SNVSB29C October   2018  – June 2021 LM5143-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1. 6.1 Wettable Flanks
  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 Switching Characteristics
    7. 7.7 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  Input Voltage Range (VIN)
      2. 8.3.2  High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
      3. 8.3.3  Enable (EN1, EN2)
      4. 8.3.4  Power Good Monitor (PG1, PG2)
      5. 8.3.5  Switching Frequency (RT)
      6. 8.3.6  Clock Synchronization (DEMB)
      7. 8.3.7  Synchronization Out (SYNCOUT)
      8. 8.3.8  Spread Spectrum Frequency Modulation (DITH)
      9. 8.3.9  Configurable Soft Start (SS1, SS2)
      10. 8.3.10 Output Voltage Setpoint (FB1, FB2)
      11. 8.3.11 Minimum Controllable On-Time
      12. 8.3.12 Error Amplifier and PWM Comparator (FB1, FB2, COMP1, COMP2)
      13. 8.3.13 Slope Compensation
      14. 8.3.14 Inductor Current Sense (CS1, VOUT1, CS2, VOUT2)
        1. 8.3.14.1 Shunt Current Sensing
        2. 8.3.14.2 Inductor DCR Current Sensing
      15. 8.3.15 Hiccup Mode Current Limiting (RES)
      16. 8.3.16 High-Side and Low-Side Gate Drivers (HO1/2, LO1/2, HOL1/2, LOL1/2)
      17. 8.3.17 Output Configurations (MODE, FB2)
        1. 8.3.17.1 Independent Dual-Output Operation
        2. 8.3.17.2 Single-Output Interleaved Operation
        3. 8.3.17.3 Single-Output Multiphase Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Standby Modes
      2. 8.4.2 Diode Emulation Mode
      3. 8.4.3 Thermal Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Power Train Components
        1. 9.1.1.1 Buck Inductor
        2. 9.1.1.2 Output Capacitors
        3. 9.1.1.3 Input Capacitors
        4. 9.1.1.4 Power MOSFETs
        5. 9.1.1.5 EMI Filter
      2. 9.1.2 Error Amplifier and Compensation
    2. 9.2 Typical Applications
      1. 9.2.1 Design 1 – High Efficiency, Dual-Output Buck Regulator for Automotive Applications
        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 Custom Design With Excel Quickstart Tool
          3. 9.2.1.2.3 Inductor Calculation
          4. 9.2.1.2.4 Current-Sense Resistance
          5. 9.2.1.2.5 Output Capacitors
          6. 9.2.1.2.6 Input Capacitors
          7. 9.2.1.2.7 Compensation Components
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Design 2 – Two-Phase, Single-Output Buck Regulator for Automotive ADAS Applications
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedures
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Power Stage Layout
      2. 11.1.2 Gate-Drive Layout
      3. 11.1.3 PWM Controller Layout
      4. 11.1.4 Thermal Design and Layout
      5. 11.1.5 Ground Plane Design
    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
      3. 12.1.3 Custom Design With WEBENCH® Tools
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
        1. 12.2.1.1 PCB Layout Resources
        2. 12.2.1.2 Thermal Design Resources
    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

9.2.2.1 Design Requirements

Table 9-4 shows the intended input, output, and performance parameters for this automotive application design example.

Table 9-4 Design Parameters
DESIGN PARAMETERVALUE
Input voltage range (steady-state)5 V to 18 V
Minimum transient input voltage (cold crank)5 V
Maximum transient input voltage (load dump)36 V
Output voltages5 V
Output currents15 A
Switching frequency2.1 MHz
Output voltage regulation±1%
Standby current, output 1 enabled, no-load< 50 µA
Shutdown current4 µA

The switching frequency is set at 2.1 MHz by resistor RRT. In terms of control loop performance, the target loop crossover frequency is 60 kHz with a phase margin greater than 50°. The output voltage soft-start time is set at 2 ms by a 68-nF soft-start capacitor.

The selected buck regulator powertrain components are cited in Table 9-5, and many of the components are available from multiple vendors. Similar to design 1, this design uses a low-DCR, metal-powder composite inductor, and ceramic output capacitor implementation.

Table 9-5 List of Materials for Application Circuit 2
REFERENCE DESIGNATORQTYSPECIFICATIONMANUFACTURERPART NUMBER
CIN410 µF, 50 V, X7R, 1210, ceramic, AEC-Q200Taiyo YudenUMJ325KB7106KMHT
10 µF, 50 V, X7S, 1210, ceramic, AEC-Q200MurataGCM32EC71H106KA03
TDKCGA6P3X7S1H106M
CO847 µF, 6.3 V, X7R, 1210, ceramic, AEC-Q200MurataGCM32ER70J476KE19L
Taiyo YudenJMK325B7476KMHTR
47 µF, 6.3 V, X7S, 1210, ceramic, AEC-Q200TDKCGA6P1X7S0J476M
LO1, LO220.68 µH, 4.8 mΩ, 25 A, 7.3 × 6.6 × 2.8 mm, AEC-Q200Würth Electronik744373460068
0.68 µH, 4.5 mΩ, 22 A, 6.95 × 6.6 × 2.8 mm, AEC-Q200CyntecVCMV063T-R68MN2T
0.68 µH, 3.1 mΩ, 20 A, 7 × 6.9 × 3.8 mm, AEC-Q200Würth Electronik744311068
0.68 µH, 7.4 mΩ, 12.2 A, 5.4 × 5.0 × 3 mm, AEC-Q200TDKSPM5030VT-R68-D
0.68 µH, 2.9 mΩ, 15.3 A, 6.7 × 6.5 × 3.1 mm, AEC-Q200CoilcraftXGL6030-681
Q1, Q2, Q3, Q4440 V, 5.7 mΩ, 9 nC, SON 5 × 6, AEC-Q101InfineonIPC50N04S5L-5R5
RS1, RS22Shunt, 7 mΩ, 0508, 1 W, AEC-Q200SusumuKRL2012E-M-R007
U11LM5143-Q1 65-V dual-channel buck controller, AEC-Q100Texas InstrumentsLM5143QRGWRQ1