TPS63806: TPS63806 to replace TPS63805

Hi  Cage,

i will try to finger out in these days. it is the same case submitted by Jack Johnson, right?

also, could you share me the output voltage and input voltage?

Regards

Tao

Hi Tao

 thanks for your feedback, I'm urgent to get your confirm due to it issue may block our build this week.

its not same case with Jack Johnson submitted

Hi Tao

   does your meaning you need have a test to check the Ripple voltage? right.

Hi  Cage,

that is right,  i need to do bench test to make sure loop is stable with 22uF output cap. for the recommeded output cap of TPS63806 is 2*47uF.

so, please share me the input and output voltage. i will start the test this afternoon.

Regards

Tao

Dear Tao

    thanks for you support for this urgent case. double confirm you will to validate TPS63806 with output capacitor as a 22uF/input is a 10uF capacitor. right?

Input Voltage range is 2.5~3.65V

Output voltage is 3.3V.

system loading max is around 300mA, continued is 40 and 80mA.

Hi  Cage,

please take the attachment as ref

i think there is almost no difference between TPS63805 and TPS63806.

for input cap. i think it depend on your system. you know you will get different performance with different parastic parameters or power supply. be carefull the voltage drop during start-up

Regards

tao

TPS63805 verus TPs63806.pptx

Hello Tao,

In the Powerpoint file you attached, what is the hardware under test?

For 63805 it is the unmodified EVM?

For 63806 is it an EVM which you've modified to use only a single 22uF capacitor on the output?

Hi  Arthur,

Yes, that is correct.

Regards

Tao

Dear Tao

        could you please have complete/bench test for us? please let us know when will it test finish? thanks

Hi  Cage,

i think it is enough for your case. please let me know if you have any other concerns.

Regards

Tao

Hi Tao,

In your powerpoint there are at least 5 curves - yellow, dark blue, light blue, pink, and white.  I can't tell what each curve represents because there is no label.  Also I can't see the scale of volts per division for the dark blue curve on the first slide or scales for any of the curves on the following slides.  I can't tell whether pink or white represents the 63805 or 63806.  I can't see much detail to compare the voltage spikes of the pink and white plots during the PFM switching operation, because they are overlapping.

Can you please add the labels and add another slide showing a FFT comparing the frequency profiles of the two voltage ripple measurements?

Did you measure phase and gain margin to confirm stability of the control loop with the 22uF output capacitor per your message earlier in this thread?  Please share your measurements.

Can you share some message from the TI factory team about the internal design differences between the 805 and 806?   Where do they expect performance differences based on their analysis of the design differences?  Is the internal control loop different between the two?

Thanks,

Arthur