SNVS737F October   2011  – June 2019 LMR24220

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Descriptions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Recommended Operating Ratings
    3. 6.3 Electrical Characteristics
    4. 6.4 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  CoT Control Circuit Overview
      2. 7.3.2  Start-up Regulator (VCC)
      3. 7.3.3  Regulation Comparator
      4. 7.3.4  Zero Coil Current Detect
      5. 7.3.5  Overvoltage Comparator
      6. 7.3.6  On-Time Timer, Shutdown
      7. 7.3.7  Current Limit
      8. 7.3.8  N-Channel MOSFET and Driver
      9. 7.3.9  Soft Start
      10. 7.3.10 Thermal Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Detailed Design Procedure
        1. 8.2.1.1 Custom Design With WEBENCH® Tools
        2. 8.2.1.2 External Components
      2. 8.2.2 Application Curve
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Package Considerations
    3. 9.3 Thermal Derating
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Custom Design With WEBENCH® Tools
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Community Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

5 Pin Configuration and Functions

YPA Package
28-Bump DSGBA
Top View
LMR24220 30167669.gif

Pin Descriptions

PIN DESCRIPTION
NO. NAME
A2, A3, B2, B3, C2, C3, D2, D3, D4 SW Switching node Internally connected to the source of the main MOSFET and the drain of the synchronous MOSFET. Connect to the inductor.
A4, B4 VIN Input supply voltage Supply pin to the device. Nominal input range is 4.5 V to 42 V.
C4 BST Connection for bootstrap capacitor Connect a 33-nF capacitor from the SW pin to this pin. An internal diode charges the capacitor during the main MOSFET off-time.
E3, E4, F1, F2, F3, G3 AGND Analog Ground Ground for all internal circuitry other than the PGND pin.
G2 SS Soft start An 8-µA internal current source charges an external capacitor to provide the soft- start function.
G1 FB Feedback Internally connected to the regulation and over-voltage comparators. The regulation setting is 0.8V at this pin. Connect to feedback resistors.
G4 EN Enable Connect a voltage higher than 1.26 V to enable the regulator. Leaving this input open circuit will enable the device at internal UVLO level.
F4 RON On-time control An external resistor from the VIN pin to this pin sets the main MOSFET on-time.
E1, E2 VCC Start-up regulator Output Nominally regulated to 6 V. Connect a capacitor of not less than 680 nF between the VCC and AGND pins for stable operation.
A1, B1, C1, D1 PGND Power ground Synchronous MOSFET source connection. Tie to a ground plane.