TPS62561: Max / Min time for Start-up and Ramp

Shunsuke Nagata

Genius 12590 points

Part Number: TPS62561

Hi,

Could you please give me Min and Max time for tStart_up ( Start-up time) and tRamp ( Vout ramp-up time)?

There are typical value in datasheet but I would like to know the minimum and maximum value.

Regards,
Nagata.

over 5 years ago

0 Alfonso Furio over 5 years ago

TI__Expert 3645 points

Hello,
please use this value only as a reference, we can't recommend anything.
t_start : typical ± 18%
t_ramp : typical ± 33%
Can you give me more detail regarding your application? Furthermore, I suggest to use a newer device.

0 Shunsuke Nagata over 5 years ago in reply to Alfonso Furio

TI__Genius 12590 points

Hi,

Thank you for your supports.
I would like to know the time from Enable to Start switching. With your infomation, The min time may be 78us. The time should be short time compare with datasheet figure 16.

Could you please let me know the MIN/MAX time?

Regards,
Nagata.

0 Alfonso Furio over 5 years ago in reply to Shunsuke Nagata

TI__Expert 3645 points

Hello,
I found the data you requested.
tramp: min= 159; max= 343
tstart-up: min= 326; max= 581

0 Shunsuke Nagata over 5 years ago in reply to Alfonso Furio

TI__Genius 12590 points

Alfonso,

The time form enabling to Vout will be 326us as min with your infomation. But the figure 16 shows about 200us...
Could you please check if 326us(Min) and 581us(Max) are correct?

Regards,
Nagata.

0 user5928270 over 5 years ago in reply to Shunsuke Nagata

Prodigy 20 points

Alfonso,

I also need this information.

I want to know the minimum and maximum values of "?" In this figure.

regards,

Otani

0 Alfonso Furio over 5 years ago in reply to Shunsuke Nagata

TI__Expert 3645 points

Hello,
The time you are looking for is the difference between (tstartup- tramp). Since these two times have a wide variation, there will be a set of value that gives you 200us.

0 Alfonso Furio over 5 years ago in reply to user5928270

TI__Expert 3645 points

Hello,
The time you highligted is the difference between (tstartup- tramp). Since these two times have a wide variation, you have different sets of this time you are looking for. The documentation shows only the typical value and only this value is ensured.

0 user5928270 over 5 years ago in reply to Alfonso Furio

Prodigy 20 points

Hello,

Thank you for your answer.

Does your answer mean Min. = - 17 (0), Max. = 422 ?
If I could not understand correctly, I'm sorry.

0 Shunsuke Nagata over 5 years ago in reply to user5928270

TI__Genius 12590 points

Hi, Alfonso,

We would like to know definition for the time "?"

Which calculation is correct?
A)
Min "?" time : tstart-up( min ) - tramp( max) = -17us
Max "?" time : tstart-up( max) - tramp(min) = 422us
B)
Min "?" time : tstart-up( min ) - tramp( min ) = 167us
Max "?" time : tstart-up( max) - tramp(max) = 238us

If the B) is correct, will tstart-up be minimum (maximum) when tramp is minimum (maximum)?

Regards,
Nagata.

0 Alfonso Furio over 5 years ago in reply to Shunsuke Nagata

TI__Expert 3645 points

Hello,
I already answered this question. The min and max value are not the absolute max and min but the extreme of a range with a certain level of confidence. We can't extend the specification of our device on this forum. The parameter in the documentation are only typical, and I couldn't comment further regarding the min and max values. I will contact you separately by email for any other clarification.

Power management

Power management forum

TPS62561: Max / Min time for Start-up and Ramp