Laser diode driving device

Abstract

The utility model belongs to the technical field of pulse power, and particularly discloses a laser diode driving device. The device comprises a thin film capacitor, a charging resistor, a laser diode and a bipolar transistor, one end of the charging resistor is connected with a power supply, and the other end is connected with the anode of the thin-film capacitor and the collector of the bipolar transistor; the cathode of the film capacitor is connected with the cathode of the laser diode; the positive electrode of the laser diode and the emitting electrode of the bipolar transistor are connected to the ground; the base electrode of the bipolar transistor is used for connecting an external driving trigger; wherein the thin film capacitor, the charging resistor, the laser diode and the bipolar transistor are all unpackaged devices; the device is obtained by integrating and then packaging a thin film capacitor, a charging resistor, a laser diode and a bipolar transistor. According to the invention, the parasitic inductance of the circuit loop of the whole device can be greatly reduced, the circuit performance of the device is improved, and the size miniaturization level of the device is improved while the normal driving output of the laser diode is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pulse power, and more particularly, relates to a laser diode driving device. BACKGROUND

[0002] A laser diode (LD) is widely used in a laser radar system to provide a laser light source due to its excellent characteristics. With the rapid development of unmanned driving technology, as one of the most important sensor systems in an unmanned driving system, a demand for a light and small, high-precision laser radar system is increasing, which makes it urgent to develop a small and high-performance LD driving device.

[0003] A traditional LD driving device is usually connected by separate discrete devices on a circuit board. Since there are many cascaded circuits on the circuit board, a large parasitic inductance is generated in the total circuit of the device, which affects the performance of the device circuit. At the same time, the volume of the device is affected by the volume of the package and the volume of the circuit board, and the overall volume is large, which cannot meet the application requirements of the current laser radar system.

[0004] Therefore, how to better realize the LD driving device has become a technical problem to be solved in the industry. CONTENT OF THE INVENTION

[0005] In view of the defects of the prior art, the purpose of the application is to better realize the LD driving device, and to solve the problems of large parasitic inductance in the total circuit of the traditional LD driving device and large overall volume.

[0006] To achieve the above purpose, in a first aspect, the application provides a laser diode driving device, comprising:

[0007] a thin film capacitor, a charging resistor, a laser diode and a bipolar transistor;

[0008] One end of the charging resistor is used to connect a direct current power supply, and the other end is connected with a positive electrode of the thin film capacitor and a collector of the bipolar transistor; a negative electrode of the thin film capacitor is connected with a negative electrode of the laser diode; a positive electrode of the laser diode and an emitter of the bipolar transistor are both connected to the ground; and a base of the bipolar transistor is used to connect an external driving trigger;

[0009] The thin film capacitor, the charging resistor, the laser diode and the bipolar transistor are all unpackaged devices, and the device is obtained by packaging the thin film capacitor, the charging resistor, the laser diode and the bipolar transistor after integration.

[0010] Optionally, the positive pole of the direct current power supply, the charging resistor, the thin film capacitor, the circuit parasitic inductance, the laser diode and the negative pole of the direct current power supply form a charging circuit for charging the thin film capacitor.

[0011] Optionally, the positive pole of the thin film capacitor, the bipolar transistor, the laser diode, the circuit parasitic inductance and the negative pole of the thin film capacitor form a discharging circuit for driving the laser diode to emit laser.

[0012] Optionally, the thin film capacitor and the charging resistor are electrically isolated from the ground side by a preset dielectric layer.

[0013] Optionally, the manufacturing material of the preset dielectric layer includes plastic film material, inorganic dielectric material or organic silicon material.

[0014] Optionally, the packaging material of the device includes plastic packaging material or ceramic packaging material.

[0015] Optionally, the bipolar transistor includes a PNP type bipolar transistor of FMMT417 series.

[0016] Optionally, the thin film capacitor includes a single-layer thin film capacitor of PE104J2A05 series.

[0017] Optionally, the charging resistor includes a chip resistor of 0603WAF series.

[0018] Optionally, the laser diode includes a laser diode of GH05035A2G series.

[0019] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects:

[0020] The present application provides a laser diode driving device, which adopts a low inductance layout mode, uses a thin film capacitor, a charging resistor, a laser diode and a high-power bipolar transistor device without independent packaging, integrates them according to a preset connection circuit and then packages them as a whole, thereby maximizing the reduction of line connection and saving the process of independent packaging of individual elements, greatly reducing the parasitic inductance of the entire device circuit loop and improving the device circuit performance; at the same time, the device can completely complete the entire process of capacitor charging, triggering of the bipolar transistor to turn on and off, discharging and triggering of the laser diode driving, which can ensure normal driving output of the laser diode and improve the level of device miniaturization. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a laser diode driving device provided by an embodiment of the present application.

