Maxim Solution Example丨Isolated Power Supply Reference Design

Isolated power supply is one of the challenges faced by industrial and medical equipment power supply design. Based on the company's advanced isolated DC-DC control technology, Maxim power engineers have developed a series of isolated power modules to help users simplify power supply design.

Each power module provides transformer products from different manufacturers (Hanren, Sumida, Halo, Wurth), which makes it convenient for users to obtain key components of isolated power supply from the market. This series of products converts 24V industrial power supply or 12V medical equipment power supply into different output voltages and provides different levels of output power (Table 1). Each design has been strictly tested and provides test data such as power regulation rate, load regulation rate, efficiency, transient characteristics, etc.

Table 1. Typical parameters

The modular design can be easily installed directly on the user's circuit board. It also provides circuit schematics, PCB layout, Gerber files and BOM. Users can easily transplant the selected isolation module design into the terminal product. For detailed design information, please visit the Maxim Support Center: https://www.maximintegrated.com/cn/support/overview.html/TechSupportForm?pl_id=0

The MAXREFDES111# is a high-efficiency flyback topology isolated power supply that converts a 24V (17V – 36V) input into a 5V output with an output power of 2W (0.4A). The design uses the MAX17498B 500KHz peak current-mode converter.

MAXREFDES112# and MAXREFDES113# are high-efficiency flyback topology isolated power supplies that convert 24V (17V – 36V) input into 12V output, with output power up to 10W (0.8A) and 20W (1.6A) respectively. The design uses the MAX17596 peak current mode converter and can flexibly adjust the switching frequency.

MAXREFDES113#

MAXREFDES114#, MAXREFDES115#, and MAXREFDES116# use the MAX17599 high-efficiency, active-clamp, current-mode controller optimized for industrial power supplies. They convert 24V input (17V - 36V) to 5V output with maximum output power of 10W (2A), 20W (4A), and 40W (8A), respectively.

MAXREFDES114#

MAXREFDES119# and MAXREFDES120# use a high-efficiency flyback topology to convert 24V input (17V - 36V) to 5V output, with output power up to 10W (2A) and 20W (4A) respectively. The circuit is based on the MAX17690 fixed-frequency, peak current-mode converter, which can detect the output voltage through the primary side, thus eliminating the need for optocoupler feedback, simplifying the design while effectively reducing costs. — The MAX17606 secondary-side synchronous rectification MOSFET driver greatly improves operating efficiency and reduces the burden of thermal design.

MAXREFDES121# and MAXREFDES122# use active clamp topology to convert 24V input (17V - 36V) to 3.3V and 5V output respectively, with output power up to 40W (3.3V@12A, 5V@8A). The circuit uses the MAX17599 active clamp, current mode PWM controller, optimized for industrial applications, and the entire circuit occupies a board area of ​​22mm x 70mm.

The MAXREFDES124# uses a high-efficiency flyback topology to convert a 12V input (9V - 18V) to a 5.5V output with up to 22W (4A) output power. The circuit is based on the MAX17690 fixed-frequency, peak current-mode converter, which can detect the output voltage on the primary side, eliminating the need for optocoupler feedback, simplifying the design and effectively reducing costs. The MAX17606 secondary-side synchronous rectification MOSFET driver greatly improves operating efficiency and reduces the burden of thermal design. It is worth emphasizing that the transformer used in this module can provide up to 5kV of electrical isolation, which meets medical and other applications with higher isolation requirements.

• Industrial Control and Industrial Automation
  

• Medical imaging, electrocardiographs

• High efficiency: reduce power consumption and simplify heat dissipation design
  

• Compact structure and flexible design: highly integrated

• High reliability, meeting the demanding requirements of industrial and medical environments

• Undervoltage protection and overvoltage protection

• Flyback topology does not require an optocoupler

• Flexible selection of transformers from different manufacturers

• Wide input voltage range: 17V - 36V

- MAXREFDES124# input range: 9V - 18V

• Output tolerance: ±5%

• Output current (continuous): 120% of nominal value

• Ripple < ±1.5%

• High efficiency (see corresponding reference design document)

• 1500V electrical isolation

  - MAXREFDES124# provides 5kV isolation

author:

Vincent Li, Applications Engineer, Maxim Integrated

David Andeen, Director of Applications, CPG, Maxim Integrated