TPS63050: Peak currents are higher on our PCB design, than what is on the eval board

Pamela Roper

Part Number: TPS63050

Our design is the same as the eval board (and webench) for Vin=3.0-4.2V, Vout=3.6V. Iout = 50uA - 30mA.

When measuring system current (powered by lipol battery, V=4V) Iout between 50uA - 8mA, the peak current is ~60mA (PFM mode). When I connect the eval board to our PCB (our boost removed), the peak currents are ~8mA. Trying to understand why our peak currents are so much higher. Note, the average between the two boosts is the same.

over 3 years ago

0 Yichen Xu over 3 years ago

TI__Expert 4760 points

Hi Pamela,

May I know what this peak current means? Is it inrush current when start-up or peak inductor current at steady state? If it is inrush current, it is related to the input and output capacitance and inductance, and PCB layout.

Best Regards,

Yichen Xu

0 Pamela Roper over 3 years ago in reply to Yichen Xu

Prodigy 80 points

The peaks are there during steady state. Our avg currents are quite low, 50uA - 11mA.

Using eval board with our system:

Using our onboard buck/boost:

Thanks

-Pam

0 Brigitte over 3 years ago in reply to Pamela Roper

TI__Guru 58225 points

Hello Pam,

Please excuse the late response. I am sorry, but I cannot see the pictures you attached. Please re-attach.

In addition, it would be great if you could share your schematic.

0 Yichen Xu over 3 years ago

TI__Expert 4760 points

Hi Pamela,

Is there any update or the issue is solved?
Best Regards,

Yichen

0 Pamela Roper over 3 years ago in reply to Brigitte

Prodigy 80 points

Hi Brigitte,

I've attached a pdf of the scope captures of the TPS63050 with my design and the evaluation board. Both had the same load connected. And captures are during steady state, the MCU and system is in sleep mode.

Maple buck-boost.pdf

0 Yichen Xu over 3 years ago in reply to Pamela Roper

TI__Expert 4760 points

Hi Pamela,

Sorry, for better understanding, please mark these waveforms with its meaning. May I know if the total input and output capacitance are the same when you replace the device with EVM board? Different output capacitance will bring different performance when the device works in PFM. Please keep all parameters the same when comparing.

Best Regards,

Yichen

0 Yichen Xu over 3 years ago in reply to Pamela Roper

TI__Expert 4760 points

Hi Pamela,

Haven't got your reply for a long time. I think it is solved. If not, welcome to contact us.

Best Regards,

Yichen

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TPS63050: Peak currents are higher on our PCB design, than what is on the eval board