TPS55288EVM-045: Noisy on above 6Vout when remove 220uF and bode plot requirement

Roy Chou1

Part Number: TPS55288EVM-045

Hi Team,

I have two questions about using TPS55288EVM-045.

1. When I removed 220uF Cout and I used GUI to set Vout = 6V or above, I could hear noisy on the board. (no load) Do you have idea why this noise occur?

2. Do we have TPS55288EVM-045 bode plot could be our reference?

Roy

over 3 years ago

0 Helen chen over 3 years ago

TI__Mastermind 40080 points

Hi Roy,

At the no load condition, the EVM default works in the PFM mode, hence the output ripple frequency is <20kHz, hence some of us can hear the acoustic noise. With the 220uF cap, the output ripple will gets smaller and lower noise.

Our 400kHz EVM design is based on the ceramic cap +220uF EL cap.

What is your Vin range and Vo/Io range? So that I can send the related bode plot to you.

0 Roy Chou1 over 3 years ago in reply to Helen chen

TI__Genius 12565 points

Hi Helen,

Thank you for your answer, we measure the low frequency ripple on Vout. We agree the noise is from the ripple.

For Bode plot, could we measure the below conditions based on original EVM components.

1. Vin = 13.5V, Vout = 6V, Iout = 5A

2. Vin = 4V, Vout = 6V, Iout = 5A

3. Vin = 6V, Vout = 6V, Iout = 5A

Regards,

Roy

0 Helen chen over 3 years ago in reply to Roy Chou1

TI__Mastermind 40080 points

Hi Roy,

Please check the attached file. E2E customer.zip

0 Helen chen over 3 years ago in reply to Roy Chou1

TI__Mastermind 40080 points

Hi Roy,

Please check the attached file. 0815.E2E customer.zip

0 Roy Chou1 over 3 years ago in reply to Helen chen

TI__Genius 12565 points

Helen,

Thank you for your help.

Roy

0 Helen chen over 3 years ago in reply to Roy Chou1

TI__Mastermind 40080 points

You're welcome Roy.

Could you please share the end application with us?

Power management

Power management forum

TPS55288EVM-045: Noisy on above 6Vout when remove 220uF and bode plot requirement