[0022] Figure 2 is a structure top view of a packaged laser diode driving device provided by an embodiment of the present application;

[0023] Figure 3 is a structure side view of a packaged laser diode driving device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0025] In the embodiments of the present application, the words such as "exemplary" or "for example" are used to mean serving as an example, instance or illustration. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. In fact, the words such as "exemplary" or "for example" are used to present related concepts in a specific manner.

[0026] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

[0027] Figure 1 is a structure schematic diagram of a laser diode driving device provided by an embodiment of the present application, as shown in the figure, the device 1 comprises: Figure 1

[0028] a film capacitor FC, a charging resistor R, a laser diode LD and a bipolar transistor (BJT);

[0029] One end of the charging resistor R is used to connect a direct current power supply DC, and the other end is connected with a positive electrode of the film capacitor FC and a collector of the bipolar transistor BJT; a negative electrode of the film capacitor FC is connected with a negative electrode of the laser diode LD; a positive electrode of the laser diode LD and an emitter of the bipolar transistor BJT are both connected to the ground; and a base of the bipolar transistor BJT is used to connect an external driving trigger 2;

[0030] Among them, the film capacitor FC, the charging resistor R, the laser diode LD and the bipolar transistor BJT are all unpackaged devices; the device 1 is obtained by integrating the film capacitor FC, the charging resistor R, the laser diode LD and the bipolar transistor BJT and then packaging.

[0031] ​Specifically, in the embodiment of the present application, the chip-level integration is implemented by using the un-encapsulated film capacitor FC, the charging resistor R, the laser diode LD and the bipolar transistor BJT, and the laser diode driving device is obtained by encapsulating the whole together.

[0032] wherein one end of the charging resistor R is led out as a charging port T2 for connecting a high-voltage direct-current power supply DC; the emitter E end of the bipolar transistor BJT with high power bearing capacity is grounded, and the base B end is led out as a driving port T1 of the whole device for connecting an external driving trigger 2; the collector C end of the bipolar transistor BJT is connected to the other end of the charging resistor R, and at the same time, the collector C end of the bipolar transistor BJT is connected to the positive electrode of the film capacitor FC, forming a three-terminal common connection; the negative electrode of the film capacitor FC is connected to the negative electrode of the light-emitting diode LD; the positive electrode of the laser diode LD is grounded; and the ground side G is led out as a ground port T3 of the whole device.

[0033] It should be noted that the inductance L represents the parasitic inductance of the discharge loop of the whole device.

[0034] Based on the content of the above embodiment, as an optional embodiment, the bipolar transistor BJT includes a PNP type bipolar transistor of FMMT417 series.

[0035] Specifically, in the embodiment of the present application, the bipolar transistor BJT can adopt a PNP type bipolar transistor of FMMT417 series, and through the patch type design of the FMMT417 series bipolar transistor BJT, the miniaturization design of the whole device is more favorable.

[0036] Based on the content of the above embodiment, as an optional embodiment, the charging resistor R includes a patch resistor of 0603WAF series.

[0037] Specifically, in the embodiment of the present application, the charging resistor R can specifically adopt a patch resistor of 0603WAF series, which can further improve the miniaturization of the whole device.

[0038] Based on the content of the above embodiment, as an optional embodiment, the laser diode LD includes a laser diode of GH05035A2G series.

[0039] Specifically, in the embodiment of the present application, the laser diode LD can specifically adopt a laser diode of GH05035A2G series, wherein the laser diode LD of GH05035A2G series includes different power types, for example, 30mW and 35mW types, and the like, which can be specifically set according to actual design requirements to meet the needs of different customers and different application scenarios.

[0040] Based on the content of the above embodiment, as an optional embodiment, the thin film capacitor FC includes a single-layer thin film capacitor (SLFC) of a PE104J2A05 series.

[0041] Specifically, the thin film capacitor FC can adopt any one of the five models of PE104J2A0501~PE104J2A0505 SLFC, which is more conducive to the miniaturization design of the entire device.

[0042] Based on the content of the above embodiment, as an optional embodiment, the thin film capacitor FC and the charging resistor R are electrically isolated from the ground side G by a preset dielectric layer.

[0043] Specifically, in the embodiment of the present application, during the charging process of the device, if the current is too large or unstable, it may cause damage to the charging resistor R, the thin film capacitor FC and other circuit elements. By electrically isolating through the preset dielectric layer, the size and flow direction of the current can be limited, thereby protecting the circuit elements from damage. At the same time, by electrically isolating, the interference between circuits can also be effectively reduced, and the overall stability of the device circuit can be improved.

