Capacitive coupling network interface circuit
The capacitive coupling network interface circuit addresses the challenge of bulky isolator transformers by using resistors and capacitors for impedance matching, enabling lightweight and compact communication interfaces.
Patent Information
- Application Number
- CN202421720614.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The use of network isolation transformers in traditional network communication interfaces is not conducive to the development trend of lightweight and miniaturization.
The capacitively coupled network interface circuit is adopted to realize PHY interface communication without network isolation transformer by adding coupling capacitors on the differential line of the PHY and adding matching resistance between the differential lines.
It realizes PHY interface communication with network-free isolation transformers, which is convenient for miniaturization and lightweight implementation.
Smart Images
Figure CN223109994U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of network communication, and specifically relates to a capacitive coupling network interface circuit. Background Art
[0002] In modern communication products, network communication interfaces are often required. In traditional designs, as shown in Figure 2 , a network isolation transformer needs to be added to each piece to achieve signal transceiver, impedance, and voltage matching. For example, one network isolation transformer is required for an RJ45 network interface, and two network isolation transformers are required for network communication between PHYs (port physical layers). However, in the trend of modern communication products towards lightweight, miniaturization, and high density, communication interfaces using network isolation transformers are not conducive to the current development direction. Summary of the Utility Model
[0003] Aiming at the above deficiencies in the prior art, a capacitive coupling network interface circuit provided by the utility model solves the problem that the existing communication interfaces using network isolation transformers are not conducive to lightweight and miniaturization.
[0004] In order to achieve the above invention purpose, the technical solution adopted by the utility model is as follows:
[0005] Provide a capacitive coupling network interface circuit, which includes a resistor R1, a resistor R2, a capacitor C1, a capacitor C2, and a capacitor C3;
[0006] One end of the resistor R1 is respectively connected to an external power supply, one end of the resistor R2, and one end of the capacitor C3; the other end of the capacitor C3 is grounded; one end of the capacitor C2 is an input end of the capacitive coupling network interface circuit, and the other end of the capacitor C2 is connected to the other end of the resistor R2 and serves as an output end of the capacitive coupling network interface circuit;
[0007] One end of the capacitor C1 is the other input end of the capacitive coupling network interface circuit, and the other end of the capacitor C1 is connected to the other end of the resistor R1 and serves as the other output end of the capacitive coupling network interface circuit.
[0008] Further, it further includes a resistor R3, in the line from the node between the resistor R1 and the resistor R2 to the external power supply.
[0009] Further, the capacitor C1 and the capacitor C2 are coupling capacitors; the resistor R1 and the resistor R2 are matching resistors; the capacitor C3 is a filtering resistor; the resistor R3 is a bias resistor.
[0010] Further, two capacitive coupling network interface circuits are parallelly configured to form a 100M network interface. The two input ends of each capacitive coupling network interface circuit are connected to a pair of differential lines; the output end of each capacitive coupling network interface circuit is connected to an RJ45 network interface.
[0011] Further, four capacitive coupling network interface circuits are combined in parallel to form a gigabit network interface. Two input terminals of each capacitive coupling network interface circuit are connected to a pair of differential lines; the output terminal of each capacitive coupling network interface circuit is connected to an RJ45 network interface.
[0012] The beneficial effects of the present utility model are as follows: By adding coupling capacitors on the differential lines of the PHY and adding matching resistors between the differential lines, the PHY interface communication without a network isolation transformer is realized, which is convenient for miniaturization and lightweight implementation. Description of the Drawings
[0013] Figure 1 This is the capacitive coupling network interface circuit;
[0014] Figure 2 This is the traditional PHY interface circuit;
[0015] Figure 3 This is the capacitive coupling circuit of the 100M Ethernet port in the embodiment;
[0016] Figure 4 This is the capacitive coupling circuit of the gigabit Ethernet port in the embodiment. Detailed Embodiment
[0017] The following describes the detailed embodiment of the present utility model to facilitate those skilled in the art of this technology to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the detailed embodiment. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present utility model are within the scope of protection.
