16
Optimizing Sense Circuitry
Overview
Proper resolution of motor signals is critical to the performance of any control system, but especially those
with software observers attempting to replace the precision of an absolute encoder. Because the
DRV83xx are built to work at over 50 Vdc-bus, the resolution of the voltage sensing is not as precise as
you would like for motors < 48V. And in the case of the DRV8301 which measures 41.25A, the current
resolution may also be unacceptable. This section describes how to update both the hardware and
corresponding software to maximize resolution and performance.
Steps to follow
1. Determine MAXIMUM phase current, adjust current gain to 3.3V ADC
2. Set MAX voltage at +30% margin of motor voltage, adjust voltage gain to 3.3V ADC
3.
Configure software to hardware changes