Packaging structure for Ethernet power supply control circuit and power receiving equipment

Abstract

The utility model discloses a packaging structure for an Ethernet power supply control circuit and power receiving equipment. The packaging structure comprises a lead frame which comprises a base island and a plurality of pins; the switching power supply controller, the power switch tube and the powered equipment controller are placed on the base island; the plastic package body wraps the switching power supply controller, the power switch tube, the power receiving equipment controller and the base island, and the floating ground end of the switching power supply controller and the reference ground end of the power receiving equipment controller are connected to different pins. Therefore, the power switch tube, the power receiving equipment controller and the switching power supply controller required by Ethernet power supply are integrated into the same lead frame, the packaging size can be greatly reduced, the electrical path between electronic elements is shortened, and compared with a traditional discrete scheme, the Ethernet power supply integrated lead frame has great advantages in cost and performance.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuit packaging, and more particularly to a packaging structure for an Ethernet power supply control circuit and a powered device. Background Art

[0002] Power over Ethernet (PoE), also known as PoE, is a technology that transmits power and data to devices over twisted-pair Ethernet cables. Compatible with existing Ethernet cabling infrastructure, PoE allows devices to be powered through their network ports, eliminating power cables and reducing wiring and hardware costs. PoE is currently widely used in video telephony, security, IoT devices, and other fields.

[0003] A Power over Ethernet system generally includes a Power Sourcing Equipment (PSE), a Powered Device (PD), and an Ethernet cable that transmits power and data between the two.

[0004] In a PoE power supply system, a PD typically needs to convert the high-voltage AC power received from an Ethernet cable into a low-voltage DC power suitable for its internal circuitry. This component primarily includes a powered device interface controller chip (also known as a powered device controller chip), a switching power supply controller chip, and power switches. Currently, the traditional approach is to use three different discrete packages within the same device, or simply package the powered device controller chip and switching power supply controller chip together, while packaging the power switches separately. These two packaging solutions require a large footprint, hindering overall device cost and increasing the complexity of PCB wiring. Utility Model Content

[0005] In view of this, an object of the present invention is to provide a packaging structure for a power over Ethernet control circuit and a powered device, so as to solve the problems of large area and high cost in traditional discrete packaging solutions.

[0006] According to one aspect of the present invention, a packaging structure for an Ethernet power supply control circuit is provided, comprising: a lead frame including a base island and a plurality of pins; a switching power supply controller, a power switch tube, and a powered device controller placed on the base island; and a plastic package covering the switching power supply controller, the power switch tube, the powered device controller, and the base island, wherein a floating ground terminal of the switching power supply controller and a reference ground terminal of the powered device controller are connected to different pins.

[0007] Optionally, the base island includes a first base island and a second base island; the powered device controller and the power switch tube are located on the first base island, and the switching power supply controller is located on the second base island.

[0008] Optionally, the plastic package body includes a first side and a second side that are opposite, and a third side and a fourth side that are opposite, the first side and the second side extend in a width direction, and the third side and the fourth side extend in a length direction, wherein the first base island is close to the first side of the plastic package body, and the second base island is close to the second side of the plastic package body.

[0009] Optionally, an area of the first base island is greater than an area of the second base island.

[0010] Optionally, the floating ground terminal of the switching power supply controller, the second end of the power switch tube and the second base island are interconnected, and the second base island extends toward the third side of the plastic package to form a floating ground pin.

[0011] Optionally, the first end of the power switch tube, the power end of the switching power supply controller and the positive power input end of the powered device controller are all interconnected with the first base island, and the first base island extends toward the third side of the plastic package to form at least one power pin.

[0012] Optionally, the multiple pins also include: a power supply pin set on the third side, which is used to be interconnected with the power supply end of the switching power supply controller; a feedback pin set on the fourth side, which is used to be interconnected with the feedback end of the switching power supply controller; a power supply negative input pin set on the fourth side, which is used to be interconnected with the power supply negative input end of the powered device controller; and a reference ground pin set on the fourth side, which is used to be interconnected with the reference ground end of the powered device controller.

[0013] Optionally, the driving end of the switching power supply controller is interconnected with the control end of the power switch tube.

[0014] Optionally, the powered device controller and the first base island are isolated by an insulating layer.

[0015] Optionally, a redundant pin is further provided on the fourth side.

[0016] Optionally, a current detection pin is provided on the fourth side, and the current detection pin is used to interconnect with a current detection terminal of a switching power supply controller and the second end of the power switch tube.

[0017] Optionally, the plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and two power supply pins.

[0018] Optionally, the plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and a power supply pin.

[0019] Optionally, the plurality of pins on the fourth side are sequentially arranged as a feedback pin, a power negative input pin, and a reference ground pin.

[0020] Optionally, the plurality of pins on the fourth side are sequentially arranged as a feedback pin, a redundant pin, a power negative input pin, and a reference ground pin.

[0021] Optionally, the plurality of pins on the fourth side are sequentially arranged as a feedback pin, a current detection pin, a power negative input pin, and a reference ground pin.

[0022] Optionally, the base island is a third base island, the switching power supply controller, the power switch tube and the powered device controller are all located on the third base island, the plastic package includes a first side and a second side relative to each other, and a third side and a fourth side relative to each other, the first side and the second side extend along the width direction, and the third side and the fourth side extend along the length direction.

[0023] Optionally, the first end of the power switch tube, the power end of the switching power supply controller and the positive power input end of the powered device controller are interconnected with the third base island, and the third base island extends toward the first side and / or the second side to form a power pin.

[0024] Optionally, the multiple pins also include: a floating ground pin arranged on the third side, the floating ground pin being interconnected with the floating ground terminal of the switching power supply controller and the source terminal of the power switch tube; a power supply pin arranged on the third side, the power supply pin being used to be interconnected with the power supply terminal of the switching power supply controller; a reference ground pin arranged on the third side, the reference ground pin being used to be interconnected with the reference ground terminal of the powered device controller; a feedback pin arranged on the fourth side, the feedback pin being used to be interconnected with the feedback terminal of the switching power supply controller; and a power supply negative input pin arranged on the fourth side, the power supply negative input pin being used to be interconnected with the power supply negative input terminal of the powered device controller.

