SNAS714C November   2016  – August 2021 LMS3635-Q1 , LMS3655-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Tables
  6. 6 Pin Configuration and Functions
  7. 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 Thermal Information (for Device Mounted on PCB)
    6. 7.6 Electrical Characteristics
    7. 7.7 System Characteristics
    8. 7.8 Timing Requirements
    9. 7.9 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
      1. 8.2.1 Control Scheme
    3. 8.3 Feature Description
      1. 8.3.1 RESET Flag Output
      2. 8.3.2 Enable and Start-Up
      3. 8.3.3 Soft-Start Function
      4. 8.3.4 Current Limit
      5. 8.3.5 Hiccup Mode
      6. 8.3.6 Synchronizing Input
      7. 8.3.7 Undervoltage Lockout (UVLO) and Thermal Shutdown (TSD)
      8. 8.3.8 Input Supply Current
    4. 8.4 Device Functional Modes
      1. 8.4.1 AUTO Mode
      2. 8.4.2 FPWM Mode
      3. 8.4.3 Dropout
      4. 8.4.4 Spread-Spectrum Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 General Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2 External Components Selection
            1. 9.2.1.2.2.1 Input Capacitors
            2. 9.2.1.2.2.2 Output Inductors and Capacitors
              1. 9.2.1.2.2.2.1 Inductor Selection
              2. 9.2.1.2.2.2.2 Output Capacitor Selection
          3. 9.2.1.2.3 Setting the Output Voltage
          4. 9.2.1.2.4 FB for Adjustable Output
          5. 9.2.1.2.5 VCC
          6. 9.2.1.2.6 BIAS
          7. 9.2.1.2.7 CBOOT
          8. 9.2.1.2.8 Maximum Ambient Temperature
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Fixed 5-V Output for USB-Type Applications
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Fixed 3.3-V Output
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
      4. 9.2.4 6-V Adjustable Output
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
        3. 9.2.4.3 Application Curves
    3. 9.3 Do's and Don't's
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Development Support
        1. 12.1.2.1 Custom Design With WEBENCH® Tools
    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

7.7 System Characteristics

The following specifications are ensured by design provided that the component values in the typical application circuit are used. These parameters are not ensured by production testing. Limits apply over the recommended operating junction temperature range of –40°C to +150°C, unless otherwise noted. Minimum and maximum limits are specified through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated the following conditions apply: VIN = 13.5 V.
PARAMETERTEST CONDITIONSMINTYPMAXUNIT
VIN-MINMinimum input voltage for full functionality at 3.5-A load, after start-up.VOUT = 3.3 V +2% or –3% regulation3.5V
Minimum input voltage for full functionality at maximum rated load 5.5 A after start-up.VOUT = 3.3 V +2% or –3% regulation3.8
VOUTOutput voltage for 5-V optionVIN = 5.6 V to 36 V, IOUT = 3.5 A4.92555.08V
Output voltage for 3.3-V optionVIN = 3.9 V to 36 V, IOUT = 3.5 A3.243.33.35
Output voltage for 5-V optionVIN = 5.5 V to 36 V, IOUT = 100 µA to 100 mA4.925.055.125
Output voltage for 3.3-V optionVIN = 3.8 V to 36 V, IOUT = 100 µA to 100 mA3.243.333.38
Output voltage for adjustable optionVIN = VOUT + 1 V to 36 V, IOUT = 3.5 A–2.252.25%
FSWSwitching frequencyVIN = 24 V, FPWM = 24V, VOUT = 3.3 V, IOUT = 200 mA400kHz
IQ_VINInput current to VIN pinVIN = 13.5 V, VOUT = 3.3 V, IOUT = 0 A, FPWM = 018µA
VIN = 13.5 V, VOUT = 5 V, IOUT = 0 A, FPWM = 024
IBBias current in AUTO mode at no loadVIN = 13.5 V, IOUT = 0 A, FPWM = 03242µA
VDROP1Minimum input to output voltage differential to maintain regulation accuracy without inductor DCR dropVOUT = 3.3 V or 5 V, IOUT= 3.5 A, +2% or –3% output accuracy0.350.6V
VOUT = 3.3 V or 5 V, IOUT= 5.5 A, +2% or –3% output accuracy0.650.85V
VDROP2Minimum input to output voltage differential to maintain FSW ≥ 330 kHz without inductor DCR dropVOUT = 3.3 V or 5 V, IOUT = 3.5 A,
FSW = 330 kHz, 2% regulation accuracy		0.50.7V
VOUT = 3.3 V or 5 V, IOUT = 5.5 A,
FSW = 330 kHz, 2% regulation accuracy		0.71.2V
EfficiencyTypical efficiencyVIN = 13.5 V, VOUT = 5 V, IOUT = 3.5 A94%
VIN = 13.5 V, VOUT = 3.3 V, IOUT = 3.5 A92%
VIN = 13.5 V, VOUT = 5 V, IOUT = 100 mA92%