Dear,
I need to finish project with DRV8825, and need your assistance to be sure
1. Can you help me with sollution for soldering thermal pad of DRV8825. I made 0.3mm vias on top layer as suggested in datasheet. I tried it on prototype board without soldering thermal pad and there were no temperature problems, it was and will running on 100 - 400mA (motor is 400mA max). Now i need to be sure about it, but it is very hard to solder thermal pad, even with a hot air, properly. Can i make some bigger vias and apply solder from bottom side or how ?
2. I saw some application on your website with 100nF capacitors parallel to Rsense resistors. Is it necessary ?
3. I put tantal capacitor of 47uF in parallel with 100nF on AVref, because of greater path, from V3P3OUT, i think it is OK ?
4. I reached inaudible motor frequencies ~30kHz , but with very lower current. Can it be accomplished in a different way ?
5. In current calculations i choose 0.5VDC for Voltage on Rsense and then calculate Rsense, knowing that range is -0.3 to 0.8 VDC. i think it is corect, otherwise choosing Vs 0.8V gives Vref=4VDC for 0.38A
6. Interafce to MCU is without serial resistors. Application note has 220ohm resistors on every line, can it be avoided, or it is important for DRV8825
Thank You