SNVS153F May   2001  – September 2016 LM2698

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 Inductor
      2. 7.3.2 Current Limit
      3. 7.3.3 Diode
      4. 7.3.4 Input Capacitor
      5. 7.3.5 Output Capacitor
    4. 7.4 Device Functional Modes
      1. 7.4.1 Continuous Conduction Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1.25-MHz Boost Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Compensation
            1. 8.2.1.2.1.1 Quick Compensator Design
            2. 8.2.1.2.1.2 Improving Transient Response Time
            3. 8.2.1.2.1.3 Additional Comments on the Open Loop Frequency Response
        3. 8.2.1.3 Application Curves
      2. 8.2.2 3.3-V SEPIC
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
      3. 8.2.3 Level-Shifted SEPIC
        1. 8.2.3.1 Design Requirements
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    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

  • 1.9-A, 0.2-Ω Internal Switch (Typical)
  • Operating Voltage as Low as 2.2 V
  • 600 kHz to 1.25 MHz Adjustable Frequency Operation
  • Switchers Made Simple® Software
  • 8-Pin VSSOP Package

2 Applications

  • 3.3 V to 5 V and 5 V to 12 V Conversion
  • Distributed Power
  • Set-Top Boxes
  • DSL Modems
  • Diagnostic Medical Instrumentation
  • Boost Converters
  • Flyback Converters
  • SEPIC Converters

3 Description

The LM2698 device is a general purpose PWM boost converter. The 1.9-A, 18-V, 0.2-Ω internal switch enables the LM2698 to provide efficient power conversion to outputs ranging from 2.2 V to 17 V. It can operate with input voltages as low as 2.2 V and as high as 12 V. Current-mode architecture provides superior line and load regulation and simple frequency compensation over the device's 2.2 V to
12 V input voltage range. The LM2698 sets the standard in power density and is capable of supplying 12 V at 400 mA from a 5-V input. The LM2698 can also be used in flyback or SEPIC topologies.

The LM2698 SIMPLE SWITCHER® features a pin selectable switching frequency of either 600 kHz or 1.25 MHz. This promotes flexibility in component selection and filtering techniques. A shutdown pin is available to suspend the device and decrease the quiescent current to 5 µA. An external compensation pin gives the user flexibility in setting frequency compensation, which makes possible the use of small, low-ESR ceramic capacitors at the output. Switchers Made Simple® software is available to ensure a quick, easy, and assured design. The LM2698 is available in a low-profile, 8-pin VSSOP (DGK) package.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM2698 VSSOP (8) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Circuit

LM2698 20012658.gif