Multi-path power supply isolation circuit

Abstract

The utility model relates to the technical field of power supply isolating circuits, in particular to a multi-path power supply isolating circuit, which comprises a gathering output port and a plurality of power supply input ports, and an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) isolating circuit is connected between each power supply input port and the gathering output port; each MOSFET isolation circuit comprises a control module and two N-channel MOSFETs, source electrodes of the N-channel MOSFETs are connected with an IN pin of the control module, drain electrodes of the N-channel MOSFETs are connected with an OUT pin of the control module, and grid electrodes of the N-channel MOSFETs are connected with a GATE pin of the control module. According to the utility model, the MOSFET isolation circuit is adopted to carry out multi-path power supply isolation, multi-path power supplies can be used in parallel without diode isolation, the working efficiency is higher, the power loss is smaller, and the number of heat dissipation elements is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power isolation circuit technology, and in particular to a multi-channel power isolation circuit. Background Technology

[0002] In power electronic systems, the architecture of multiple power sources connected in parallel is widely used to improve system redundancy and reliability. However, existing parallel power source solutions still have many technical bottlenecks, especially in terms of light-load isolation, dynamic differential voltage regulation, and surge protection.

[0003] Traditional parallel power supply solutions typically employ diode isolation or simple MOSFET control. For example, under light load conditions, directly turning on the MOSFETs can cause secondary feedback between power supplies to generate crosstalk through the MOSFETs, leading to the failure of some power modules. Furthermore, in existing solutions, the MOSFETs are switched on as soon as a voltage is detected by the sensing resistor. Since this cannot be dynamically adjusted according to load changes, and the MOSFETs lack isolation, voltage differences under light loads can cause oscillations and interference with front-end power supply equipment. Summary of the Invention

[0004] This utility model addresses the problems of existing technologies by providing a multi-power isolation circuit with a novel structure and ingenious design. It uses a MOSFET isolation circuit for multi-power isolation, eliminating the need for diode isolation. This allows multiple power supplies to be used in parallel simultaneously, with higher efficiency, lower power loss, and fewer heat dissipation components, meaning that the function can be achieved with a smaller thermal layout.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention provides a multi-channel power isolation circuit, which includes a summary output port and multiple power input ports. Each power input port is connected to the summary output port via a MOSFET isolation circuit. The multiple power input ports are used to receive different power inputs, and the summary output port is used to output the power from the multiple power sources. Each power input port is connected to the summary output port via the MOSFET isolation circuit. Each MOSFET isolation circuit includes a control module and two N-channel MOSFETs. The sources of the two N-channel MOSFETs are connected to the IN pin of the control module, the drains of the two N-channel MOSFETs are connected to the OUT pin of the control module, and the gates of the two N-channel MOSFETs are connected to the GATE pin of the control module. The control module is used to turn off the MOSFETs and provide voltage differential regulation.

[0007] Each of the power input ports is connected to a TVS diode.

[0008] The control module is connected to a Schottky diode.

[0009] The multiple power input ports include two power input ports, namely power input port TJ1 and power input port TJ2. Power input port TJ1 is connected to TVS diode TD1, and power input port TJ2 is connected to TVS diode TD2.

[0010] The control module is model JW7260.

[0011] The control module includes an operational amplifier circuit, which is used to adjust the voltage difference between the drain and source of the N-channel MOSFET to 30mV. When the load power increases, the voltage difference is allowed to rise to 700mV to achieve a fully on state.

[0012] The beneficial effects of this utility model are:

[0013] This utility model has a novel structure and ingenious design. It uses a MOSFET isolation circuit for multi-power supply isolation, which eliminates the need for diode isolation. It enables multiple power supplies to be used in parallel at the same time, with higher working efficiency, lower power loss, and fewer heat dissipation components, which means that the function can be achieved with a smaller thermal layout. Attached Figure Description

[0014] Figure 1 This is a circuit diagram of a multi-channel power isolation circuit according to the present invention. Detailed Implementation

[0015] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0016] A multi-channel power isolation circuit includes a summed output port and multiple power input ports. Each power input port is connected to the summed output port via a MOSFET isolation circuit. The multiple power input ports are used to receive different power inputs, and the summed output port is used to output the summed power from the multiple power sources. Each power input port is connected to the summed output port via the MOSFET isolation circuit. Each MOSFET isolation circuit includes a control module and two N-channel MOSFETs. The sources of the two N-channel MOSFETs are respectively connected to the IN pin of the control module, the drains of the two N-channel MOSFETs are respectively connected to the OUT pin of the control module, and the gates of the two N-channel MOSFETs are respectively connected to the GATE pin of the control module. The control module is used to turn off the MOSFETs and provide voltage differential regulation. Specifically, this utility model features a novel structure and ingenious design. An N-channel MOSFET is used to isolate the outputs of multiple parallel power supplies. The control module controls the MOSFET, turning it off and providing voltage differential regulation, while ensuring smooth sharing of load current among the MOSFETs without oscillation. Initial power-on: Current flows through the body diode of the N-channel MOSFET, forming the positive power supply for the control module. Normal operation: The GATE pin of the control module drives the N-channel MOSFET to fully turn on, and the back-end device enters normal operation. Light load protection: Under light load conditions, the control module adjusts the gate voltage of the N-channel MOSFET to operate in the variable resistance region, reducing secondary feedback crosstalk between power supplies. Voltage differential regulation: The control module monitors the voltage differential between the drain and source of the N-channel MOSFET in real time and adjusts it to 30mV. When the load power increases, the voltage differential is allowed to rise to 700mV. This utility model uses a MOSFET isolation circuit for multi-power supply isolation, eliminating the need for diode isolation. It enables multiple power supplies to be used simultaneously in parallel, with higher efficiency, lower power loss, and fewer heat dissipation components, meaning that functionality can be achieved with a smaller thermal layout.

