SNVSCL2 December   2024 LM51770

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Gate Driver Rise Time and Fall Time
    2. 7.2 Gate Driver Dead (Transition) Time
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Power-On Reset (POR System)
      2. 8.3.2  Buck-Boost Control Scheme
        1. 8.3.2.1 Boost Mode
        2. 8.3.2.2 Buck Mode
        3. 8.3.2.3 Buck-Boost Mode
      3. 8.3.3  Power Save Mode
      4. 8.3.4  Supply Voltage Selection – VMAX Switch
      5. 8.3.5  Enable and Undervoltage Lockout
      6. 8.3.6  Oscillator Frequency Selection
      7. 8.3.7  Frequency Synchronization
      8. 8.3.8  Voltage Regulation Loop
      9. 8.3.9  Output Voltage Tracking
      10. 8.3.10 Slope Compensation
      11. 8.3.11 Configurable Soft Start
      12. 8.3.12 Peak Current Sensor
      13. 8.3.13 Current Monitoring and Current Limit Control Loop
      14. 8.3.14 Short Circuit - Hiccup Protection
      15. 8.3.15 nFLT Pin and Protections
      16. 8.3.16 Device Configuration Pin
      17. 8.3.17 Dual Random Spread Spectrum – DRSS
      18. 8.3.18 Gate Driver
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Detailed Design Procedure
        1. 9.2.1.1  Custom Design with WEBENCH Tools
        2. 9.2.1.2  Frequency
        3. 9.2.1.3  Feedback Divider
        4. 9.2.1.4  Inductor and Current Sense Resistor Selection
        5. 9.2.1.5  Slope Compensation
        6. 9.2.1.6  Output Capacitor
        7. 9.2.1.7  Input Capacitor
        8. 9.2.1.8  UVLO Divider
        9. 9.2.1.9  Soft-Start Capacitor
        10. 9.2.1.10 MOSFETs QH1 and QL1
        11. 9.2.1.11 MOSFETs QH2 and QL2
        12. 9.2.1.12 Frequency Compensation
        13. 9.2.1.13 External Component Selection
      2. 9.2.2 Application Curves
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Power Stage Layout
      2. 11.1.2 Gate Driver Layout
      3. 11.1.3 Controller Layout
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Development Support
        1. 12.1.2.1 Custom Design with WEBENCH Tools
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information
    1.     80

Package Options

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

6.6 Typical Characteristics

The following conditions apply (unless otherwise noted): TJ = 25°C; V(VCC) = 5V

LM51770 Switching Frequency Versus RT ResistanceFigure 6-1 Switching Frequency Versus RT Resistance
LM51770 VIN LDO - VCC Voltage versus VCC Load CurrentFigure 6-3 VIN LDO - VCC Voltage versus VCC Load Current
LM51770 BIAS LDO - VCC Voltage versus VCC Load CurrentFigure 6-5 BIAS LDO - VCC Voltage versus VCC Load Current
LM51770 FB Pin Reference Voltage versus TemperatureFigure 6-7 FB Pin Reference Voltage versus Temperature
LM51770 CSA Input Current versus Temperature Figure 6-9 CSA Input Current versus Temperature
LM51770 Minimum Controllable On-time versus Switching FrequencyFigure 6-11 Minimum Controllable On-time versus Switching Frequency
LM51770 UVLO Threshold Voltage versus Temperature Figure 6-13 UVLO Threshold Voltage versus Temperature
LM51770 Shutdown Current into VIN versus Temperature VEN/UVLO = 0V ,V(VIN) = 12V,V(BIAS) = 0VFigure 6-15 Shutdown Current into VIN versus Temperature
VEN/UVLO = 0V ,V(VIN) = 12V,V(BIAS) = 0V
LM51770 Shutdown Current into VIN versus Temperature VEN/UVLO = 0 V ,V(BIAS) = 12 V, V(VIN) = 3.5 VFigure 6-17 Shutdown Current into VIN versus Temperature
VEN/UVLO = 0 V ,V(BIAS) = 12 V, V(VIN) = 3.5 V
LM51770 Quiescent Current into BIAS versus Pin Voltage VEN/UVLO = 3.3 V, V(VIN) = 12 VFigure 6-19 Quiescent Current into BIAS versus Pin Voltage
VEN/UVLO = 3.3 V, V(VIN) = 12 V
LM51770 Soft-Start current versus Temperature Figure 6-21 Soft-Start current versus Temperature
LM51770 Switching Frequency Versus Temperature R(RT) = 75 kΩFigure 6-2 Switching Frequency Versus Temperature R(RT) = 75 kΩ
LM51770 VIN LDO - VCC Voltage versus VIN Voltage I(VCC) = 20 mAFigure 6-4 VIN LDO - VCC Voltage versus VIN Voltage
I(VCC) = 20 mA
LM51770 BIAS LDO - VCC Voltage versus BIAS Voltage I(VCC) = 50 mAFigure 6-6 BIAS LDO - VCC Voltage versus BIAS Voltage
I(VCC) = 50 mA
LM51770 Current Limit Threshold Voltage Versus TemperatureFigure 6-8 Current Limit Threshold Voltage Versus Temperature
LM51770 CSB Input Current versus Temperature Figure 6-10 CSB Input Current versus Temperature
LM51770 Minimum Controllable Off-time versus Switching FrequencyFigure 6-12 Minimum Controllable Off-time versus Switching Frequency
LM51770 Shutdown Current into VIN versus Pin Voltage VEN/UVLO = 0 V ,V(VIN) = 12 V, V(BIAS) = 0 VFigure 6-14 Shutdown Current into VIN versus Pin Voltage
VEN/UVLO = 0 V ,V(VIN) = 12 V, V(BIAS) = 0 V
LM51770 Shutdown Current into BIAS versus Pin Voltage VEN/UVLO = 0 V ,V(VIN) = 12 V, V(VIN) = 3.5 VFigure 6-16 Shutdown Current into BIAS versus Pin Voltage
VEN/UVLO = 0 V ,V(VIN) = 12 V, V(VIN) = 3.5 V
LM51770 Standby Current into VIN versus Temperature VEN/UVLO = 0.8 V, V(VIN) = 12 VFigure 6-18 Standby Current into VIN versus Temperature
VEN/UVLO = 0.8 V, V(VIN) = 12 V
LM51770 Quiescent Current into BIAS versus Temperature VEN/UVLO = 3.3 V, V(VIN) = 12 VFigure 6-20 Quiescent Current into BIAS versus Temperature
VEN/UVLO = 3.3 V, V(VIN) = 12 V
LM51770 Hysteresis Current on EN/UVLO versus Temperature Figure 6-22 Hysteresis Current on EN/UVLO versus Temperature