TPSM8D6B24: Excel calculator and schematics review

PYTsai

Part Number: TPSM8D6B24

Tool/software:

Can you help review my customer's excel calculator file and schematics attached below ?

we would like to check if any where we can improve the phase marging and gain margin, and also improve the output ripple. thanks !

1881.Copy of 12Vin to 1.8Vout_TPS546x24y_ExcelCalculator_SchematicLayoutChecklist_bodeplot_V2p2_12172024.xlsx

8737.TI_AIP01_VDDPA-Vdd.pdf

8 months ago

0 Calan Elaya 8 months ago

TI__Genius 11435 points

Hello,

Due to TI Holidays, response will be delayed. Please allow Savith some time to respond to this next week.

Thank you,
Calan

0 Savith Kumar Rayakanti 8 months ago in reply to Calan Elaya

TI__Expert 5990 points

Hi PYTSai

This is already answered in the email, is this module stacked ? or are the rails different for 2 different Vouts?

The excel calculator you attached is what I have sent to customer over email

here is my updated excel , with one setting that can help achieve required spec

/cfs-file/__key/communityserver-discussions-components-files/196/1881.Copy-of-12Vin-to-1.8Vout_5F00_TPS546x24y_5F00_ExcelCalculator_5F00_SchematicLayoutChecklist_5F00_bodeplot_5F00_V2p2_5F00_12262024.xlsx

1. increase the frequency to 650kHz

2. Increase the Cout to 2000uF

3.2 ways to adjust compensation

a) pinstrap compensation setting can only do so much from the available options but

b) compensation can be adjusted with PMBus and can be stored to NVM to achieve required transient , ripple, phase margin

below shown section can help you with PMBus compensation code

compensation config : 12 C4 82 65 02 (Hex value)

4. MSEL1 resistors to R1230: 38.3kohm and R1235:68.1kohm

5. if application is not stacked and bothe rails have same spec you can use the above mentioned for the other rail

Thank you

Savith

0 Jackrose Kuo 8 months ago in reply to Savith Kumar Rayakanti

Prodigy 30 points

Hi Savith

For the design case where the rails are different for two different Vouts, another path will follow this configuration as well.

=> MSEL1 resistors should be set to R1230: 38.3 kΩ and R1235: 68.1 kΩ.

For the register configuration, could you send me the corrected firmware loaded file?

By the way, could you share the protection password for that Excel file?

My email is Jackrose_Kuo@tmy.tek.com.

Thanks, Jackrose.

0 Savith Kumar Rayakanti 8 months ago in reply to Jackrose Kuo

TI__Expert 5990 points

Hi Jackrose,

MSEL1 resistors should be set to R1230: 38.3 kΩ and R1235: 68.1 kΩ. will help at startup with new frequency and capacitance to set an acceptable compensation before you tune the compensation with PMBus as mentioned in the e2e to achieve <50mV pk-pk transient spec.
May I know what you are looking for within the excel? when you select a cell it shows the formula of cell .
Can you provide the an csv file which can be exported by the fusion gui for a starting point so that I can make edits to make new for a new file with new settings

But if it helps Attached is the csv file I created to best of my knowledge from Power Fusion GUI Version 7.10.1

/cfs-file/__key/communityserver-discussions-components-files/196/TPS546D24A_5F00_TPSM8D6B24_5F00_Vdd_5F00_1P8_5F00_AIP1_5F00_Address-20-TXT_5F00_12272024.csv

Thank you

Savith

0 Jackrose Kuo 8 months ago in reply to Savith Kumar Rayakanti

Prodigy 30 points

Hi Savith

Thank you for confirming the resistors for both paths.

Regarding Excel, I am seeking the optimal configuration that works with our hardware design to achieve a sufficient phase margin, with the aim of maximizing mitigation/avoid the interference for RF performance.

Is the CSV configuration you provided optimized for our hardware design?

Thanks, Jackrose.

0 Calan Elaya 8 months ago in reply to Jackrose Kuo

TI__Genius 11435 points

Hello,

Due to TI Holidays, response will be delayed. Please allow Savith some time to respond to this next week.

Thank you,

Calan

0 Jackrose Kuo 8 months ago in reply to Calan Elaya

Prodigy 30 points

Happy New Year! Calan, Savith. Thanks for support!

0 Savith Kumar Rayakanti 8 months ago in reply to Jackrose Kuo

TI__Expert 5990 points

Hi Jackrose

1. current excel tab device calculator cells C166 to C168 shows phase margin 42.7kHz, bandwidth 56.5 degrees, Gain margin12.8dB, you can adjust the compensation settings using PMBus with rows 122 to 152 and use the hex code from cell F155 and the CSV is generated with the above loop response

2. As said earlier you can also use pin strap MSel1 to adjust the compensation using rows 66 to 111

Thank you

Savith

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TPSM8D6B24: Excel calculator and schematics review