System Board 7052

MAXREFDES1084: Miniature 12W DC-DC Flyback Converter Using the MAX17596


 Download Reference Design Document



Designed, Built, Tested

The Reference Design Document describes the hardware pictured below. It provides a detailed systematic technical guide to designing a miniature 12W DC-DC flyback converter using the MAX17596. The hardware was built according to the linked Schematic, Bill of Materials and PCB Artwork. It was tested by Maxim Integrated’s expert applications engineering team in a state-of-the-art design lab and the Test Results are fully documented.

Description

Input Type VIN (MIN)
(V)
VIN (MAX)
(V)
IOUT
(A)
Single/Multiple
Output
VOUT
(V)
POUT
(W)
Isolated/Non-Isolated Topology
DC 17 60 0.5 Single 24 12 Isolated Flyback

The MAXREFDES1084 is a miniature, 24V output, isolated power supply that can deliver up to 0.5A of load current. The design uses the MAX17596 peak-currentmode controller in discontinuous-conduction mode (DCM) flyback topology running at 125kHz. The input voltage range of the MAX17596 is 4.5V to 36V. However, an extra bias winding from the transformer is used to power the controller. This allows the input operating voltage to go up to 60V for this design.

The transformer provides a galvanic isolation of 1500VRMS between the primary and the secondary. In addition, an optocoupler is used to provide secondary-side feedback to the controller for voltage regulation while maintaining isolation. This document also discusses a step-by-step procedure to implement this reference design and presents design equations for the calculation of all the design parameters. These equations show how to calculate the component values to allow users to modify this design for their applications. Key features of the MAXREFDES1084 are as follows:

Key Features

  • Miniature Design Optimized for Small Size
  • 17V to 60V Input Range
  • Isolated Output of 24V DC at 12W
  • Cycle-by-Cycle Current Limit
  • Resistor-Programmable UVLO/OVI Threshold
  • Low-Cost DCM Flyback Design
  • Galvanic Isolation Up to 1500VRMS
  • Proven PCB Layout
  • Fully Assembled and Tested
MAXREFDES1084 Hardware Enlarge+
 
 

Schematic

PCB Layout

Bill of Materials

Test Results


 
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Temperature:

MAX17596
Peak-Current-Mode Controllers for Flyback and Boost Regulators

  • Programmable Switching Frequency Allows Optimization of the Magnetic and Filter Components, Resulting in Compact, Cost-Effective, Efficient Isolated/Non-Isolated Power Supplies
  • Programmable Frequency Dithering Enables Low-EMI Spread-Spectrum Operation
  • Integrated Protection Features Enhance System Reliability