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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.1.2.3 Input Capacitor Selection

Input capacitors serve two important functions: The first is to reduce input voltage ripple into the LM53601-Q1 and the input filter of the system. The second is to reduce high frequency noise. These two functions are implemented most effectively with separate capacitors, see Table 9-4.

Table 9-4 Input Capacitor
CAPACITORRECOMMENDED VALUECOMMENT
CIN_HF0.1 µFThis capacitor is used to suppress high frequency noise originating during switching events. It is important to place capacitor as close to the LM53600-Q1 and LM53601-Q1 devices as design rules allow. Position is more important than exact capacity. Once high frequency propagates into a system, it can be hard to suppress or filter. Since this capacitor will be exposed to battery voltage in systems that operate directly off of battery, 50 V or greater rating is recommended.
CIN10 µFThis capacitance is used to suppress input ripple and transients due to output load transients. If CIN is too small, input voltage may dip during load transients resetting the system if the system is operated under low voltage conditions. 10 µF is intended to include all capacitance in the LM53600-Q1/LM53601-Q1’s input node. 4.7 µF adjacent to the LM53600-Q1 and LM53601-Q1 devices is recommended. Since this capacitor will be exposed to battery voltage in systems that operate directly off of battery, 50 V or greater rating is recommended.

Table 9-5 shows recommended capacitor values other than input and output capacitors.

Table 9-5 Other Capacitors
CAPACITORMINIMUM VALUECOMMENT
CBOOT0.1 µFWhile a voltage rating of only 5 V is necessary, using a higher voltage rating is recommended.
CVCC1 µFWhile a voltage rating of only 5 V is necessary, 16-V capacitors have a low voltage coefficient.
CBIAS0.01 µFThis capacitor should be rated to survive output voltage.

Note that performance of converters utilizing an adjustable version of the LM53600-Q1 and LM53601-Q1 devices may be enhanced by adding CFF, a capacitor in parallel with RFBT. 100 pF is recommended.