MAXREFDES1163

Description

The MAX17681/MAX17681A is a high-voltage, high efficiency, iso-buck DC-DC converter designed to provide isolated power up to 5W. The device operates over a wide 4.5V to 42V input and uses primary-side feedback to regulate the output voltage. The MAX17681/MAX17681A uses peak-current-mode control. Low-resistance, on-chip MOSFETs ensure high efficiency at full load while simplifying the PCB layout. The MAX17681/MAX17681A devices generate a well-regulated primary side voltage, which is then scaled by a suitable transformer turns ratio to derive isolated secondary output rails. While both the MAX17681 and MAX17681A support primary side overcurrent protection, the MAX17681A is an enhanced design that also supports robust secondary-side overcurrent protection. The MAX17681/MAX17681A is available in a compact 10-pin (3mm × 2mm) TDFN package.

Features & Benefits

• Reduces External Components and Total Cost
• No Optocoupler
• Synchronous Primary Operation
• All-Ceramic Capacitors, Compact Layout
• Reduces Number of DC-DC Regulators to Stock
• Wide 4.5V to 42V Input
• 0.9V to 0.96 x VIN Primary Output Voltage
• Delivers Up to 5W Output Power
• Reduces Power Dissipation
• Peak Efficiency > 90%
• 0.9μA (typ) Shutdown Current
• Operates Reliably in Adverse Industrial Environments
• Peak and Sink Current-Limit Protection
• Robust Secondary-Side Output Overcurrent Protection (MAX17681A)
• ±1.7% Feedback Accuracy
• Programmable EN/UVLO Threshold
• Adjustable Soft-Start
• Overtemperature Protection
• -40°C to +125°C Operation