Design design - why not use second DRV8301 as 3.3v buck reg

I see on the schematics the odrive drops motor voltage to 5v on the first drv8301 but why not use the second DRV8301 to generate 3.3v instead of an extra buck regulator that drops 5v to 3.3v?

I’d guess it’s done this way because the 3.3V doesn’t need much power, but needs to be very clean and free of voltage ripple, and traditionally, linear LDO regulators are better for this. Switching buck converters are normally used where power and efficiency are more important than low noise and precision.

1 Like