Power device driving apparatus

Abstract

This disclosure provides a power device driving device, including: a light emitting unit for emitting light signals; a light guiding channel for guiding light signals from the light emitting unit; and a light receiving and conversion unit, including a silicon-based chip and a plurality of photodiodes integrated on the silicon-based chip. The plane of the silicon-based chip is perpendicular to the optical axis of the light emitting unit, and the foot of the perpendicular is located at the center of the silicon-based chip. The distribution density of each photodiode on the silicon-based chip decreases as the distance between the photodiode and the center of the silicon-based chip increases. The photodiodes form a series path, and the photogenerated voltage generated by the photodiodes based on the light signals is superimposed through the series path as the driving voltage for driving the power device.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and more specifically to a power device driving device. Background Technology

[0002] With the widespread application of wide-bandgap semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) in power electronics, power devices are rapidly developing towards higher switching frequencies, higher operating voltages, and higher power densities. As a key module for controlling the switching of power devices, the gate driver not only needs to provide sufficient driving capability, but also must achieve highly reliable and high-speed electrical isolation between the control side (low-voltage domain) and the power side (high-voltage domain) to ensure system safety and dynamic performance.

[0003] Currently, mainstream electrical isolation technologies mainly include three types: optocoupler isolation, capacitive isolation, and magnetic isolation. Among them, optocoupler isolation dominates industrial applications due to its mature technology, low cost, and strong anti-interference capabilities. However, traditional optocoupler-isolated gate drivers typically require the integration of complex auxiliary circuitry at the receiving end, such as output driver stages, undervoltage lockout (UVLO) protection, noise filtering, and level shifting modules. This not only increases chip area and manufacturing costs but may also introduce additional transmission delays, limiting overall switching speed and energy efficiency.

[0004] In recent years, passive optical driving schemes based on the photovoltaic generator (PVG) principle have attracted widespread attention. This scheme efficiently connects multiple photodiodes 310 in series within a limited area, utilizing the photovoltaic effect to directly generate a gate voltage (typically above 10 V) sufficient to drive the gate driver. This eliminates the need for active amplification and power management circuits in traditional driving architectures, significantly simplifying the system structure and improving integration. However, existing PVG designs often employ a uniform arrangement, failing to fully consider the spatial irradiance distribution characteristics of the light source. This results in limited light energy utilization per unit area, making it difficult to achieve optimal voltage output within a compact size. Summary of the Invention

[0005] This disclosure provides a power device driving device.

[0006] According to one aspect of this disclosure, a power device driving apparatus is provided, including an optical emitting unit for emitting an optical signal; a light guiding channel for guiding the optical signal from the optical emitting unit; and an optical receiving and conversion unit, including a silicon-based chip and a plurality of photodiodes integrated on the silicon-based chip, wherein the plane of the silicon-based chip is perpendicular to the optical axis of the optical emitting unit, and the foot of the perpendicular is located at the center of the silicon-based chip, the distribution density of each photodiode on the silicon-based chip decreases as the distance between the photodiode and the center of the silicon-based chip increases, and the photodiodes form a series path, wherein the photogenerated voltage generated by the photodiodes based on the optical signal is superimposed through the series path as the driving voltage for driving the power device.

[0007] According to one technical solution, by arranging photodiodes on a silicon-based chip with increasing center-to-center distance and decreasing density, and connecting them in series, it is possible to accurately match the spatial illuminance distribution of the optical signal and maximize the superposition output of photogenerated voltage within a limited chip area.

[0008] According to at least one embodiment of the power device driving apparatus of the present disclosure, the silicon-based chip includes an illuminance core region and an illuminance compensation region. The illuminance core region is a region whose distance from the center position of the silicon-based chip is less than or equal to a distance threshold. The illuminance compensation region is a region outside the illuminance core region. The illuminance core region of the silicon-based chip integrates photodiodes at a first density, and the illuminance compensation region of the silicon-based chip integrates photodiodes at a second density, wherein the first density is greater than the second density.

