SLVUBU4 March   2021

 

  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 Two Back-Back Connected MOSFETs (Q1/Q3 and Q2):
    5. 2.5 Output Slew Rate Control (R2 and C4):
    6. 2.6 Output Schottky Diode (D3) and LED Indication:
    7. 2.7 TVS Selection for 200-V Unsuppressed Load Dump Protection:
    8. 2.8 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. 5.3 200-V Unsuppressed Load Dump Protection
    4. 5.4 ISO 7637-2 Pulse 1 –600 V 50 Ω
  7. 6Board Layout and Bill of Materials
    1. 6.1 Board Layout
    2. 6.2 Bill of Materials
  8.   Revision History

2.8 Test Points:

Test point labeled DGATE (TP4) is used for monitoring gate voltage of Q2 and HGATE (TP3) is used for gate voltage of Q1. Test Point labelled VIN (TP1) measures input voltage, VOUT (TP2) measure output voltage. Test Point labelled VA (TP6) measures the source voltage of Q1 and Q2 MOSFETs which is also connected to the A pin. 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
ConnectorDescription
J1Power input connector to the positive rail of the input power supply
J3Ground connection for the power supply
J2Power output connector to the positive side of the load
J4Ground connection for the load
Table 2-2 Test Points Description
Test Points Description
VIN Input power supply to the EVM
VOUT Output from the EVM
VA Common-source point of Q1 and Q2 MOSFETs and A pin of LM7480x-Q1
DGATE Output of Ideal Diode MOSFET Gate Control
HGATE Output of Hot-Swap MOSFET Gate Control
GND1, GND 2, GND3 and GND4 Test Point for EVM Ground
Table 2-3 Jumpers and LED Description
Jumpers Description
J5 EN/UVLO Control
  • 1-2 Enables by connecting to VIN
  • 2-3 Disables by connecting to GND
J6 OVP Setting
  • 1-2 OVP set to Output Clamp (hysteretic) at 37.5 V
  • 2-3 OVP set to Input OVP Cutoff at 38.4 V
J7 Enables LED indication for output