DRV8714-Q1: question about Split HS and LS control mode

Jay wang

Expert 3581 points

Part Number: DRV8714-Q1

Hi expert

i saw the following description in 8714 datasheet. i have some questions

Q1: how to understand the "Inactive" word?

Q2:in the above picture, GH1 and GL2 are connected for controlling relay? why not are GH1 and GL1 connected?

Q3: in my design, i want to only use GL1/2/3/4 as low-side(like below picture shown) to control four independent relays.(only using low-side to control relay, not using high-side) is it ok?

over 1 year ago

0 Shinya Morita over 1 year ago

TI__Mastermind 46035 points

Hi,

Thank you for your questions.

1) By Inactive state, pre-driver drive external FET's gate as "Pull down". Therefore Vgs of FET are low, then FET is OFF.

2) GH1 and GL2 is connected because this is intention for this split mode. Key point is we need SH1 and SH2. GH1 and SH1 is pair, GL2 and SH2 is pair. This is how split mode works.

3) Yes. Then connection should be like bellow.

regards

Shinya Morita

0 Jay wang over 1 year ago in reply to Shinya Morita

TI__Expert 3581 points

Hi Shinya

i have a further question about Q3.

from my narrow view, one pcs DRV8714 cannot be as 4 pcs HS(using GH1/2/3/4 control 4 pcs relays) and 4 pcs LS(using GL1/2/3/4 to control 4pcs relays) to control 8 relays. am i right?

0 Shinya Morita over 1 year ago in reply to Jay wang

TI__Mastermind 46035 points

Hi Jay,

Yes, your understanding is correct. Cannot control 8 relays, up to 4 relays. Each HBx(Half Bridge) can be used as HB, HS or LS. Not HS and LS.

regards

Shinya Morita

0 Jay wang over 1 year ago in reply to Shinya Morita

TI__Expert 3581 points

hi Shinya

thank you for your comments.

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DRV8714-Q1: question about Split HS and LS control mode