[0009] According to the technical solution of this embodiment, by integrating photodiodes in the illuminance core region at a higher density than in the illuminance compensation region, non-uniform optimized arrangement of photosensitive units can be achieved based on the spatial distribution characteristics of incident light flux, significantly improving light energy capture efficiency and photogenerated voltage output without increasing chip area and total number of devices.

[0010] According to at least one embodiment of the power device driving apparatus of this disclosure, the method for determining the distance threshold includes: determining an illuminance scaling factor; calculating a first illuminance value at the center position of the silicon-based chip according to a generalized Lambertian model; constructing an objective function based on a radial distance to calculate a second illuminance value according to the generalized Lambertian model, wherein the second illuminance value is the illuminance value at a position at a distance from the center position equal to the radial distance; and solving for a radial distance that satisfies the objective function being equal to the product of the illuminance scaling factor and the first illuminance value, thereby obtaining the distance threshold.

[0011] According to the technical solution of this embodiment, the characteristic of the incident light flux being concentrated in the central region can be fully utilized to prioritize the efficient utilization of light energy in high-illuminance areas. Thus, without increasing the total number of devices or chip area, the light capture efficiency and photovoltage output can be significantly improved.

[0012] According to at least one embodiment of the power device driving apparatus of the present disclosure, the optical emitting unit employs a narrow divergence angle single-mode semiconductor laser based on 850nm.

[0013] According to the technical solution of this embodiment, reliable optical signal input can be provided.

[0014] According to at least one embodiment of the power device driving apparatus of this disclosure, the material of the light emitting unit is aluminum gallium arsenide.

[0015] According to the technical solution of this embodiment, narrow divergence angle single-mode laser output with a wavelength of 850 nm can be accurately achieved.

[0016] According to at least one embodiment of the power device driving apparatus of this disclosure, the light guide channel is made of transparent epoxy resin.

[0017] According to the technical solution of this embodiment, the absorption and scattering loss of optical signals during transmission can be significantly reduced, ensuring that optical energy is efficiently transmitted to the optical receiving and conversion unit. According to at least one embodiment of the power device driving apparatus of the present disclosure, the light guide channel is in the shape of a cube, the light emitting unit is disposed below the bottom surface of the cube, and the light receiving and conversion unit is disposed above the top surface of the cube.

[0018] According to the technical solution of this embodiment, efficient coupling with vertical, symmetrical and low-loss optical paths can be achieved, providing reliable optical input conditions.

[0019] According to at least one embodiment of the power device driving device of the present disclosure, the contact surface between the silicon-based chip and the light guide channel is a square with a side length of 1 mm.

[0020] According to the technical solution of this embodiment, precise matching with the cubic light guide channel can be achieved.

[0021] According to at least one embodiment of the power device driving apparatus of the present disclosure, the optical receiving and conversion unit further includes a discharge circuit module connected to the gate of the power device. When the optical receiving and conversion unit stops receiving the optical signal, the discharge circuit module is turned on to release the charge stored in the gate of the power device.

[0022] According to the technical solution of this embodiment, the power device can be automatically turned on and quickly released when the optical signal stops, thereby ensuring reliable and rapid turn-off of the power device and improving the switching speed.

[0023] According to at least one embodiment of the power device driving device of the present disclosure, the discharge circuit module is composed of a depletion-type metal-oxide-semiconductor field-effect transistor.

[0024] According to the technical solution of this embodiment, the discharge circuit module can be turned on naturally when there is no light signal, so as to realize the rapid discharge of the gate charge of the power device.

[0025] According to at least one embodiment of the power device driving device of the present disclosure, the discharge circuit module is integrated in the corner region of the silicon-based chip.

[0026] According to the technical solution of this embodiment, the space of the low-illuminance area at the edge can be effectively utilized without occupying the area of ​​the high-illuminance area at the center, thereby achieving a compact layout of functional circuits and synergistic optimization of photoelectric conversion efficiency.

