CN104111715A - Method for designing server board-level power supply with input being 48V - Google Patents

Abstract

The invention provides a method for designing a server board-level power supply with input being 48V and belongs to the field of design of server board-level power supplies. By virtue of the method, two-stage voltage conversion is used; the first-stage voltage conversion is characterized by converting 48V to 12V; the second-stage voltage conversion is characterized by converting 12V to power supplies which are applied to other server systems; the input voltage being 48V is converted to a power supply which is applied to a 12V server; subsequently the voltage is used for supplying power for a DC/DC power supply for a CPU and a memory BUCK, so that the input voltage being 48V is converted to voltage being 5V, 3.3V and the like used by the CPU, the Memory and a system in the server, and the overall conversion efficiency of the power supply is improved.

Description

A design method of server board-level power supply with 48V input

technical field

The present invention relates to the field of server board-level power supply design, specifically a method for designing a server board-level power supply with an input of 48V, which converts the input voltage of 48V into 5V, 3.3V and other voltages used in the CPU, Memory, and system used in the server .

Background technique

Many electrical appliances are powered by low-voltage DC, but the most common form of power supply is AC 220V. So, how do these low-voltage DC appliances work? To make them work, we have to solve two problems: how to step down the voltage, and how to convert AC to DC. Transformers made according to Faraday's law of electromagnetic induction can reduce the voltage of alternating current; alternating current to direct current must first pass through rectified current (generally bridge rectification), in order to obtain pure direct current, a filter circuit (generally composed of capacitors or inductors) is required , so that direct current can be obtained.

The traditional server power supply converts 220V AC power into 12V DC power for the server through AC/DC power supply. When the number of servers is small, this method is simple to connect, easy to install, and strong in practicability; but in large computing centers and server rooms. , the disadvantages of using traditional 12V DC power supply applications appear. First of all, the conversion efficiency of AC/DC power supply to 12V voltage is lower than that of direct conversion to 48V voltage. Secondly, the power consumption of the server is about kilowatts. Using 12V power supply, the current reaches hundreds of amperes, and the current transmission loss is prominent. Using 48V power supply can reduce the current to the original current. 1/4 of the current transmission loss will be as low as 1/16 of the original current. Finally, P12V power supply is affected by transmission loss and needs to be close to the server, which has a great impact on the server layout of the computer center.

Contents of the invention

This patent describes a multi-level power supply application method, using this method to apply an open-loop step-down circuit to convert the 48V input voltage into a 12V server power supply, and then use this voltage to supply power to the CPU and memory BUCK DC/DC power supply . This method is simple in design, easy to control, low in efficiency loss, and easy to design with board-level power supply.

This patent describes a multi-level power supply application method, the main invention content is:

1. Establish a first-level power conversion method. Through an open-loop high-efficiency step-down line, use this line to step down the server board-level 48V power supply to 12V. This line has low voltage control and large ripples, but the server The line power line input end does not require high voltage accuracy; because of its open-loop characteristics, the current output can meet the basic requirements of the load end;

2. The parts with high power consumption in the server are uniformly powered, and the BUCK lines of the CPU and memory are arranged as a whole, which is defined as a secondary power supply, which is independently powered by the primary power supply. Thereby improving the conversion efficiency of the high power consumption part.

(1) The first-level power supply uses the power forwarding method to convert 48V power supply to 12V. 48V input two-stage power design architecture.

(2) The open-loop circuit used by the first-level power supply is designed for the first-level circuit. This method has fewer peripheral components, low cost, and high efficiency.

The primary power supply and the secondary power supply form the power structure. In the primary power supply, it can be completed by connecting two capacitors in parallel and then connecting a two-phase converter in parallel. The parts with high power consumption in the server are uniformly powered, and the BUCK lines of the CPU and memory are arranged as a whole, which is defined as a secondary power supply, which is independently powered by the primary power supply.

