SNVSCW3 November   2024 LM644A2-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1. 5.1 Wettable Flanks
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage Range (VIN)
      2. 7.3.2  Enable EN Pin and Use as VIN UVLO
      3. 7.3.3  Output Voltage Selection and Soft Start
      4. 7.3.4  SYNC Allows Clock Synchronization and Mode Selection
      5. 7.3.5  Clock Locking
      6. 7.3.6  Adjustable Switching Frequency
      7. 7.3.7  Power-Good Output Voltage Monitoring
      8. 7.3.8  Internal LDO, VCC UVLO, and BIAS Input
      9. 7.3.9  Bootstrap Voltage and VCBOOT-UVLO (CB1 and CB2 Pin)
      10. 7.3.10 CONFIG Device Configuration Pin
      11. 7.3.11 Spread Spectrum
      12. 7.3.12 Soft Start and Recovery From Dropout
      13. 7.3.13 Overcurrent and Short-Circuit Protection
      14. 7.3.14 Hiccup
      15. 7.3.15 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
        1. 7.4.3.1 Peak Current Mode Operation
        2. 7.4.3.2 Auto Mode Operation
          1. 7.4.3.2.1 Diode Emulation
        3. 7.4.3.3 FPWM Mode Operation
        4. 7.4.3.4 Minimum On-time (High Input Voltage) Operation
        5. 7.4.3.5 Dropout
        6. 7.4.3.6 Recovery from Dropout
        7. 7.4.3.7 Other Fault Modes
  9. 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  Choosing the Switching Frequency
        2. 8.2.2.2  Setting the Output Voltage
        3. 8.2.2.3  Inductor Selection
        4. 8.2.2.4  Output Capacitor Selection
        5. 8.2.2.5  Input Capacitor Selection
        6. 8.2.2.6  BOOT Capacitor
        7. 8.2.2.7  VCC
        8. 8.2.2.8  CFF and RFF Selection
        9. 8.2.2.9  SYNCHRONIZATION AND MODE
        10. 8.2.2.10 External UVLO
        11. 8.2.2.11 Typical Thermal Performance
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Ground and Thermal Considerations
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.3 Application Curves

Unless otherwise specified, the following conditions apply: Device: LM644A2-Q1, VIN = 13.5V, TA = 25°C. The circuit is shown in Figure 8-1, and Figure 8-2 with the appropriate BOM from Table 8-7. No heatsink was attached during radiated emissions tests.

LM644A2-Q1 Efficiency
VOUT = 5V FSW = 400kHz Auto mode Single Output
Figure 8-9 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 400kHz FPWM mode Single Output
Figure 8-11 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 400kHz Auto mode Single Output
Figure 8-13 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz Auto mode Single Output
Figure 8-15 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz FPWM mode Single Output
Figure 8-17 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz Auto mode Single Output
Figure 8-19 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz Auto mode Dual Output
Figure 8-21 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz FPWM mode Dual Output
Figure 8-23 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz Auto mode Dual Output
Figure 8-25 Efficiency
LM644A2-Q1 Load and Line Regulation
VOUT = 3.3V FSW = 2.1MHz FPWM mode Single Output
Figure 8-27 Load and Line Regulation
LM644A2-Q1 Load and Line Regulation
VOUT = 3.3V FSW = 2.1MHz FPWM mode Dual Output
Figure 8-29 Load and Line Regulation
LM644A2-Q1 Load and Line Regulation
VOUT = 5V FSW = 2.1MHz FPWM mode Dual Output
Figure 8-31 Load and Line Regulation
LM644A2-Q1 Dropout
VOUT = 5V FSW = 400kHz FPWM mode Single Output
Figure 8-33 Dropout
LM644A2-Q1 Dropout
VOUT = 3.3V FSW = 400kHz FPWM mode Single Output
Figure 8-35 Dropout
LM644A2-Q1 Dropout Recovery
VOUT = 5V FSW = 400kHz Auto mode
IOUT = 3A VIN = 5 to 7V Single Output
Figure 8-37 Dropout Recovery
LM644A2-Q1 Start-Up With 100mA Load
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 100mA VIN = 13.5V Dual Output
Figure 8-39 Start-Up With 100mA Load
LM644A2-Q1 Short-Circuit Protection
VOUT = 3.3V FSW = 400kHz Auto mode
IOUT = 0A to short circuit VIN = 13.5V Single Output
Figure 8-41 Short-Circuit Protection
LM644A2-Q1 Short-Circuit Hiccup
VOUT = 3.3V FSW = 400kHz Auto mode
IOUT = short circuit to 0A VIN = 13.5V Single Output
Figure 8-43 Short-Circuit Hiccup
LM644A2-Q1 Load Transient
VOUT = 5V FSW = 2.1MHz FPWM mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-45 Load Transient
LM644A2-Q1 Load Transient
VOUT = 5V FSW = 400kHz Auto mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-47 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 2.1MHz FPWM mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-49 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 2.1MHz FPWM mode
IOUT = 3A to 6A to 3A VIN = 13.5V Dual Output
Figure 8-51 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 400kHz Auto mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-53 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 4A to 12A to 4A VIN = 13.5V Single Output
Figure 8-55 Load Transient
LM644A2-Q1 Single Output Monopole Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 150kHz to 30MHz
Figure 8-57 Single Output Monopole Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Single Output Log Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 200MHz to 1000MHz
