SNVS239C October   2004  – October 2015 LM3475

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
    3. 6.3 Recommended Operating Ratings
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 Hysteretic Control Circuit
      2. 7.3.2 Soft-Start
      3. 7.3.3 Under Voltage Detection
      4. 7.3.4 PGATE
      5. 7.3.5 Minimum On or Off Time
      6. 7.3.6 Enable Pin (EN)
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting Output Voltage
        2. 8.2.2.2 Setting Operating Frequency and Output Ripple
        3. 8.2.2.3 Using a Feed-forward Capacitor
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 Diode Selection
        8. 8.2.2.8 P-Channel MOSFET Selection
        9. 8.2.2.9 Reducing Switching Noise
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Easy-to-Use Control Methodology
  • 0.8 V to VIN Adjustable Output Range
  • High Efficiency (90% Typical)
  • ±0.9% (±1.5% Over Temperature) Feedback Voltage
  • 100% Duty Cycle Capable
  • Maximum Operating Frequency up to 2 MHz
  • Internal Soft-Start
  • Enable Pin

2 Applications

  • TFT Monitor
  • Auto PC
  • Vehicle Security
  • Navigation Systems
  • Notebook Standby Supply
  • Battery Powered Portable Applications
  • Distributed Power Systems

3 Description

The LM3475 is a hysteretic P-FET buck controller designed to support a wide range of high efficiency applications in a very small SOT-23-5 package. The hysteretic control scheme has several advantages, including simple system design with no external compensation, stable operation with a wide range of components, and extremely fast transient response. Hysteretic control also provides high efficiency operation, even at light loads. The PFET architecture allows for low component count as well as 100% duty cycle and ultra-low dropout operation.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM3475 SOT-23 (5) 1.60 mm × 2.90 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application

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