P2 smartpin Imax without load

Comments

• cgracey Posts: 14,133

  2021-03-16 14:12

  @pic18f2550 said:
  Hello,
  since the current load of the IO pins is very small, I would like to know what the propeller needs here.

  E.g. V0003

  Which operation mode, needs the most current?
  Or is it only a sore µA?
  The many LDOs make me wonder.

  What happens if I leave the unused V0407 open?
  That would correspond to a 3.3V voltage drop.

  The many LDOs are there to provide quiet zones every 8 pins. If you want quiet DACs or sensitive ADCs, you can locate them on an LDO that is not driving anything digital, where noise is being generated.

  When you select a current-drive mode, there is about 100uA of quiescent current flowing inside the pin. The comparator mode takes maybe 40uA. The DAC modes take most when they are outputting middle values, like $80, because half the resistors are pulling high and half are pulling low. In 124-ohm mode, it amounts to two 248-ohm resistors in series, between 3.3V and GND. That is 13mA.

  If a pin is configured for normal digital operation (WRPIN #0,#pin) and is either pulled high or low or driving high or low without any load, it is taking less than 1uA. There's no need to not drive VIO pins to save power.
• pic18f2550 Posts: 392

  2021-03-16 14:39

  Now I know that I can manage with 2 LDOs.
  1x for analog signals and once for the digital signals.

  Thanks.
• cgracey Posts: 14,133

  2021-03-16 16:14

  @pic18f2550 said:
  Now I know that I can manage with 2 LDOs.
  1x for analog signals and once for the digital signals.

  Thanks.

  That should be fine.