SNVS336F June   2006  – August 2015 LP38856

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 Enable Operation
      2. 7.3.2 Input Voltage
      3. 7.3.3 Bias Voltage
      4. 7.3.4 Undervoltage Lockout
      5. 7.3.5 Supply Sequencing
      6. 7.3.6 Reverse Voltage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation with 3 V ≤ VBIAS ≤ 5.5 V , VOUT(TARGET) + 0.3 V ≤ VIN ≤ VBIAS
      2. 7.4.2 Operation with VEN Control
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 External Capacitors
          1. 8.2.2.1.1 Output Capacitor
          2. 8.2.2.1.2 Input Capacitor
          3. 8.2.2.1.3 Bias Capacitor
        2. 8.2.2.2 Power Dissipation and Heatsinking
      3. 8.2.3 Application Curves
  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 Community Resources
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10 Layout

10.1 Layout Guidelines

Good layout practices will minimize voltage error and prevent instability which can result from ground loops. The input and output capacitors must be directly connected to the device pins with short traces that have no other current flowing in them (Kelvin connect).

The best way to do this is to place the capacitors very near the device and make connections directly to the device pins via short traces on the top layer of the PCB. The regulator’s ground pin must be connected through vias to the internal or backside ground plane so that the regulator has a single point ground.

The external resistors which set the output voltage must also be located very near the device with all connections directly tied via short traces to the pins of the device (Kelvin connect). Do not connect the resistive divider to the load point or DC error will be induced.

10.2 Layout Example

LP38856 layout_TO-263.gifFigure 26. LP38856 Layout Example