SNVS782C October   2010  – August 2015 LM3243

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 System Characteristics
    7. 6.7 Timing Requirements
    8. 6.8 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 ACB
      2. 7.3.2 Bypass Operation
      3. 7.3.3 Mode Pin
      4. 7.3.4 Dynamic Adjustment Of Output Voltage
      5. 7.3.5 Internal Synchronous Rectification
      6. 7.3.6 Current Limit
      7. 7.3.7 Timed Current Limit
      8. 7.3.8 Thermal Overload Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Operation
      2. 7.4.2 PFM Mode
      3. 7.4.3 Mode Selection
      4. 7.4.4 Shutdown Mode
  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 Inductor Selection
        2. 8.2.2.2 Capacitor Selection
        3. 8.2.2.3 Setting The Output Voltage
          1. 8.2.2.3.1 DAC Control
          2. 8.2.2.3.2 PDM-Based VCON Signal
          3. 8.2.2.3.3 VCON Pin
        4. 8.2.2.4 EN Input Control
        5. 8.2.2.5 Start-Up
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 PCB Considerations
        1. 10.1.1.1 Energy Efficiency
        2. 10.1.1.2 EMI
      2. 10.1.2 Manufacturing Considerations
    2. 10.2 Layout Example
      1. 10.2.1 LM3243 RF Evaluation Board
      2. 10.2.2 DC-DC Converter Section
      3. 10.2.3 VBATT Star Supply Connection
    3. 10.3 DSBGA Package Assembly and Use
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

5 Pin Configuration and Functions

TMD Package
16-Pin DSBGA
LM3243 30132103.gif

Pin Functions

PIN TYPE DESCRIPTION
NO. NAME
A1 PGND Ground Power ground to the internal NFET switch.
B1
C1 SGND Ground Signal analog and control ground (low current).
D1 VDD Power Analog supply input.
A2 SW Analog Switching node connection to the internal PFET switch and NFET synchronous rectifier. Connect to an inductor with a saturation current rating that exceeds the ILIM,PFET,Steady State current limit specification of the LM3243.
B2
C2 EN Digital/Input Enable input. Set this digital input HIGH for normal operation. For shutdown, set low. Pin has an 800-kΩ internal pulldown resistor.
D2 VCON Analog Voltage control analog input. VOUT = 2.5 × VCON.
A3 PVIN Power Power supply voltage input to the internal PFET switch and ACB.
B3
C3 BP Digital Bypass mode input. Set the pin HIGH for forced Bypass mode operation. Set the pin LOW for automatic analog bypass mode (recommended).
D3 MODE Digital/Input PWM/PFM mode selection input. Setting the pin HIGH allows for PFM or PWM, depending on the load current. Setting the pin LOW forces the part to be in PWM only.
A4 ACB Output Analog Current Bypass (ACB). Connect to the output at the output filter capacitor.
B4
C4 BGND Ground ACB ground (high current).
D4 FB Analog Feedback analog input. Connect to the output at the output filter capacitor.