The first pin, C20B1, is coupled to the second connection point, C200. The second pin, C20B2, is adapted to receive control signals not indicated. Finally, the third pin, C20B3, is coupled to an electrical reference, such as ground.
[0009] Finally, the load represented by inductance L is coupled to the second connection point C200.
[0010] The first connection point C100 is also coupled to the first resistor R1, which in turn is coupled to terminal D10B1 of the control circuit type circuit D10. Finally, the second resistor R2 is coupled to the first connection point C100 on one hand and to the second connection point C200 on the other.
[0011] The control circuit type circuit D10 also includes a second terminal D10B2 coupled to the second connection point C200 and also coupled to the first capacitor C1. The first capacitor C1 includes a first capacitor terminal C1B1 coupled to the second connection point C200 and a second capacitor terminal C1B2 coupled to the third terminal D10B3 of the control circuit type circuit D10. Finally, diode D1 is coupled to the first capacitor C1 in the ON position. The anode of the diode D1 is coupled to a first voltage V1. For example, the first voltage V1 is an auxiliary voltage that enables the power mechanism to operate without being directly used for power transmission.
[0012] exist Figure 1 In the diagram, the transistor is schematically represented by a diode, which utilizes the internal electronic structure of the transistor.
[0013] There are various ways to control such a circuit and thus control the current flowing in the load represented by the inductor L.
[0014] For example, the first approach involves using an actuation mechanism known as “bootstrap” to control a first switch C10 (which may also be referred to as the high-side first switch C10) that serves as a cue for being located on the high-voltage side.
[0015] The principle of this mechanism is known to those skilled in the art, and it is based on the fact that whenever the second switch C20 (connected to ground) is activated, i.e., closed, a first voltage V1 is applied to the first capacitor C1. Therefore, the first capacitor C1 is at the potential of the first voltage V1.
[0016] Once the first switch C10 is activated, the potential at the load L will be the high supply voltage minus the voltage at the terminal of the first capacitor C1. Diode D1 is blocked in this situation.
[0017] Another common solution is to use an electrically isolated circuit adapted to enable activation of the first switch C10. Examples include push-pull or flyback type circuits. These devices are known.
[0018] Therefore, the generation of the control signal for the first switch C10 causes many drawbacks. In fact, generating a negative voltage at the first switch C10 can be complex, and this negative voltage may be indispensable depending on the technology of the first switch C10.
[0019] It may also require the use of numerous electronic components or circuits to achieve control and / or generate the negative voltage, increasing the manufacturing cost of the circuit.
[0020] Therefore, there is a practical need to generate the negative control voltage of the first switch C10 in a simple and inexpensive manner. Summary of the Invention
[0021] This invention relates to an electronic circuit, comprising:
[0022] A first switch, comprising a first pin, a second pin, and a third pin, and a second switch, comprising a first pin, a second pin, and a third pin.
[0023] • The first pin is coupled to a positive voltage source, the second pin is coupled to the first connection point, and the third pin is coupled to the second connection point.
[0024] The first pin is coupled to the second connection point, the second pin is adapted to receive control signals, and the third pin is coupled to an electrical reference.
[0025] • The load coupled to the second connection point
[0026] The first connection point is also coupled to the first resistor, which in turn is coupled to the circuit terminals.
[0027] The second resistor is coupled to both the first connection point and the second connection point.
[0028] The circuit includes a second terminal coupled to a third connection point and a third terminal coupled to a first capacitor, the first capacitor including a first capacitor terminal coupled to a second connection point and a second capacitor terminal coupled to the third terminal of the circuit.
[0029] A first diode, in its on-position, is coupled to a first capacitor, and the anode of the first diode is coupled to a first voltage. The electronic circuit includes:
[0030] A second diode has a first diode terminal and a second diode terminal, the first diode terminal being coupled to a positive voltage source, and the second diode terminal being coupled to a third connection point.
[0031] • A second capacitor having a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled to a third connection point and the second capacitor terminal being coupled to a second connection point.
[0032] With this invention, negative voltage can be generated.
[0033] As a variant, the first switch is a transistor based on SiC technology.
[0034] As a variant, the first switch is a transistor based on SiC / GaN technology. Attached Figure Description
[0035] Other features and advantages of the invention will become more apparent from the following description. The following description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:
[0036] [ Figure 1 ] Figure 1 This is a schematic representation of a control circuit in the prior art.
[0037] [ Figure 2 ] Figure 2 Representative curves of the "forward" voltage of the body diode of SiC type transistors are given.
[0038] [ Figure 3 ] Figure 3 This is a schematic representation of the control circuit according to the present invention. Detailed Implementation
[0039] This invention ingeniously proposes to utilize the inherent characteristics of SiC or SiC / GaN type transistors to enable the switching of high-side transistors using associated control logic.
[0040] Figure 2 An example of a representative curve of the reverse voltage of the body diode of a SiC transistor is given.
[0041] like Figure 3 As shown in the diagram, the electronic circuit 1000 according to the present invention includes a first switch C1000 and a second switch C2000. Each switch is a SiC type transistor. As a variation, they are made of SiC / GaN.
