Circuit Protection Rules

The page documents the standard circuit protection features common to all Plug & Program modules

IO Socket Protection

Short circuit IO sockets: Every pin that can supply or sink current has a series resistor limiting maximum current possible to < that per the datasheet.

Example: The PIC340F512H datsheet specifies the maximum current sourced or sunk is 25mA per IO pin, so 150R 1% resistors are used to limit the current to 22mA on every MC32MX64GP mainboard Io Socket pin

Power supply modules

Power Supply Modules

Some modules provide power to a PlugAndProgram solution.

Each power supply module incorporates additional design protection features:

  • Input supply polarity protection diodes
  • Self resetting Poly fuses for short circuit protection
  • All output lines have inline 40V diodes:
    • Prevents power leakage backwards through voltage regulators when more than one supply module connected
    • Prevents power feeding back into the module supply (particularly important for PNP-USB2Serial module) when more than one supply module connected