SNVS077J May   2004  – June 2016 LM2677

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 - 3.3 V
    6. 6.6  Electrical Characteristics - 5 V
    7. 6.7  Electrical Characteristics - 12 V
    8. 6.8  Electrical Characteristics - Adjustable
    9. 6.9  Electrical Characteristics - All Output Voltage Versions
    10. 6.10 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 Switch Output
      2. 7.3.2 CBoost
      3. 7.3.3 Ground
      4. 7.3.4 Sync
      5. 7.3.5 Feedback
      6. 7.3.6 ON/OFF
      7. 7.3.7 DAP (VSON Package)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Inductor
      2. 8.1.2 Output Capacitor
      3. 8.1.3 Input and Output Capacitor Codes
      4. 8.1.4 Input Capacitor
      5. 8.1.5 Catch Diode
      6. 8.1.6 Boost Capacitor
      7. 8.1.7 SYNC Components
      8. 8.1.8 Additional Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Fixed Output Voltage Applications
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Adjustable Output Voltage Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 VSON Package Devices
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Efficiency up to 92%
  • Simple and Easy to Design Using Off-the-Shelf External Components
  • 100-mΩ DMOS Output Switch
  • 3.3-V, 5-V, and 12-V Fixed Output and Adjustable (1.2 V to 37 V) Versions
  • 50-μA Standby Current When Switched OFF
  • ±2% Maximum Output Tolerance Over Full Line and Load Conditions
  • Wide Input Voltage Range: 8 V to 40 V
  • External Sync Clock Capability (280 kHz to
    400 kHz)
  • 260-kHz Fixed Frequency Internal Oscillator
  • −40°C to 125°C Operating Junction Temperature Range

2 Applications

  • Simple to Design, High Efficiency (> 90%) Step-Down Switching Regulators
  • Efficient System Preregulator for Linear Voltage Regulators
  • Battery Chargers
  • Communications and Radio Equipment Regulator With Synchronized Clock Frequency

3 Description

The LM2677 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 5-A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low on-resistance DMOS power switch. The series consists of fixed output voltages of 3.3-V, 5-V, and 12-V and an adjustable output version.

The SIMPLE SWITCHER® concept provides for a complete design using a minimum number of external components. The switching clock frequency can be provided by an internal fixed frequency oscillator
(260 kHz) or from an externally provided clock in the range of 280 kHz to 400 kHz, which allows the use of physically smaller-sized components. A family of standard inductors for use with the LM2677 are available from several manufacturers to greatly simplify the design process. The external Sync clock provides direct and precise control of the output ripple frequency for consistent filtering or frequency spectrum positioning.

The LM2677 series also has built-in thermal shutdown, current-limiting, and an ON/OFF control input that can power down the regulator to a low
50-μA quiescent-current standby condition. The output voltage is ensured to a ±2% tolerance.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM2677 TO-263 (7) 10.16 mm × 8.69 mm
TO-220 (7) 10.16 mm × 8.94 mm
VSON (14) 6.10 mm × 5.10 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application

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