TPS7A8101 noise spec

Hi Masa,

Please allow us up to two weeks to take these measurements for you.  As all three of your Cnr caps are relatively close in capacitance, please note that there will not be much variation in the noise of these conditions.

Very Respectfully,

Ryan

Hi Ryan

Thank you for your quick response!
We will talk with coustomer to wait for 2 weeks.

Best regards,

masa

Hi Ryan

I am very sorry.

Would you  measure additional following below conditions?

Vin:5.6V Vout:5.1V Cnr:10nF Cbypass:10nF

All condition is below.

Vin:5.6V

Vout:5.1V

Iout:0.5A

Cin=10uF

Cout=10uF

①Cnr=10nF  Cbypass=470nF

②Cnr=5nF Cbypass=470nF

③Cnr=15nF Cbypass=470nF

④Cnr=10nF  Cbypass=10nF

⑤Cnr=5nF Cbypass=10nF

⑥Cnr=15nF Cbypass=10nF

Best regards,

masa

Hi Masa,

Very Respectfully,

Ryan

Hi Ryan

Thank you for your mesurement data and quick responce!

Best regards,

masa

Hi Ryan-san

Thank you for your support this device.

Do you have a recomend Cnr and Cbypass value?

Coustomer condition
Start up time : Less than 5ms
Output noise  : Less than 30uV RMS(10Hz-100kHz)
R1 : 10kΩ or 13kΩ

We calculate is below.
Cnr:10nF
Cbypass:130nF
RFB1:13kΩ
→start up time is 5.24ms.

Cnr:10nF
Cbypass:170nF
RFB1:10kΩ
→start up time is 5.27

Best regards,

masa

Hi Masa-san,

You can use the following equation to help calculate start-up time:

start-up time = 170000*Cnr + 3*(Cbypass*RFB1)

Very Respectfully,

Ryan

Hi Ryan-san

Thank you for your reply.

I have a one question.

start-up time = 170000*Cnr + 3*(Cbypass*RFB1)

Regarding this start-up time,I will think need include charging Cnr time.

This delay time is also include your equation?
Or this equation include deley time?

Because delay time will be longer Cnr is large value.

So this is correct, I need to think deley time.

(coustomer need a less than 5ms....)

Best regards,

masa