SNVS891H September   2012  – September 2015 LM3642

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 Timing Requirements
    7. 6.7 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 Power Amplifier Synchronization (TX/TORCH)
      2. 7.3.2 Input Voltage Flash Monitor (IVFM)
      3. 7.3.3 Fault and Protections
        1. 7.3.3.1 Fault Operation
        2. 7.3.3.2 Flash Time-Out
        3. 7.3.3.3 Overvoltage Protection (OVP)
        4. 7.3.3.4 Current Limit
        5. 7.3.3.5 Undervoltage Lockout (UVLO)
        6. 7.3.3.6 Thermal Shutdown (TSD)
        7. 7.3.3.7 LED and/or VOUT Fault
    4. 7.4 Device Functional Modes
      1. 7.4.1 Start-up (Enabling the Device)
      2. 7.4.2 Pass Mode
      3. 7.4.3 Flash Mode
      4. 7.4.4 Torch Mode
      5. 7.4.5 Indicator Mode
    5. 7.5 Programming
      1. 7.5.1 I2C-Compatible Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 Start and Stop Conditions
        3. 7.5.1.3 Transferring Data
        4. 7.5.1.4 I2C-Compatible Chip Address
        5. 7.5.1.5 Transferring Data
    6. 7.6 Register Map
      1. 7.6.1 Register Descriptions
        1. 7.6.1.1 Enable Register (0x0A)
        2. 7.6.1.2 Flags Register (0x0B)
        3. 7.6.1.3 Flash Features Register (0x08)
        4. 7.6.1.4 Current Control Register (0x09)
        5. 7.6.1.5 Input Voltage Flash Monitor (IVFM) Mode Register (0x01)
        6. 7.6.1.6 Torch Ramp Time Register (0x06)
        7. 7.6.1.7 Silicon Revision Register
  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 Output Capacitor Selection
        2. 8.2.2.2 Input Capacitor Selection
        3. 8.2.2.3 Inductor Selection
      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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Trademarks
    4. 11.4 Community Resources
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

5 Pin Configuration and Functions

YZR Package
9-Pin DSBGA
Top View
LM3642 30178902.gif

Pin Functions

PIN I/O DESCRIPTION
NO. NAME
A1 OUT Power Step-up DC-DC converter output. Connect a 10-µF ceramic capacitor between this pin and GND.
A2 SW Power Drain connection for internal NMOS and synchronous PMOS switches.
A3 GND Ground Ground
B1 LED Output High-side current source output for Flash LED.
B2 STROBE Input Active high hardware Flash enable. Drive STROBE high to turn on Flash pulse. Has an internal pulldown resistor of 300 kΩ between STROBE and GND.
B3 IN Power Input voltage connection. Connect IN to the input supply, and bypass to GND with a 10-µF or larger ceramic capacitor.
C1 TX/TORCH Input Configurable power amplifier synchronization input or configurable active high Torch enable. Has an internal pulldown resistor of 300 kΩ between TX and GND.
C2 SDA Input/Output Serial data input/output.
C3 SCL Input Serial clock input.