SNAS660D June   2015  – May 2021 LM53600-Q1 , LM53601-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  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 Electrical Characteristics
    6. 7.6 System Characteristics
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Control Scheme
      2. 8.3.2 Soft-Start Function
      3. 8.3.3 Current Limit
      4. 8.3.4 Hiccup Mode
      5. 8.3.5 RESET Function
      6. 8.3.6 Forced PWM Operation
      7. 8.3.7 Auto Mode Operation and IQ_VIN
      8. 8.3.8 SYNC Operation
      9. 8.3.9 Spread Spectrum
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown
      2. 8.4.2 FPWM Operation
      3. 8.4.3 Auto Mode Operation
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Off-Battery 5-V, 1-A Output Automotive Converter with Spread Spectrum
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Inductor Selection
          2. 9.2.1.2.2 Output Capacitor Selection
          3. 9.2.1.2.3 Input Capacitor Selection
          4. 9.2.1.2.4 FB Voltage Divider for Adjustable Versions
          5. 9.2.1.2.5 RPU - RESET Pull Up Resistor
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Off-Battery 3.3 V, 1 A Output Automotive Converter with Spread Spectrum
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Design Procedure
        3. 9.2.2.3 Application Curves
    3. 9.3 Do's and Don't's
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Thermal Plane Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information
9.2.1.2.2 Output Capacitor Selection

The current mode control scheme of the LM53600-Q1 and LM53601-Q1 devices allows operation over a wide range of output capacitance. A minimum of 10 µF is needed to ensure stability. Capacitance above 20 µF is recommended to ensure load transient response typically desired in systems. 40 µF is recommended for applications with demanding load transient requirements and for which Auto mode ripple is important. 40 µF also aids devices with output voltage below 4-V transition into high voltage mode. Capacitance above 400 µF can cause excessive current to be drawn during start up so is not recommended. These capacitance values include load capacitance – only 10 µF is needed near to the LM53600-Q1 and LM53601-Q1 devices. Output capacitors should have low ESR to reduce output ripple. These capacitors should have at least X7R rating and should be of automotive grade if used in automotive applications.

Table 9-3 Output Capacitor
LM53600-Q1 AND LM53601-Q1
TYPE AND SYSTEM NEED		RECOMMENDED MINIMUM TOTAL OUTPUT CAPACITANCECOMMENTS
LM53600-Q1 5 V20 µFApproximately 200-mV/A step load response with 1-µs rise/fall time.
LM53601-Q1 5 V with typical system requirements20 µFApproximately 200-mV/A step load response with 1-µs rise/fall time.
LM53601-Q1 5V in high performance systems40 µFApproximately 150-mV/A step load, approximately 20-mV maximum Auto mode ripple
LM53600-Q1/LM53601-Q1 3.3 V and adjustable parts with less than 4.2-V output setting with typical system requirements20 µFApproximately 200-mV/A step load response with 1µs rise/fall time, up to 60 mV of ripple during transition into high voltage mode and in Auto mode.
LM53600-Q1/LM53601-Q1 3.3 V and adjustable parts with less than 4.2 V in high performance systems40 µFApproximately 150-mV/A step load, approximately 30-mV maximum Auto mode ripple, and 15-mV maximum HV mode transition ripple.
LM53600-Q1 ADJ set to greater than 4.2-V output40 µFLarger capacitance is necessitated by higher inductance needed.