SNVS069E February   2000  – January 2022 LM2767

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 Parameter Measurement Information
    1. 7.1 Test Circuit
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Positive Voltage Doubler
        2. 9.2.2.2 Capacitor Selection
        3. 9.2.2.3 Paralleling Devices
        4. 9.2.2.4 Cascading Devices
        5. 9.2.2.5 Regulating VOUT
      3. 9.2.3 Application Curve
  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 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.2 Capacitor Selection

As discussed in Section 9.2.2.1, the output resistance and ripple voltage are dependent on the capacitance and ESR values of the external capacitors. The output voltage drop is the load current times the output resistance, and the power efficiency is

Equation 3. GUID-63DD8783-1999-4E09-9A5D-0040A8E8027B-low.gif

where

  • IQ(V+) is the quiescent power loss of the device; and
  • IL2Rout is the conversion loss associated with the switch on-resistance, the two external capacitors and their ESRs.

The selection of capacitors is based on the allowable voltage droop (which equals Iout Rout), and the desired output voltage ripple. Low-ESR capacitors (Table 9-2) are recommended to maximize efficiency, reduce the output voltage drop and voltage ripple.

Table 9-2 Low-ESR Capacitor Manufacturers
MANUFACTURER PHONE WEBSITE CAPACITOR TYPE
Nichicon Corp. (847)-843-7500 www.nichicon.com PL & PF series, through-hole aluminum electrolytic
AVX Corp. (843)-448-9411 www.avxcorp.com TPS series, surface-mount tantalum
Sprague (207)-324-4140 www.vishay.com 593D, 594D, 595D series, surface-mount tantalum
Sanyo (619)-661-6835 www.sanyovideo.com OS-CON series, through-hole aluminum electrolytic
Murata (800)-831-9172 www.murata.com Ceramic chip capacitors
Taiyo Yuden (800)-348-2496 www.t-yuden.com Ceramic chip capacitors
Tokin (408)-432-8020 www.tokin.com Ceramic chip capacitors