SNVSCT1 October   2025 LM5066H

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Current Limit
      2. 7.3.2  Foldback Current Limit
      3. 7.3.3  Soft Start Disconnect (SFT_STRT)
      4. 7.3.4  Circuit Breaker
      5. 7.3.5  Power Limit
      6. 7.3.6  UVLO
      7. 7.3.7  OVLO
      8. 7.3.8  Power Good
      9. 7.3.9  VDD Sub-Regulator
      10. 7.3.10 Remote Temperature Sensing
      11. 7.3.11 Damaged MOSFET Detection
      12. 7.3.12 Analog Current Monitor (IMON)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Up Sequence
      2. 7.4.2 Gate Control
      3. 7.4.3 Fault Timer and Restart
      4. 7.4.4 Shutdown Control
      5. 7.4.5 Enabling/Disabling and Resetting
    5. 7.5 Programming
      1. 7.5.1 PMBus Command Support
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 54V, 100A PMBus Hot Swap Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design-In Procedure
          1. 8.2.1.2.1 Selecting the Hotswap FETs
          2. 8.2.1.2.2 dv/dt-Based Start-Up
            1. 8.2.1.2.2.1 Choosing the VOUT Slew Rate
          3. 8.2.1.2.3 Select RSNS and CL Setting
          4. 8.2.1.2.4 Select Power Limit
          5. 8.2.1.2.5 Set Fault Timer
          6. 8.2.1.2.6 Check MOSFET SOA
          7. 8.2.1.2.7 Set UVLO and OVLO Thresholds
            1. 8.2.1.2.7.1 Option A
            2. 8.2.1.2.7.2 Option B
            3. 8.2.1.2.7.3 Option C
            4. 8.2.1.2.7.4 Option D
          8. 8.2.1.2.8 Power Good Pin
          9. 8.2.1.2.9 Input and Output Protection
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Package Option Addendum
    2. 11.2 Tape and Reel Information
    3. 11.3 Mechanical Data

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PWP|28
Thermal pad, mechanical data (Package|Pins)

7.3.10 Remote Temperature Sensing

The LM5066Hx features remote temperature sensing using an external MMBT3904 NPN transistor. Connect the transistor's base and collector to the DIODE pin and the emitter to the LM5066Hx ground. Position the transistor near the component requiring temperature monitoring, such as the hot swap pass MOSFET (Q1). The temperature measurement works by detecting changes in diode voltage in response to current steps from the DIODE pin. This pin supplies a constant 10μA with periodic 250μA pulses every 50μs to measure temperature. For accurate readings, minimize parasitic resistance between the DIODE pin and transistor, implement a Kelvin connection from the transistor emitter to device ground, and place a 1 nF bypass capacitor in parallel with the transistor to reduce noise.

Temperature readings are accessible through the READ_TEMPERATURE_1 PMBus command (8Dh). The default temperature fault and warning thresholds are set to 256°C (effectively disabled), but can be configured through the PMBus interface using OT_WARN_LIMIT (51h) and OT_FAULT_LIMIT (4Fh) commands. When not using the temperature sensing function, ground the DIODE pin. Note that inaccurate temperature readings may occur when input voltage falls below the minimum operating level (5.5V), as this causes VREF to drop below its nominal 2.97 V. At higher ambient temperatures, this condition may produce readings exceeding the OT_FAULT_LIMIT, triggering a fault that disables Q1. To recover, clear faults and reset the device by writing 0h followed by 80h to the OPERATION (03h) register.