SNVSA67B December   2016  – June 2017 LM5166

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Switching Characteristics
    7. 6.7 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  Integrated Power MOSFETs
      2. 7.3.2  Selectable PFM or COT Mode Converter Operation
        1. 7.3.2.1 PFM Mode Operation
        2. 7.3.2.2 COT Mode Operation
          1. 7.3.2.2.1 Ripple Generation Methods
          2. 7.3.2.2.2 COT Mode Light-Load Operation
      3. 7.3.3  Low Dropout Operation and 100% Duty Cycle Mode
      4. 7.3.4  Adjustable Output Voltage (FB)
      5. 7.3.5  Adjustable Current Limit
      6. 7.3.6  Precision Enable (EN) and Hysteresis (HYS)
      7. 7.3.7  Power Good (PGOOD)
      8. 7.3.8  Configurable Soft Start (SS)
      9. 7.3.9  Short-Circuit Operation
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode - COT
      4. 7.4.4 Sleep Mode - COT
      5. 7.4.5 Active Mode - PFM
      6. 7.4.6 Sleep Mode - PFM
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1: Wide VIN, Low IQ, High-Efficiency COT Converter Rated at 5 V, 500 mA
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Feedback Resistors - RFB1, RFB2
          3. 8.2.1.2.3 Switching Frequency - RT
          4. 8.2.1.2.4 Filter Inductance - LF
          5. 8.2.1.2.5 Output Capacitors - COUT
          6. 8.2.1.2.6 Ripple Generation Network - RESR, CFF
          7. 8.2.1.2.7 Input Capacitor - CIN
          8. 8.2.1.2.8 Soft-Start Capacitor - CSS
          9. 8.2.1.2.9 Application Curves
      2. 8.2.2 Design 2: Wide VIN, Low IQ COT Converter Rated at 3.3 V, 500 mA
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Feedback Resistors - RFB1, RFB2
          2. 8.2.2.2.2 Switching Frequency - RT
          3. 8.2.2.2.3 Filter Inductance - LF
          4. 8.2.2.2.4 Output Capacitors - COUT
          5. 8.2.2.2.5 Ripple Generation Network - RESR
          6. 8.2.2.2.6 Input Capacitor - CIN
          7. 8.2.2.2.7 Soft-Start Capacitor - CSS
          8. 8.2.2.2.8 Application Curves
      3. 8.2.3 Design 3: High-Density PFM Converter Rated at 3.3 V, 0.3 A
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Peak Current Limit Setting - RILIM
          2. 8.2.3.2.2 Switching Frequency - LF
          3. 8.2.3.2.3 Output Capacitors - COUT
          4. 8.2.3.2.4 Input Capacitor - CIN
          5. 8.2.3.2.5 Application Curves
      4. 8.2.4 Design 4: Wide VIN, Low IQ PFM Converter Rated at 5 V, 500 mA
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
          1. 8.2.4.2.1 Feedback Resistors - RFB1, RFB2
          2. 8.2.4.2.2 Peak Current Limit Setting - RILIM
          3. 8.2.4.2.3 Switching Frequency - LF
          4. 8.2.4.2.4 Output Capacitors - COUT
          5. 8.2.4.2.5 Input Capacitor - CIN
        3. 8.2.4.3 Application Curves
      5. 8.2.5 Design 5: 12-V, 300-mA COT Converter Operating From 24-V or 48-V Input
        1. 8.2.5.1 Design Requirements
        2. 8.2.5.2 Detailed Design Procedure
          1. 8.2.5.2.1 Peak Current Limit Setting - RILIM
          2. 8.2.5.2.2 Switching Frequency - RRT
          3. 8.2.5.2.3 Inductor - LF
          4. 8.2.5.2.4 Input and Output Capacitors - CIN, COUT
          5. 8.2.5.2.5 Feedback Resistors - RFB1, RFB2
          6. 8.2.5.2.6 Ripple Generation Network - RA, CA, CB
          7. 8.2.5.2.7 Undervoltage Lockout Setpoint - RUV1, RUV2, RHYS
          8. 8.2.5.2.8 Soft Start - CSS
        3. 8.2.5.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact PCB Layout for EMI Reduction
      2. 10.1.2 Feedback Resistors
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
      3. 11.1.3 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

1 Features

  • Wide Input Voltage Range of 3 V to 65 V
  • 9.7-µA No-Load Quiescent Current
  • –40°C to 150°C Junction Temperature Range
  • Fixed (3.3-V, 5-V) or Adjustable VOUT Options
  • Meets EN55022 / CISPR 22 EMI Standards
  • Integrated 1-Ω PFET Buck Switch
    • Supports 100% Duty Cycle for Low Dropout
  • Integrated 0.5-Ω NFET Synchronous Rectifier
    • Eliminates External Schottky Diode
  • Programmable Peak Current Limit Supports:
    • 500-mA, 300-mA, or 200-mA Loads
  • Selectable PFM or COT Mode Operation
  • 1.223-V ±1.2% Internal Voltage Reference
  • Switching Frequency up to 600 kHz
  • 900-µs Internal or Externally-Adjustable Soft Start
  • Diode Emulation and Pulse Skipping for Ultra-High Light-Load Efficiency
  • No Loop Compensation or Bootstrap Components
  • Precision Enable and Input UVLO With Hysteresis
  • Open-Drain Power Good Indicator
  • Thermal Shutdown Protection With Hysteresis
  • Pin-to-Pin Compatible With the LM5165
  • 10-Pin, 3-mm × 3-mm VSON Package
  • Create a Custom Regulator Design Using WEBENCH® Power Designer

2 Applications

  • Factory and Building Automation
  • Automotive and Battery-Powered Applications
  • High Voltage LDO Replacement
  • Low Power Bias Supplies

3 Description

The LM5166 is a compact, easy-to-use, 3-V to 65-V, ultra-low IQ synchronous buck converter with high efficiency over wide input voltage and load current ranges. With integrated high-side and low-side power MOSFETs, up to 500 mA of output current can be delivered at fixed output voltages of 3.3 V or 5 V, or an adjustable output. The converter is designed to simplify implementation while providing options to optimize the performance for the target application. Pulse frequency modulation (PFM) mode is selected for optimal light-load efficiency or constant on-time (COT) control for nearly constant operating frequency. Both control schemes do not require loop compensation while providing excellent line and load transient response and short PWM on-time for large step-down conversion ratios.

The high-side P-channel MOSFET can operate at 100% duty cycle for lowest dropout voltage and does not require a bootstrap capacitor for gate drive. Also, the current limit setpoint is adjustable to optimize inductor selection for a particular load current requirement. Selectable and adjustable start-up timing options include minimum delay (no soft start), internally fixed (900 μs), and externally programmable soft start using a capacitor. An open-drain PGOOD indicator can be used for sequencing, fault reporting, and output voltage monitoring. The LM5166 is available in a 10-pin VSON package with 0.5-mm pin pitch.

Device Information(1)

PART NUMBER OUTPUT PACKAGE
LM5166 Adjustable VSON (10)
LM5166X 5-V fixed
LM5166Y 3.3-V fixed
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical COT Mode Application

LM5166 Typ_App_COT1_SNVSA67.gif

Typical COT Mode Application Efficiency

LM5166 D003_SNVSA67.gif