SNVS543N January   2008  – June 2017 LM26480

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Options
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions: Bucks
    4. 7.4  Thermal Information
    5. 7.5  General Electrical Characteristics
    6. 7.6  Low Dropout Regulators, LDO1 and LDO2
    7. 7.7  Buck Converters SW1, SW2
    8. 7.8  I/O Electrical Characteristics
    9. 7.9  Power On Reset Threshold/Function (POR)
    10. 7.10 Typical Characteristics — LDO
    11. 7.11 Typical Characteristics — Buck 2.8 V to 5.5 V
    12. 7.12 Typical Characteristics — Bucks 1 and 2
    13. 7.13 Typical Characteristics — Buck 3.6 V
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 DC-DC Converters
        1. 8.3.1.1 Linear Low Dropout Regulators (LDOs)
          1. 8.3.1.1.1 No-Load Stability
        2. 8.3.1.2 SW1, SW2: Synchronous Step-Down Magnetic DC-DC Converters
          1. 8.3.1.2.1  Functional Description
          2. 8.3.1.2.2  Circuit Operation Description
          3. 8.3.1.2.3  Sync Function
          4. 8.3.1.2.4  PWM Operation
          5. 8.3.1.2.5  Internal Synchronous Rectification
          6. 8.3.1.2.6  Current Limiting
          7. 8.3.1.2.7  PFM Operation
          8. 8.3.1.2.8  SW1, SW2 Control
          9. 8.3.1.2.9  Shutdown Mode
          10. 8.3.1.2.10 Soft Start
          11. 8.3.1.2.11 Low Dropout Operation
          12. 8.3.1.2.12 Flexible Power-On Reset (Power Good with Delay)
          13. 8.3.1.2.13 Undervoltage Lockout
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 External Component Selection
      2. 9.1.2 Feedback Resistors for LDOs
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 High VIN- High Load Operation
        2. 9.2.1.2 Junction Temperature
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Inductors and Capacitors for SW1 AND SW2
          1. 9.2.2.1.1 Inductor Selection for SW1 and SW2
          2. 9.2.2.1.2 Suggested Inductors and Their Suppliers
        2. 9.2.2.2 Output Capacitor Selection for SW1 and SW2
        3. 9.2.2.3 Input Capacitor Selection for SW1 and SW2
        4. 9.2.2.4 LDO Capacitor Selection
          1. 9.2.2.4.1 Input Capacitor
          2. 9.2.2.4.2 Output Capacitor
          3. 9.2.2.4.3 Capacitor Characteristics
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Input Voltage: 2.8 V to 5.5 V
  • Compatible with Advanced Applications Processors and FPGAs
  • Two LDOs for Powering Internal Processor Functions and I/Os
  • Precision Internal Reference
  • Thermal Overload Protection
  • Current Overload Protection
  • External Power-On-Reset Function for Buck1 and Buck2
  • Undervoltage Lockout Detector to Monitor Input Supply Voltage
  • Step-Down DC-DC Converters (Buck)
    • 1.5-A Output Current
    • VOUT from:
    • Buck1 : 0.8 V to 2 V at 1.5 A
    • Buck2 : 1 V to 3.3 V at 1.5 A
    • Up to 96% efficiency
    • ±3% FB Voltage Accuracy
    • 2-MHz PWM Switching Frequency
    • PWM-to-PFM Automatic Mode Change Under Low Loads
    • Automatic Soft Start
  • Linear Regulators (LDO)
    • VOUT of 1 V to 3.5 V
    • ±3% FB Voltage Accuracy
    • 300-mA Output Current
    • 25-mV (Typical) Dropout

2 Applications

  • Core Digital Power
  • Applications Processors
  • Peripheral I/O Power
  • Digital Radios
  • Robot Drives
  • Image Transmission Module
  • Low-Power Digital Applications

3 Description

The LM26480 is a multi-functional power management unit (PMU), optimized for low-power digital applications. This device integrates two highly efficient 1.5-A step-down DC-DC converters and two 300-mA linear regulators. The DC-DC buck converters provide typical efficiencies of 96%, allowing for minimal power consumption. Features include soft start, undervoltage lockout, current overload protection, thermal overload protection, and an internal power-on-reset (POR) circuit, which monitors the output voltage levels on bucks 1 and 2.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM26480 WQFN (24) 4.00 mm × 4.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

LM26480 typapp_snvs543.gif

4 Revision History

Changes from M Revision (December 2016) to N Revision

  • Deleted the maximum lead temperature (soldering) from the Absolute Maximum Ratings tableGo
  • Changed the PBUCK1 and PBUCK2 equations in the Junction Temperature sectionGo
  • Changed the Electrostatic Discharge Caution statement Go

Changes from L Revision (June 2016) to M Revision

  • Changed title of data sheet; add content to Description sectionGo
  • Deleted SQ-BF option from Table 1 Go

Changes from K Revision (January 2015) to L Revision

  • Added additional items to Applications Go
  • Changed "θn" to "eN" as symbol for supply output noise in Low Dropout Regulators EC tableGo

Changes from J Revision (October 2014) to K Revision

  • Changed Handling Ratings table to ESD Ratings table Go
  • Added full Thermal Information values.Go
  • Added additional paragraph to Functional Description subsection to describe enable signal.Go

Changes from I Revision (May 2013) to J Revision

  • Added Device Information and ESD Rating tables, Feature Description, Device Functional Modes, Application and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support, and Mechanical, Packaging, and Orderable Information sections; moved some curves to Application Curves section. Go