[0044] Based on the content of the above embodiment, as an optional embodiment, the manufacturing material of the preset dielectric layer includes plastic film material, or inorganic dielectric material, or organic silicon material.

[0045] Among them, the plastic film material can specifically use polyethylene or polypropylene plastic film material; the inorganic dielectric material can specifically use ceramic material or glass material, etc., which has excellent insulation performance and chemical stability.

[0046] Based on the content of the above embodiment, as an optional embodiment, the packaging material of the laser diode driving device can include plastic packaging material, or ceramic packaging material.

[0047] Among them, the plastic packaging material can specifically use epoxy resin material, or polyimide material, etc., which has good insulation performance and mechanical strength; the ceramic packaging material can specifically use aluminum oxide material or aluminum nitride material, which not only has good thermal conductivity, but also has high mechanical strength and chemical stability.

[0048] Figure 2 is the structure top view of the packaged laser diode driving device provided by the embodiment of the present application, Figure 3 is the structure side view of the packaged laser diode driving device provided by the embodiment of the present application, combined with Figure 2 and Figure 3In the embodiment of the present application, the package P of the laser diode LD driving device fully encapsulates the high-power bipolar transistor BJT, the capacitor SLFC, the charging resistor R, the laser diode LD, the preset dielectric layer, and the ground side G. Among them, the capacitor SLFC in the device is a single-layer thin film capacitor, the high-power bipolar transistor BJT, the capacitor SLFC, the charging resistor R, and the laser diode LD are all unpackaged chip-level devices, and the chip-level connection is performed on the ground side G.

[0049] As shown in Figure 3 , in the device of the embodiment of the present application, the base B of the high-power bipolar transistor BJT is led out as a driving port T1, one end of the charging resistor R is led out as a charging port T2, and one end of the ground side G is led out as a ground port T3. Among them, the driving port T1 of the device is used to connect an external driving source Trigger, the charging port T2 is used to connect a high-voltage direct current power supply DC, and the ground port T3 is used for grounding.

[0050] The integrated laser diode LD driving device based on the high-power BJT provided by the embodiment of the present application utilizes the special single-layer thin film capacitor SLFC to perform chip-level integration with the high-power BJT and the laser diode LD, which can effectively reduce the parasitic inductance of the entire driving device loop to about 1 nH, and can completely complete the entire process of charging, triggering the BJT, discharging, and triggering the LD to drive the laser diode. After integration, overall packaging is performed, which has obvious advantages in miniaturization in device size.

[0051] Continuing to refer to Figure 1 , based on the content of the above embodiment, as an optional embodiment, the positive electrode of the direct current power supply DC, the charging resistor R, the thin film capacitor FC, the circuit parasitic inductance L, the laser diode LD, and the negative electrode of the direct current power supply DC form a charging circuit, which is used to charge the thin film capacitor FC.

[0052] Specifically, in the embodiment of the present application, first, the single-layer thin film capacitor SLFC is charged by using the direct current power supply DC through one end of the charging resistor R. The charging circuit can be represented as DC-R-SLFC-L-LD-DC, which is formed by the positive electrode of the direct current power supply DC, the charging resistor R, the thin film capacitor FC, the circuit parasitic inductance L, the laser diode LD, and the negative electrode of the direct current power supply DC, thereby realizing charging of the entire device by the direct current power supply DC.

[0053] Continuing to refer to Figure 1 , based on the content of the above embodiment, as an optional embodiment, the positive electrode of the thin film capacitor FC, the bipolar transistor BJT, the laser diode LD, the circuit parasitic inductance L, and the negative electrode of the thin film capacitor FC form a discharging circuit, which is used to drive the laser diode to emit laser.

[0054] Specifically, when the overall device is working normally, after the thin-film capacitor FC completes charging, the trigger signal end Trigger of the external drive trigger 2 applies a narrow pulse trigger signal to the T1 port and transmits to the base of the bipolar transistor BJT, the BJT is controlled to be turned on, the single-layer thin-film capacitor SLFC is discharged through the bipolar transistor BJT and the laser diode LD, and a discharge loop is formed by the anode of the single-layer thin-film capacitor SLFC, the bipolar transistor BJT, the laser diode LD, the circuit parasitic inductance L and the cathode of the thin-film capacitor SLFC, which can be expressed as SLFC-BJT-LD-L-SLFC, and the process of emitting laser light is completed by driving the laser diode LD through discharging, thereby realizing the driving control of the device on the light emission of the laser diode LD.

