text.skipToContent text.skipToNavigation


Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits



  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well as an adjustable version
  • SOT23-5 package
  • Low drop out operation - 100% duty cycle mode
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.1 microA typical shutdown current
  • Operates from a single Li-Ion cell or 3 cell NIMH/NiCd batteries
  • Only three tiny surface-mount external components required (one inductor, two ceramic capaitors)
  • Current overload protection


  • Mobile phones
  • Hand-Held Radios
  • Personal Digital Assistants
  • Palm-top PCs
  • Portable Instruments
  • Battery Powered Devices


Texas Instruments  LM3670MF-1.8EV

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output option available as well as an adjustable output voltage version. This device offers superior features and performance for mobile phones and similar portable applications with complex power management systems.