MP28275 4.5-7V, 5A, 1.1MHz Synchronous Step-down Converter QFN14

MP28275 4.5-7V, 5A, 1.1MHz Synchronous Step-down Converter QFN14

The MP28275 is a high frequency synchronous rectified step-down switch mode converter with built-in internal power MOSFETs.

Key Specifications

Features

• 4.5V to 7V Operating Input Range
• 5A Output Current
• Low RDS(ON) Internal Power MOSFETs
• Proprietary Switching Loss Reduction Technique
• Fixed 1.1MHz Switching Frequency
• Sync from 300kHz to 2MHz External Clock
• Internal Compensation
• Thermal Shutdown
• Over-Current-Protection and Hiccup
• Output Adjustable from 0.8V

Typical Application Circuit

Applications

• Notebook Systems and I/O Power
• Networking Systems
• Digital Set Top Boxes
• Personal Video Recorders
• Flat Panel Television and Monitors

Design Notes

• Size the inductor for the ripple current at the actual switching frequency, typically 30% of the DC load — not for the DC rating alone.
• The hot loop from input capacitor through the switch to ground sets conducted EMI. Keep that copper area as small as the layout allows.
• Output ripple is set by the capacitor ESR and its DC-bias derating; a 10 µF ceramic often behaves like 4 µF at the rated output voltage.
• Route the feedback divider from the output capacitor terminals, away from the switch node.

Common Questions