TPS65266: Design Implementation

Shifali N

Expert 2085 points

Part Number: TPS65266

Hi,

I am planning to use TPS65266 in my design. My requirement is as below.

Buck1: 1.8V

Buck2: 3.3V

Buck3: 1.15V

Kindly help me in solving below queries:

1. I will be enabling Buck2 first and then Buck1 and Buck3. This should not be a problem.

2. Can I generate 1.15V output from Buck3.

over 3 years ago

0 Lishuang Zhao over 3 years ago

TI__Expert 7500 points

Hi,

1. Yes, the sequence can be set to Buck2-->Buck1-->Buck3. You can refer figure 27 on DS which shows the power sequence (ENx shows each channel can be enable first.)

2. It is okay.

Thanks,

Lishuang

0 Shifali N over 3 years ago in reply to Lishuang Zhao

Expert 2085 points

Hi Lishuang Zhao,

Thankyou for your response.

My design requirement is as below:

1. Vin=5V

2. Buck1: Vout=1.8V Iout=3A

3. Buck2: Vout=3.3V Iout=2A

4. Buck1: Vout=1.15V Iout=2A

Can you confirm whether the Buck regulators can support these output currents for desired output voltage. I'm not able to find this details in datasheet. Kindly confirm the same.

0 Lishuang Zhao over 3 years ago in reply to Shifali N

TI__Expert 7500 points

Yes，TPS65266 can support your above requirements.

Thanks,

Lishuang

0 Shifali N over 3 years ago in reply to Lishuang Zhao

Expert 2085 points

Hi Lishuang,

TPS65266 can support 5.4W from Buck1, 6.6W from Buck2 and 2.3W from Buck3 for Vin=5V. Kindly confirm

0 Lishuang Zhao over 3 years ago in reply to Shifali N

TI__Expert 7500 points

Hi Shifali,

Yes, as long as the input power can support these power.

Thanks,

Lishuang

0 Shifali N over 3 years ago in reply to Lishuang Zhao

Expert 2085 points

Hi,

Thanks Lishuang for your response.

Can you please share any reference schematics for same.

0 Lishuang Zhao over 3 years ago in reply to Shifali N

TI__Expert 7500 points

You can refer to the EVM user guide.

https://www.ti.com/lit/ug/slvuad7a/slvuad7a.pdf

Thanks,

Lishuang

0 Shifali N over 3 years ago in reply to Lishuang Zhao

Expert 2085 points

Hi Lishuang,

How do we calculate CC if the value. I dont know the value of RL. I checked the evaluation module and its 1000pF for all the bucks. Can you please provide an insight on how the value is selected. I am selecting the fc=1/10fsw

0 Ruby Li over 3 years ago in reply to Shifali N

TI__Expert 7430 points

Hi Shifali

RL you mentioned is the load resistor right? It can be calculated by Vout/Io. The value of the CC is figured out based on the equation in the datasheet, but it can be changed. Sometimes we want to simplify the BOM, so the compensation parameters of the three channels may share the same value. 1000pF has been verified to make the EVM works well so I think you can also use 1000pF, if you have any concern about this, you can double-check the loop using pspice model in the Design&Development section in this page: https://www.ti.com/product/TPS65266?utm_source=google&utm_medium=cpc&utm_campaign=app-bsr-null-prodfolderdynamic-cpc-pf-google-sa&utm_content=prodfolddynamic&ds_k=DYNAMIC+SEARCH+ADS&DCM=yes&gclid=EAIaIQobChMIoKvRoKPr8AIVDVVgCh1XOgY-EAAYASAAEgKBs_D_BwE&gclsrc=aw.ds#design-development.

Thanks.

Ruby

0 Young Zhao over 3 years ago

TI__Genius 9280 points

Hi ,

Sorry that I will close this post first as there is no further concern . You can re-open it if you have any other question .

thanks for understanding .

BRs,

Young

0 Shifali N over 3 years ago in reply to Young Zhao

Expert 2085 points

Hi Young,

I have attached the schematics. Can you please review the same.0842.PMIC.pdf

My design requirement is as below:

1. Vin=5V

2. Buck1: Vout=1.8V Iout=3A

3. Buck2: Vout=3.3V Iout=2A

4. Buck1: Vout=1.15V Iout=2A

Can you please confirm what is pin 32 of IC. AGND or GND. In the IC diagram and EVKs its mentioned as AGND. But explanation its mentioned GND. Kindly confirm.

0 Ruby Li over 3 years ago in reply to Shifali N

TI__Expert 7430 points

Hi Shifali

I am looking into this now, and will give you feedback soon. Would you please tell me what is endequipment of the part? If possible, would you please share the power rail of the application? Thanks!

Ruby

0 Ruby Li over 3 years ago in reply to Ruby Li

TI__Expert 7430 points

Hi Shifali

Sorry for the delay. I have reviewed the schematic and it looks good. Pin 32 is AGND.

Thanks.

Ruby

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TPS65266: Design Implementation