LM3671MFX-3.3

Voltage Regulators - DC DC Switching Regulators Overview

The LM3671MFX-3.3 is a fixed-output synchronous step-down DC-DC converter manufactured by Texas Instruments. It operates within an input voltage range of 2.7 V to 5.5 V and provides a fixed output voltage of 3.3 V with a maximum load current capability of 600 mA. The device utilizes a typical switching frequency of 2 MHz, enabling the use of compact external components. It features automatic transition between Pulse Width Modulation (PWM) and Pulse Frequency Modulation (PFM) modes to optimize efficiency across varying load conditions.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrates internal synchronous rectification for high energy conversion efficiency during PWM operation.
• Automatically switches between low-noise PWM mode and low-current PFM mode to extend battery life in portable applications.
• Includes built-in protection mechanisms such as internal soft-start, current overload protection, and thermal shutdown.
• Requires only three external surface-mount components: one inductor and two ceramic capacitors.

Voltage Regulators - DC DC Switching Regulators Applications

• Powering low-voltage circuits from single-cell lithium-ion batteries
• Portable electronic devices including mobile phones and PDAs
• Consumer electronics such as MP3 players and digital cameras
• Automotive electronic systems requiring AEC-Q100 qualified components

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix 'MFX' corresponds to the SOT-23-5 package configuration required for your layout. Confirm that the fixed 3.3 V output meets your system voltage requirements, as adjustable or other fixed voltage variants exist within the same family. Ensure compatibility with the -40°C to +85°C operating temperature range specified for this component.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed 3.3 V rail is needed from a 2.7 V to 5.5 V source. It is suitable for designs prioritizing small footprint due to the 2 MHz switching frequency. Consider the LM3671MFX-ADJ if variable output voltage flexibility is required instead of a fixed setting.

Voltage Regulators - DC DC Switching Regulators Part Context

This part belongs to the LM3671 series of high-efficiency synchronous buck converters designed for portable applications. The series offers various fixed voltage outputs and an adjustable version, all sharing the same core architecture and control logic. The MFX suffix specifically denotes the SOT-23-5 package variant optimized for space-constrained printed circuit board layouts.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

LM3671MF-3.3/NOPB is a direct equivalent offering the same electrical specifications in a different package variant.

Voltage Regulators - DC DC Switching Regulators FAQ

Does the LM3671MFX-3.3 support adjustable output voltage?

No, the LM3671MFX-3.3 provides a fixed output voltage of 3.3 V. For adjustable output capabilities, the LM3671MFX-ADJ variant should be used.

What is the typical quiescent current in light-load conditions?

In PFM mode, which activates during light loads, the typical static current is 16 µA, helping to maximize battery life in portable devices.