DS14185 RS232 Driver Power-On Sequence

g.f.

Hi,

I have a question about RS232 Driver "DS14185" power-on sequence.
www.ti.com/.../snls093c.pdf

There are 3 power supply (Vcc= 5V, V+= +12V, V-= -12V).
Is there specified power-on sequence for these power supply?
In DS14185 datasheet, there seem no specified power-on sequence.

In our customer's board, Vcc are supplied first and then V+/V- are supplied.
And there is delay until V+/V-is supplied after Vcc was supplied.
Is there any problem for this delay?

best regards,
g.f.

over 9 years ago

0 Michael Lu (Santa Clara) over 9 years ago

TI__Mastermind 29655 points

Hi g.f.,

Since the Vcc power supply is relevant to device internal logic and the V+ and V- pins are related to the output driver supply levels, I would advise supplying Vcc first, then V+/V- afterwards. I do not see any specific issues with the setup you currently have.

Regards,

Michael

0 g.f. over 9 years ago in reply to Michael Lu (Santa Clara)

Guru 15520 points

Hi Michael,

I understood that I can supply Vcc first.
By the way, atcually this question was from my customer for their new product.
In their previous product, V+/V- was supplied first, then Vcc. In this case, is there any known issue?

best regards,
g.f.

0 Michael Lu (Santa Clara) over 9 years ago in reply to g.f.

TI__Mastermind 29655 points

Hi g.f.,

Since this part has been publicly available for a while, we do not have a recent list of known issues that we can refer back to.

If the previous product has been working already without issue, then I do not see a strong need for the customer to re-do the power sequence structure.

Thanks,

Michael

0 g.f. over 9 years ago in reply to Michael Lu (Santa Clara)

Guru 15520 points

Hi Michael,

Thank you for the reply.
I understood.

best regards,
g.f.

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DS14185 RS232 Driver Power-On Sequence