LM3671MFX-1.8

Voltage Regulators - DC DC Switching Regulators Overview

The LM3671MFX-1.8/NOPB is a synchronous step-down DC-DC converter manufactured by Texas Instruments, designed for portable applications powered by single lithium-ion batteries. It operates within an input voltage range of 2.7V to 5.5V and provides a fixed output voltage of 1.8V with a maximum load current of 600mA. The device features a typical switching frequency of 2MHz, allowing the use of compact surface-mount components. It automatically switches between PWM low-noise mode and PFM low-current mode, achieving a typical quiescent current of 16µA in light-load conditions. The component is housed in a SOT-23-5 package and supports an operating temperature range from -40°C to +85°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Intelligent automatic switching between PWM low-noise mode and PFM low-current mode to optimize system control and efficiency across varying load conditions.
• Internal synchronous rectification ensures high energy conversion efficiency during PWM mode operation.
• High switching frequency enables the use of miniature external surface-mount components, specifically one inductor and two ceramic capacitors.
• Integrated protection mechanisms include cycle-by-cycle current limiting and thermal shutdown to safeguard against overcurrent and overheating.

Voltage Regulators - DC DC Switching Regulators Applications

• Powering low-voltage circuits in mobile phones and similar portable systems
• Battery-powered consumer electronics requiring efficient step-down conversion
• Portable devices utilizing single lithium-ion battery inputs

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix (e.g., MFX) to confirm the SOT-23-5 package type and tape-and-reel packaging format. Ensure the part number includes the NOPB designation if lead-free compliance is required. Cross-reference the fixed 1.8V output requirement against other available voltage options within the LM3671 family to prevent selection errors. Confirm that the application environment remains within the specified -40°C to +85°C operating temperature range.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed 1.8V output is required from a 2.7V to 5.5V input source. It is suitable for designs prioritizing small footprint due to the 2MHz switching frequency and minimal external component count. Consider the LM3671Q1 variant if automotive qualification under AEC-Q100 standards is necessary. Evaluate the 600mA current limit against peak load demands to ensure adequate headroom without triggering protection circuits.

Voltage Regulators - DC DC Switching Regulators Part Context

The LM3671 series comprises optimized buck converters tailored for portable equipment. This specific model belongs to the standard commercial grade, distinct from the automotive-grade LM3671-Q1 which meets AEC-Q100 standards. The series offers various fixed voltage outputs and adjustable versions, all sharing core features like synchronous rectification and intelligent mode switching for extended battery life in mobile applications.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Direct substitutes include other LM3671 variants with different fixed output voltages or packages, such as LM3671MFX-1.25/NOPB or LM3671LCX-1.8/NOPB, provided the voltage requirement changes. For automotive environments, consider the LM3671QTLX-1.8/NOPB. Verify pin compatibility and thermal performance before substituting.