[0025] Optionally, a driving end of a switching power supply controller is interconnected with a control end of the power switch tube.

[0026] Optionally, the switching power supply controller, the powered device controller, and the third base island are isolated by an insulating layer.

[0027] Optionally, a redundant pin is further provided on the third side; and two redundant pins are further provided on the fourth side.

[0028] Optionally, a current detection pin is provided on the fourth side.

[0029] Optionally, the plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and a reference ground pin.

[0030] Optionally, the plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin, a redundant pin and a reference ground pin.

[0031] Optionally, the plurality of pins on the fourth side are sequentially arranged as a feedback pin and a power negative input pin.

[0032] Optionally, the plurality of pins on the fourth side are sequentially arranged as a feedback pin, one or two redundant pins, and a power negative input pin.

[0033] Optionally, the plurality of pins on the fourth side are sequentially arranged as a current detection pin, a feedback pin and a power negative input pin.

[0034] Optionally, the plurality of pins on the fourth side are sequentially arranged as a current detection pin, a redundant pin, a feedback pin and a power negative input pin.

[0035] Optionally, the power switch tube is bonded to the corresponding base island using conductive silver glue.

[0036] Optionally, the insulating layer is an adhesive film.

[0037] Optionally, the packaging structure further includes: a central rib provided on the first side and the second side for supporting.

[0038] According to another aspect of the present invention, a powered device is provided, comprising: a power circuit; and the above-mentioned packaging structure for the Ethernet power control circuit, wherein the packaging structure is connected to the power circuit.

[0039] Optionally, the power supply circuit is a buck topology structure or a flyback topology structure.

[0040] In summary, the present invention packages the power switch tube, powered device controller, and switching power supply controller required for Ethernet power supply into the same package structure, which can greatly reduce the package size and shorten the electrical path between electronic components. Compared with traditional discrete solutions, it has significant advantages in cost and performance.

[0041] Furthermore, in the package structure of this utility model, the floating ground pin of the switching power supply controller and the reference ground of the powered device controller are connected to different pins. This allows the external power supply circuit to sample the output voltage without the use of an auxiliary winding, significantly reducing the production cost and difficulty of the flyback converter. Furthermore, the lack of an auxiliary winding reduces electromagnetic interference within the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0043] Figure 1 FIG. 4 shows a schematic circuit diagram of a PD device according to a first embodiment of the present utility model.

[0044] Figure 2 Show Figure 1 An internal structure layout diagram of the package structure.

[0045] Figure 3 Show Figure 1 Another internal structure layout diagram of the package structure.

[0046] Figure 4 FIG. 4 shows a schematic circuit diagram of a PD device according to a second embodiment of the present invention.

[0047] Figure 5 Show Figure 4 An internal structure layout diagram of the package structure.

[0048] Figure 6 Show Figure 4 Another internal structure layout diagram of the package structure.

[0049] Figure 7 FIG. 4 shows a schematic circuit diagram of a PD device according to a third embodiment of the present invention.

[0050] Figure 8 FIG. 4 is a schematic circuit diagram of a PD device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0051] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, identical elements are represented by identical or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0052] The present invention may be embodied in various forms, some examples of which will be described below.

[0053] Figure 1FIG. 1 shows a schematic circuit diagram of a PD device according to a first embodiment of the present invention. Figure 1 As shown, the PD device (powered device) 100 generally needs to convert the high-voltage AC power received from the Ethernet cable into a low-voltage DC power suitable for use by the internal circuit, and includes a power circuit and a packaging structure 200 .

[0054] The power circuit is located outside the package structure 200 and is connected to the package structure 200 via pins. The power circuit includes a rectifier bridge 110, a capacitor C1, an electrolytic capacitor Cp, a power conversion circuit 120, and a feedback circuit 130. For example, the package structure 200 encapsulates a powered device controller 210, a switching power supply controller 220, and a power switch Q1.

[0055] The rectifier bridge 110 is used to rectify the AC input voltage to obtain a DC input voltage Vin. The electrolytic capacitor Cp is connected between the DC input voltage Vin and the reference ground GND1.

[0056] The input signal of the powered device controller 210 is connected between the DC input voltage Vin and the negative input terminal VSS of the power supply. The output signal of the powered device controller 210 is connected between the DC input voltage Vin and the reference ground GND1. It is used to perform a handshake protocol with the power supply equipment (PSE) in the PoE system, obtain the required energy, and then output it to the subsequent switching power supply controller 220. For example, when the powered device 100 is connected to the Ethernet cable, the powered device controller 210 communicates with the PSE to confirm the device's presence and determine its power requirements, thereby ensuring that the PSE can provide appropriate power without overloading or damaging the network. In addition, the powered device controller 210 has a protection function, which can monitor various parameters during the power transmission process, such as current, voltage, and temperature. If an abnormality is detected, the powered device controller 210 will quickly take action, such as disconnecting the power supply or adjusting the power output, to protect the powered device and the entire PoE system. Furthermore, the powered device controller 210 also supports various PoE standards and protocols, such as IEEE 802.3af, IEEE 802.3at, and IEEE 802.3bt. These standards specify different power levels and communication methods, and the powered device controller needs to be compatible with these standards to ensure interoperability with various PSE devices.

[0057] The switching power supply controller 220, the power switch Q1, the feedback circuit 130, and the power conversion circuit 120 together constitute the switching power converter of the powered device 100, which is used to perform power conversion and regulation functions, converting the DC input voltage Vin into a DC output voltage Vout suitable for use by the powered device, thereby minimizing energy loss and ensuring stable operation of the device.

