MAXREFDES120#: Isolated 24V to 5V–12.5W Optocouplerless Flyback Power Supply

Maxim’s power supply experts have designed and built a series of isolated, industrial power-supply reference designs. Each of these power supplies efficiently converts 24V 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. As with all Maxim reference designs, the BOM, schematics, layout files, and Gerber files are all available. In addition, boards are available for purchase; most boards feature through-hole pins for immediate board placement and accelerated prototyping.

MAXREFDES120# is an efficient no-opto flyback topology with 24V input, and a 5V output at 12.5W of power (2.5A). The design features the MAX17690 (a peak-current-mode converter with flexible switching frequency) and the MAX17606 (a secondary side MOSFET driver for flyback converter). The combination of no opto-coupler and a secondary side MOSFET result in a design that is optimized for space, cost, and efficiency. This entire circuit fits on a 20.3mm (0.8in) x 59.7mm (2.35in) board.

Features

• Functional insulation
• Compact and flexible
• Minimal external components
• Robust operation in adverse industrial environments
• 5V output at 2.5A
• ±5% output accuracy

Competitive Advantages

• Rapid prototyping
• Accelerated design time
• Cool system operation

Applications

• Industrial control and automation
• Process control
• PLC
• Telecom and Datacom power supplies