I am currently finishing a circuit with TIVA C TM4C123G where the user manual indicate the following:
"decoupling capacitor typically 0.1uF in value and should be accompanied by a bulk capacitor. The combined VDD and VDDA bulk capacitance of the microcontroller is typically between 2uF and 22uF" "For optimal performance, locate one decoupling capacitor adjacent to each VDD power and ground pin par. At a minimum there should be one decoupling capactiro on each side of the microcontroller package connected betxeen VDD and Ground"
1./ Looking at the launchpad board TMC123G and other board EVM, the number of decoupling capacitor and bulk capacitor are not respecting those indication. So, how to know how many capacitor and of which value I should put (particularly for the bulk) ?
2./ What can happen if I put too many decoupling capacitor on one pin
3./What can happen if I put too many bulk capacitor on one pin ?
I am a bit lost here , sorry if my question look stupid
Launchpad guide reference: http://www.ti.com/lit/ug/spmu296/spmu296.pdf DK guide: http://www.ti.com/lit/ds/spms375e/spms375e.pdf Chip guide: http://www.ti.com/lit/an/spma059/spma059.pdf
I don't understand because in the chip they say some decoupling capacitor should be placed on each side of the mcu, but on the LQFP144 package there are several VDD +GNd pair... so i am supposed to put decoupling capacitor and bulk capacitor on all ?