DRV8714-Q1: DRV8714-Q1 GH1 is always high when decreased DVDD from 5V to 2.5V and back to 5V

Jayden Li

Part Number: DRV8714-Q1

Tool/software:

Hi team,

Here is a new question about DRV8714-Q1.

Customer found that the GH1 is always high after a DVDD cycle from 5V->2.5V->5V。 Shown as below: CH1 is PWM input, CH2 is the GH1.

Support need: What is the root cause of this phenomenon?

Thanks!

Jayden Li

3 months ago

0 Jayden Li 3 months ago

TI__Expert 3205 points

Hi team,

Customer also confirmed that no fault reported.

Thanks!

Jayden Li

0 Shinya Morita 3 months ago in reply to Jayden Li

TI__Mastermind 44155 points

Hi Jayden,

You are posting on public E2E.

I guess your customer is considering why GH is high while OUTPUT is expected be HiZ?

Please refer this FAQ. While output is HiZ, both HS and LS FET are OFF. Since SH is pulled to PVDD, GH is also ~PVDD, then HS gate is OFF because VGS of external HS FET = 0V.

(+) DRV8714-Q1: DRV8714-Q1 - Motor drivers forum - Motor drivers - TI E2E support forums

regards

Shinya

0 Jayden Li 3 months ago in reply to Shinya Morita

TI__Expert 3205 points

Hi Shinya,

I don't think you got my question. Is it possible that we had a quick call to clarify my question?

Thanks!

Jayden Li

0 Jayden Li 3 months ago in reply to Jayden Li

TI__Expert 3205 points

Shinya,

Let me clarify this issue more clearly:

When DVDD is 5V, the output is sync w/ PWM input shown as below:

Then they decreased the DVDD from 5V to 2.5V and back to 5V, then they found the GH1 is always high and not sync w/ PWM input.

So the question is why GH has this difference after through a 5V->2.5V->5V cycle?

Thanks!

Jayden Li

0 Shinya Morita 3 months ago in reply to Jayden Li

TI__Mastermind 44155 points

Hi Jayden,

Thank you for your questions.

When DVDD goes to 2.5V, DRV's digital core has the reset. Therefore, all SPI registers back to default setting.

With SPI register default condition, EN_DRV=0. Therefore output/SH is OFF/HiZ.

With OUTPUT=HiZ, GH should be ~PVDD. Please refer the link of FAQ I have attached in previous post. It explains why GH= ~PVDD ("High" as your customer mentioned).

Thanks,

regards

Shinya