Tool/software:
I'm trying to use DRV8874 to control a 24V 5A DC motor.
However, it does not include sensorless speed control.
DRV8235 seems to be capable of sensorless speed control, but the current is 3.7A max.
Using DRV8874, can I make a Ripple Count function with an algorithm in MCU by High Speed ADC at IPROPI?
Is there a function that IPROPI's output can output Ripple?
Hi Byoungjin,
Thank you for your post.
DRV8235 seems to be capable of sensorless speed control, but the current is 3.7A max.
Using DRV8874, can I make a Ripple Count function with an algorithm in MCU by High Speed ADC at IPROPI?
Yes this is possible. Please check out this application note, https://www.ti.com/lit/ug/tidud30a/tidud30a.pdf.
Is there a function that IPROPI's output can output Ripple?
The IPROPI is this device outputs a proportional current to the current through the low-side FETs. You may have to take into account delay time and blanking time etc. The IPROPI is an unipolar output which means it would be positive for both the drive directions. Thank you.
Regards, Murugavel
The current is the FET current on the low side, and I know that the low side current flows only when PWM is On, and does not flow when it is Off.
Then, when PWM is switched On and Off, the current itself have ripples.
Can I still use the ripple count algorithm?
The current sensing method used in this document is the inline method.
https://www.ti.com/lit/ug/tidud30a/tidud30a.pdf
