Category: Driver Boards
There are at least three ways to generate a bipolar analog voltage from PWM
1. Using PWM/DIR (typically using an op-amp circuit that
is changed from inverting to non-inverting by a analog switch)
(this has the disadvantage of a glitch when direction changes)
2. Using the PWM generators UP/DOWN mode and summing
a positive and negative filtered voltage.
(this has the disadvantage that the filter time constant
varies with the input)
3. Using the PWM generators offset mode (so 0 = 50%) and an op-amp
filter that has a DC offset of - full scale
(This has the disadvantage that you lose 1 bit of resolution, which may not matter
if you use dithering)