[0017] In this embodiment of the application, the control module includes an operational amplifier circuit, which is used to adjust the voltage difference between the drain and source of the N-channel MOSFET to 30mV. When the load power increases, the voltage difference is allowed to rise to 700mV to achieve a fully on state.

[0018] In this embodiment, each power input port is connected to a TVS diode to prevent surge damage to the device. The control module is also connected to a Schottky diode, with its cathode connected to the IN pin of the control module and its anode connected to the GND pin. This protects the IN pin of the control module from surge negative voltage. In this embodiment, the Schottky diode and TVS diode constitute a surge protection system, enhancing the reliability and stability of the circuit.

[0019] In this embodiment, taking multiple power input ports including two power input ports as an example: the two power input ports include power input port TJ1 and power input port TJ2. Power input port TJ1 is connected to TVS diode TD1, and power input port TJ2 is connected to TVS diode TD2. The control module is model JW7260; the control module includes control module U1 and control module U2. N-channel MOSFETs U17 and U18 are connected between control module U1 and power input port TJ1, and N-channel MOSFETs U19 and U20 are connected between control module U2 and power input port TJ2. Schottky diodes D1 and D2 are connected to control module U1 and control module U2, respectively. The N-channel MOSFETs are configured with their gates connected to the power input terminal and their drains output power. The internal body diode of the N-channel MOSFET is used to achieve isolation before the N-channel MOSFET is turned on.

[0020] Specifically, in a full-load application scenario with two 54V input voltages, each channel uses control modules U1 and U2 to control and drive the N-channel MOSFET. The IN and OUT pins of control modules U1 and U2 constitute the anode and cathode of an ideal diode. The source pin of the N-channel MOSFET is connected to the IN pin, and the drain of the N-channel MOSFET is connected to the OUT pin. When initially powered on, the current conducts through the body diode of the N-channel MOSFET, forming the positive power supply of control modules U1 and U2. The gate of the N-channel MOSFET is driven by the GATE pin of control modules U1 and U2. At this time, the N-channel MOSFET is fully turned on, and the back-end device enters normal operation.

[0021] In light-load applications with two 54V inputs, if the MOSFET is directly turned on under light load, the secondary feedback between the power supplies may be subject to crosstalk through the N-channel, leading to partial power circuit failure. This application's embodiment addresses the problem of MOSFET isolation failure under light load. Upon initial power-up, current flows through the body diode of the N-channel MOSFET, forming the positive power supply for control modules U1 and U2. At this time, the operational amplifiers of control modules U1 and U2 attempt to adjust the voltage difference between the drain and source to 30mV. Only when there is a certain load power at the downstream end, a large current flows through the body diode of the N-channel MOSFET, raising the voltage drop between the IN and OUT pins of control modules U1 and U2 by more than 30mV to 700mV. At this point, the N-channel MOSFET will be fully turned on under the drive of the GATE pin of control modules U1 and U2, and the downstream device will enter normal operation.

[0022] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A multi-channel power supply isolation circuit, characterized in that: The system includes a summary output port and multiple power input ports. Each power input port is connected to the summary output port via a MOSFET isolation circuit. The multiple power input ports are used to receive different power inputs, and the summary output port is used to output the power from the multiple power sources. Each power input port is connected to the summary output port via the MOSFET isolation circuit. Each MOSFET isolation circuit includes a control module and two N-channel MOSFETs. The sources of the two N-channel MOSFETs are connected to the IN pin of the control module, the drains of the two N-channel MOSFETs are connected to the OUT pin of the control module, and the gates of the two N-channel MOSFETs are connected to the GATE pin of the control module. The control module is used to turn off the MOSFETs and provide voltage differential regulation.

2. The multi-channel power isolation circuit according to claim 1, characterized in that: Each of the power input ports is connected to a TVS diode.

3. The multi-channel power isolation circuit according to claim 1, characterized in that: The control module is connected to a Schottky diode.

4. A multi-channel power isolation circuit according to claim 1, characterized in that: The multiple power input ports include two power input ports, namely power input port TJ1 and power input port TJ2. Power input port TJ1 is connected to TVS diode TD1, and power input port TJ2 is connected to TVS diode TD2.

5. A multi-channel power isolation circuit according to claim 1, characterized in that: The control module is model JW7260.

6. A multi-channel power supply isolation circuit according to claim 1, characterized in that: The control module includes an operational amplifier circuit, which is used to adjust the voltage difference between the drain and source of the N-channel MOSFET to 30mV. When the load power increases, the voltage difference is allowed to rise to 700mV to achieve a fully on state.

Images