SNVS036K April   2000  – June 2016 LM2670

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 - All Output Voltage Versions
    9. 6.9 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 Input
      3. 7.3.3 C Boost
      4. 7.3.4 Ground
      5. 7.3.5 SYNC
      6. 7.3.6 Feedback
      7. 7.3.7 ON/OFF
    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 Design Considerations
      2. 8.1.2 Inductor
      3. 8.1.3 Output Capacitor
      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 Applications
      1. 8.2.1 Typical Application for All Output Voltage Versions
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Capacitor Selection Guides
          2. 8.2.1.2.2 Inductor Selection Guides
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Fixed Output Voltage Application
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Capacitor Selection Guides
      3. 8.2.3 Adjustable Output Voltage Application
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Capacitor Selection Guides
  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 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    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
    1. 12.1 DAP (VSON Package)

Package Options

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

1 Features

  • Efficiency Up to 94%
  • Simple and Easy to Design With (Using Off-the-Shelf External Components)
  • 150-mΩ DMOS Output Switch
  • 3.3-V, 5-V, 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 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 LM2670 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 3-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 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 LM2670 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 LM2670 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)
LM2670 TO-263 (7) 10.10 mm × 8.89 mm
TO-220 (7) 14.986 mm × 10.16 mm
VSON (14) 6.00 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application

LM2670 10094203.png