[0027] According to at least one embodiment of the power device driving apparatus of the present disclosure, the discharge circuit module includes a plurality of sub-components, which are divided into four groups, and the sub-components corresponding to different groups are integrated in different corner regions of the silicon-based chip.

[0028] According to the technical solution of this embodiment, it is possible to achieve multi-path discharge of gate charge while making full use of the low-light edge space. Attached Figure Description

[0029] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0030] Figure 1 This is a schematic diagram of the structure of a power device driving device according to one embodiment of the present disclosure.

[0031] Figure 2 This is a schematic diagram of the structure of an optical receiving and converting unit according to one embodiment of the present disclosure.

[0032] Figure 3 This is a flowchart illustrating a distance threshold determination method according to one embodiment of the present disclosure. Detailed Implementation

[0033] The present disclosure will now be described in further detail with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0034] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0036] Figure 1 This is a schematic diagram of the structure of a power device driving device according to one embodiment of this disclosure. Figure 1 The power device driving device shown includes an optical emitting unit 100, a light guiding channel 200, and an optical receiving and conversion unit 300.

[0037] Power devices are semiconductor devices used to control and convert electrical energy. They are capable of handling high-voltage, high-current, or high-power power signals and can be widely used in power management, motor drives, new energy power generation, electric vehicles, and industrial frequency conversion. As one possible implementation, a power device can be a metal-oxide-semiconductor transistor (MOST).

[0038] The optical emitting unit 100 is used to emit optical signals. As one possible implementation, the optical emitting unit 100 can employ a narrow divergence angle single-mode semiconductor laser (AlGaAs material) based on 850nm. The 850nm wavelength is located in the high response range of the photodiode 310, effectively exciting electron-hole pairs. By employing a narrow divergence angle single-mode laser structure, the output beam can have high directionality and spatial concentration, effectively reducing lateral diffusion of light energy during transmission and ensuring a high-throughput, highly uniform illumination distribution on the limited area surface of the silicon-based chip 320. The optical emitting unit 100 used in this embodiment has stable Lambertian radiation characteristics, providing reliable optical signal input.

[0039] As a further embodiment, the light emitting unit 100 is made of aluminum gallium arsenide (AlGaAs). By using aluminum gallium arsenide to fabricate the light emitting unit 100, it is possible to accurately achieve narrow divergence angle single-mode laser output at a wavelength of 850 nm.

[0040] The light guide channel 200 is used to guide the optical signal from the light emitting unit 100. In one possible implementation, the light guide channel 200 is cubic in shape. The light emitting unit 100 is disposed below the bottom surface of the cube, and the light receiving and conversion unit 300 is disposed above the top surface of the cube. The light guide channel 200 used in this embodiment has been optimized by optical software to maximize the light flux transmission efficiency and form a uniform light field distribution on the light-receiving surface.

[0041] As one possible implementation, the light guide channel 200 can be made of transparent epoxy resin. This embodiment utilizes the high transmittance of transparent epoxy resin at a wavelength of 850 nm, which can significantly reduce absorption and scattering losses of the optical signal during transmission, ensuring efficient transmission of light energy to the light receiving and conversion unit 300. Different structures of the light guide channel formed by transparent epoxy resin can be well matched with the optical interfaces of the silicon-based photodiode 310 and the aluminum gallium arsenide light emitting unit 100, minimizing light energy loss.

[0042] The optical receiving and conversion unit 300 is used to receive optical signals and convert them into electrical signals to generate the (high) voltage required to drive the power devices. Figure 2 A schematic diagram of the structure of an optical receiving and conversion unit 300 according to one embodiment of this disclosure is shown. Figure 2 As shown, the light receiving and conversion unit 300 includes a silicon-based chip 320 and a plurality of photodiodes 310 integrated on the silicon-based chip 320. The plane of the silicon-based chip 320 is perpendicular to the optical axis of the light emitting unit 100, and the foot of the perpendicular is located at the center of the silicon-based chip 320. A series path is formed between the photodiodes 310. The photogenerated voltage generated by the photodiodes 310 based on the photoelectric signal is superimposed through the series path as the driving voltage for driving the power devices.