Figure 8-59 Single Output Log Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Single Output Conducted Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 150kHz to 30MHz
Figure 8-61 Single Output Conducted Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Monopole Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 150kHz to 30MHz
Figure 8-63 Dual Output Monopole Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Log Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 200MHz to 1000MHz
Figure 8-65 Dual Output Log Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Conducted Emissions versus CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 150kHz to 30MHz
Figure 8-67 Dual Output Conducted Emissions versus CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Recommended Input EMI FilterFigure 8-69 Recommended Input EMI Filter
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 400kHz Auto mode Single Output
Figure 8-10 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 400kHz Auto mode Single Output
Figure 8-12 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 400kHz FPWM mode Single Output
Figure 8-14 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz Auto mode Single Output
Figure 8-16 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz Auto mode Single Output
Figure 8-18 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz FPWM mode Single Output
Figure 8-20 Efficiency
LM644A2-Q1 Efficiency
VOUT = 5V FSW = 2.1MHz Auto mode Dual Output
Figure 8-22 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz Auto mode Dual Output
Figure 8-24 Efficiency
LM644A2-Q1 Efficiency
VOUT = 3.3V FSW = 2.1MHz FPWM mode Dual Output
Figure 8-26 Efficiency
LM644A2-Q1 Load and Line Regulation
VOUT = 3.3V FSW = 2.1MHz Auto mode Single Output
Figure 8-28 Load and Line Regulation
LM644A2-Q1 Load and Line Regulation
VOUT = 3.3V FSW = 2.1MHz Auto mode Dual Output
Figure 8-30 Load and Line Regulation
LM644A2-Q1 Load and Line Regulation
VOUT = 5V FSW = 2.1MHz Auto mode Dual Output
Figure 8-32 Load and Line Regulation
LM644A2-Q1 Dropout
VOUT = 5V FSW = 2.1MHz FPWM mode Single Output
Figure 8-34 Dropout
LM644A2-Q1 Dropout
VOUT = 3.3V FSW = 2.1MHz FPWM mode Single Output
Figure 8-36 Dropout
LM644A2-Q1 Start-Up With 100mA Load
VOUT = 5V FSW = 400kHz FPWM mode
IOUT = 100mA VIN = 13.5V Dual Output
Figure 8-38 Start-Up With 100mA Load
LM644A2-Q1 Start-Up With 12A Load
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 12A VIN = 13.5V Single Output
Figure 8-40 Start-Up With 12A Load
LM644A2-Q1 Short-Circuit Protection
VOUT1 = 3.3V FSW = 400kHz Auto mode
IOUT = 0A to short circuit VIN = 13.5V Dual Output
Figure 8-42 Short-Circuit Protection
LM644A2-Q1 Short-Circuit Hiccup
VOUT = 3.3V FSW = 400kHz Auto mode
IOUT = short circuit to 0A VIN = 13.5V Dual Output
Figure 8-44 Short-Circuit Hiccup
LM644A2-Q1 Load Transient
VOUT = 5V FSW = 400kHz FPWM mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-46 Load Transient
LM644A2-Q1 Load Transient
VOUT = 5V FSW = 400kHz FPWM mode
IOUT = 3A to 6A to 3A VIN = 13.5V Dual Output
Figure 8-48 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 2.1MHz Auto mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-50 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 100mA to 6A to 100mA VIN = 13.5V Dual Output
Figure 8-52 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 3A to 6A to 3A VIN = 13.5V Dual Output
Figure 8-54 Load Transient
LM644A2-Q1 Load Transient
VOUT = 3.3V FSW = 400kHz FPWM mode
IOUT = 6A to 12A to 4A VIN = 13.5V Single Output
Figure 8-56 Load Transient
LM644A2-Q1 Single Output Bicon Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 30MHz to 200MHz
Figure 8-58 Single Output Bicon Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Single Output Horn Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 1000MHz to 2500MHz
Figure 8-60 Single Output Horn Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Single Output Conducted Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 30MHz to 108MHz
Figure 8-62 Single Output Conducted Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Bicon Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 30MHz to 200MHz
Figure 8-64 Dual Output Bicon Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Horn Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 1000MHz to 2500MHz
Figure 8-66 Dual Output Horn Radiated Emissions vs CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
LM644A2-Q1 Dual Output Conducted Emissions versus CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
VOUT = 3.3V FSW = 2100kHz IOUT = 12A
Frequency tested: 30MHz to 108MHz
Figure 8-68 Dual Output Conducted Emissions versus CISPR25 Class 5 Limits (Orange: Peak Signal, Red: Average Signal, Green: Quasi-Peak Signal)
Table 8-3 BOM for Typical Application Curves
VOUT FREQUENCY RFBB COUT EACH PHASE CIN + CHF EACH PHASE L CFFFOR ADJUSTABLE OUTPUT
3.3V 400kHz 32.4kΩ 47 + 22µF 2 × 10µF + 1 × 100nF 2.8µH 10pF
3.3V 2200kHz 32.4kΩ 47 + 22µF 2 × 10µF + 1 × 100nF 1µH 10pF
5V 400kHz 19.1kΩ 47 + 22µF 2 × 10µF + 1 × 100nF 2.8µH 10pF
5V 2200kHz 19.1kΩ 47 + 22µF 2 × 10µF + 1 × 100nF 1µH 10pF