[0042] The first switch C1000 includes a first pin C1000B1, a second pin C1000B2, and a third pin C1000B3. Each pin corresponds to the gate, source, or drain of the transistor. The second switch C2000 includes a first pin C2000B1, a second pin C2000B2, and a third pin C2000B3.
[0043] In this case and as Figure 3 As shown in the diagram, the first pin C1000B1 is coupled to a positive voltage source, such as a 600-volt source. The second pin C1000B2 is coupled to the first connection point C10000. Finally, the third pin C1000B3 is coupled to the second connection point C20000.
[0044] The first pin C2000B1 is coupled to the second connection point C20000. The second pin C2000B2 is adapted to receive control signals (not shown). Finally, the third pin C2000B3 is coupled to an electrical reference such as ground.
[0045] Finally, the load represented by inductance L is coupled to the second connection point C20000.
[0046] The first connection point C10000 is also coupled to the first resistor R1, which in turn is coupled to terminal D10B1 of the control circuit type circuit D10. Finally, the second resistor R2 is coupled to the first connection point C10000 on one hand and to the second connection point C20000 on the other.
[0047] The control circuit type circuit D10 also includes a second terminal D10B2 coupled to the third connection point C30000.
[0048] The third terminal D10B3 of the control circuit type circuit D10 is coupled to the first capacitor C1. The first capacitor C1 includes a first capacitor terminal C1B1 coupled to the second connection point C20000 and a second capacitor terminal C1B2 coupled to the third terminal D10B3 of the control circuit type circuit D10. Finally, the first diode D1 is coupled to the first capacitor C1 in the on position. The anode of the first diode D1 is coupled to the first voltage V1.
[0049] This invention proposes positioning a second diode D2 having a first diode terminal D2B1 and a second diode terminal D2B2. The first diode terminal D2B1 is coupled to a positive voltage source. The second diode terminal D2B2 is coupled to a third connection point C30000.
[0050] Similarly, the present invention proposes the use of a second capacitor C2 having a first capacitor terminal C2B1 and a second capacitor terminal C2B2. The first capacitor terminal C2B1 is coupled to a third connection point C30000 and the second capacitor terminal C2B2 is coupled to a second connection point C30000.
[0051] Therefore, with the device of the present invention, when a control voltage needs to be generated on the first switch C1000, a positive voltage can be generated according to the same mechanism as the discussed mechanism, namely the so-called "bootstrapping" mechanism. Therefore, the existence of the present invention does not preclude the possibility of using a positive control transistor.
[0052] Furthermore, cleverly, by virtue of the presence of the second diode D2 and the second capacitor C2 located at the first switch C1000, a negative gate voltage can be generated on the first switch C1000.
[0053] In practice, the second capacitor C2 is charged over a defined period of time by means of the current flowing through the internal diode (also called the body diode) of the first switch C1000 and the second diode D2, so that the potential at the pin of the second transistor C2 is equal to the forward voltage of the body diode of the SiC transistor minus the reverse voltage of the second diode D2.
[0054] Therefore, with this invention, SiC type transistors at high-side positions can be controlled without the need for complex electronic devices.
Claims
1. An electronic circuit (1000), comprising: • A first switch (C1000) and a second switch (C2000). The first switch (C1000) includes a first pin (C1000B1), a second pin (C1000B2), and a third pin (C1000B3). The second switch (C2000) also includes a first pin (C2000B1), a second pin (C2000B2), and a third pin (C2000B3). • Pin 1 (C1000B1) is coupled to a positive voltage source, pin 2 (C1000B2) is coupled to the first connection point (C10000), and pin 3 (C1000B3) is coupled to the second connection point (C20000). • The first pin (C2000B1) is coupled to the second connection point (C20000), the second pin (C2000B2) is adapted to receive control signals, and the third pin (C2000B3) is coupled to an electrical reference. • The load (L) is coupled to the second connection point (C20000). The first connection point (C10000) is also coupled to the first resistor (R1), which in turn is coupled to terminal (D10B1) of the circuit (D10). The second resistor (R2) is coupled to both the first connection point (C10000) and the second connection point (C20000). The circuit (D10) includes a second terminal (D10B2) coupled to a third connection point (C30000) and a third terminal (D10B3) coupled to a first capacitor (C1). The first capacitor (C1) includes a first capacitor terminal (C1B1) coupled to a second connection point (C20000) and a second capacitor terminal (C1B2) coupled to the third terminal (D10B3) of the circuit (D10). • A first diode (D1), in its on-position, is coupled to a first capacitor (C1), and the anode of the first diode (D1) is coupled to a first voltage (V1). The electronic circuit is characterized by: • A second diode (D2) has a first diode terminal (D2B1) and a second diode terminal (D2B2). The first diode terminal (D2B1) is coupled to a positive voltage source, and the second diode terminal (D2B2) is coupled to a third connection point (C30000). • A second capacitor (C2) having a first capacitor terminal (C2B1) and a second capacitor terminal (C2B2), the first capacitor terminal (C2B1) being coupled to a third connection point (C30000) and the second capacitor terminal (C2B2) being coupled to a second connection point (C30000).
2. The electronic circuit (1000) according to claim 1, wherein the first switch (C1000) is a transistor of SiC technology.
3. The electronic circuit (1000) according to claim 2, wherein the first switch (C1000) is a transistor of SiC / GaN technology.