[0058] For example, the power conversion circuit 120 is a flyback topology structure, including: a transformer T1 (including a primary winding L1 and a secondary winding L2), a freewheeling diode D1, and an output capacitor Co. Among them, the first end of the power switch tube Q1 (such as a transistor, a field effect tube, a thyristor, etc.) is connected to the DC input voltage Vin, the second end is connected to the floating ground VS, and the control end is connected to the drive pin of the switching power supply controller 220 to receive the switch drive signal DRV. The power switch tube Q1 is used to control the power transmission from the input end to the output end of the power conversion circuit 120 according to the switch drive signal DRV. In an exemplary embodiment, the power switch tube Q1 is an NMOS tube, and its first end, second end, and control end are respectively a drain, a source, and a gate. Of course, the present invention is not limited to this. In some other embodiments, the power switch tube Q1 can be a PMOS tube, and its first end, second end, and control end are respectively a source, a drain, and a gate.

[0059] A first end of the primary winding L1 is connected to the floating ground VS, and a second end is connected to the reference ground GND1. The anode of the diode D1 is connected to the first end of the secondary winding L2, and the cathode of the diode D1 is connected to the first end of the output capacitor Co and the load Ro. The second end of the output capacitor Co is connected to the second end of the secondary winding L2 and the reference ground GND2.

[0060] Feedback circuit 130 is connected between floating ground VS and reference ground GND1 and is configured to divide the output voltage Vout to generate a feedback signal FB. For example, feedback circuit 130 includes resistors R1 and R2 connected in series between floating ground VS and reference ground GND1. A node between resistors R1 and R2 is configured to provide the feedback signal FB.

[0061] The switching power supply controller 220 has a power supply terminal VIN, a power supply terminal VCC, a feedback terminal FB, a floating ground terminal VS, and a driver terminal DRV. The power supply terminal VIN of the switching power supply controller 220 is connected to the DC input voltage Vin, the power supply terminal VCC is connected to the floating ground terminal VS via a capacitor C1, the driver terminal DRV is connected to the control terminal of the power switch Q1, and the feedback terminal FB is connected to the feedback circuit 130. The switching power supply controller 220 is configured to generate a switch drive signal DRV applied to the power switch Q1 based on a feedback signal FB of the output voltage Vout, thereby controlling the on and off state of the power switch Q1.

[0062] Figure 2 Show Figure 1 An internal structure layout diagram of the package structure. Figure 2As shown, this embodiment provides a package structure 200-1 for Ethernet power supply, including a lead frame, a powered device controller 210, a switching power supply controller 220, a power switch tube Q1 and a plastic package 201. The plastic package 201 covers the powered device controller 210, the switching power supply controller 220, the power switch tube Q1 and part of the lead frame. The pins in the lead frame are located outside the plastic package 201 for electrical connection.

[0063] Furthermore, the lead frame includes a base island 211, a base island 212, and a plurality of pins arranged around the base islands 211 and 212. The base islands 211, 212, and the plurality of pins are connected by bonding wires, thereby achieving an electrical connection between the chip on the base island and the outside world. After the chip is bonded, it should be ensured that the chip can withstand the physical pressure generated after packaging and can dissipate the heat generated during chip operation.

[0064] The base island 211 is a "large base island" for supporting the powered device controller 210 and the power switch Q1, and the base island 212 is a "small base island" for supporting the switching power supply controller 220. In this application, the terms "large base island" and "small base island" have the following definitions: within the same lead frame, a base island with a relatively large area is a large base island, and a base island with a relatively small area is a small base island.

[0065] Furthermore, the plastic package body 201 is rectangular, and includes a first side 251 and a second side 252 arranged opposite to each other, and a third side 253 and a fourth side 254 arranged opposite to each other. The first side 251 and the second side 252 extend along the first direction in the figure, and the third side 253 and the fourth side 254 extend along the second direction in the figure. The first side 251 and the third side 253 are perpendicular, and the second side 252 and the fourth side 254 are perpendicular.

[0066] Specifically, the lead frame provided in this embodiment has two base islands, namely base island 211 and base island 212. Base islands 211 and 212 are insulated and isolated from each other, and do not interfere with each other. Base island 211, which is close to the first side 251, is used to support the powered device controller 210 and the power switch tube Q1. Since the first end contact of the power switch tube Q1 is usually located on the back of the tube die, the base island 211 is bonded to the back of the power switch tube Q1. The base island 211 extends toward the third side 253 of the plastic package 201 to lead out two power pins 242 and 243, thereby achieving an electrical connection between the first end of the power switch tube Q1 and the power pins 242 and 243. At the same time, the heat generated by the power switch tube Q1 during operation is also conducted to the outside through the base island 211 and its two pins 242 and 243. Furthermore, the provision of multiple power pins 242 and 243 can also facilitate the wiring of external circuits and optimize the PCB routing outside the package structure. Due to its excellent conductivity and adhesion, conductive silver paste with high silver content is preferably used to bond the power switch Q1 to the base island 211 to achieve good electrical contact. Due to the large area of the base island 211, the powered device controller 210 is also placed on the base island 211, with an insulating layer 221 used to electrically isolate the powered device controller 210 from the base island 211. Furthermore, a die-attach film (DAF) is used to bond the powered device controller 210 to the base island 211 to ensure good insulation and control chip tilt. To accommodate bonding and isolation requirements, the insulating layer 221 is smaller than the base island 211 and larger than the powered device controller 210 to achieve optimal performance.

[0067] Continue to refer Figure 2 The base island 212, located near the second side 252 of the plastic package 201, is used to support the switching power supply controller 220. Because the switching power supply controller 220 has lower power and requirements than the power switch Q1, to reduce costs, conductive silver glue is not required. Instead, standard conductive glue can be used to bond the switching power supply controller 220 to the base island 212. Heat generated during operation is conducted to the outside world through the base island 212 and its pins 241.

[0068] Specifically, the power switch Q1 has the following pads: a control terminal G, a second terminal S, and a first terminal (not shown). The powered device controller 210 has the following pads: a positive power input terminal VDD, a negative power input terminal VSS, and a reference ground terminal GND1. The switching power supply controller 220 has the following pads: a power supply terminal VIN, a power supply terminal VCC, a feedback terminal FB, a drive terminal DRV, and a floating ground terminal VS.

