DRV8300: Drive brushed DC motor with DRV8300

One more question about control signal:

As DRV8874 only have two input pin and the logic control mode have shown below:

As DRV8300 need 4 control signal for H-brigh control, it mean we need two extra GPIO for it.

I noticed that DRV8300 have INL inverting version, I think if we select inverting version and tie INL and INH together could achieve the same control logic without changing the software. Am I right? Thanks in advance.

Hi Gabriel, 

I will get you an answer to this later today. Thanks for your patience.

Regards,

Michael

Hi Michael

Thansks for your reply. I am promoting this solution to customer.

As we only use 2-ch of DR8300, what's the recommend connection for unused channel of DRV8300? (Both INX and OUT pin)

Could you help me to confirm that if we design with inverting input configuration of DRV8300, we could achieve the sample logic as DRV8874?

(DRV8874 only have two input control pin IN1 and IN2, and the control logic have shown in previous threads)

Hi Gabriel,

Please ground the inputs of the unused channel.

Since you are using DRV8300 in inverting mode and tying the inputs together then yes the configuration will be the same logic as OUT1 and OUT2.

Thanks,

Michael

Hi Michael

Thanks for your reply. Few more questions about OCP and GVDD supply.

Base on the DRV8300 block diagram GVDD will directly supply the internal gate driver without any voltage regulation.

Any specific requirement for this GVDD power supply? (voltage level? voltage accuracy? voltage ripple?)

In the meantime, we planning to use external OP AMPS+ comparater to achieve OCP and stall protection feature.

What's your reommend method to shut down the gate driver output when overcurrent even happen?

Hi Gabriel,

Yes GVDD will directly supply the internal gate driver as long as long as GVDD doesn't fall under GVDDUV.

We recommend operating with GVDD with a minimum of 4.7V and a maximum of 21.5V.

I think that if you detect an overcurrent event it would be a good idea to stop PWM the inputs. This device doesn't have any SPI communication so you could use a microcontroller and whenever your comparator goes high, you could stop PWM the inputs. 

Thanks,

Michael

Michael

As DRV8300 didn't have any shut down function for the gate driver so OCP protection could only execute by MCU?

So it will be a software overcurrent protection and I afraid the respond time will be too long. 

One more question, what's the purpose and functionality of high-side sensing pin? (SHA/SHB/SHC)?

Hi,

That's a good point, there could be a longer than desired response time depending on the application. Since this is a very simple device, and does not have SPI, I'm not sure what else to suggest other than a MCU. To your question, SHx needs to be tied to the motor windings, as this is how the coil windings get energized to make the motor spin. 

We have other devices in the drv8x family that you may be interested in if DRV8300 doesn't suite your needs. 

Thanks,

Michael

Understood. Thanks for your help.

Best of luck, I will close this thread now.

Thanks,

Michael