SNVSAH5 September 2017 LM73605 , LM73606

PRODUCTION DATA. 

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1Absolute Maximum Ratings
    2. 6.2ESD Ratings
    3. 6.3Recommended Operating Conditions
    4. 6.4Thermal Information
    5. 6.5Electrical Characteristics
    6. 6.6Timing Characteristics
    7. 6.7Switching Characteristics
    8. 6.8System Characteristics
    9. 6.9Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1 Synchronous Step-Down Regulator
      2. 7.3.2 Auto Mode and FPWM Mode
      3. 7.3.3 Fixed-Frequency Peak Current-Mode Control
      4. 7.3.4 Adjustable Output Voltage
      5. 7.3.5 Enable and UVLO
      6. 7.3.6 Internal LDO, VCC_UVLO, and BIAS Input
      7. 7.3.7 Soft Start and Voltage Tracking
      8. 7.3.8 Adjustable Switching Frequency
      9. 7.3.9 Frequency Synchronization and Mode Setting
      10. 7.3.10Internal Compensation and CFF
      11. 7.3.11Bootstrap Capacitor and VBOOT-UVLO
      12. 7.3.12Power-Good and Overvoltage Protection
      13. 7.3.13Overcurrent and Short-Circuit Protection
      14. 7.3.14Thermal Shutdown
    4. 7.4Device Functional Modes
      1. 7.4.1Shutdown Mode
      2. 7.4.2Standby Mode
      3. 7.4.3Active Mode
        1. 7.4.3.1CCM Mode
        2. 7.4.3.2DCM Mode
        3. 7.4.3.3PFM Mode
        4. 7.4.3.4Fault Protection Mode
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Application
      1. 8.2.1Design Requirements
      2. 8.2.2Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Setpoint
        3. 8.2.2.3 Switching Frequency
        4. 8.2.2.4 Input Capacitors
        5. 8.2.2.5 Inductor Selection
        6. 8.2.2.6 Output Capacitor Selection
        7. 8.2.2.7 Feed-Forward Capacitor
        8. 8.2.2.8 Bootstrap Capacitors
        9. 8.2.2.9 VCC Capacitor
        10. 8.2.2.10BIAS
        11. 8.2.2.11Soft Start
        12. 8.2.2.12Undervoltage Lockout Setpoint
        13. 8.2.2.13PGOOD
      3. 8.2.3Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
      1. 10.1.1Layout For EMI Reduction
      2. 10.1.2Ground Plane
      3. 10.1.3Optimize Thermal Performance
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Device Support
      1. 11.1.1Third-Party Products Disclaimer
      2. 11.1.2Custom Design With WEBENCH® Tools
    2. 11.2Related Documentation
    3. 11.3Related Links
    4. 11.4Receiving Notification of Documentation Updates
    5. 11.5Community Resources
    6. 11.6Trademarks
    7. 11.7Electrostatic Discharge Caution
    8. 11.8Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Features

  • Synchronous Rectification
  • Wettable Flanks QFN Package (WQFN)
  • Low Quiescent Current
    • 0.8 µA in Shutdown (typical)
    • 15 µA in Active Mode with No Load (typical)
  • Wide Voltage Conversion Range:
    • tON_MIN = 60 ns (typical)
    • tOFF_MIN = 70 ns (typical)
  • Low MOSFET ON-Resistance:
    • RDS_ON_HS = 53 mΩ (typical)
    • RDS_ON_LS = 31 mΩ (typical)
  • External Bias Input to Improve Efficiency
  • Pin-Selectable Auto Mode or Forced PWM Operation
  • Adjustable Frequency Range: 350 kHz to 2.2 MHz
  • Synchronizable to External Clock
  • Internal Compensation
  • Power-Good Flag
  • Precision Enable to Program System UVLO
  • Flexible Soft-Start Features:
    • Start-up into Pre-Biased Load
    • Fixed or Adjustable Soft-Start Time
    • Output Voltage Tracking
  • Cycle-by-Cycle Current Limiting
  • Short-Circuit Protection With Hiccup Mode
  • Thermal Shutdown Protection
  • Create a Custom Design With the WEBENCH® Power Designer using LM73605 or LM73606
  • Simplified Schematic

    LM73605 LM73606 LM73605-simplified-schematic-snvsah5.gif

Applications

  • Industrial Distributed Power Applications
  • Telecommunications Systems
  • General-Purpose Wide VIN Regulation

Description

The LM73605/LM73606 family of devices are easy-to-use synchronous step-down DC-DC converters capable of driving up to 5 A (LM73605) or 6 A (LM73606) of load current from a supply voltage ranging from 3.5 V to 36 V. The LM73605/LM73606 provide exceptional efficiency and output accuracy in a very small solution size. Peak current-mode control is employed. Additional features such as adjustable switching frequency, synchronization to an external clock, FPWM option, power-good flag, precision enable, adjustable soft start, and tracking provide both flexible and easy-to-use solutions for a wide range of applications. Automatic frequency foldback at light load and optional external bias improve efficiency over the entire load range. The family requires few external components and has a pinout designed for simple PCB layout with optimal EMI and thermal performance. Protection features include thermal shutdown, input undervoltage lockout, cycle-by-cycle current limiting, and hiccup short-circuit protection. The LM73605 and LM73606 devices are pin-to-pin compatible for easy current scaling.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
LM73605WQFN (30)
Wettable Flanks
6.00 mm × 4.00 mm
LM73606
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Efficiency vs Load Current
VOUT = 5 V, fSW = 500 kHz, Auto Mode

LM73605 LM73606 Eff_5V_500k_SNVSAH5.gif

Revision History

DATEREVISIONNOTES
September 2017*Initial release