[0069] Specifically, the several pins of the lead frame include: two power pins (VIN) 242 and 243 extending from the base island 211 to the third side 253 of the plastic package 201, a floating ground pin (VS) 241 extending from the base island 212 to the third side 253 of the plastic package 201, a power supply pin (VCC) 231 arranged on the third side 253 of the plastic package 201, and a feedback pin (FB) 232, a negative power input pin (VSS) 233 and a reference ground pin (GND1) 234 arranged on the fourth side 254 of the plastic package 201.

[0070] Furthermore, the power supply terminal VCC of the switching power supply controller 220 is connected to the power supply pin 231, the power supply terminal VIN of the switching power supply controller 220 is connected to the base island 211, the drive terminal DRV of the switching power supply controller 220 is connected to the control terminal G of the power switch Q1, the feedback terminal FB of the switching power supply controller 220 is connected to the feedback pin 232, and the floating ground terminal VS of the switching power supply controller 220 is connected to the base island 212 and is led out through the floating ground pin 241 of the base island 212. The second terminal S of the power switch Q1 is connected to the base island 212 and then connected to the floating ground terminal VS of the switching power supply controller 220 through the base island 212. The positive power input terminal VDD of the powered device controller 210 is connected to the base island 211, the negative power input terminal VSS of the powered device controller 210 is connected to the negative power input pin 233, and the reference ground terminal GND1 of the powered device controller 210 is connected to the reference ground pin 234. It is understandable that the connection method of the pins of the package structure for Ethernet power supply is not limited to the above description. In practice, the pin arrangement and the pin connection method can be adjusted according to specific application requirements.

[0071] Furthermore, the second end pin S of the power switch tube Q1 is connected to the base island 212 through three metal wires. At the same time, the negative power input terminal VSS of the powered device controller 210 is connected to the negative power input pin 233 through three metal wires, and the reference ground terminal GND1 of the powered device controller 210 is connected to the reference ground pin 234 through three metal wires.

[0072] Furthermore, the lead frame also includes a plurality of center ribs 213 arranged on the first side 251 and the second side 252 of the plastic package body 201. The center ribs 213 are made of metal copper, for example, and are used to support the entire base island together with the floating ground pin 241 and the power pins 242 and 243. They are also used to connect multiple packaging structures during the manufacturing process and to cut and separate multiple packaging structures after manufacturing is completed.

[0073] Furthermore, the lead frame further includes redundant pins 235 disposed on the fourth side 254 of the plastic package body 201 , wherein the reserved redundant pins 235 can be used as pins for other functions, thereby reducing the difficulty of circuit modification and design.

[0074] This embodiment uses a package structure 200-1 with dual base islands. The number of pins meets the requirements for combined package bonding. The base island 211 supports the power switch Q1 and the powered device controller 210, and an insulating layer such as DAF film is used to achieve electrical isolation between the two. The base island 212 supports the switching power supply controller 220. This integrates the powered device controller, switching power supply controller, and power switch required for the Power over Ethernet package structure into the same lead frame. This can greatly reduce the package size and shorten the electrical paths between electronic components. Compared with traditional discrete solutions, it has significant advantages in cost and performance.

[0075] Figure 3 Show Figure 1 Another internal structure layout diagram of the package structure. Figure 3 As shown, another packaging structure 200-2 includes a lead frame, a powered device controller 210, a switching power supply controller 220, a power switch tube Q1 and a plastic package 301. The plastic package 301 covers the powered device controller 210, the switching power supply controller 220, the power switch tube Q1 and part of the lead frame. The pins in the lead frame are located outside the plastic package 301 for electrical connection.

[0076] Furthermore, the lead frame comprises only one base island 311 and several pins arranged around the base island 311. The base island 311 is used to support the powered device controller 210, the switching power supply controller 220, and the power switch Q1 in Power over Ethernet. Similarly, the back of the power switch Q1 is bonded to the base island 311. The base island 311 extends toward the first side 351 and the second side 352 of the plastic package 301, leading to two power pins 341. This electrically connects the first end of the power switch Q1 to the power pins 341. Heat generated by the power switch Q1 during operation is also conducted to the outside world through the base island 311 and its pins 341. Similarly, the provision of multiple power pins 341 also facilitates external circuit wiring and optimizes PCB routing outside the package structure. Because conductive silver glue has excellent conductivity and adhesion, high-silver conductive silver glue is preferably used to bond the power switch Q1 to the base island 311 to achieve good electrical contact. Furthermore, because the powered device controller 210 and the switching power supply controller 220 are also placed on the base island 311, the powered device controller 210 is electrically isolated from the base island 311 by an insulating layer 321, and the switching power supply controller 220 is electrically isolated from the base island 311 by an insulating layer 322. Furthermore, the insulating layers 321 and 322 are, for example, DAF films to ensure good insulation and control chip tilt.

[0077] Similarly, the pins of the lead frame include: a floating ground pin (VS) 331, a power supply pin (VCC) 332, a reference ground pin (GND1) arranged on the third side 353 of the plastic package 301, and a feedback pin (FB) 334 and a negative power input pin (VSS) 335 arranged on the fourth side 354 of the plastic package 301.

[0078] Furthermore, the power supply terminal VCC of the switching power supply controller 220 is connected to the power supply pin 332, the power supply terminal VIN of the switching power supply controller 220 is connected to the base island 311, the drive terminal DRV of the switching power supply controller 220 is connected to the control terminal G of the power switch Q1, the feedback terminal FB of the switching power supply controller 220 is connected to the feedback pin 334, and the floating ground terminal VS of the switching power supply controller 220 is connected to the floating ground pin 331. The second terminal S of the power switch Q1 is connected to the floating ground pin 331 and then to the floating ground terminal VS of the switching power supply controller 220 via the floating ground pin 331. The positive power input terminal VDD of the powered device controller 210 is connected to the base island 311, the negative power input terminal VSS of the powered device controller 210 is connected to the negative power input pin 335, and the reference ground terminal GND1 of the powered device controller 210 is connected to the reference ground pin 333. It is understandable that the connection method of the pins of the package structure for Ethernet power supply is not limited to the above description. In practice, the pin arrangement and the pin connection method can be adjusted according to specific application requirements.

