TPS23756: 如何實現power good function

eason

Prodigy 20 points

Part Number: TPS23756
Other Parts Discussed in Thread: TPS2378

想要實現一個function ,當TPS23756 output ready ,turn on MOS(PQ5) 連接兩個P_GND,所以不知TPS23756 哪個PIN 可做到? PPD PIN or ?

8 个月前

0 Lydia 8 个月前

TI__Mastermind 31685 points

您好，感谢您对TI产品的关注！为更加有效地解决您的问题，我需要多一些时间查看这款芯片，稍后会为您解答。

0 Lydia 8 个月前回复 Lydia

TI__Mastermind 31685 points

您好，感谢您对TI产品的关注！由于问题比较复杂，我需要询问更了解这款芯片的TI资深工程师，再为您解答，一旦得到回复会立即回复给您。

0 eason 8 个月前回复 Lydia

Prodigy 20 points

Please tell me when you will get the answer,感謝~

0 Lydia 8 个月前回复 eason

TI__Mastermind 31685 points

Hi,

I need to ask a senior TI engineer who knows more about this chip, and then answer for you, and I will reply to you as soon as I get a reply.

0 Lydia 8 个月前回复 Lydia

TI__Mastermind 31685 points

Hi Eason，

May I know where are the two P_GND grounds? TPS23756 does not have a dedicated power good pin, but if PoE is your only power source, you may consider to use DC/DC's output as indicator.

Best regards,

Lydia

0 eason 8 个月前回复 Lydia

Prodigy 20 points

Hi, this propose for the PD+PSE design,plan to the PD gnd as PGND , PSE gnd as PD_GND1. When the PD power ready ( to control PQ5 ,let PGND to connected to PD_GND1). Avoid seeing PD+PSE at the same time.

Thanks!

0 Lydia 8 个月前回复 eason

TI__Mastermind 31685 points

Hi ,

Thanks for your information.

Do you have a PoE passthrough structure? Like below but can have different devices.

If so, we normally not disconnect PSE's and PD's ground, but set a delay for the PSE. If PSE has enable or reset pin, you can set a RC delay to make the PSE slower turn on to avoid causing trouble with PD's start up. Also TI's PDs without PWM controller (like TPS2378, TPS2372-3, TPS2372-4) have PG pins can be considered too.

Best regards,

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TPS23756: 如何實現power good function