Custom T4.1 Move R6 from under the BGA


Well-known member
I'm working on a new custom T4.1, and I'm having trouble getting all the pins I need broken out of the BGA. To make a little more space for routing, I was hoping to move R6 from its usual position (directly under the BGA), to a new position right next to the bootloader chip. This should be okay right?
R6-100K resistor to PTA3.png
As far as I can see, that resistor is just a pull-down resistor. No high-speed signals there. So should be OK to move a short distance
But probably Paul Stoffregen should confirm.

Given its 100k that's a lot higher than the impedances seen by fast signals - its effectively an open circuit at nanosecond timescales(!). Typical pcb-trace characteristic impedances will be in the 30 to 500 ohms range or so, in other words the high speed currents flowing are completely dominated by stray capacitance and inductance which are much lower impedance than 100k at logic speeds. So if it were 100 ohms, different story, but 100k can probably go anywhere...