[0079] Furthermore, the second terminal S of the power switch tube Q1 is connected to the floating ground pin 331 through three metal wires. At the same time, the negative power input terminal VSS of the powered device controller 210 is connected to the negative power input pin 335 through three metal wires, and the reference ground terminal GND1 of the powered device controller 210 is connected to the reference ground pin 333 through three metal wires.

[0080] Furthermore, the lead frame also includes a redundant pin 336 arranged on the third side 353 of the plastic package 301, and redundant pins 337 and 338 arranged on the fourth side 354 of the plastic package 301, wherein the reserved redundant pins 336-338 can be used as pins for other functions, reducing the difficulty of circuit modification design.

[0081] This embodiment uses a package structure 200-2 with a single base island. The number of pins meets the requirements for combined package bonding. The power switch Q1, powered device controller 210, and switching power supply controller 220 are separately placed on the base island 311. Insulation layers 321 and 322 are used to achieve electrical isolation between the three. This integrates the powered device controller, switching power supply controller, and power switch required for the Power over Ethernet package structure into the same lead frame. This significantly reduces the package size and shortens the electrical paths between electronic components. Compared with traditional discrete solutions, this approach offers significant advantages in both cost and performance.

[0082] As previously mentioned, the ground terminal of the powered device controller 210 of this embodiment is connected to the reference pin GND1, and the ground terminal of the switching power supply controller 220 is connected to the floating ground pin VS. Since these two controllers are connected to different grounds, the powered device controller cannot be used to directly control the subsequent switching power converter. Therefore, the switching power supply controller 220 of this embodiment is further configured to sample the DC input voltage Vin to obtain a first sampled voltage referenced to the floating ground VS, convert the first sampled voltage to a second sampled voltage referenced to the reference ground GND1, compare the second sampled voltage with a predetermined threshold voltage, and enable the power conversion circuit when the second sampled voltage exceeds the threshold voltage. This avoids the problem of the powered device controller 210 starting to operate while still in the inrush current limiting phase, which could cause the entire PoE system to fail to start normally, thereby improving circuit reliability.

[0083] Furthermore, the switching power supply controller 220 is further configured to enable the power conversion circuit after a preset time has passed since the second sampled voltage exceeds the threshold voltage, ensuring that the power converter begins operation after the inrush current limiting of the powered device controller ends. This prevents insufficient PoE energy from charging the electrolytic capacitor Cp at the powered device controller during startup, preventing the target output voltage from being output, thereby further improving circuit reliability. For example, the preset time can be set based on the time required for the electrolytic capacitor Cp to charge to the platform voltage.

[0084] Figure 4 FIG. 2 shows a schematic circuit diagram of a PD device according to a second embodiment of the present invention. Figure 4 As shown, the PD device (powered device) 300 generally needs to convert the high-voltage AC power received from the Ethernet cable into low-voltage DC power suitable for internal circuit use, including a power circuit and a packaging structure 400.

[0085] The power circuit is located outside the package structure 400 and is connected to the power circuit via pins. The power circuit includes a rectifier bridge 310, a capacitor C1, an electrolytic capacitor Cp, a current sampling resistor Rcs, a power conversion circuit 320, and a feedback circuit 330. For example, the package structure 400 encapsulates a powered device controller 410, a switching power supply controller 420, and a power switch Q1.

[0086] The rectifier bridge 410 is used to rectify the AC input voltage to obtain a DC input voltage Vin. The electrolytic capacitor Cp is connected between the DC input voltage Vin and the reference ground GND1.

[0087] The input signal of the powered device controller 410 is connected between the DC input voltage Vin and the negative power supply input terminal VSS. The output signal of the powered device controller 410 is connected between the DC input voltage Vin and the reference ground GND1. It is used to perform a handshake protocol with the power supply equipment (PSE) in the PoE system, obtain the required energy, and then output it to the subsequent switching power supply controller 420. For example, when the powered device 300 is connected to the Ethernet cable, the powered device controller 410 communicates with the PSE to confirm the device's presence and determine its power requirements, thereby ensuring that the PSE can provide appropriate power without overloading or damaging the network. In addition, the powered device controller 410 has a protection function, which can monitor various parameters during the power transmission process, such as current, voltage, and temperature. If an abnormality is detected, the powered device controller 410 will quickly take action, such as disconnecting the power supply or adjusting the power output, to protect the powered device and the entire PoE system. Furthermore, the powered device controller 410 also supports various PoE standards and protocols, such as IEEE 802.3af, IEEE 802.3at, and IEEE 802.3bt. These standards specify different power levels and communication methods, and the powered device controller needs to be compatible with these standards to ensure interoperability with various PSE devices.

[0088] The switching power supply controller 420, the power switch Q1, the feedback circuit 330, and the power conversion circuit 320 together constitute the switching power converter of the powered device 300, which is used to perform power conversion and regulation functions, converting the DC input voltage Vin into a DC output voltage Vout suitable for use by the powered device, thereby minimizing energy loss and ensuring stable operation of the device.

[0089] For example, the power conversion circuit 320 is a flyback topology structure, including: a transformer T1 (including a primary winding L1 and a secondary winding L2), a freewheeling diode D1, and an output capacitor Co. A power switch Q1 (e.g., a transistor, a field-effect transistor, a thyristor, etc.) has a first terminal connected to a DC input voltage Vin, a second terminal connected to a first terminal of a current sampling resistor Rcs, a second terminal of which is connected to a floating ground VS, and a control terminal connected to a drive pin of a switching power supply controller 420 to receive a switch drive signal DRV. The power switch Q1 is configured to control the transmission of power from the input terminal to the output terminal of the power conversion circuit 320 according to the switch drive signal DRV. A first terminal of the primary winding L1 is connected to the floating ground VS, a second terminal is connected to a reference ground GND1, an anode of the diode D1 is connected to a first terminal of the secondary winding L2, a cathode of the diode D1 is connected to a first terminal of the output capacitor Co and a load Ro, and a second terminal of the output capacitor Co is connected to a second terminal of the secondary winding L2 and the reference ground GND2.

