SNVS294S November   2004  – May 2016 LM3671 , LM3671-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings: LM3671
    3. 6.3 ESD Ratings: LM3671-Q1
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Dissipation Ratings
    7. 6.7 Electrical Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Circuit Operation
      2. 7.3.2 Soft Start
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Operation
        1. 7.4.1.1 Internal Synchronous Rectification
        2. 7.4.1.2 Current Limiting
      2. 7.4.2 PFM Operation
      3. 7.4.3 Shutdown
      4. 7.4.4 Low Dropout Operation (LDO)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Typical Application: Fixed-Voltage Version
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Inductor Selection
            1. 8.2.1.2.1.1 Method 1
            2. 8.2.1.2.1.2 Method 2
          2. 8.2.1.2.2 Input Capacitor Selection
          3. 8.2.1.2.3 Output Capacitor Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application: ADJ Version
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Output Voltage Selection for LM3671-ADJ
        3. 8.2.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 DSBGA Package Assembly and Use
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • LM3671-Q1 is Qualified for Automotive Applications
  • AEC Q100-Qualified With the Following Results
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature Range
  • 16-µA Typical Quiescent Current
  • 600-mA Maximum Load Capability
  • 2-MHz PWM Fixed Switching Frequency (Typical)
  • Automatic PFM-PWM Mode Switching
  • Internal Synchronous Rectification for High Efficiency
  • Internal Soft Start
  • 0.01-µA Typical Shutdown Current
  • Operates from a Single Li-Ion Cell Battery
  • Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)
  • Current Overload and Thermal Shutdown Protection
  • Available in Fixed Output Voltages and Adjustable Version

2 Applications

  • Mobile Phones
  • PDAs
  • MP3 Players
  • W-LAN
  • Portable Instruments
  • Digital Still Cameras
  • Portable Hard Disk Drives
  • Automotive
  • Portable Medical Equipment
  • Handheld Transaction Terminals
  • Wireless Home-Automation Equipment

3 Description

The LM3671 step-down DC-DC converter is optimized for powering low voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.7 V to 5.5 V. It provides up to 600-mA load current, over the entire input voltage range. There are several different fixed voltage output options available as well as an adjustable output voltage version range from 1.1 V to 3.3 V.

The device offers superior features and performance for mobile phones and similar portable systems. Automatic intelligent switching between PWM low-noise and PFM low-current mode offers improved system control. During PWM mode, the device operates at a fixed-frequency of 2 MHz (typical). Hysteretic PFM mode extends the battery life by reducing the quiescent current to 16 µA (typical) during light load and standby operation. Internal synchronous rectification provides high efficiency during PWM mode operation. In shutdown mode, the device turns off and reduces battery consumption to 0.01 µA (typical).

A high-switching frequency of 2 MHz (typical) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor, and two ceramic capacitors, are required.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE
LM3671 USON (6) 2.00 mm × 2.00 mm (NOM)
LM3671
LM3671-Q1		 SOT-23 (5) 2.90 mm × 1.60 mm (NOM)
DSBGA (5) 1.413 mm × 1.083 mm (MAX)
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Typical Application Circuit: Fixed-Voltage

LM3671 LM3671-Q1 20108401.gif

Typical Application Circuit: ADJ

LM3671 LM3671-Q1 20108431.gif