MAXREFDES124#: Isolated 12V to 5.5V 22W optocoupler-less flyback power supply

Maxim’s power supply experts have designed and built a series of isolated, industrial and medical power-supply reference designs. Each of these power supplies efficiently converts 24V or 12V into useful voltage rails at a variety of power levels. Each design has been tested for load and line regulation, as well as efficiency and transient performance.

MAXREFDES124# is an efficient no-opto flyback topology with 12V input, and a 5.5V output at 22W of power (4A). The design features the MAX17690, a peak-current-mode converter with flexible switching frequency and the MAX17606, a secondary side MOSFET driver for a flyback converter. The combination of no opto-coupler and a secondary-side MOSFET results in a design that is optimized for space, cost, and efficiency. This entire circuit fits on a 20mm (0.7874in) × 66mm (2.5984in) board.

Refer to the Details tab Details tab for more information. Design files including schematic, PCB files and bill of materials (BOM) can be downloaded from the Design Resources tab. Most boards feature through-hole pins for immediate board placement and accelerated prototyping. As with all Maxim reference designs, boards are available for purchase.

Features

• Functional insulation
• Compact and flexible
• Minimal external components
• 5kV of isolation for medical and other high-isolation applications
• ±5% output accuracy

Competitive Advantages

• Rapid prototyping
• Accelerated design time
• Cool system operation

Applications

• Medical equipment
• High-isolation applications