[0090] Feedback circuit 330 is connected between floating ground VS and reference ground GND1 and is configured to divide the output voltage Vout to generate a feedback signal FB. For example, feedback circuit 330 includes resistors R1 and R2 connected in series between floating ground VS and reference ground GND1. A node between resistors R1 and R2 is configured to provide the feedback signal FB.

[0091] The switching power supply controller 420 has a power pin VIN connected to the DC input voltage Vin, a drive pin DRV connected to the control terminal of the power switch Q1, a current sense pin CS connected to the first end of the current sampling resistor Rcs, and a feedback pin FB connected to the feedback circuit 330. The switching power supply controller 420 is configured to generate a switch drive signal DRV applied to the power switch Q1 based on a feedback signal FB of the output voltage Vout, thereby controlling the on and off state of the power switch Q1.

[0092] Figure 5 Show Figure 4 An internal structure layout diagram of the package structure. Figure 5 As shown, the package structure 400-1 also includes a lead frame, a powered device controller 210, a switching power supply controller 220, a power switch tube Q1 and a plastic package 401. The plastic package 401 covers the powered device controller 210, the switching power supply controller 220, the power switch tube Q1 and part of the lead frame. The pins in the lead frame are located outside the plastic package 401 for electrical connection.

[0093] Furthermore, the lead frame also has two base islands 411 and 412, a plurality of pins 441, 431, 442 and 443 arranged on the third side 453 of the plastic package 401, a plurality of pins 432, 433, 434 and 435 arranged on the fourth side 454 of the plastic package 401, and a center rib 413 arranged on the first side 451 and the second side 452 of the plastic package 401. The base island 411 is used to support the power switch Q1 and the powered device controller 410, and the base island 412 is used to support the switching power supply controller 420. The package structure 400-1 of this embodiment is similar to the package structure 400-1 of the embodiment. Figure 2 The difference between the package structure 200-1 in the embodiment is that the package structure 400-1 further includes a power detection pin 435, which is used to electrically connect the second terminal S of the power switch tube Q1 to the current detection terminal CS of the switching power supply controller 420. In addition, the internal structure of the package structure 400-1 of this embodiment is the same as that of the embodiment. Figure 2 The internal structure of the lead frame 200-1 is exactly the same as that of the lead frame 200-1, and will not be repeated here.

[0094] Figure 6 Show Figure 4 Another internal structure layout diagram of the package structure. Figure 6 As shown, the package structure 400-2 also includes a lead frame, a powered device controller 210, a switching power supply controller 220, a power switch tube Q1 and a plastic package 501. The plastic package 501 covers the powered device controller 210, the switching power supply controller 220, the power switch tube Q1 and part of the lead frame. The pins in the lead frame are located outside the plastic package 501 for electrical connection.

[0095] Furthermore, the lead frame also has only one base island 511, pins 541 disposed on the first side 551 and second side 552 of the plastic package 501, pins 531, 532, 537, and 533 disposed on the third side 553 of the plastic package 501, and pins 534, 538, 536, and 535 disposed on the fourth side 554 of the plastic package 501. The base island 511 is used to support the powered device controller 410, the switching power supply controller 420, and the power switch Q1 in Power over Ethernet. Similarly, the back surface of the power switch Q1 is bonded to the base island 511, and the first end of the power switch Q1 is led out through the pin 541 of the base island 511. At the same time, the heat generated by the power switch Q1 during operation is also conducted to the outside through the base island 511 and its pins 541. Because conductive silver paste has excellent conductivity and adhesion, high-silver conductive silver paste is preferably used to bond the power switch Q1 to the base island 511 to achieve good electrical contact. Furthermore, since the powered device controller 410 and the switching power supply controller 420 are also placed on the base island 511, the powered device controller 410 is electrically isolated from the base island 511 by an insulating layer 521, and the switching power supply controller 420 is electrically isolated from the base island 511 by an insulating layer 522. Furthermore, the insulating layers 521 and 522 are, for example, DAF films to ensure good insulation and control chip tilt.

[0096] The package structure 400-2 of this embodiment is Figure 3 The difference between the package structure 200-2 in the embodiment is that the package structure 400-2 further includes a current detection pin 534, which is used to electrically connect the second terminal S of the power switch tube Q1 to the current detection terminal CS of the switching power supply controller 420. In addition, the internal structure of the package structure 400-2 of this embodiment is the same as that of the embodiment. Figure 3 The internal structure of the lead frame 200-2 is exactly the same and will not be repeated here.

[0097] Figure 7 FIG. 1 shows a schematic circuit diagram of a PD device according to a third embodiment of the present invention. Figure 7In the illustrated embodiment, the package structure 200 of the above-described embodiment is applied to a powered device (PD) with a buck topology. The power circuit of the PD device 600 includes a rectifier bridge 610, a capacitor C1, an electrolytic capacitor Cp, a power conversion circuit 620, and a feedback circuit 630. As described above, the package structure 200 encapsulates the powered device controller 210, the switching power supply controller 220, and the power switch Q1.

[0098] like Figure 7 As shown, pin VIN of package structure 200 is a power pin, pin VCC is a power supply pin for switching power supply controller 220 within package structure 200, pin VS is a floating ground pin for switching power supply controller 220 and power switch Q1, pin GND1 is a reference ground pin for powered device controller 210 within package structure 200, pin FB is a feedback pin for switching power supply controller 220, and pin VSS is a negative power input terminal for powered device controller 210. A rectifier bridge 610 is connected to pins VIN and VSS of package structure 200, respectively, to rectify the AC input voltage to generate a DC input voltage Vin. Capacitor C1 is a filter capacitor connected between pins VCC and VS of package structure 200. Capacitor Cp is a storage capacitor connected between pins VIN and GND1 of package structure 200. The power conversion circuit 620 is used to control the transmission of power from the input terminal to the output terminal to convert the DC input voltage Vin into a DC output voltage Vout. The power conversion circuit 620 is connected to pins VS and GND1 of the package structure 200. The feedback circuit 630 is used to divide the output voltage Vout to generate a feedback signal FB, which is connected to pin FB of the package structure.

