DRV8424E: Bout waveform output exception

Cherry Zhou

Part Number: DRV8424E
Other Parts Discussed in Thread: DRV8424, ,

As shown in the figure above, can several configuration pins be selected high or low by a dial switch? According to the specification, it can be connected directly to GND, as shown in the following figure. May I know is it OK?

As shown in the following figure: Green for Bout, pink for Aout, and Bout output exception

Best Regards,
Cherry Zhou

over 4 years ago

0 Ryan Kehr over 4 years ago

TI__Guru 55655 points

Cherry,

I have assigned this to Wang who will support within 24 hours.

Regards,

Ryan

0 Wang5577 over 4 years ago

TI__Guru 56650 points

Cherry,

The dial switch pull-up resistor is 1kohm and pull-down resistor is 10k.

1. it doesn't support 330kohm pull-down setting.

2. Does it support high resistance mode?

If the motor driver setting doesn't need 300kohm pull-down and high resistance input, it is OK to me.

Regards,
Wang Li

0 Cherry Zhou over 4 years ago in reply to Wang5577

TI__Mastermind 22235 points

Hi Wang,

The customer mistakenly treated the DRV8424E as DRV8424. He would like to know what kind of driving waveform would PH/EN give, if it were to be controlled by PH/EN (in DRV8424E)?

Best Regards,

Cherry

0 Wang5577 over 4 years ago in reply to Cherry Zhou

TI__Guru 56650 points

Cherry,

If the customer uses it to drive a stepper motor with full step setting, he can keep xVREF voltage. PH pin change the coil current direction, EN pin enable the output current. The two coil current sequence can be found in DRV8424 datasheet indexer table.

BTW, DRV8424EEVM firmware supports DRV8424E to drive a stepper motor. You can check the waveform or use it as reference.

Regards,

Wang Li

0 Cherry Zhou over 4 years ago in reply to Wang5577

TI__Mastermind 22235 points

Hi Wang,

Thanks for your reply.

The customer would like to know if we can provide the input waveform of PH/EN and the output waveform of AOUTx, BOUTx.

Best Regards,

Cherry Zhou

0 Shinya Morita over 4 years ago in reply to Cherry Zhou

TI__Mastermind 46915 points

Hello,

We are investigating and will reply within 24 hours.

Regards,

Shinya Morita

0 Wang5577 over 4 years ago in reply to Cherry Zhou

TI__Guru 56650 points

Shinya,

Thanks,

Cherry,

Please check this application note which provide the input waveform of PH/EN and the output waveform of AOUTx, BOUTx: https://www.ti.com/lit/an/slva416/slva416.pdf

Regards,

Wang Li

0 Cherry Zhou over 4 years ago in reply to Wang5577

TI__Mastermind 22235 points

Hi Wang,

Thanks for your reply.

With your help now the motor can be driven. But the noise is very loud, and the output waveform looks like little strange, as the figure below. Could you help to figure out what's the reason for that? Thanks again.

Best Regards,

Cherry

0 Wang5577 over 4 years ago in reply to Cherry Zhou

TI__Guru 56650 points

Hi, Cherry,

The motor vibration noise could be related to the motor torque variation. Please check output current. And then, we can understand it better. Would you change the decay mode setting? For example: smart tune dynamic decay...

Regards,
Wang Li

0 Cherry Zhou over 4 years ago in reply to Wang5577

TI__Mastermind 22235 points

Hi Wang,

Thanks for your reply!

The latest updates are as follows:

1. The output current is small, about 0.2A.

2. The VREF voltage is set at 0.8 V and the output current is set at approximately 0.6 A.

3. The stepper motor is rated to operate at 0.6A

Best Regards,

Cherry

0 Wang5577 over 4 years ago in reply to Cherry Zhou

TI__Guru 56650 points

Cherry,

What is the input voltage and motor coil resistance? What is the motor inductance? If you can share the output current waveform, we can check it together.

If the output current is same our expectation, we may have to increase the micro-stepping resolution to reduce teh noise.

Regards,

Wang Li

Motor drivers

Motor drivers forum

DRV8424E: Bout waveform output exception