用于电信/数据通信的隔离式电源

用于电信/数据通信的隔离式电源
  Abstract: A 50W switching supply suitable for telecom applications is described. The supply, a high-frequency forward converter, provides an isolated 5V @ 10A with 1% line and load regulation. A buck converter topology is selected after considering flyback and buck converters. The MAX5003 control IC is selected; its features and circuit are described. Important waveforms are shown and discussed; the power transformer is detailed; input, output, and feedback circuits are discussed. Performance is detailed and preferred PCB layout is provided.

Also see:
MAX5003 QuickView Data Sheet

MAX5003-50WEVKIT

MAX5003EVKIT

Design and simulate isolated power supplies with free MAX5003 Isolated Power Supply Design Software.
  This 50W, isolated power-supply design can be used to replace purchased supplies with minimal additional engineering effort. The advantages of such an approach also include the accommodation of custom footprint and substantially lower cost. The Challenge
  Power supplies are often an afterthought. Purchased power-supply "bricks" are a quick solution, but with significant disadvantages, such as size, heat-sink and airflow requirements, long lead times, limited configurations, and higher overall costs. An in-house design usually fits product requirements better, but may not seem possible without a dedicated group of power-supply design engineers.

"Off-the-Shelf" Design
  A few semiconductor companies are providing reference designs that can greatly streamline power-supply design and bring custom supply designs within reach. An "off-the-shelf design" makes it possible to quickly produce a supply that is smaller and simpler to integrate, performs better, and delivers much lower cost and superior time-to-market.

Telecom/Datacom/Server Power Supplies
  A kind of power supply that is currently in great demand is the telecom, datacom type. Such power supplies are utilized in central offices, PBXs, and servers, and typically use an input voltage of 36V to 72V. Their typical output power levels range from about 10W to 100W or even higher. Important requirements for these power supplies are galvanic isolation between primary and secondary, high efficiency over a wide input-voltage range, and ruggedness. The design of such power supplies, however, is relatively complex due to the requirements of isolation.

50W Isolated Power Supply
  Figure 1 shows a 50W "off-the-shelf-designed" power supply. This is an isolated power supply with a 5V regulated output. Table 1 summarizes some of the target specifications.


Figure 1. Schematic diagram of ≈48V in and 5V out @ 10A isolated power supply.

Table 1. Summary of Target Specifications
Pout