Power up sequence of SN74AVC1T45

Shreenidhi Patil

My customer VNL has used a "SN74AVC1T45DBVR" in one of the design.

So as per its datasheet, Power-Up sequence for VCCA & VCCB to be maintained as follows:
1. Connect gnd before any supply is applied

2 power up VccA

3.Vccb can be ramped up along with or after Vcca

And the operating voltage of VCCA & VCCB is 1.2V-3.6V.

Is point 3 to be followed for whole voltage range OR to be followed till the device get entered into operating range?
Kindly also comment on the attached waveform for power-up sequencing of VCCA, VCCB.

Also i have attached the powering up sequence
please share your views on the same

over 7 years ago

0 Nirav Patel over 7 years ago

TI__Expert 6335 points

Shreenidhi,

The power sequencing steps are to be maintained during the entire power ramp. Has the customer observed any functional issues with their existing power ramp scheme?

Best Regards,
Nirav

0 Shreenidhi Patil over 7 years ago in reply to Nirav Patel

TI__Expert 3126 points

HI nirav ,

The customer is not facing any issue in particular ,
i think he wants to verify if what he is doing is correct and wont cause any issue later

If you see the wave forms , Vcc_B is a step response as soon after Vcca > 2

if this acceptable ?
Or should he wait for Vcc A to completely ramp u[ to 3.6V

Thank you for your quick and prompt response

0 Nirav Patel over 7 years ago in reply to Shreenidhi Patil

TI__Expert 6335 points

Shreenidhi,

My recommendation is to keep VCCA >= VCCB during power up. Please let me know if this is acceptable to the customer. Thanks.

Best Regards,
Nirav

0 Shreenidhi Patil over 7 years ago in reply to Nirav Patel

TI__Expert 3126 points

they cannot delay VccB step any further ,
This is the best waveform they could get

I apologize for the repetitive questioning
The only reason is that i do not want to loose socket for this reason

Thank you for the quick response

0 Shreenidhi Patil over 7 years ago in reply to Shreenidhi Patil

TI__Expert 3126 points

Hello team ,
Can you please help me out here

0 Shreenidhi Patil over 7 years ago in reply to Shreenidhi Patil

TI__Expert 3126 points

Hello team ,
can i get a definite yes or no ?
is the power sequencing followed but he customer acceptable or not ?

Please reply as my customer is following up hard
Thank you

0 aozer over 7 years ago in reply to Shreenidhi Patil

TI__Mastermind 23855 points

Hello,

Sorry for the late response. I think if they are not currently seeing any issues with their power up sequence it would be acceptable to continue to use this sequence.

Logic

Logic forum

Power up sequence of SN74AVC1T45