Hello everyone,
I have been trying to make a stepper motor driver board using DRV8432 for sometime now. I will be using it at frequencies of around 400-600Hz. The datasheet says:
"For applications with lower than 10kHz switching frequency, and not to trigger BST_UVP protection, a larger bootstrap capacitor can bused (eg 1 uF cap for 800 Hz operation). When using a bootstrap cap larger than 220nF, it is recommended to add 5 ohms resistors between 12V GVDD power supply and GVDD_X pins to limit the inrush current on the internal bootstrap circuitry."
I have added 5 ohms resistors between 12V GVDD power supply and GVDD_X pins as instructed. My questions are:
1. Will 2.2uF bootstrap capacitor be sufficient for my application?
2. The 1uF / 2.2uF capacitors that I have are polarised. Can anyone please tell me how I am to connect these capacitors between BCT_X & OUT_X? Wrong polarity will certainly blow off the capacitors.
Motor details are: Rated Phase current= 4.2A, Phase resistance= 1.4 ohms, Phase inductance= 1.8 mH. It is a Constant Current drive motor (told by the seller).
Thanks and Regards to everyone...