4 ms·
> it would require 4x the circuit area A DAC would involve a larger PCB. A small DDS (si5341) would be pretty good though at 3x3mm. Three phased channels cou
by topspin 3y ago
> it would require 4x the circuit area
A DAC would involve a larger PCB. A small DDS (si5341) would be pretty good though at 3x3mm. Three phased channels could drive the six inductors far beyond any feasible speed here.
> Plus adding some Z axis height for the optical encoder.
A SMT photodiode and IR LED could do this off the edge with some fiddling, which appears to be in ample supply here.
- cushychicken 3y agoHuh? That DDS is a silly choice. For one thing, those chips are $27 a pop and only available in QFN44 and QFN64. (May have been smaller FF at some other point, but not any more.) The final BLDC driver he selected is like $1.50. Not to mention that you can't adjust the drive phases of a DDS with I2C fast enough to be of any use for BLDC. Once you add in a sensor/feedback element, it definitely wouldn't have the latency performance you'd need for BLDC.