LM3671LC-1.8

Voltage Regulators - DC DC Switching Regulators Overview

The LM3671LC-1.8 is a step-down DC-DC converter from Texas Instruments, optimized for single-cell lithium-ion battery applications. It operates within an input voltage range of 2.7V to 5.5V and provides a fixed output voltage of 1.8V. The device delivers a maximum load current of 600mA across the entire input voltage range. It features a typical switching frequency of 2MHz, enabling the use of small surface-mount components. The converter includes internal synchronous rectification for high efficiency in PWM mode and automatically switches between PWM and PFM modes to minimize quiescent current during light loads.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Automatically switches between PWM low-noise mode and PFM low-current mode to optimize system control and extend battery life.
• Features internal synchronous rectification to achieve high efficiency during PWM operation.
• Requires only three external surface-mount components: one inductor and two ceramic capacitors.
• Includes internal soft-start functionality and protection against overcurrent and thermal shutdown.

Voltage Regulators - DC DC Switching Regulators Applications

• Mobile phones and similar portable systems
• Low-voltage circuits powered by single-cell lithium-ion batteries
• Portable consumer electronics requiring efficient power management

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific package type, as the LC suffix typically denotes DSBGA-5, while other variants may use SOT-23-5 or USON. Confirm that the fixed 1.8V output aligns with circuit requirements, as adjustable versions exist. Ensure compatibility with automotive AEC-Q100 standards if used in vehicle applications, noting that the standard LM3671 may differ from the LM3671-Q1 qualification level.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when designing portable devices needing a compact, efficient buck converter from a single lithium cell. The 2MHz frequency allows for smaller passive components compared to lower-frequency alternatives. Consider the fixed 1.8V output constraint; if variable voltage is needed, choose an adjustable variant instead. Evaluate the trade-off between the low quiescent current in PFM mode and the noise performance required in PWM mode for sensitive analog sections.

Voltage Regulators - DC DC Switching Regulators Part Context

The LM3671 series represents Texas Instruments' solution for powering low-voltage logic and peripherals in mobile devices. It succeeds earlier regulators by integrating synchronous rectification and smart mode switching. The LC-1.8 variant specifically targets applications requiring a stable 1.8V rail from a 2.7V-5.5V source, fitting into the broader PMIC portfolio for portable electronics.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

LM3671MF-1.8/NOPB offers identical electrical specifications but utilizes a SOT-23-5 package instead of DSBGA-5. LM3671QTLX-1.8/NOPB provides the same 1.8V output and 600mA capability with automotive AEC-Q100 qualification. Verify pinout compatibility and thermal dissipation requirements when substituting packages.