MAX17681ATB+T

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. The 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 MAX17681 and MAX17681A support primary side overcurrent protection, the MAX17681A is an enhanced design that supports robust secondary-side overcurrent protection as well. The MAX17681/MAX17681A is available in a compact 10-pin (3mm×2mm) TDFN package. Simulation models are available.

Applications

• Isolated Fieldbus Interfaces PLC I/O Modules
• Smart Meters
• Isolated Power Supplies in Medical Equipment
• Floating Power Supply Generation

Key features

• 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×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
• ±1.7% Feedback Accuracy
• Programmable EN/UVLO Threshold
• Adjustable Soft-Start Overtemperature Protection
• -40°C to +125°C Operation
• Short-Circuit Protection
• MAX17681A Supports Robust Secondary-Side Short-Circuit Protection
• MAX17681A Is Recommended for All New Designs