TPS2549-Q1 / VIN-EN direct connection

Kuramochi Tadahiko

Other Parts Discussed in Thread: TPS2549-Q1

Hi,

I received the following question from my customer.

Does the TPS2549-Q1 allow connecting VIN and EN directly?

(Other-bender's device has caused problem with above connection on their circuit. The problem is what the device doesn't change to enable)

Best Regards,

Kuramochi

over 8 years ago

0 Eric Wright over 8 years ago

TI__Mastermind 42795 points

EN has the same voltage rating as IN so it is OK to directly connect EN and IN together.

0 Kuramochi Tadahiko over 8 years ago in reply to Eric Wright

Guru 28715 points

Eric-san,

My customer hopes to be mentioned what this is no problem. on the datasheet.
Please refer it.

Best Regards,
Kuramochi

0 Eric Wright over 8 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 42795 points

EN has the same MAX voltage rating as IN so it is OK to directly connect EN and IN together.

0 Kuramochi Tadahiko over 8 years ago in reply to Eric Wright

Guru 28715 points

Hi Eric-san,

Thank you for your information.

Connecting the EN pin with VIN has been occurred problem before on my customer's circuit.
The IC is not manufactured by TI.

It is why they mind this.

Best Regards,
Kuramochi

0 Kuramochi Tadahiko over 8 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Eric-san,

My customer is requesting to show the evidence that the problem is not happened by connecting EN and IN together.

Can you show me anything?

Best Regards,

Kuramochi

0 Eric Wright over 8 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 42795 points

Hi Kuramochi-san,

Here is evidence using the EVM with a direct connection from IN to EN (red jumper wire). The input voltage is >6.5V and the OUT voltage is 6.52V.

0 Kuramochi Tadahiko over 8 years ago in reply to Eric Wright

Guru 28715 points

Eric-san,

Thank you for your answer.
I appreciate you support.

I received an additional request...
They request to confirm what this problem is not occurred over operating temperature.
For the present, could you confirm it with dryer and cold spray?
Sorry for my trouble.

Best Regards,
Kuramochi

0 Eric Wright over 8 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 42795 points

Kuramochi,

The operation of the TPS2549Q1 is guaranteed when operated within the recommended ratings. Much testing was done over temperature and supply voltage on many devices (over 30) and lots (3x since this is an automotive grade device) to verify this reliability.

I will also mention that the device test hardware which performs the many hundreds of tests over temperature and supply voltage will make the direct connection of EN to IN so there is no need to verify this again. Hopefully, this information is enough to give your customer confidence.

What probably occurred in the customer's past experience is that they exceeded the other manufacturers ABS MAX ratings on the pin and that was why it failed (I suspect there wasn't a design defect that caused the issue).

0 Kuramochi Tadahiko over 8 years ago in reply to Eric Wright

Guru 28715 points

Eric-san,

Thank you for your attentive support.
I'll let my customer accept.

Best Regards,
Kuramochi

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TPS2549-Q1 / VIN-EN direct connection