DRV8824-Q1 Questions

Hello,

Please answer following questions from customer.

Q1. Chopping frequency in Fast Decay Mode

Customer is evaluating using DRV424EVM.

Please refer attached file.

In case of Slow Decay mode, chopping frequency is 50kHz and stable, but it is not stable in Fast Decay mode.

Please advise why the chopping frequency is not stable.

(Please visit the site to view this file)

Q2. Motor current of FULL STEP Drive

Datasheet of WINDING CURRENT when FULL STEP Drive are 71% and 70% as below.

Please confirm WINDING CURRENT is 70% or 71%.

(Current accuracy is important for customer application.)

Q3.

Customer evaluated FULL STEP drive with Slow Decay and Fast Decay.

Motor noise and vibration of Fast Decay is larger than Slow Decay.

Please advise the reason of this.

Q4.

Please advise the influence if 0.1uF capacitor is connected between A1/A2 and B1/B2 terminal and GND.

For example OC current flow through capacitor and DRV8824 may detect OC protection.

Customer needs 0.1uF capacitor because of ESD protection

Q5.

Customer may have to add ceramic capacitor for specific terminal to GND for EMI countermeasure.

Please advise allowable capacitance range for following terminal

1)    V3P3PUT

2)    AVREF/BVREF

3)    ISENA/ISENB

4)    nENBL, STEP, DIR, MODE0/MODE1, nRESET, nSLEEP

Best Regards.