I have a battery powered circuit using a MCU and several peripherial circuits (eg. an SD Card slot, small audio amplifier).
The peripherials are rarely used, but the MCU is constantly running. So the peripherials are switched on and off by low side FETs to stop them draining the batteries.
However, the inrush current from switching a SD-Card or audio amplifier creates a temporary voltage drop, that causes the MCU to restart by brownout / blackout detection.
I don't like to add capacitance to the main circuit, as it's leakage would drain the batteries while the peripherials are off.
So what else can I do?
Experimentally adding resistors to the peripherial power lines do stop MCU resets, but I don't want to risk flaky behaviour / incompatibilities of the SD-Cards of course, or audio distortions.