SNVSA46B June   2014  – January 2018 LM46001

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Radiated Emission Graph VOUT = 3.3 V, VIN = 24 V, FS= 500 kHz, IOUT = 1 A
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Switching Characteristics
    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  Fixed-Frequency, Peak-Current Mode Controlled Step-Down Regulator
      2. 7.3.2  Light Load Operation
      3. 7.3.3  Adjustable Output Voltage
      4. 7.3.4  Enable (ENABLE)
      5. 7.3.5  VCC, UVLO, and BIAS
      6. 7.3.6  Soft-Start and Voltage Tracking (SS/TRK)
      7. 7.3.7  Switching Frequency (RT) and Synchronization (SYNC)
      8. 7.3.8  Minimum ON-Time, Minimum OFF-Time and Frequency Foldback at Dropout Conditions
      9. 7.3.9  Internal Compensation and CFF
      10. 7.3.10 Bootstrap Voltage (CBOOT)
      11. 7.3.11 Power Good (PGOOD)
      12. 7.3.12 Overcurrent and Short-Circuit Protection
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Stand-by Mode
      3. 7.4.3 Active Mode
      4. 7.4.4 CCM Mode
      5. 7.4.5 Light Load Operation
      6. 7.4.6 Self-Bias Mode
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Output Voltage Setpoint
        3. 8.2.2.3  Switching Frequency
        4. 8.2.2.4  Input Capacitors
        5. 8.2.2.5  Inductor Selection
        6. 8.2.2.6  Output Capacitor Selection
        7. 8.2.2.7  Feed-Forward Capacitor
        8. 8.2.2.8  Bootstrap Capacitors
        9. 8.2.2.9  VCC Capacitor
        10. 8.2.2.10 BIAS Capacitors
        11. 8.2.2.11 Soft-Start Capacitors
        12. 8.2.2.12 Undervoltage Lockout Setpoint
        13. 8.2.2.13 PGOOD
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact Layout for EMI Reduction
      2. 10.1.2 Ground Plane and Thermal Considerations
      3. 10.1.3 Feedback Resistors
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    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

6.8 Typical Characteristics

Unless otherwise specified, VIN = 24 V, VOUT = 3.3 V, FS = 500 kHz, L = 18 µH, COUT = 100 µF, CFF = 33 pF. See Application Curves for bill of materials (BOM) for other VOUT and FS combinations.
LM46001 C002_Eff_46001_3p3V500k.png
VOUT = 3.3 V FS = 500 kHz
Figure 1. Efficiency
LM46001 C004_Eff_46001_5V200k.png
VOUT = 5 V FS = 200 kHz
Figure 3. Efficiency
LM46001 C007_Eff_46001_12V500k.png
VOUT = 12 V FS = 500 kHz
Figure 5. Efficiency
LM46001 C012_Reg_46001_3p3V500k.png
VOUT = 3.3 V FS = 500 kHz
Figure 7. VOUT Regulation
LM46001 C014_Reg_46001_5V200k.png
VOUT = 5 V FS = 200 kHz
Figure 9. VOUT Regulation
LM46001 C017_Reg_46001_12V500k.png
VOUT = 12 V FS = 500 kHz
Figure 11. VOUT Regulation
LM46001 C022_DO_46001_3p3V500k.png
VOUT = 3.3 V FS = 500 kHz
Figure 13. Dropout Curve
LM46001 C024_DO_46001_5V200k.png
VOUT = 5 V FS = 200 kHz
Figure 15. Dropout Curve
LM46001 C027_DO_46001_12V500k.png
VOUT = 12 V FS = 500 kHz
Figure 17. Dropout Curve
LM46001 46001_3V3_500kHz_Freq_Drop.png
VOUT = 3.3 V FS = 500 kHz
Figure 19. Switching Frequency vs VIN in Dropout Operation
LM46001 LM46001_3p3V_500k_Radiated.gif
VOUT = 3.3 V FS = 500 kHz IOUT = 1 A
Measured on the LM46001PWPEVM with default BOM. No input filter used.
Figure 21. Radiated EMI Curve
LM46001 LM46001_3p3_500k_Conducted.gif
VOUT = 3.3 V FS = 500 kHz IOUT = 1 A
Measured on LM46001PWPEVM with default BOM. EVM input filter: Lin = 1 µH Cd = 47 µF CIN4 = 68 µF
Figure 23. Conducted EMI Curve
LM46001 Gen_Curve_On_Resistance.png
Figure 25. High-Side and Low-side On Resistance vs Junction Temperature
LM46001 Gen_Curve_EN_Threshold.png
Figure 27. Enable Threshold vs Junction Temperature
LM46001 Gen_Curve_PG_Threshold.png
Figure 29. PGOOD Threshold vs Junction Temperature
LM46001 Gen_Curve_46001Curr_Lim.png
VIN = 24 V VOUT = 3.3 V FS = 500 kHz
Figure 31. Peak and Valley Current Limits vs Junction Temperature
LM46001 C003_Eff_46001_5V500k.png
VOUT = 5 V FS = 500 kHz
Figure 2. Efficiency
LM46001 C005_Eff_46001_5V1M.png
VOUT = 5 V FS = 1 MHz
Figure 4. Efficiency
LM46001 C008_Eff_46001_24V500k.png
VOUT = 24 V FS = 500 kHz
Figure 6. Efficiency
LM46001 C013_Reg_46001_5V500k.png
VOUT = 5 V FS = 500 kHz
Figure 8. VOUT Regulation
LM46001 C015_Reg_46001_5V1M.png
VOUT = 5 V FS = 1 MHz
Figure 10. VOUT Regulation
LM46001 C018_Reg_46001_24V500k.png
VOUT = 24 V FS = 500 kHz
Figure 12. VOUT Regulation
LM46001 C023_DO_46001_5V500k.png
VOUT = 5 V FS = 500 kHz
Figure 14. Dropout Curve
LM46001 C025_DO_46001_5V1M.png
VOUT = 5 V FS = 1 MHz
Figure 16. Dropout Curve
LM46001 C028_DO_46001_24V500k.png
VOUT = 24 V FS = 500 kHz
Figure 18. Dropout Curve
LM46001 46001_5V_1MHz_Freq_Drop.png
VOUT = 5 V FS = 1 MHz
Figure 20. Switching Frequency vs VIN in Dropout Operation
LM46001 LM46001_5V_500k_Radiated.gif
VOUT = 5 V FS = 500 kHz IOUT = 1 A
Measured on the LM46001PWPEVM with L = 27 µH, COUT = 66 µF, CFF = 33 pF. No input filter used.
Figure 22. Radiated EMI Curve
LM46001 LM46001_5_500k_Conducted.gif
VOUT = 5 V FS = 500 kHz IOUT = 1 A
Measured on LM46001PWPEVM with L = 27 µH, COUT = 66 µF, CFF = 33 pF. EVM input filter Lin = 1 µH Cd = 47 µF CIN4 = 68 µF
Figure 24. Conducted EMI Curve
LM46001 Gen_Curve_Shdn_Current.png
Figure 26. Shutdown Current vs Junction Temperature
LM46001 Gen_Curve_EN_Leakage_Curr.png
Figure 28. Enable Leakage Current vs
Junction Temperature
LM46001 Gen_Curve_FB_Voltage.png
Figure 30. Feedback Voltage vs Junction Temperature
LM46001 Gen_Curve_46001Iq.png
i.
VOUT = 3.3 V FS = 500 kHz IOUT = 0 A
Figure 32. Operating IQ vs VIN with BIAS Connected to VOUT