TPA3255EVM: TPA3255DDVR

Muhammad Abdullah

Part Number: TPA3255EVM
Other Parts Discussed in Thread: TPA3255

Hello,

I've encountered some challenges in designing a product that involves using a TPA3255EVM evaluation board. Initially, the evaluation board performed well in powering a small three-phase motor, meeting the product requirements effectively.

However, when I designed my PCB based on the TPA3255EVM schematic and sourced the chip from Mouser (refer to the link), the performance fell short. The new PCB doesn't deliver as much power as the development board, despite generating a similar voltage waveform. It appears unable to provide sufficient current to drive the motor under load conditions. When increasing the voltage to start the motor, it runs at lower voltages, but under even a slight load, the waveform disappears, resulting in a flat line. Additionally, the motor struggles to initiate movement at higher voltages.

Comparing this to the development board, I never encountered these issues. I am uncertain if the chip on my board is identical to the one on the development board.

Could you help me understand if the chip I am using matches the one employed in the development board? I have also linked the schematic of the amplifier part of PCB.

https://www.mouser.co.uk/ProductDetail/Texas-Instruments/TPA3255DDVR?qs=KuuZdrM3jLz8froI3AXsFA%3D%3D

Thanks,

Abdullah

over 1 year ago

0 Luis Fernandes de Pina over 1 year ago

TI__Genius 14640 points

Hello Abdullah,

DO you have a higher resolution picture of the schematic? It's somewhat hard to see. What was your layer stackup and copper thickness on your PCB? do you have an image of your PCB Layout?

That mouser link looks like the correct device but if you had the lot information on the sample you bought on the bag/box/reel you received i could look that up as well.
best regards,
Luis

0 Muhammad Abdullah over 1 year ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hello Luis,

Thank you for your prompt reply.

I have attached the PDF files for the schematic and PCB layout images.

The PCB comprises four layers, and the copper thickness is 0.2mm.

We have procured a reel of TPA3255.

Schematic

PCB

Best regards,

Abdullah

0 Muhammad Abdullah over 1 year ago in reply to Muhammad Abdullah

Prodigy 10 points

Hello,

I'll be on holiday and will get back to you on Monday, December 18th.

Best regards,

Abdullah

0 Luis Fernandes de Pina over 1 year ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Abdullah,

Enjoy your holiday. Will respond here for further comments for you to look at on your return.

best regards,
luis

0 Muhammad Abdullah over 1 year ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hi Luis,

I am back from holiday Do you have any comments on my PCB?

Best regards,

Abdullah

0 Shadow He over 1 year ago in reply to Muhammad Abdullah

TI__Mastermind 40070 points

Hi Abdullah

Luis may not in the office today, you could e-mail to luisvf@ti.com to contact him. Thank you.

0 Luis Fernandes de Pina over 1 year ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Abdullah,

For the PCB diagram you had a composite image but wanted to confirm if you had a ground copper pour on all the layers of your PCB?

How is your heatsink compared to that of the EVM?

What does your PVDD waveform look under a load before the device shuts down?

best regards,
Luis

0 Muhammad Abdullah over 1 year ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hi Luis,

All four layers of PCB have grounded copper, I deleted the grounded layers so you can see traces more clearly. I have linked the new image with the ground layers.

I have got the identical heatsink.

I am using three channels to produce three three-phase sine waves. I have linked the before and after images when the device shuts down.

https://matrixts-my.sharepoint.com/:f:/g/personal/muhammad_abdullah_matrixtsl_com/EnIH6dbQAkJOqZvWJ1ebBTYByRp9RgIFKl0AHGxy1P8mHA?e=QDOPKm

Best regards,

Abdullah

0 Luis Fernandes de Pina over 1 year ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Abdullah,

For your PVDD supply voltage, what is the source of this 30V you are using is this a bench top supply or generated in some other way. Also to clarify for your tests on the evm you used this same motor no issue?

best regards,
Luis

0 Muhammad Abdullah over 1 year ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hi Luis,

For the PVDD supply voltage, I am using a bench-top power supply to apply 36V.

I am using the same motor and power supply.

The only issue is that the EVM board used to give up to 9A per channel (depending on supply voltage) which was enough for our product but with our new PCB, we see the distorted signal and motor stop running after 3A.

Best regards,

Abdullah

0 Luis Fernandes de Pina over 1 year ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Abdullah,

So for your application the device is in 4xSE mode correct?

On the EVM had you modified J22 to use the C21/C34/C42/C56 DC-blocking caps or was it being directly connected to your load?

Also is there a certain Point where the CLIP_OTW is being triggered as you are driving up the load or is it never triggered before your fault condition?

Can you explain in your schematic on what is populated and done on the input for INPUT_D.

best regards,
Luis

0 Muhammad Abdullah over 1 year ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hello Luis,

We are operating in 4xSE mode.

On the EVM, we opted not to use C21/C34/C42/C56; instead, we utilized J22/J23/J24.

The CLIP_OTW never triggered prior to the fault condition.

For input D, it serves as a neutral connection. We require three phases and a neutral connection, we only use the three phases during the motor test.

RV1 is a potentiometer, during the test phase to determine the midpoint. If the peak-to-peak of the other three phases is 30V, the output D will consistently be 15V. Once the midpoint is established, we will substitute it with a specific resistor value and eliminate the potentiometer for the production version.

Any component value starting with "_" indicates it is not connected. For instance, _0R (R105) is not connected.

Best regards,

Abdullah

0 Muhammad Abdullah over 1 year ago in reply to Muhammad Abdullah

Prodigy 10 points

Hello Luis,

Mouser is offering two different manufacturer part numbers for the amplifier, what is the difference between the two? Their cost difference is £3.

TPA3255TDDVRQ1

TPA3255DDVR

Best regards,

Abdullah

0 Luis Fernandes de Pina over 1 year ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Abdullah,

The Q1 is an automotive grade version of this device. functionally it's very similar but has automotive grade qualification.

best regards,Luis

0 Muhammad Abdullah 11 months ago in reply to Luis Fernandes de Pina

Prodigy 10 points

Hello Luis,

My issue is resolved, it sounds like PCB had a problem. We assembled a new PCB, problem was fixed.

Would you recommend using Q1 if we are using high current often, which heats up the chip?

Best regards,

Abdullah

+1 Luis Fernandes de Pina 11 months ago in reply to Muhammad Abdullah

TI__Genius 14640 points

Hello Muhammed,

I would only recommend using Q1 if you are using it for automotive applications, functionally the devices would be the same.

best regards,
luis

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TPA3255EVM: TPA3255DDVR