NB639 4.5-28V, 8A Synchronous Step-down Converter QFN20

NB639 4.5-28V, 8A Synchronous Step-down Converter QFN20

Key Specifications

Features

• Wide 4.5V to 28V Operating Input Range
• 8A Output Current
• Internal 30mΩ High-Side, 12mΩ Low-Side Power MOSFETs
• Proprietary Switching Loss Reduction Technique
• 1% Reference Voltage
• Programmable Soft Start Time
• Soft Shutdown
• Programmable Switching Frequency
• SCP, OCP, OVP, UVP Protection and Thermal Shutdown
• Output Adjustable from 0.8V to 13V

Applications

• Notebook Systems and I/O Power
• Networking Systems
• Optical Communication Systems

Design Notes

• The step-down topology needs an inductor and output capacitor sized for the ripple at the switching frequency, not just the DC load.
• Keep the input loop short — high di/dt at the switch node sets conducted EMI.
• Power switches are integrated, so the thermal path is the PCB copper under the pad.
• Package QFN20 — check the land pattern in the datasheet before layout.

Common Questions