Hi,
I’m wondering which ground pin type best describes each ground connection of the IMP002. There are 15 ground pins, but since I don’t know how they are connected internally inside the IMP002, I wonder if it is possible to classify each pin as digital ground(digital circuits connected to that pin like clocks and logic), analog ground(analog circuits connected to it such as linear analog, ADC, references) and power ground(such as current path for the TX). I want to isolate as much as I can the sensitive analog ground from power and digital grounds.
cheers, Raul
The STM32F205 in the WLCSP package has no AVSS pin, so it’s just a single ground; you can only isolate analog power.
The IMP003 uses the F405 WLCSP which does have AVSS and so this one is labelled appropriately.
Hey Hugo,
I imagine what you mean by analog power is the 250mA TX current flow, which ground pin(s) on the IMP002 module would those correspond to?
cheers
No, “analog power” is the supply to the STM32’s ADC and DAC.
There is a single supply rail (VDD) to both STM32 digital and WiFi power. Inside the module there is a load switch that allows total power removal from the WiFi chip as it leaks quite badly without this.
There is no segmented ground within the module; this is generally very inadvisable from a receiver desense point of view. All ground pins are tied to the same full plane within the module.