[0099] For example, the power conversion circuit 620 is a buck topology structure, including: an inductor L1, a freewheeling diode D1, and an output capacitor Co. The first end of the inductor L1 is connected to the pin VS of the package structure 200, the second end is connected to the output capacitor Co and the first end of the load Ro, the cathode of the diode D1 is connected to the pin VS of the package structure 200 and the first end of the inductor L1, and the anode of the diode D1 is connected to the second end of the output capacitor Co and the load Ro, and the pin GND1 of the package structure 200.

[0100] Figure 8 FIG. 1 shows a schematic circuit diagram of a PD device according to a fourth embodiment of the present invention. Figure 8In the illustrated embodiment, the package structure 400 of the above-described embodiment is applied to a powered device (PD) with a buck topology. The power circuit of the PD device 700 includes a rectifier bridge 710, a capacitor C1, an electrolytic capacitor Cp, a current sampling resistor Rcs, a power conversion circuit 720, and a feedback circuit 730. As described above, the package structure 400 encapsulates the powered device controller 410, the switching power supply controller 420, and the power switch Q1.

[0101] like Figure 8 As shown, pin VIN of package structure 400 is a power pin, pin VCC is a power supply pin for switching power supply controller 420 within package structure 400, pin VS is a floating ground pin for switching power supply controller 420 and power switch Q1, pin CS is a current sense pin for switching power supply controller 420, pin GND1 is a first terminal pin of the power transistor integrated in powered device controller 410 within package structure 400, pin FB is a feedback pin for switching power supply controller 420, and pin VSS is a negative power input terminal for powered device controller 410. A rectifier bridge 710 is connected to pins VIN and VSS of package structure 400, respectively, to rectify the AC input voltage to generate a DC input voltage Vin. Capacitor C1 is a filter capacitor connected between pins VCC and VS of package structure 400. Capacitor Cp is an energy storage capacitor connected between pins VIN and GND1 of package structure 400. A current sampling resistor Rcs is connected between pins VS and CS. The power conversion circuit 720 is used to control the transmission of power from the input terminal to the output terminal to convert the DC input voltage Vin into a DC output voltage Vout. The power conversion circuit 720 is connected to pins VS and GND1 of the package structure 400. The feedback circuit 730 is used to divide the output voltage Vout to generate a feedback signal FB, which is connected to pin FB of the package structure.

[0102] For example, the power conversion circuit 720 is a buck topology structure, including: an inductor L1, a freewheeling diode D1, and an output capacitor Co. The first end of the inductor L1 is connected to the pin VS of the package structure 400, and the second end is connected to the output capacitor Co and the first end of the load Ro. The cathode of the diode D1 is connected to the pin VS of the package structure 400 and the first end of the inductor L1, and the anode of the diode D1 is connected to the second end of the output capacitor Co and the load Ro, and the pin GND1 of the package structure 400.

[0103] It should be noted that, although the above embodiments illustrate the present invention using switching power converters of buck topology and flyback topology as examples, the present invention is not limited thereto. Those skilled in the art can apply the packaging structure of the present invention to switching power converters of floating Buck-Boost topology, solid-state Buck-Boost topology, floating Buck topology, solid-state Buck topology, Boost topology and flyback topology as needed.

[0104] In summary, the present invention integrates the power switch tube, powered device controller, and switching power supply controller required for Ethernet power supply into the same lead frame, which can greatly reduce the size of the package and shorten the electrical path between electronic components. Compared with traditional discrete solutions, it has significant advantages in cost and performance.

[0105] Furthermore, in the package structure of this utility model, the floating ground pin of the switching power supply controller and the reference ground of the powered device controller are connected to different pins. This allows the external power supply circuit to sample the output voltage without the use of an auxiliary winding, significantly reducing the production cost and difficulty of the flyback converter. Furthermore, the lack of an auxiliary winding reduces electromagnetic interference within the circuit.

[0106] In addition, the switching power supply controller of the present invention is also provided with a startup control circuit. The startup control circuit converts the first sampling voltage of the DC input voltage, which is referenced to the floating ground, into a second sampling voltage, which is referenced to the ground terminal of the powered device controller. This allows the sampling voltage of the DC input voltage to be compared with the threshold voltage, which is referenced to the ground terminal of the powered device controller. This allows the subsequent switching power converter to start operating a certain period of time after the surge current limiting of the powered device controller ends. This design ensures that the switching power converter does not start operating until the surge current limiting of the powered device controller ends, avoiding the problem of insufficient PoE power due to the need to charge the electrolytic capacitor on the powered device controller side during startup, and thus failing to output the target output voltage. This solution not only reduces system cost, but also improves system reliability and stability, ensuring the normal startup and operation of the power converter.

[0107] In addition, in the PD device using the packaging structure of the present invention, the power switch tube and the switching power supply controller are set on the high side, and the inductor element of the external circuit is set on the low side, so that the switching power supply controller and the power switch tube both use the floating ground end as the reference ground, thereby reducing the difficulty of the drive design and the cost of the chip.

[0108] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0109] While embodiments of the present invention have been described above, these embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, numerous modifications and variations are possible based on the above description. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better utilize the present invention and its modifications. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A packaging structure for an Ethernet power supply control circuit, characterized in that: include: a lead frame including a base island and a plurality of leads; The switching power supply controller, the power switch tube and the powered device controller are placed on the base island; The plastic package covers the switching power supply controller, the power switch tube, the powered device controller and the base island. Wherein, the floating ground terminal of the switching power supply controller and the reference ground terminal of the powered device controller are connected to different pins.

2. The packaging structure according to claim 1, wherein: The base island includes a first base island and a second base island; The powered device controller and the power switch tube are located on the first base island, and the switching power supply controller is located on the second base island.