[0043] In one possible implementation, a light emitting unit 100 is disposed below the light guide channel 200, and a light receiving and conversion unit 300 is disposed above it. Both the top and bottom surfaces of the light guide channel 200 are 1mm × 1mm squares. The silicon-based chip 320 in the light receiving and conversion unit 300 is also a 1mm × 1mm square, and is positioned above the top surface of the light guide channel 200 after being aligned with it. The light emitting unit 100 is located at the center of the bottom surface of the light guide channel 200, and the optical axis of the light emitting unit 100 is perpendicular to the plane containing the bottom surface of the light guide channel 200. This embodiment allows the light beam emitted by the light emitting unit 100 to be incident vertically upward along the light guide channel 200, ensuring that an irradiance field with a peak value at the center position and conforming to the generalized Lambertian distribution is formed on the 1mm×1mm receiving surface (i.e., the surface of the silicon-based chip 320). This achieves optimal light energy matching with the photodiode 310 array (each photodiode 310 forming a series path) in the light receiving and conversion unit 300, which is arranged based on the optimized spatial distribution of light intensity, thereby maximizing the output of photogenerated voltage per unit area.

[0044] In a specific example, using TracePro software... Figure 1 The illuminance values ​​of the optical signals received at different locations of the silicon-based chip 320 in the power device driving device shown are simulated. The illuminance distribution of the light emitting unit 100 can usually be described by a generalized Lambertian model, such as: Among them, E Lam (r, z) represents the illuminance value at the point with coordinates (x, y) on the receiving plane. r(x, y) represents the position vector of the point with coordinates (x, y) on the receiving plane. z represents the distance between the light emitting unit 100 and the receiving plane (such as the surface of the silicon-based chip 320). E0 represents the illuminance value at the position where the optical axis of the light emitting unit 100 is projected onto the receiving plane. θ This represents the polar angle of a point on the observation plane relative to the light emitting unit 100. The Lambertian exponent is a dimensionless parameter that characterizes the directionality of a light beam. The larger the value, the more concentrated the beam (the smaller the divergence angle).

[0045] Under the condition that the relative attitude of the light emitting unit 100 and the receiving plane is fixed and the distance is z, the radial distance corresponding to the point of position vector r(x, y) on the receiving plane is... With polar angle θ satisfy .

[0046] Since the receiving plane is perpendicular to the optical axis of the light emitting unit 100, the horizontal illuminance (or irradiance) at each position on the receiving plane is... follow: From the formula, we can obtain the horizontal illuminance. radial distance Monotonically decreasing, and the maximum value appears at... .

[0047] Based on the above conclusions, in one possible implementation, the following arrangement of photodiode 310 on silicon-based chip 320 is proposed.

[0048] In one possible arrangement, the distribution density of each photodiode 310 on the silicon chip 320 decreases as the distance from the center of the silicon chip 320 increases. By making the distribution density of the photodiodes 310 continuously decrease with radial distance, it is possible to precisely match the generalized Lambertian distribution of the incident illuminance field (i.e., high at the center and low at the edges) formed by the light emitting unit 100 through the light guide channel 200. This allows for high alignment between the spatial response of the photosensitive unit and the spatial distribution of the light energy input, thereby maximizing the photon capture efficiency per unit area.

[0049] In another possible implementation, the silicon-based chip 320 includes an illuminance core region and an illuminance compensation region. The illuminance core region is the area at a distance less than or equal to a distance threshold from the center of the silicon-based chip 320. The illuminance compensation region is the area outside the illuminance core region. Photodiodes 310 are integrated in the illuminance core region of the silicon-based chip 320 at a first density. Photodiodes 310 are integrated in the illuminance compensation region of the silicon-based chip 320 at a second density, where the first density is greater than the second density. This embodiment divides the surface of the silicon-based chip 320 into an illuminance core region and an illuminance compensation region, and integrates photodiodes 310 in the illuminance core region at a higher density than in the illuminance compensation region. This allows full utilization of the concentrated distribution of incident light flux in the central region, prioritizing efficient light energy utilization in high-illuminance areas. Thus, without increasing the total number of devices or chip area, the light capture efficiency and photogenerated voltage output are significantly improved.

