SNVSC55 September   2025 LM51770-Q1

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 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 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 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Custom Design with WEBENCH Tools
        2. 9.2.2.2  Frequency
        3. 9.2.2.3  Feedback Divider
        4. 9.2.2.4  Inductor and Current Sense Resistor Selection
        5. 9.2.2.5  Slope Compensation
        6. 9.2.2.6  Output Capacitor
        7. 9.2.2.7  Input Capacitor
        8. 9.2.2.8  UVLO Divider
        9. 9.2.2.9  Soft-Start Capacitor
        10. 9.2.2.10 MOSFETs QH1 and QL1
        11. 9.2.2.11 MOSFETs QH2 and QL2
        12. 9.2.2.12 Output Voltage Frequency Compensation
        13. 9.2.2.13 External Component Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Bi-Directional Power Backup
      2. 9.3.2 Parallel (Multiphase) Operation
      3. 9.3.3 External Gate Driver with Logic Level High Side Gate Signals
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
        1. 9.5.1.1 Power Stage Layout
        2. 9.5.1.2 Gate Driver Layout
        3. 9.5.1.3 Controller Layout
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
      2. 10.1.2 Development Support
        1. 10.1.2.1 Custom Design with WEBENCH Tools
    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
    1.     86

9.2.2.13 External Component Selection

Table 9-3 Components Example for Typical Application
Reference Description Part Number
RCOMP 1.91kΩ
CCOMP1 47nF, 50V Ceramic Capacitor
CCOMP2 1.8nF, 50V Ceramic Capacitor
CSS 18nF, 50V Ceramic Capacitor or 20nF, 80V Ceramic Capacitor GCM21B5C1H183JA16 or GCM21B5C1K203JA16
RFB,top 71.5kΩ
RFB,bot 4.7kΩ
RnFLT 10kΩ
RIMONOUT 82kΩ
CIN1 2× 10µF, 50V Ceramic Capacitor GCM32EC71H106KA03
CIN2 1× 100μF, 63V Aluminum Capacitor PCR1J101MCL1GS
M1 N-Channel 40V MOSFET, RDS(on) = 4.3mΩ SQJ422EP
M2 N-Channel 40V MOSFET, RDS(on) = 4.3mΩ SQJ422EP
M3 N-Channel 40V MOSFET, RDS(on) = 4.3mΩ SQJ422EP
M4 N-Channel 40V MOSFET, RDS(on) = 4.3mΩ SQJ422EP
RCS

1.00mΩ

 3xKRL2012E-C-R003-F
L1 1.8μH, DCR = 3.2mΩ IHLP-5050FD-A1
COUT1 5× 10µF, 50V Ceramic Capacitor GCM32EC71H106KA03
COUT2 1× 100μF, 63V Aluminum Capacitor PCR1J101MCL1GS
RISNS 4mΩ KRL2012E-C-R004-F
CBST1 0.1µF, 35V Ceramic Capacitor GRT033R6YA104KE01
CBST2 0.1µF, 35V Ceramic Capacitor GRT033R6YA104KE01
CVCC 47µF, 6.3V Ceramic Capacitor GRM188R60J476ME15D
RUVLO,top 75kΩ
RUVLO,bot 20.5kΩ
RSLOPE 69.8kΩ
RCFG 13.3kΩ
RRT 75kΩ