SNVSCV4 September   2024 LM3645

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
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 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 Power Amplifier Synchronization (TORCH/TX)
      2. 6.3.2 Input Voltage Flash Monitor (IVFM)
      3. 6.3.3 Fault/Protections
        1. 6.3.3.1  Fault Operation
        2. 6.3.3.2  Flash Time-Out
        3. 6.3.3.3  Overvoltage Protection (OVP)
        4. 6.3.3.4  Current Limit
        5. 6.3.3.5  NTC Thermistor Input/Outputs (TEMP1, TEMP2)
        6. 6.3.3.6  Thermal Scale Back
        7. 6.3.3.7  Thermal Shutdown (TSD)
        8. 6.3.3.8  Undervoltage Lockout (UVLO)
        9. 6.3.3.9  LED and/or VOUT Short Fault
        10. 6.3.3.10 Fault Behavior Table
    4. 6.4 Device Functioning Modes
      1. 6.4.1 Flash Mode
      2. 6.4.2 Torch Mode
      3. 6.4.3 IR Mode
      4. 6.4.4 Voltage Mode
      5. 6.4.5 Mode Transitions
      6. 6.4.6 Boost Operation
        1. 6.4.6.1 Start-Up (Enabling The Device)
        2. 6.4.6.2 Pass Mode
        3. 6.4.6.3 Output Voltage Regulation
    5. 6.5 Programming and Control
      1. 6.5.1 Dx_EN Bits
      2. 6.5.2 STR1 and STR2 Usage
      3. 6.5.3 TOR/TX Usage
      4. 6.5.4 Control State Diagram
      5. 6.5.5 I2C-Compatible Interface
        1. 6.5.5.1 Data Validity
        2. 6.5.5.2 Start and Stop Conditions
        3. 6.5.5.3 Transferring Data
        4. 6.5.5.4 I2C-Compatible Chip Address
    6. 6.6 Register Descriptions
      1. 6.6.1 MainReg Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Output Control Examples
        1. 7.2.2.1 Four Channel Flash with Strobe1 Trigger Starting in Standby
        2. 7.2.2.2 Four Channel Flash with Strobe1 Trigger Starting in I2C Torch
        3. 7.2.2.3 Mixed Mode Functionality
        4. 7.2.2.4 Voltage Mode Only
        5. 7.2.2.5 Voltage Mode With Advanced IR
      3. 7.2.3 Detailed Design Procedure
        1. 7.2.3.1 Snubber Requirement
        2. 7.2.3.2 Output Capacitor Selection
        3. 7.2.3.3 Input Capacitor Selection
        4. 7.2.3.4 Inductor Selection
      4. 7.2.4 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

4 Pin Configuration and Functions

LM3645 YCG Package, 25-Pin DSBGAFigure 4-1 YCG Package, 25-Pin DSBGA
Table 4-1 Pin Functions
PINTYPEDESCRIPTION
NO.NAME
A3INPInput voltage connection. Connect this pin to the input supply and bypass to GND with a 10-µF or larger ceramic capacitor
B1SWPDrain connection for internal N-channel MOSFET and synchronous P-channel MOSFET switches
B2
C1OUTPStep-up DC-DC converter output. Connect 2 × 10-µF ceramic capacitors between this terminal and GND
C2
C3
C4
A1GNDGGround
A2
E1D1PHigh-side current source outputs for flash LEDs
E2
D1D2P
D2
D4D3P
D5
E4D4P
E5
A4ENIActive high hardware enable. Drive EN pin high to turn on the device. An internal pulldown resistor of 300 kΩ is between EN and GND.
A5SDAI/OI2C serial data input/output
B5SCLII2C serial clock input
B3STR1IActive high hardware flash enable. Drive STR1 high to turn on flash or IR pulse. An internal pulldown resistor of 300 kΩ is between STR1 and GND.
B4STR2IActive high hardware flash enable. Drive STR2 high to turn on flash or IR pulse. An internal pulldown resistor of 300 kΩ is between STR2 and GND.
C5TORCH/TXIActive high hardware torch enable or power amplifier synchronization input. Internal pulldown resistor of 300 kΩ between TORCH/TX and GND.
E3TEMP1I/OThreshold detector for NTC temperature sensing and current scale back
D3TEMP2I/O