[0050] Figure 3 A flowchart illustrating a distance threshold determination method according to one embodiment of this disclosure is shown. Figure 3 The method shown includes steps S310 to S340.

[0051] In step S310, the illuminance ratio coefficient (α) is determined. The illuminance ratio coefficient is used to characterize the proportional relationship between the illuminance value at the boundary of the illuminance core area and the maximum illuminance value corresponding to the center position. The value range of the illuminance ratio system can be (0, 1), and the specific value can be set according to the actual application. For example, the illuminance ratio coefficient can be set to 0.5, 0.7, etc.

[0052] In step S320, the first illuminance value at the center position of the silicon-based chip 320 is calculated according to the generalized Lambertian model.

[0053] In step S330, an objective function for calculating the second illuminance value based on radial distance is constructed according to the generalized Lambertian model. The second illuminance value is the illuminance value at a position at a radial distance from the center position.

[0054] In step S340, the radial distance that satisfies the objective function being equal to the product of the illuminance ratio coefficient and the first illuminance value is calculated to obtain the distance threshold.

[0055] The distance threshold obtained through the above steps can be used to divide the silicon-based chip 320 into an illuminance core region and an illuminance compensation region. The illuminance core region includes all areas where the illuminance value is not less than α times the maximum illuminance value corresponding to the center position, while the illuminance compensation region corresponds to the outer areas where the illuminance value is lower than this threshold. This guides the integration of photodiodes 310 at a higher density (first density) in high-illuminance areas and at a lower density (second density) in low-illuminance areas, achieving synergistic optimization of light capture efficiency and silicon-based chip 320 area utilization.

[0056] As a further implementation, to improve the switching control performance of the power device's gate, the receiving and conversion unit also includes a discharge circuit module 330. The discharge circuit module 330 is connected to the gate of the power device. When the optical receiving and conversion unit 300 stops receiving optical signals, the discharge circuit module 330 is turned on to release the charge stored in the gate of the power device. By providing the discharge circuit module 330 connected to the gate of the power device, it can automatically turn on and quickly release the gate charge when the optical signal stops. This ensures reliable and rapid turn-off of the power device and improves the switching speed.

[0057] As a further implementation, the discharge circuit module 330 is composed of a depletion-type metal-oxide-semiconductor field-effect transistor (MOSFET). When the optical signal disappears, the output voltage of the light receiving and conversion unit 300 drops to zero, and the discharge circuit module is turned on, forming a low-resistance discharge path. By using a depletion-type MOSFET to construct the discharge circuit module 330, the discharge circuit module can be naturally turned on without additional control voltage when there is no optical signal, achieving rapid discharge of the gate charge of the power device.

[0058] As a further implementation, the discharge circuit module 330 is integrated into the corner area of ​​the silicon-based chip 320 (such as the four corners of a 1mm×1mm square). By integrating the discharge circuit module 330 into the corner area of ​​the silicon-based chip 320, the space of the low-illuminance edge area can be effectively utilized without occupying the area of ​​the high-illuminance area in the center, thereby achieving a compact layout of the functional circuit and synergistic optimization of photoelectric conversion efficiency.

[0059] As a further implementation, the discharge circuit module 330 includes multiple sub-components, which are divided into four groups. Sub-components corresponding to different groups are integrated into different corner regions of the silicon-based chip 320. Each corner region of the silicon-based chip 320 integrates a partial depletion-mode metal-oxide-semiconductor (MOSFET). The MOSFET is connected between the gate of the power device and a reference ground, forming a discharge channel, which can significantly reduce the equivalent discharge impedance and thus accelerate the discharge of gate charge. By integrating the discharge circuit module 330 into the four corner regions of the silicon-based chip 320, not only is the idle area in the low-light region fully utilized, but also multi-path parallel discharge of gate charge of the power device can be achieved, further improving turn-off speed and discharge uniformity.

