SNVSCD4 September   2024 LM70660 , LM706A0

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 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  Input Voltage Range (VIN)
      2. 6.3.2  High-Voltage Bias Supply Regulator (VCC, BIAS, VDDA)
      3. 6.3.3  Enable (EN)
      4. 6.3.4  Power-Good Monitor (PG)
      5. 6.3.5  Switching Frequency (RT)
      6. 6.3.6  Dual Random Spread Spectrum (DRSS)
      7. 6.3.7  Soft Start
      8. 6.3.8  Output Voltage Setpoint (FB)
      9. 6.3.9  Minimum Controllable On-Time
      10. 6.3.10 Error Amplifier and PWM Comparator (FB, EXTCOMP)
      11. 6.3.11 Slope Compensation
      12. 6.3.12 Shunt Current Sensing
      13. 6.3.13 Hiccup Mode Current Limiting
      14. 6.3.14 Device Configuration (CONFIG)
      15. 6.3.15 Single-Output Dual-Phase Operation
      16. 6.3.16 Pulse Frequency Modulation (PFM) / Synchronization
      17. 6.3.17 Thermal Shutdown (TSD)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Standby Mode
      3. 6.4.3 Active Mode
      4. 6.4.4 Sleep Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power Train Components
        1. 7.1.1.1 Buck Inductor
        2. 7.1.1.2 Output Capacitors
        3. 7.1.1.3 Input Capacitors
        4. 7.1.1.4 EMI Filter
      2. 7.1.2 Error Amplifier and Compensation
      3. 7.1.3 Maximum Ambient Temperature
        1. 7.1.3.1 Derating Curves
    2. 7.2 Typical Applications
      1. 7.2.1 Design 1 – High Efficiency, Wide Input, 400kHz Synchronous Buck Regulator
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 7.2.1.2.2 Custom Design With Excel Quickstart Tool
          3. 7.2.1.2.3 Buck Inductor
          4. 7.2.1.2.4 Current-Sense Resistance
          5. 7.2.1.2.5 Output Capacitors
          6. 7.2.1.2.6 Input Capacitors
          7. 7.2.1.2.7 Frequency Set Resistor
          8. 7.2.1.2.8 Feedback Resistors
          9. 7.2.1.2.9 Compensation Components
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Design 2 – High Efficiency 24V to 3.3V 400kHz Synchronous Buck Regulator
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Thermal Design and Layout
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
        1. 8.2.1.1 PCB Layout Resources
        2. 8.2.1.2 Thermal Design Resources
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Tape and Reel Information

7.2.2.3 Application Curves

VOUT = 3.3V FSW = 400kHz FPWM
Figure 7-24 Efficiency versus IOUT, Linear Scale
VOUT = 3.3V FSW = 400kHz PFM
Figure 7-26 Efficiency versus IOUT, Linear Scale
VIN = 24V
VOUT = 3.3V		 IOUT = 10A
FSW = 400kHz		 FPWM
Figure 7-28 Full Load Switching
VIN stepped to 24V
VOUT = 3.3V		 IOUT = 10A (resistive)
FSW = 400kHz		 FPWM
Figure 7-30 VIN Start-Up Characteristic
VIN = 24V
VOUT = 3.3V		 FPWM
Figure 7-32 Load Transient, 0A to 5A
VIN = 24V
VOUT = 3.3V		 IOUT = 10A (resistive)
FSW = 400kHz		 FPWM
Figure 7-34 Short-Circuit Recovery
VOUT = 3.3V FSW = 400kHz FPWM
Figure 7-25 Efficiency versus IOUT, Log Scale
VOUT = 3.3V FSW = 400kHz PFM
Figure 7-27 Efficiency versus IOUT, Log Scale
VIN = 24V
VOUT = 3.3V		 No load PFM
Figure 7-29 PFM Switching
VIN = 24V
VOUT = 3.3V		 IOUT = 10A (resistive)
FSW = 400kHz		 FPWM
Figure 7-31 EN Start-Up and Shutdown Characteristic
VIN = 24V
VOUT = 3.3V		 FPWM
Figure 7-33 Load Transient, 5A to 10A
Fc = crossover frequency, PM = phase margin.
VIN = 24V
VOUT = 3.3V		 FSW = 400kHz
IOUT = 10A (resistive)		 FPWM
L = 2.2μH
Figure 7-35 Bode Plot