LM3670

ACTIVE

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

Product details

Rating Catalog Operating temperature range (°C) -40 to 85 Topology Buck Type Converter Iout (max) (A) 0.35 Vin (min) (V) 2.5 Vin (max) (V) 5.5 Switching frequency (min) (kHz) 550 Switching frequency (max) (kHz) 1300 Features Enable, Light Load Efficiency, Light load efficiency, Synchronous Rectification Control mode Voltage mode Vout (min) (V) 0.7 Vout (max) (V) 3.3 Iq (typ) (µA) 15 Duty cycle (max) (%) 100
Rating Catalog Operating temperature range (°C) -40 to 85 Topology Buck Type Converter Iout (max) (A) 0.35 Vin (min) (V) 2.5 Vin (max) (V) 5.5 Switching frequency (min) (kHz) 550 Switching frequency (max) (kHz) 1300 Features Enable, Light Load Efficiency, Light load efficiency, Synchronous Rectification Control mode Voltage mode Vout (min) (V) 0.7 Vout (max) (V) 3.3 Iq (typ) (µA) 15 Duty cycle (max) (%) 100
SOT-23 (DBV) 5 8.12 mm² 2.9 x 2.8
  • Input Voltage Range: 2.5 V to 5.5 V
  • Adjustable Output Voltages (VOUT): 0.7 V to 2.5 V
  • Fixed Output Voltages: 1.2 V, 1.5 V, 1.6 V, 1.8 V, 1.875 V, 3.3V
  • 15-µA Typical Quiescent Current
  • 350-mA Maximum Load Capability
  • 1-MHz PWM Fixed Switching Frequency (Typical)
  • Automatic PFM and PWM Mode Switching
  • Low Dropout Operation – 100% Duty Cycle Mode
  • Internal Synchronous Rectification for High Efficiency
  • Internal Soft Start
  • 0.1-µA Typical Shutdown Current
  • Current Overload Protection
  • Operates from a Single Li-Ion Cell or Three-Cell NiMH/NiCd Batteries
  • Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)
  • Input Voltage Range: 2.5 V to 5.5 V
  • Adjustable Output Voltages (VOUT): 0.7 V to 2.5 V
  • Fixed Output Voltages: 1.2 V, 1.5 V, 1.6 V, 1.8 V, 1.875 V, 3.3V
  • 15-µA Typical Quiescent Current
  • 350-mA Maximum Load Capability
  • 1-MHz PWM Fixed Switching Frequency (Typical)
  • Automatic PFM and PWM Mode Switching
  • Low Dropout Operation – 100% Duty Cycle Mode
  • Internal Synchronous Rectification for High Efficiency
  • Internal Soft Start
  • 0.1-µA Typical Shutdown Current
  • Current Overload Protection
  • Operates from a Single Li-Ion Cell or Three-Cell NiMH/NiCd Batteries
  • Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)

The LM3670 step-down DC-DC converter is optimized for powering ultralow voltage circuits from a single Li-Ion cell or three-cell NiMH/NiCd batteries. It provides up to 350-mA load current, over an input voltage range from 2.5 V to 5.5 V. There are several different fixed voltage output options available as well as an adjustable output voltage version.

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between pulse width modulation (PWM) low-noise and pulse frequency modulation (PFM) low-current mode offers improved system control. During full-power operation, a fixed-frequency 1-MHz (typical) PWM mode drives loads from approximately 70 mA to 350 mA maximum, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 15 µA (typical) during light current loads and system standby. Internal synchronous rectification provides high efficiency (90% to 95% typical at loads between 1 mA and 100 mA). In shutdown mode (enable (EN) pin pulled low) the device turns off and reduces battery consumption to 0.1 µA (typical).

The LM3670 is available in a 5-pin SOT-23 package. A high switching frequency (1 MHz typical) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.

For all available packages, see the orderable addendum at the end of the data sheet.

The LM3670 step-down DC-DC converter is optimized for powering ultralow voltage circuits from a single Li-Ion cell or three-cell NiMH/NiCd batteries. It provides up to 350-mA load current, over an input voltage range from 2.5 V to 5.5 V. There are several different fixed voltage output options available as well as an adjustable output voltage version.

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between pulse width modulation (PWM) low-noise and pulse frequency modulation (PFM) low-current mode offers improved system control. During full-power operation, a fixed-frequency 1-MHz (typical) PWM mode drives loads from approximately 70 mA to 350 mA maximum, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 15 µA (typical) during light current loads and system standby. Internal synchronous rectification provides high efficiency (90% to 95% typical at loads between 1 mA and 100 mA). In shutdown mode (enable (EN) pin pulled low) the device turns off and reduces battery consumption to 0.1 µA (typical).

The LM3670 is available in a 5-pin SOT-23 package. A high switching frequency (1 MHz typical) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.

For all available packages, see the orderable addendum at the end of the data sheet.

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Technical documentation

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* Data sheet LM3670 Miniature Step-Down DC-DC Converter for Ultralow Voltage Circuits datasheet (Rev. F) PDF | HTML 18 Feb 2016
Application note Quick Reference Guide To TI Buck Switching DC/DC Application Notes (Rev. B) PDF | HTML 23 May 2022
Selection guide Power Management Guide 2018 (Rev. R) 25 Jun 2018
EVM User's guide AN-1348 LM3670 Evaluation Board (Rev. D) 30 Apr 2013

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

LM3670MF-1.8EV — Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits

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 (...)

User guide: PDF
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Evaluation board

TMDSLCD1EVM — 1280x800 LCD display accessory kit

The 1280x800 LCD display accessory kit is an add-on accessory for the AM65x IDK (TMDX654IDKEVM) to add touch and display functions for the evaluation of HMI, industrial PC, and other use cases requiring display. The 1280x800 LCD display accessory kit comes bundled with the AM65x EVM (TMDX654GPEVM) (...)

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SOT-23 (DBV) 5 Ultra Librarian

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