DRV8308 sequence start running

Alberto Lubeiro

Prodigy 170 points

Other Parts Discussed in Thread: DRV8308

Hi everyone,

Im working with the driver DRV8308 but so far i didnt achieved to make it works.

I have doubts about the sequence or steps i must follow to do so.

First of all, let me show you my registers table

Address	Value
0x00	0x6941
0x01	0x0000
0x02	0x04B4
0x03	0x5F82
0x04	0x0350
0x05	0x300C
0x06	0x0258
0x07	0x0140
0x08	0x012C
0x09	0x02BC
0x0A	0xF140
0x0B	0x09C4

Well, so far im able to write these registers and to read them so i can check they are correctly written.

Once this is done it is suppossed that the ENABLE pin is active already, because the ENPOL bit is = 1 (ENABLE active with low level) and the GPIO is low.

But i cant see the motor working.

My ask is ¿what is the correct sequence so the motor starts moving?

Thanks and best reagrds

over 9 years ago

0 Rick Duncan over 9 years ago

TI__Guru** 114905 points

Hi Alberto,

Our experts have been notified and should reply soon.

0 Alberto Lubeiro over 9 years ago in reply to Rick Duncan

Prodigy 170 points

Hi Rick,

I forgot saying that im also applying a 25Khz signal at "CLKIN" pin.

thanks

0 Phil Beard over 9 years ago in reply to Alberto Lubeiro

TI__Expert 4650 points

Hi Alberto,

A typical startup sequence would look something like this:

1.) Apply Power

2.) Pull RESET pin Logic Low

3.) Write SPI Registers

4.) Begin input CLKIN PWM.

Are you getting any fault reporting when you try to start the motor is it just not starting at all?

0 Alberto Lubeiro over 9 years ago in reply to Phil Beard

Prodigy 170 points

Hi Phil,

Fisrt of all, thanks for answering.
As for the sequence i follow, so far i am doing the following.

1- Apply power
2- Apply power to the halls
3- A little delay of 50ms to stablish the voltage
4- Write SPI Registers
5- Start the PWM at 25Khz
6- A delay of 5sec
7- Read the fail register

When i read the register i get a 0x79
The reset pin in NC (it has a pull down)

The motor doesnt move at all. It makes a little noise though.

If I make any progress ill post here.

Thanks and best regards.

0 Alberto Lubeiro over 9 years ago in reply to Alberto Lubeiro

Prodigy 170 points

Hi Phil,

Now i am reading 0x01 (OPC fail) but the motor has no load connected.
- Vfetocp and Tocp are configured as their maximun values, this is, 1000mV and 5us
- Vsenseocp = 0.25V but here i have 1V which last 5us (maximun allowed time) at ISENSE pin, there is not a sense resistance though cause i have made a shortcut.

I cant attach the pic of the Isense voltage.

Any help will be apreciated.

Thanks and regards

0 Phil Beard over 9 years ago in reply to Alberto Lubeiro

TI__Expert 4650 points

Hi Alberto,

Are you sure the Motor Phases and Hall Sensors are connected correctly? The motor may be trying to start but improper commutation is causing an OCP condition.

Do you have a schematic of you hall sensor / motor phase connections and a motor datasheet?

Thanks,

0 Alberto Lubeiro over 9 years ago in reply to Phil Beard

Prodigy 170 points

Hi Phil,

I have achieved to make the motor run.
I have just try it with other PCB. We don't know if the driver has broken trying to move the motor or what could happen.

Thanks for yor help and best regards.

Alberto

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DRV8308 sequence start running