SNVS560E March   2008  – October 2017 LM2854

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 Conditions
    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  Switching Frequency
      2. 7.3.2  Enable
      3. 7.3.3  Soft-Start
      4. 7.3.4  Tracking
      5. 7.3.5  Pre-Biased Start-up Capability
      6. 7.3.6  Feedback Voltage Accuracy
      7. 7.3.7  Positive Current Limit
      8. 7.3.8  Negative Current Limit
      9. 7.3.9  Overtemperature Protection
      10. 7.3.10 Loop Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Soft-Start and Track Mode
      3. 7.4.3 Normal Operating Mode
  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 Input Filter Capacitor
        2. 8.2.2.2 AVIN Filtering Components
        3. 8.2.2.3 Soft-Start Capacitor
        4. 8.2.2.4 Tracking - Equal Soft-Start Time
        5. 8.2.2.5 Tracking - Equal Slew Rates
        6. 8.2.2.6 Enable and UVLO
        7. 8.2.2.7 Output Voltage Setting
        8. 8.2.2.8 Compensation Component Selection
        9. 8.2.2.9 Filter Inductor and Output Capacitor Selection
      3. 8.2.3 Application Curves
      4. 8.2.4 System Examples
  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 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Input Voltage Range of 2.95 V to 5.5 V
  • Maximum Load Current of 4 A
  • Wide Bandwidth Voltage Mode Control Loop, Partial Internal Compensation
  • Fixed Switching Frequency of 500 kHz or 1 MHz
  • 35-mΩ Integrated MOSFET Switches
  • Adjustable Output Voltage Down to 0.8 V
  • Optimized Reference Voltage Initial Accuracy and Temperature Drift
  • External Soft-Start Control With Tracking Capability
  • Enable Pin With Hysteresis
  • Low Standby Current of 230 µA
  • Pre-Biased Load Start-up Capability
  • Integrated UVLO, OCP, and Thermal Shutdown
  • 100% Duty Cycle Capability
  • HTSSOP-16 Exposed Pad Package

2 Applications

  • Low Voltage POL Regulation from 5-V or 3.3-V Rail
  • Local Solution for FPGA/DSP/ASIC/µP Core or I/O Power
  • Broadband Networking and Communications Infrastructure
  • Portable Computing

3 Description

The LM2854 PowerWise™ buck regulator is a 500-kHz or 1-MHz step-down switching voltage regulator capable of driving up to a 4-A load with exceptional power conversion efficiency, line and load regulation, and output accuracy. The LM2854 can accept an input voltage rail between 2.95 V and 5.5 V, and deliver an adjustable and highly accurate output voltage as low as 0.8 V. Externally established soft-start with a small capacitor facilitates controlled start-up, and the LM2854 is capable of starting gracefully into a pre-biased output voltage. Partial internal compensation reduces the number of external passive components and PC board space typically necessary in a voltage mode buck converter application, yet preserving flexibility to deal with ceramic and/or electrolytic based load capacitors. Lossless cycle-by-cycle peak current limit is used to protect the load from an overcurrent or short-circuit fault, and an enable comparator simplifies sequencing applications. The LM2854 is available in an exposed pad HTSSOP-16 package that enhances the thermal performance of the regulator.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM2854 HTSSOP (16) 4.40 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Circuit

LM2854 30052801.gif