SNVS029L March   2000  – June 2025 LM2678

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics – 3.3 V
    6. 5.6  Electrical Characteristics – 5 V
    7. 5.7  Electrical Characteristics – 12 V
    8. 5.8  Electrical Characteristics – Adjustable
    9. 5.9  Electrical Characteristics – All Output Voltage Versions
    10. 5.10 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Switch Output
      2. 6.3.2 Input
      3. 6.3.3 C Boost
      4. 6.3.4 Ground
      5. 6.3.5 Feedback
      6. 6.3.6 ON/OFF
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Active Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Design Considerations
      2. 7.1.2 Inductor
      3. 7.1.3 Output Capacitor
      4. 7.1.4 Input Capacitor
      5. 7.1.5 Catch Diode
      6. 7.1.6 Boost Capacitor
      7. 7.1.7 Additional Application Information
    2. 7.2 Typical Application
      1. 7.2.1 All Output Voltage Versions
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 7.2.1.2.2 Capacitor Selection Guides
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Fixed Output Voltage Design Example
        1. 7.2.2.1 Detailed Design Procedure
          1. 7.2.2.1.1 Capacitor Selection
      3. 7.2.3 Adjustable Output Design Example
        1. 7.2.3.1 Detailed Design Procedure
          1. 7.2.3.1.1 Capacitor Selection
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 VSON Package Devices

4 Pin Configuration and Functions

LM2678 KTW Package, 7-Pin TO-263 (Top View)Figure 4-1 KTW Package, 7-Pin TO-263 (Top View)
LM2678 NDZ Package, 7-Pin TO-220 (Top View)Figure 4-2 NDZ Package, 7-Pin TO-220 (Top View)
LM2678 NHM Package, 14-Pin VSON (Top View)
DAP connect to pin 9
Figure 4-3 NHM Package, 14-Pin VSON (Top View)
Table 4-1 Pin Functions
PIN TYPE(1) DESCRIPTION
NAME TO-263, TO-220 VSON
Switch output 1 12, 13, 14 O Source pin of the internal high-side FET. This is a switching node. Attached this pin to an inductor and the cathode of the external diode.
Input 2 2, 3 I Supply input pin to collector pin of high-side FET. Connect to power supply and input bypass capacitors CIN. Path from VIN pin to high frequency bypass CIN and GND must be as short as possible.
CB 3 4 I Boot-strap capacitor connection for high-side driver. Connect a high-quality 100-nF capacitor from CB to VSW Pin.
GND 4 9 — Power ground pins. Connect to system ground. Ground pins of CIN and COUT. Path to CIN must be as short as possible.
FB 6 7 I Feedback sense input pin. Connect to the midpoint of feedback divider to set VOUT for ADJ version or connect this pin directly to the output capacitor for a fixed output version.
ON/ OFF 7 8 I Enable input to the voltage regulator. High = ON and low = OFF. Pull this pin high or float to enable the regulator.
NC 5 1, 5, 6, 10, 11 — No connect pins
DAP — — — All DAP, tab, and paddle connections are at ground potential and must be connected to system ground to allow for correct thermal and electrical performance.
(1) I = input, O = output