SNVS628H October   2009  – December 2019 LM5060

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power-Up Sequence
      2. 7.4.2 Status Conditions
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Gate Control
      2. 8.1.2  Fault Timer
      3. 8.1.3  VGS Considerations
      4. 8.1.4  VDS Fault Condition
      5. 8.1.5  Overcurrent Fault
      6. 8.1.6  Restart After Overcurrent Fault Event
      7. 8.1.7  Enable
      8. 8.1.8  UVLO
      9. 8.1.9  OVP
      10. 8.1.10 Restart After OVP Event
      11. 8.1.11 nPGD Pin
    2. 8.2 Typical Applications
      1. 8.2.1 Example Number 1: LM5060EVAL Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 VDS Fault Detection and Selecting Sense Pin Resistor RS
          2. 8.2.1.2.2 Turn-On Time
          3. 8.2.1.2.3 Fault Detection Delay Time
          4. 8.2.1.2.4 MOSFET Selection
          5. 8.2.1.2.5 Input and Output Capacitors
          6. 8.2.1.2.6 UVLO, OVP
          7. 8.2.1.2.7 POWER GOOD Indicator
          8. 8.2.1.2.8 Input Bypass Capacitor
          9. 8.2.1.2.9 Large Load Capacitance
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Example Number 2: Reverse Polarity Protection With Diodes
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Application Curve
      3. 8.2.3 Example Number 3: Reverse Polarity Protection With Resistor
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Reverse Polarity Protection With a Resistor
          2. 8.2.3.2.2 Fault Detection With RS and RO
        3. 8.2.3.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.3.2.1 Reverse Polarity Protection With a Resistor

An alternative to using external diodes to protect the LM5060 OUT pin in the reverse polarity input condition is a resistor in series with the OUT pin. Adding an OUT pin resistor may require modification of the resistor in series with the SENSE pin. A resistor in series with the OUT pin will limit the current through the internal zener diode between OUT and GATE as well as through the diode between OUT and SENSE. The value of these resistors should be calculated to limit the current through the diode across the input terminals of the VDS fault comparator to be no more than 4 mA. Figure 42 shows the internal circuitry relevant for calculating the values of the resistor RO in the OUT path to limit the current into the OUT pin to 4 mA.

LM5060 30104243.gifFigure 42. Current Limiting Resistor for Negative SENSE Condition

When calculating the minimum RO resistor required to limit the current into the OUT pin, the internal current sources of 8 µA and 16 µA may be neglected. The following formulas can be used to calculate the resistor value RO(MIN) which is necessary to keep the IO current to less than 4 mA.

Case A is for situations where VOUT > VIN and reverse polarity situation is present (see Figure 42). VIN is negative, but the voltage at the SENSE pin can roughly be assumed to be 0.0 V due to the internal diode from the SENSE pin to GND.

Equation 16. LM5060 30104244.gif

In this case, VIN also has to be limited to a negative voltage so that reverse current through the SENSE pin does not exceed 25 mA.

Equation 17. LM5060 30104245.gif
LM5060 30104257.gifFigure 43. Current Limiting Resistor in the OUT Path for OUT > SENSE Condition

Case B is for situations where VOUT > VIN and there is no reverse polarity situation present (see Figure 43). VIN is positive and VOUT is also positive, but VOUT is higher than VIN:

Equation 18. LM5060 30104246.gif

In this case the voltage on the SENSE pin should not exceed 65 V.

Case C is for situations where VOUT < VIN and both VIN and VOUT are positive as well. In such cases there is no risk of excessive OUT pin current. No current limiting resistors are necessary. Both the SENSE and OUT voltages should be limited to less than 65 V.

LM5060 30104258.gifFigure 44. Current Limiting Resistor for Negative OUT Conditions

Case D for situations where VOUT < VIN, while VOUT is negative and VIN is positive (see Figure 44). RO needs to be selected to protect the OUT pin from currents exceeding 25 mA.

Equation 19. LM5060 30104247.gif