TPS22958 Adjustable Rise Time

masahiko shimizu

Hi,

Could you measure Rise Time at the following condition, please?
Customer would like to know Rise Time at this condition.

- CL=2 [μF]、RL=150 [Ω]、CIN＝1 [μF]、VBIAS=3.3 [V]
- VIN=3.3
- CT=0,220,470,1000,1500,2200,4700,10000pF

and is there calculation formula of SR at Vbias=3.3V?

Best regards,
Shimizu

over 9 years ago

0 Aleksandras_Kaknevicius over 9 years ago

TI__Genius 15740 points

Hi Shimizu,

Using your loading conditions, I took the following data:

Using these numbers gives a linear approximation defined by the equation below:

Rise time [us] = ( 0.711 * CT [pF] ) + 31.7

Let me know if you have any other questions.

Thanks,

Alek Kaknevicius

0 masahiko shimizu over 9 years ago in reply to Aleksandras_Kaknevicius

Guru 11235 points

Hi Alek,

Thank you for your support.
I have a question.

There is value deference between Measured value and calculation value by formula.
Is cause load condition?
"Rise time [us] = ( 0.711 * CT [pF] ) + 31.7" is calculation without load condition?

Thanks,
Shimizu

0 Aleksandras_Kaknevicius over 9 years ago in reply to masahiko shimizu

TI__Genius 15740 points

Hi Shimizu,

The equation Rise time [us] = ( 0.711 * CT [pF] ) + 31.7 is with the load conditions specified (VIN = VBIAS = 3.3V, CIN = 1uF, CL = 2uF, RL = 150Ω). Because there is some variation with the capacitors, the equation will not be perfect. However, it should be a good approximation.

Thanks,

Alek Kaknevicius

0 masahiko shimizu over 9 years ago in reply to Aleksandras_Kaknevicius

Guru 11235 points

Hi Alek,

Thank you for your support.
I understand.

Thanks,
Shimizu

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TPS22958 Adjustable Rise Time