3. The packaging structure according to claim 2, wherein: The plastic package body includes a first side and a second side facing each other, and a third side and a fourth side facing each other, wherein the first side and the second side extend in a width direction, and the third side and the fourth side extend in a length direction. The first base island is close to the first side of the plastic package body, and the second base island is close to the second side of the plastic package body. The package structure according to claim 3 , wherein an area of the first base island is larger than an area of the second base island.

5. The packaging structure according to claim 3, wherein: The floating ground terminal of the switching power supply controller, the second end of the power switch tube and the second base island are interconnected, and the second base island extends toward the third side of the plastic package to form a floating ground pin.

6. The packaging structure according to claim 5, wherein: The first end of the power switch tube, the power end of the switching power supply controller and the positive power input end of the powered device controller are all interconnected with the first base island, and the first base island extends toward the third side of the plastic package to form at least one power pin.

7. The packaging structure according to claim 6, wherein: The plurality of pins also include: A power supply pin provided on the third side, the power supply pin being used to be interconnected with a power supply terminal of the switching power supply controller; A feedback pin provided on the fourth side, the feedback pin being used to be interconnected with a feedback terminal of the switching power supply controller; A power negative input pin provided on the fourth side, the power negative input pin being used to be interconnected with a power negative input terminal of the powered device controller; and A reference ground pin is provided on the fourth side, and the reference ground pin is used to be interconnected with a reference ground terminal of the powered device controller.

8. The packaging structure according to claim 7, wherein: The driving end of the switching power supply controller is interconnected with the control end of the power switch tube.

9. The packaging structure according to claim 2, wherein: The powered device controller is isolated from the first base island by an insulating layer.

10. The packaging structure according to claim 7, wherein: A redundant pin is also provided on the fourth side.

11. The packaging structure according to claim 7, wherein: A current detection pin is provided on the fourth side, and the current detection pin is used to interconnect with the current detection end of the switching power supply controller and the second end of the power switch tube.

12. The packaging structure according to claim 7, wherein: The plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and two power supply pins.

13. The packaging structure according to claim 7, wherein: The plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and a power supply pin.

14. The packaging structure according to claim 7, wherein: The plurality of pins on the fourth side are sequentially arranged as a feedback pin, a power negative input pin, and a reference ground pin.

15. The packaging structure according to claim 10, wherein: The plurality of pins on the fourth side are sequentially arranged as a feedback pin, a redundant pin, a power negative input pin, and a reference ground pin.

16. The packaging structure according to claim 11, wherein: The plurality of pins on the fourth side are sequentially arranged as a feedback pin, a current detection pin, a power negative input pin and a reference ground pin.

17. The packaging structure according to claim 1, wherein: The base island is a third base island, and the switching power supply controller, the power switch tube, and the powered device controller are all located on the third base island. The plastic package body includes a first side and a second side facing each other, and a third side and a fourth side facing each other. The first side and the second side extend in a width direction, and the third side and the fourth side extend in a length direction.

18. The packaging structure according to claim 17, wherein: The first end of the power switch tube, the power end of the switching power supply controller and the positive power input end of the powered device controller are interconnected with the third base island, and the third base island extends toward the first side and / or the second side to form a power pin.

19. The packaging structure according to claim 18, wherein: The plurality of pins further comprises: A floating ground pin is provided on the third side, wherein the floating ground pin is interconnected with the floating ground terminal of the switching power supply controller and the source terminal of the power switch tube; A power supply pin provided on the third side, the power supply pin being used to be interconnected with a power supply terminal of the switching power supply controller; A reference ground pin provided on the third side, the reference ground pin being used to be interconnected with a reference ground terminal of the powered device controller; A feedback pin provided on the fourth side, the feedback pin being configured to be interconnected with a feedback terminal of the switching power supply controller; and A power negative input pin is provided on the fourth side, and the power negative input pin is used to be interconnected with the power negative input terminal of the powered device controller.

20. The packaging structure according to claim 19, wherein: The driving end of the switching power supply controller is interconnected with the control end of the power switch tube.

21. The packaging structure according to claim 17, wherein: The switching power supply controller and the powered device controller are isolated from the third base island by an insulating layer.

22. The packaging structure according to claim 21, wherein: A redundant pin is also provided on the third side; and two redundant pins are also provided on the fourth side.

23. The packaging structure according to claim 21, wherein: A current detection pin is provided on the fourth side.

24. The packaging structure according to claim 21, wherein: The plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin and a reference ground pin.

25. The packaging structure according to claim 21, wherein: The plurality of pins on the third side are sequentially arranged as a floating ground pin, a power supply pin, a redundant pin and a reference ground pin.

26. The packaging structure according to claim 21, wherein: The plurality of pins on the fourth side are sequentially arranged as a feedback pin and a power negative input pin.

27. The packaging structure according to claim 21, wherein: The plurality of pins on the fourth side are sequentially arranged as a feedback pin, one or two redundant pins, and a power negative input pin.

28. The packaging structure according to claim 23, wherein: The plurality of pins on the fourth side are sequentially arranged as a current detection pin, a feedback pin and a power negative input pin.

29. The packaging structure according to claim 23, wherein: The plurality of pins on the fourth side are sequentially arranged as a current detection pin, a redundant pin, a feedback pin and a power negative input pin.

30. The packaging structure according to any one of claims 2 to 29, characterized in that: The power switch tube is bonded to the corresponding base island using conductive silver glue.

31. The packaging structure according to claim 9 or 21, characterized in that: The insulating layer is a die-bonding film.

32. The packaging structure according to claim 3, wherein: The packaging structure further includes: Central ribs are provided on the first side and the second side for supporting.

33. A powered device, characterized in that: include: Power supply circuit; as well as The packaging structure for a Power over Ethernet control circuit according to any one of claims 1 to 32, wherein the packaging structure is connected to the power supply circuit.

34. The powered device according to claim 33, wherein: The power supply circuit is a buck topology structure or a flyback topology structure.

Images