TPS40170 Enable pin current

Hi

I would like to ask additional question.

Can EN pin connect to UVLO pin directly?

Our customer would like to use this device with that configuration.
However UVLO pin has internal current source.
Is there any concerns if the EN pin connect to UVLO pin directly?
(This is why I ask the previous question.)

Regards,
Koji Hamamoto

Hi

Could you follow this post?

Regards,
Koji Hamamoto

Let me see if I can find someone to assist you.

Hi Koji,

The 300nA is maximum souring current goes out of EN pin. The test condition is EN voltage is 0V.

We don't have the data when EN voltage is 1V.

What's the purpose to connect EN to UVLO pin?

Can customer consider to connect EN to VDD pin?

Thanks

Qian

Hi Qian,

Thank you for your reply.

The purpose is that they would like to reduce the PCB pattern area.
If these pins connected together, they can set the UVLO by external divider.
(They does not need to connect the EN pin individually in this case.)

Also they can pull down to GND the connected point if they would like to disenable.

The concerns is that the EN pin can sink the UVLO hysteresis current if the EN pin connected to UVLO pin.  

How can we estimate the UVLO hysteresis voltage when EN pin connect to UVLO pin? 

Regards,

Koji Hamamoto

Hi Koji,

I see. Because UVLO pin is next to EN, so customer want to connect EN pin to UVLO pin to save PCB area.

Because the souring curreng from EN pin alway exist, it does not affect UVLO hysteresis.

Thanks

Qian

Hi Qian,

Thank you.

Can I ask additional question?

1. As you mentioned above post, the sourcing current from EN pin always exist.
Is it the same current at any VEN conditions? (300nA max @0~8.8V?)

2. On the datasheet , the sink current into ENpin should not be exceed 10uA.
Is it the same sink current at any VEN condition?

We are concerned that the sink current and source current are different at some EN pin voltage.

Regards,
Koji Hamamoto

Hi

Could you follow the above post ?

Regards,
Koji Hamamoto

Hi Koji,

1. As you mentioned above post, the sourcing current from EN pin always exist.
Is it the same current at any VEN conditions? (300nA max @0~8.8V?)

Qian: The source current should be same when EN voltage is from 0V to 8.8V.

2. On the datasheet , the sink current into ENpin should not be exceed 10uA.
Is it the same sink current at any VEN condition?

Qian: Where is this information on datasheet?

Thanks

Qian

Hi

I apologize for the delay in replying to you.

Regarding the your question, there is mentioned about the sink current on the datasheet.

P,12  http://www.tij.co.jp/jp/lit/ds/symlink/tps40170.pdf

Regards,

Koji Hamamoto

Hi

Regarding the sink current of EN pin, is that depended on EN voltage?

Regards,
Koji Hamamoto