SLVUBU3A April   2020  – October 2020 LM7480-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 Applications
  3. 2Description
    1. 2.1  Input Power and Load (J1/J3 and J2/J4):
    2. 2.2  Enable Control (J5):
    3. 2.3  Over Voltage Protection (J6):
    4. 2.4  Input Voltage Monitor (J8 and VIN_MON):
    5. 2.5  Two back-back connected MOSFETs (Q1/Q3 and Q2/Q4):
    6. 2.6  Output slew rate control (R2 and C2):
    7. 2.7  Output Schottky Diode (D2) and LED indication:
    8. 2.8  TVS selection for 12-V battery protection:
    9. 2.9  TVS selection for 24-V battery protection:
    10. 2.10 Test Points:
  4. 3Schematic
  5. 4Test Equipment Requirements
    1. 4.1 Power Supplies
    2. 4.2 Meters
    3. 4.3 Oscilloscope
    4. 4.4 Loads
  6. 5Test Setup and Results
    1. 5.1 Initial Setup
    2. 5.2 Power up
    3. 5.3 Over Voltage Protection
    4. 5.4 Enable Control
    5. 5.5 Hot-plug and Disable using EN
    6. 5.6 Inrush Current Control
    7. 5.7 Load Response
  7. 6Board Layout and Bill of Materials
    1. 6.1 Board Layout
    2. 6.2 Bill of Materials
  8. 7Revision History

2.10 Test Points:

Test point labeled DGATE is used for monitoring gate voltage of Q1A and HGATE is used for gate voltage of Q1B. Test Point labelled VIN measures input voltage, VOUT measure output voltage. Test Point labelled VOUT_ALWAYS_ON measures the drain voltage of Q1 MOSFET. Test Points GND1, GND3 and GND4 provides access to the input GND voltage and GND2 provides access to the LM74800-Q1 GND pin.

Table 2-1 Connectors: Input and Output
Connector Description
J1 Power input connector to the positive rail of the input power supply
J3 Ground connection for the power supply
J2 Power output connector to the positive side of the load
J4 Ground connection for the load
Table 2-2 Test Points Description
Test PointsDescription
VINInput power supply to the EVM
VOUTOutput from the EVM
VOUT_ALWAYS_ONOutput voltage after the Ideal Diode MOSFET for connecting always ON loads
VIN_MONInput monitoring for battery inputs
DGATEOutput of Ideal Diode MOSFET Gate Control
HGATEOutput of Hot-Swap MOSFET Gate Control
GND1, GND 2, GND3 and GND4Test Point for EVM Ground
Table 2-3 Jumpers and LED Description
JumpersDescription
J5EN/UVLO Control
  • 1-2 Enables by connecting to VIN
  • 2-3 Disables by connecting to GND
J6OVP Setting
  • 1-2 OVP set to Output Clamp (hysteretic) at 37.5 V
  • 2-3 OVP set to Input OVP Cutoff at 37.5 V
J7Enables LED indication for output
J8Input Voltage Sense
  • 1-2 Input Voltage Sense after Ideal Diode MOSFET
  • 2-3 Input Voltage Sense directly on input supply