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LM3670

ACTIVE

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

Product details

Vin (min) (V) 2.5 Vin (max) (V) 5.5 Vout (min) (V) 0.7 Vout (max) (V) 3.3 Iout (max) (A) 0.35 Iq (typ) (mA) 0.015 Switching frequency (min) (kHz) 550 Switching frequency (max) (kHz) 1300 Features Enable, Light load efficiency, Synchronous Rectification Operating temperature range (°C) -40 to 85 Rating Catalog Regulated outputs (#) 1 Control mode Voltage mode Duty cycle (max) (%) 100 Type Converter
Vin (min) (V) 2.5 Vin (max) (V) 5.5 Vout (min) (V) 0.7 Vout (max) (V) 3.3 Iout (max) (A) 0.35 Iq (typ) (mA) 0.015 Switching frequency (min) (kHz) 550 Switching frequency (max) (kHz) 1300 Features Enable, Light load efficiency, Synchronous Rectification Operating temperature range (°C) -40 to 85 Rating Catalog Regulated outputs (#) 1 Control mode Voltage mode Duty cycle (max) (%) 100 Type Converter
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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Type Title Date
* 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

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Evaluation board

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

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User guide: PDF
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Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Package Pins Download
SOT-23 (DBV) 5 View options

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