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

7.2.4 Application Curves

Ambient temperature is 25°C, input voltage is 3.6 V, EN = VIN, CIN = 2 × 10 µF, COUT = 2 × 10 µF and L = 1 µH, unless otherwise noted.
Ambient temperature is 25°C, input voltage is 3.6 V, EN = VIN, CIN = 2 × 10 µF, COUT = 2 × 10 µF and L = 1 µH, unless otherwise noted.LM3645 2-MHz LED Efficiency vs Input Voltage
ILED = 1.5 AƒSW = 2 MHzFlash
Figure 7-3 2-MHz LED Efficiency vs Input Voltage. Ambient temperature is 25°C, input voltage is 3.6 V, EN = VIN, CIN = 2 × 10 µF, COUT = 2 × 10 µF and L = 1 µH, unless otherwise noted.
LM3645 LED Efficiency vs Input Voltage
ILED = 1.5 AƒSW = 2 MHzFlash
VLED = 3.55 V
Figure 7-5 LED Efficiency vs Input Voltage
LM3645 4-MHz LED Efficiency vs Input Voltage
ILED = 1.5 AƒSW = 2 MHzFlash
Figure 7-4 4-MHz LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED = 1.5 AƒSW = 4 MHzFlash
VLED = 3.55 V
Figure 7-6 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED = 1 AƒSW = 2 MHzFlash
VLED = 3.32 V
Figure 7-7 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED1 and LED2 = 729 mAFlash
VLED = 3.18 VƒSW = 2 MHz
Figure 7-9 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED = 179 mAƒSW = 4 MHz
VLED = 2.83 VTorch
Figure 7-11 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED1 and LED2 = 179 mAƒSW = 4 MHz
VLED = 2.83 VTorch
Figure 7-13 LED Efficiency vs Input Voltage
LM3645 Ramp Down
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 V
Figure 7-15 Ramp Down
LM3645 Ripple @ 2 MHz
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 V
Figure 7-17 Ripple @ 2 MHz
LM3645 IVFM - Ramp and Hold
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 VVIVFM = 3.2 V
Figure 7-19 IVFM - Ramp and Hold
LM3645 IVFM - Up and Down Adjust
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 VVIVFM = 3.2 V
Figure 7-21 IVFM - Up and Down Adjust
LM3645 LED Efficiency vs Input Voltage
ILED = 729 mAƒSW = 2 MHzFlash
VLED = 3.18 V
Figure 7-8 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED = 179 mATorch
VLED = 2.83 VƒSW = 2 MHz
Figure 7-10 LED Efficiency vs Input Voltage
LM3645 LED Efficiency vs Input Voltage
ILED1 and LED2 = 179 mAƒSW = 2 MHz
VLED = 2.83 VTorch
Figure 7-12 LED Efficiency vs Input Voltage
LM3645 Start-Up
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 V
Figure 7-14 Start-Up
LM3645 TX Interrupt
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 V
Figure 7-16 TX Interrupt
LM3645 Ripple @ 4 MHz
ILED1 = ILED2 = 730 mAƒSW = 4 MHz
VLED = 3.18 V
Figure 7-18 Ripple @ 4 MHz
LM3645 IVFM - Down Adjust Only
ILED1 = ILED2 = 730 mAƒSW = 2 MHz
VLED = 3.18 VVIVFM = 3.2 V
Figure 7-20 IVFM - Down Adjust Only