[0018] As Figure 1 shown, the capacitive coupling network interface circuit includes a resistor R1, a resistor R2, a capacitor C1, a capacitor C2, and a capacitor C3;
[0019] One end of the resistor R1 is respectively connected to an external power supply, one end of the resistor R2, and one end of the capacitor C3; the other end of the capacitor C3 is grounded; one end of the capacitor C2 is an input terminal of the capacitive coupling network interface circuit, and the other end of the capacitor C2 is connected to the other end of the resistor R2 and serves as an output terminal of the capacitive coupling network interface circuit;
[0020] One end of the capacitor C1 is the other input terminal of the capacitive coupling network interface circuit, and the other end of the capacitor C1 is connected to the other end of the resistor R1 and serves as the other output terminal of the capacitive coupling network interface circuit.
[0021] In the specific implementation process, it also includes a resistor R3, in the line from the node between resistor R1 and resistor R2 to the external power supply.
[0022] Capacitors C1 and C2 are coupling capacitors; resistors R1 and R2 are matching resistors; capacitor C3 is a filtering resistor; resistor R3 is a bias resistor.
[0023] Two capacitor-coupled network interface circuits are combined in parallel to form a 100M network interface. The 100M network port has 2 pairs of differential lines, and the two input terminals of each capacitor-coupled network interface circuit are connected to a pair of differential lines; the output terminals of each capacitor-coupled network interface circuit are all connected to the RJ45 network interface. As Figure 3 shown, no isolation transformer is used between the 100M PHY chip and the RJ45 network interface. Capacitors C1, C2, C21 (equivalent to C1), and C22 (equivalent to C2) are signal coupling capacitors, and resistors R1, R2, R21 (equivalent to R1), and R22 (equivalent to R2) are impedance matching resistors. Resistors R3 and R23 are connected to VCC (external power supply) to provide bias current for the voltage-driven PHY. If the PHY is current-driven, resistors R3 and R23 are not required. Therefore, resistor R3 is not an essential component of this capacitor-coupled network interface circuit.
[0024] As Figure 4 shown, similar to the 100M network interface, four capacitor-coupled network interface circuits can be combined in parallel to form a 1G network interface. The 1G network port has 4 pairs of differential lines, and the two input terminals of each capacitor-coupled network interface circuit are connected to a pair of differential lines; the output terminals of each capacitor-coupled network interface circuit are all connected to the RJ45 network interface.
[0025] In summary, the present utility model realizes PHY interface communication without a network isolation transformer by adding coupling capacitors on the differential lines of the PHY and adding matching resistors between the differential lines, facilitating the realization of miniaturization and light weight.
Claims
1. A capacitive coupling network interface circuit, characterized in that It includes resistor R1, resistor R2, capacitor C1, capacitor C2 and capacitor C3; One end of resistor R1 is respectively connected to an external power supply, one end of resistor R2 and one end of capacitor C3; the other end of capacitor C3 is grounded; one end of capacitor C2 is an input terminal of the capacitive coupling network interface circuit, and the other end of capacitor C2 is connected to the other end of resistor R2 and serves as an output terminal of the capacitive coupling network interface circuit; One end of capacitor C1 is the other input terminal of the capacitive coupling network interface circuit, and the other end of capacitor C1 is connected to the other end of resistor R1 and serves as the other output terminal of the capacitive coupling network interface circuit.
2. The capacitive coupling network interface circuit according to claim 1, wherein It also includes resistor R3, in the line from the node between resistor R1 and resistor R2 to the external power supply.
3. The capacitive coupling network interface circuit according to claim 2, characterized in that, Capacitor C1 and capacitor C2 are coupling capacitors; resistor R1 and resistor R2 are matching resistors; capacitor C3 is a filtering resistor; resistor R3 is a bias resistor.
4. The capacitive coupling network interface circuit according to any one of claims 1 to 3, characterized in that Two capacitive coupling network interface circuits are parallelly configured to form a 100M network interface, and the two input terminals of each capacitive coupling network interface circuit are connected to a pair of differential lines; the output terminal of each capacitive coupling network interface circuit is connected to an RJ45 network interface.
5. The capacitive coupling network interface circuit according to any one of claims 1 to 3, characterized in that Four capacitive coupling network interface circuits are parallelly configured to form a 1G network interface, and the two input terminals of each capacitive coupling network interface circuit are connected to a pair of differential lines; the output terminal of each capacitive coupling network interface circuit is connected to an RJ45 network interface.