[0060] The operation of the power device driving device provided in this disclosure follows a linear conversion chain of light-electricity-drive. When the control signal triggers the light emitting unit 100, the light signal (such as a light beam) generated by the light emitting unit 100 is transmitted to the light receiving and conversion unit 300 through the light guide channel 200. Each photodiode 310 integrated on the silicon-based chip 320 of the light receiving and conversion unit 300 captures photons (i.e., receives the light signal) and generates electron-hole pairs by means of the photovoltaic effect, which are separated under the action of an electric field to form a photogenerated voltage. Since the photodiodes 310 are connected in series, the photogenerated voltage (such as 0.5V) generated by a single photodiode 310 is accumulated, and the accumulated result (such as 16V obtained by accumulating 32 photodiodes 310) is used as the output voltage to directly drive the gate of the power device.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A power device driving device, characterized in that, include: An optical emitting unit is used to emit optical signals; A light guiding channel is used to guide the light signal from the light emitting unit; as well as The optical receiving and conversion unit includes a silicon-based chip and multiple photodiodes integrated on the silicon-based chip. The plane of the silicon-based chip is perpendicular to the optical axis of the optical emitting unit, and the foot of the perpendicular is located at the center of the silicon-based chip. The distribution density of each photodiode on the silicon-based chip decreases as the distance between the photodiode and the center of the silicon-based chip increases. The photodiodes form a series path. The photogenerated voltage generated by the photodiodes based on the optical signal is superimposed through the series path and used as the driving voltage to drive the power device.

2. The power device driving device as described in claim 1, characterized in that, The silicon-based chip includes an illuminance core region and an illuminance compensation region. The illuminance core region is the area whose distance from the center of the silicon-based chip is less than or equal to a distance threshold. The illuminance compensation region is the area outside the illuminance core region. The illuminance core region of the silicon-based chip integrates photodiodes at a first density, and the illuminance compensation region of the silicon-based chip integrates photodiodes at a second density, wherein the first density is greater than the second density.

3. The power device driving device as described in claim 2, characterized in that, The method for determining the distance threshold includes: Determine the illuminance ratio coefficient; Calculate the first illuminance value at the center of the silicon-based chip according to the generalized Lambertian model; Based on the generalized Lambertian model, an objective function is constructed to calculate the second illuminance value based on radial distance, where the second illuminance value is the illuminance value at a position whose distance from the center position is equal to the radial distance; and The distance threshold is obtained by solving for the radial distance that satisfies the objective function being equal to the product of the illuminance ratio coefficient and the first illuminance value.

4. The power device driving device as described in claim 1, characterized in that, The optical emission unit employs a narrow divergence angle single-mode semiconductor laser based on 850nm.

5. The power device driving device as described in claim 4, characterized in that, The material of the light emitting unit is aluminum gallium arsenide.

6. The power device driving device as described in claim 1, characterized in that, The light guide channel is made of transparent epoxy resin.

7. The power device driving device as described in claim 1, characterized in that, The light guide channel is cube-shaped, with the light emitting unit located below the bottom surface of the cube and the light receiving and conversion unit located above the top surface of the cube.

8. The power device driving device as described in claim 7, characterized in that, The contact surface between the silicon-based chip and the light guide channel is a square with a side length of 1 mm.

9. The power device driving device as described in claim 1, characterized in that, The optical receiving and conversion unit also includes a discharge circuit module, which is connected to the gate of the power device. When the optical receiving and conversion unit stops receiving the optical signal, the discharge circuit module is turned on to release the charge stored in the gate of the power device.

10. The power device driving device as described in claim 9, characterized in that, The discharge circuit module is composed of depletion-type metal-oxide-semiconductor field-effect transistors.

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