TPS65266: TPS65266RHBT

Jay Kevalramani

Part Number: TPS65266
Other Parts Discussed in Thread: TPSM861253,

Hello everyone,
We are planning to utilize the TPS65266RHBT multi-switcher IC to meet specific parameters for our project. Here are the requirements:
Input Voltage: 5V
Output1: 0.9V @ 3A
Output2: 1.5V @ 1.5A
Output3: 1.8V @ 1.5A
Additionally, we are employing the TPSM861253RDXR switcher to achieve 3.3V @ 500mA for another aspect of our design.
We have drafted a schematic accordingly and have attached it for your review. We eagerly await your feedback and any suggestions you may have.
Regards,
Jay

over 1 year ago

+1 Lucia Gao over 1 year ago

TI__Mastermind 30671 points

Hi Jay,

Could you pls kindly share me what is your end equipment or application where TPS65266 and TPSM861253 are used?

I can't find the schematic, Could you please attach it?

Thanks!

BRs

Lucia

0 Jay Kevalramani over 1 year ago

Prodigy 30 points

I have attached the schematic please find this and help me with this

0 Jay Kevalramani over 1 year ago in reply to Lucia Gao

Prodigy 30 points

Hi Lucia Gao ,
Please find the attached schematic. My end equipment is to get multiple power rails required to power up my MCU.
Regards
Jay

+1 Lucia Gao over 1 year ago in reply to Jay Kevalramani

TI__Mastermind 30671 points

Hi Jay,

See my comments shown below:

(1) Pls add one 0.1uF input capacitor for high frequency filtering,

(2) You can reserve a place for feedforward capacitor which in parallel with feedback top resistor in case you need optimize loop response performance. It's not a must requirement but a recommendation.

Thanks!

BRs

Lucia

0 Jay Kevalramani over 1 year ago in reply to Lucia Gao

Prodigy 30 points

Hi Lucia,
Do I need to add 0.1uF to each Vin rails ?
Regards
Jay

0 Lucia Gao over 1 year ago in reply to Jay Kevalramani

TI__Mastermind 30671 points

Hi Jay,

Better to be. And place it as close as possible to each VIN pin. Thanks!

BRs

Lucia

0 Jay Kevalramani over 1 year ago in reply to Lucia Gao

Prodigy 30 points

Hi Lucia ,
(1)Regarding feedforward capacitor what value is recommended for good optimization.
(2)Please also verify my voltage divider value of resistor will give me my required output?
Regards
Jay

0 Lucia Gao over 1 year ago in reply to Jay Kevalramani

TI__Mastermind 30671 points

Hi Jay,

Type 3 compensation can be implemented with the addition of one capacitor, C1. This allows for slightly higher loop bandwidths and higher phase margins. if used, C1 is calculated with below equation:

Thanks!

BRs

Lucia

0 Lucia Gao over 1 year ago in reply to Lucia Gao

TI__Mastermind 30671 points

And voltage divider value of resistor is no problem. Thanks!

BRs

Lucia

0 Pratik Panchal1 over 1 year ago in reply to Lucia Gao

Prodigy 225 points

Hello Lucia

Let us know the no load current for this part#

0 Lucia Gao over 1 year ago in reply to Pratik Panchal1

TI__Mastermind 30671 points

(+) TPS65266: What is the no load current - Power management forum - Power management - TI E2E support forums

See my comments above. Thanks!

BRs

Lucia

0 Pratik Panchal1 over 1 year ago in reply to Lucia Gao

Prodigy 225 points

Hello Lucia,

My bad i am looking for the no load current for the TPSM861253 IC.

0 Lucia Gao over 1 year ago in reply to Pratik Panchal1

TI__Mastermind 30671 points

Hi Pratik,

I would suggest you can create a separate thread to discuss about questions related with TPSM861253, each thread for each different part. There will be expert who supports TPSM861253 that can help you.

Thanks!

BRs

Lucia

0 Jay Kevalramani over 1 year ago in reply to Lucia Gao

Prodigy 30 points

Hi Lucia ,

For the required output parameters

Output 1@ 0.9V/2.5A,

Output 2@1.5V/1A,

Output 3@1.8V/1.5A

We are using the value of inductor with part number SRN4018-2R2M

do the value of L4,L5,L6 as its saturation current is 2.9A. please help me confirm with this and also please verify the compensation network I have attach below in the schematics snapshot.

Regards

Jay

0 Lucia Gao over 1 year ago in reply to Jay Kevalramani

TI__Mastermind 30671 points

Hi Jay,

Pls let me check soon. Thanks!

BRs

Lucia

0 Lucia Gao over 1 year ago in reply to Lucia Gao

TI__Mastermind 30671 points

Hi Jay,

For inductor, In any case, the inductor saturation current must not be less than the maximum peak inductor current at full load. Ideally, the saturation current rating of the inductor is at least as large as the high-side switch current limit, IHS_LIMIT. This ensures that the inductor does not saturate even during a short circuit on the output. When the inductor core material saturates, the inductance falls to a very low value, causing the inductor current to rise very rapidly.

For compensation circuit, the snapshot you shared is of low resolution. I can't figure out the value. Could you pls re-send me with higher resolution.

Thanks!

BRs

Lucia

0 Jay Kevalramani over 1 year ago in reply to Lucia Gao

Prodigy 30 points

Hi lucia

Please check out for the compensation circuit attached and check if it is ok with perspective of EMI and stability, if not then please provide the calculation sheet for the same.

Regards,

Jay

0 Lucia Gao over 1 year ago in reply to Jay Kevalramani

TI__Mastermind 30671 points

Hi Jay,

I would suggest you can check loop stability with below Pspice average model.

TPS65266 Unencrypted PSpice Average Model Package (Rev. A)

Thanks!

BRs

Lucia