[0055] In a specific embodiment of the present application, compared with the typical parasitic inductance of about 5nH of a typical commercial packaged laser diode LD, the inductance of a commercial patch transistor is about 2nH, and the inductance of a patch capacitor is about 2nH, so that the total loop inductance of the traditional laser diode LD driving device is 10nH or more, while the laser diode driving device provided by the present application can effectively reduce the parasitic inductance to about 1nH, and the circuit performance of the device is greatly improved.

[0056] The laser diode driving device of the embodiment of the present application, by adopting a low-inductance layout mode, using a thin-film capacitor, a charging resistor, a laser diode and a high-power bipolar transistor device which are not independently packaged, and performing integration first and then overall packaging according to a preset connection circuit, maximizes the reduction of line connection and saves the process of independent packaging of individual elements, can greatly reduce the parasitic inductance of the entire device circuit loop and improve the circuit performance of the device; at the same time, it can completely complete the entire process of capacitor charging, triggering the on-off of the bipolar transistor, and discharging and triggering the driving of the laser diode, which can ensure the normal driving output of the laser diode while improving the level of miniaturization of the device.

[0057] It can be understood that the various numbers involved in the embodiments of the present application are only for the convenience of differentiation and do not limit the scope of the embodiments of the present application.

[0058] It should be understood that expressions such as "include" and "may include" used in the present application represent the existence of the disclosed functions, operations or constituent elements, and do not limit one or more additional functions, operations and constituent elements. In the present application, terms such as "include" and / or "have" can be interpreted to represent a specific feature, number, operation, constituent element, component or combination thereof, but cannot be interpreted to exclude the existence or addition of one or more other features, numbers, operations, constituent elements, components or combinations thereof.

[0059] In the description of the embodiments of the present application, it should be noted that unless specifically defined and limited otherwise, the term "connected" should be construed broadly, for example, "connected" can be detachably connected, or can not be detachably connected; can be directly connected, or can be indirectly connected through an intermediate medium. Among them, "fixedly connected" means connected to each other and the relative positional relationship after connection does not change. "Rotatably connected" means connected to each other and capable of relative rotation after connection. "Slidably connected" means connected to each other and capable of relative sliding after connection. The orientation language mentioned in the embodiments of the present application, such as "upper", "lower", "inner", "outer", etc., is only the direction of reference to the drawings, therefore, the orientation language used is to better, more clearly illustrate and understand the embodiments of the present application, and is not indicative or implied that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore, it cannot be understood as a limitation on the embodiments of the present application.

[0060] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A laser diode driving device, characterized by comprising: The device comprises: a thin film capacitor, a charging resistor, a laser diode and a bipolar transistor; one end of the charging resistor is connected to a DC power supply, and the other end is connected to the positive electrode of the thin film capacitor and the collector of the bipolar transistor; the negative electrode of the thin film capacitor is connected to the negative electrode of the laser diode; the positive electrode of the laser diode and the emitter of the bipolar transistor are both connected to the ground; and the base of the bipolar transistor is used to connect an external driving trigger; wherein the thin film capacitor, the charging resistor, the laser diode and the bipolar transistor are all unpackaged devices; the device is obtained by packaging the thin film capacitor, the charging resistor, the laser diode and the bipolar transistor after integration.

2. The laser diode driving device according to claim 1, wherein The positive electrode of the DC power supply, the charging resistor, the thin film capacitor, the circuit parasitic inductance, the laser diode and the negative electrode of the DC power supply form a charging circuit for charging the thin film capacitor.

3. The laser diode driving device according to claim 2, wherein The positive electrode of the thin film capacitor, the bipolar transistor, the laser diode, the circuit parasitic inductance and the negative electrode of the thin film capacitor form a discharge circuit for driving the laser diode to emit laser.

4. The laser diode driving apparatus according to claim 1, wherein The thin film capacitor and the charging resistor are electrically isolated from the ground side by a preset dielectric layer.

5. The laser diode driving device according to claim 4, wherein The manufacturing material of the preset dielectric layer includes plastic film material, inorganic dielectric material or organic silicon material.

6. The laser diode driving apparatus according to claim 1, wherein The packaging material of the device includes plastic packaging material or ceramic packaging material.

7. The laser diode driving apparatus according to any one of claims 1 to 6, characterized by The bipolar transistor includes a PNP type bipolar transistor of FMMT417 series.

8. The laser diode driving apparatus according to any one of claims 1 to 6, characterized by The thin film capacitor includes a single-layer thin film capacitor of PE104J2A05 series.

9. The laser diode driving apparatus according to any one of claims 1 to 6, characterized by The charging resistor includes a chip resistor of 0603WAF series.

10. The laser diode driving apparatus according to any one of claims 1 to 6, characterized by The laser diode includes a laser diode of GH05035A2G series.

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