SNVSBZ3 June   2021 LM5168-Q1

ADVANCE INFORMATION  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Control Architecture
      2. 8.3.2  Internal VCC Regulator and Bootstrap Capacitor
      3. 8.3.3  Internal Soft Start
      4. 8.3.4  On-Time Generator
      5. 8.3.5  Current Limit
      6. 8.3.6  N-Channel Buck Switch and Driver
      7. 8.3.7  Synchronous Rectifier
      8. 8.3.8  Enable/Undervoltage Lockout (EN/UVLO)
      9. 8.3.9  Power Good (PGOOD)
      10. 8.3.10 Thermal Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
      3. 8.4.3 Sleep Mode
  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  Switching Frequency (RT)
        2. 9.2.2.2  Transformer Selection
        3. 9.2.2.3  Output Capacitor Selection
        4. 9.2.2.4  Secondary Output Diode
        5. 9.2.2.5  Regulation Comparator
        6. 9.2.2.6  Input Capacitor
        7. 9.2.2.7  Type-3 Ripple Network
        8. 9.2.2.8  Minimum Secondary Output Load
        9. 9.2.2.9  Example Design Summary
        10. 9.2.2.10 Thermal Considerations
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Compact PCB Layout for EMI Reduction
      2. 11.1.2 Feedback Resistors
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Description

The LM5169-Q1 and LM5168-Q1 synchronous buck converters are designed to regulate over a wide input voltage range, minimizing the need for external surge suppression components. A minimum controllable on time of 50 ns facilitates large step-down conversion ratios, enabling the direct step-down from a 48-V nominal input to low-voltage rails for reduced system complexity and solution cost. The LM5169-Q1 operates during input voltage dips as low as 6 V, at nearly 100% duty cycle if needed, making it an excellent choice for wide input supply range industrial and high cell count battery pack applications.

With integrated high-side and low-side power MOSFETs, the LM5169-Q1 delivers up to 0.65-A of output current and the LM5168-Q1 delivers up to 0.3-A of output current. A constant on time (COT) control architecture provides nearly constant switching frequency with excellent load and line transient response. The LM5169-Q1 is available in FPWM or Auto mode operation. FPWM mode ensures forced CCM operation across the entire load range supporting isolated Fly-buck operation. Auto mode enables ultra-low IQ and diode emulation mode operation for high light-load efficiency.

Device Information
PART NUMBER PACKAGE(1) BODY SIZE (NOM)
LM5169-Q1 SO PowerPAD (8) 4.89 mm × 3.90 mm
LM5168-Q1
For all available packages, see the orderable addendum at the end of the data sheet.
GUID-43DA543F-FC83-488D-A322-AFDB7C343EEB-low.gifTypical Buck Application Circuit
GUID-2812ACA6-4747-4412-B794-895C7AB281EB-low.gifTypical Fly-Buck Application Circuit