The two-phase variable current tube is mainly composed of a series circuit composed of MOSFETQ1 and MOSFETQ2 and a series circuit composed of MOSFETQ3 and MOSFETQ4 in parallel. A capacitor C2 can be connected to the middle connection part of MOSFETQ1 and MOSFETQ2 and the middle connection part of MOSFETQ3 and MOSFETQ4.

The beneficial effects of the present invention are:

This method can be realized in a simple way, with few peripheral components and low efficiency loss. It does not use the traditional 48V to 12V isolated power design architecture, and has a low impact on cost;

The invention replaces the common 12V power supply in the server with a 48V power supply, improves the power conversion efficiency from AC/DC, and controls the conversion efficiency of 48V to 12V at about 98%, which improves the power conversion efficiency as a whole.

Description of drawings

The present invention will be further described below according to accompanying drawing,

Accompanying drawing 1 is a design circuit diagram of a power supply;

Accompanying drawing 2 is the schematic diagram of the power structure of the present invention.

Detailed ways

According to the main invention content of this method:

(1) The primary power supply uses the power forwarding method to convert 48V power to 12V. 48V input two-stage power supply design architecture;

(2) The open-loop circuit used by the first-level power supply is designed for the first-level circuit. This method has fewer peripheral components, low cost and high efficiency.

According to the accompanying drawings of the description, the method is further assisted in the description.

1. First-level power supply realization:

As shown in Figure 1, the circuit is designed for a primary power supply, where Q1~Q4 MOSFETs need to be turned on and off using a control IC with a duty cycle of 25%. C1=C2=36uf, C3=47uf. Through this device, the 48V voltage in the server can be reduced to 12V.

The two-phase variable current tube here includes a series circuit composed of Q1 and Q2, and Q3 and Q4 are connected in parallel to form a series circuit; capacitors C1 and C3 are connected in parallel, and then connected in parallel with the two-phase variable current tube. As required, a capacitor C2 may be connected to the middle connection part of Q1 and Q2 and the middle connection part of Q3 and Q4. An ammeter is connected between the other ends of MOSFETQ3 and MOSFETQ4 with respect to connection capacitor C2.

2. Realization of overall power supply architecture

As shown in Figure 2 power supply architecture, AC/DC power supply 48V is input to the primary power supply, and the primary power supply converts the voltage to 12V, which is supplied to the CPU and memory power input terminals, and the CPU and memory power supply converts 12V power into CPU, memory and the voltage used by the system power supply.

Metal-Oxide Semiconductor Field-Effect Transistor, referred to as Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), is a field-effect transistor (field-effect transistor) that can be widely used in analog circuits and digital circuits. ).

Claims (4)

1. A design method for a server board-level power supply with an input of 48V, which is characterized in that two-stage voltage conversion is used, the first stage is 48V to 12V, and the second stage is 12V to other server system power supplies; the 48V input voltage is converted into a 12V server The used power supply, and then use this voltage to power the CPU and memory BUCK DC/DC power supply. 2. The method according to claim 1, characterized in that 1) Establish a first-level power conversion method, through an open-loop high-efficiency step-down line, use this line to step down the server board-level 48V power supply to 12V; 2) Unified power supply for the parts with high power consumption in the server, overall arrangement of the BUCK lines of the CPU and memory, defined as a secondary power supply, which is independently powered by the primary power supply. 3. The method according to claim 2, wherein a power supply framework is formed by a primary power supply and a secondary power supply, and a two-phase converter is formed by a series circuit composed of MOSFETQ1 and MOSFETQ2 in parallel with a series circuit composed of MOSFETQ3 and MOSFETQ4, The two-phase variable current tube is set as a primary power supply; two capacitors C1 and C3 are connected in parallel, and then connected in parallel with the aforementioned two-phase variable current tube; the primary power supply independently supplies the secondary power supply. 4. The method according to claim 3, characterized in that a capacitor C2 is connected between the middle connection part of MOSFETQ1 and MOSFETQ2 and the middle connection part of MOSFETQ3 and MOSFETQ4.