SLVSES8A October   2020  – December 2020 LM5127-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
  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 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  Device Enable (EN, VCC_HOLD)
      2. 8.3.2  Dual Input VCC Regulator (BIAS, VCCX, VCC)
      3. 8.3.3  Dual Input VDD Switch (VDD, VDDX)
      4. 8.3.4  Device Configuration and Light Load Switching Mode Selection (CFG/MODE)
      5. 8.3.5  Fixed or Adjustable Output Regulation Target (VOUT, FB)
      6. 8.3.6  Overvoltage Protection (VOUT, FB)
      7. 8.3.7  Power Good Indicator (PGOOD)
      8. 8.3.8  Programmable Switching Frequency (RT)
      9. 8.3.9  External Clock Synchronization (SYNC)
      10. 8.3.10 Programmable Spread Spectrum (DITHER)
      11. 8.3.11 Programmable Soft Start (SS)
      12. 8.3.12 Fast Re-start using VCC_HOLD (VCC_HOLD)
      13. 8.3.13 Transconductance Error Amplifier and PWM (COMP)
      14. 8.3.14 Current Sensing and Slope Compensation (CSA, CSB)
      15. 8.3.15 Constant Peak Current Limit (CSA, CSB)
      16. 8.3.16 Maximum Duty Cycle and Minimum Controllable On-time Limits (Boost)
      17. 8.3.17 Bypass Mode (Boost)
      18. 8.3.18 Minimum Controllable On-time and Minimum Controllable Off-time Limits (Buck)
      19. 8.3.19 Low Dropout Mode for Extended Minimum Input Voltage (Buck)
      20. 8.3.20 Programmable Hiccup Mode Overload Protection (RES)
      21. 8.3.21 MOSFET Drivers and Hiccup Mode Fault Protection (LO, HO, HB)
      22. 8.3.22 Battery Monitor (BMOUT, BMIN_FIX, BMIN_PRG)
      23. 8.3.23 Dual-phase Interleaved Configuration for High Current Supply (CFG)
      24. 8.3.24 Thermal Shutdown Protection
      25. 8.3.25 External VCCX Supply Reduces Power Dissipation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Status
        1. 8.4.1.1 Shutdown Mode
        2. 8.4.1.2 Configuration Mode
        3. 8.4.1.3 Active Mode
        4. 8.4.1.4 Sleep Mode
        5. 8.4.1.5 Deep Sleep Mode
          1. 8.4.1.5.1 Cutting Leakage Path in Deep Sleep Mode (DIS, SLEEP1, SENSE1)
        6. 8.4.1.6 VCC HOLD Mode
      2. 8.4.2 Light Load Switching Mode
        1. 8.4.2.1 Forced PWM (FPWM) Operation
        2. 8.4.2.2 Diode Emulation (DE) Operation (Connect RSS at SS)
        3. 8.4.2.3 Forced Diode Emulation Operation in FPWM Mode
        4. 8.4.2.4 Skip Mode Operation
      3. 8.4.3 LM5127 Cheat Sheet
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Recommended Power Tree Architecture
        2. 9.2.2.2 Application Ideas
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
  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
    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

5 Description (continued)

The input voltage range covers both of automotive cold-cranking and load dump scenarios. The switching frequency is dynamically programmed in the range of 100 kHz to 2.2 MHz with an external resistor. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response.

The device features a low shutdown IQ and an ultra-low IQ sleep mode, which minimizes battery drain at no/light load condition and eliminates the need for an additional low IQ LDO regulator as the CAN supply during standby.

The device includes flexible topology channels that support boost or SEPIC, and two independent single-phase bucks or a dual-phase buck to serve as a high current automotive processor supply. In boost mode, the device supports bypass operation which eliminates the need for an external bypass switch. In buck mode, the device supports low dropout operation to minimize dropout voltage. The battery monitor detects low battery voltage and signals when a backup process should start.

Minimal power dissipation is realized with a low current limit threshold and the use of an external VCC supply. The device has built-in protection features such as peak current limit which is constant over VIN, optional hiccup mode overload protection, overvoltage protection, and thermal shutdown.

External clock synchronization, programmable spread spectrum switching frequency, as well as a leadless package with minimal parasitics help to reduce EMI and avoid cross talk. Additional features include FPWM, DCR sensing, programmable soft start, a precision reference, and power-good indicators.