DRV8834: Need the Environment/Grade Information

Hello Alpesh,

The DRV8834 is not an automotive tailored device but you could still use it in certain automotive applications. You just have to make sure to regulate the current and configure the device such that it complies with automotive regulations.

TI has automotive specific devices. If you can tell me a little bit about your application, I can suggest other devices.

-Are you driving a Stepper or Brush DC motor?

-What is the input voltage range?

-What is the expected output current?

Hello Pablo,

Thanks for your valuable Information,

Below is the requirement for the Stepper Motor Driver,

1) Motor Type :                           Stepper

2) Motor Voltage :                      +5V

3) Motor Resistance :                 5 Ohms

4) Motor Current :-                     1A

5) Motor RMS Current:-             1.41A

6) Function need from Driver :-  Stall detection

My concern:-

I have check IC DRV8889-Q1, but I am confused for the statement mentioned in datasheet " High current capacity per bridge – 2.5-A peak, 1.5-A full-scale, 1.1-A rms."

I thought that : If 1.5 A is the full current then RMS current (1.5*1.41=2.1 A)should be 1.41 times than full current.

So I am confusing that can I use this IC OR not?

Also this IC's samples are not available on TI and it is also not available to be purchase.

Kindly check and share your thought.

Regards,

Alpesh

Hi Alpesh,

The RMS current shown in the DRV8889-Q1 is correct. The calculation should be 1.5/1.41=1.06A rms. 

Given your requirements, you can use the DRV8889-Q1 IC. If you check on the ti.com website, there are some preproduction samples available on the TI inventory.

Hello Pablo,

Thank you for the Information.

I am going to use Stepper Motor as per below Image.

Confusion : - Stepper Motor is operating on 5V and 5 Ohms resistance but the current says 1.41A instead of 1A.

Can you help to solve my confusion? Also Guide me that the DRV8889-Q1 is useful for this Motor or not?

Thanks in advance.

Regards,

Alpesh. 

Hello Alpesh,

The 1.41A is the rated current per Phase when only 1 phase is ON and the other phase is OFF. 1.41^2*5=10W so the input power calculations match up. If both phases are ON, then the rated current would be 1A since 1*5*2=10W. 

The DRV8889-Q1 has a rated full scale current of 1.5A which meets the 1.41A motor specification. It also has an operating voltage range of 4.5V to 45V which will meet the operating voltage rating of 5V for this motor. The DRV8889-Q1 also has stall detection capabilities which is a function that you need for your application. 

You can take a look at the DRV8889-Q1 EVMs here to evaluate the driver with your motor.