TPA3221: Frequency Plot

Mark Philip Felipe

Part Number: TPA3221
Other Parts Discussed in Thread: TPA3220

Hi Team, I would like to ask if there is an available Frequency Plot with an LC cutoff high enough to see the response of the TPA3221 chip by itself, up to 100kHz. The customer is interested to operate the 60-80kHz of the chip.

Thanks in advance.

-Mark

over 6 years ago

0 Robert Clifton56 over 6 years ago

TI__Mastermind 30720 points

Hi Mark,

Does the customer also have a specific load and LC filter in mind? This could affect the frequency response before it reaches 100kHz.

Regards,

Robert Clifton

0 Mark Philip Felipe over 6 years ago in reply to Robert Clifton56

TI__Genius 11280 points

Hi Robert, thank you for responding to our post.

Based on the customer, they have no requirements for the LC filter so long as our passband (60-80kHz) is largely flat. Based on my understanding they are looking for the ideal response at 100KHz.

Thanks!

Regards,

Mark

0 Robert Clifton56 over 6 years ago in reply to Mark Philip Felipe

TI__Mastermind 30720 points

Hi Mark,

What about the expected load impedance? The larger the load's impedance the higher out the cutoff frequency will be for the LCR filter.

Regards,

Robert Clifton

0 Mark Philip Felipe over 6 years ago in reply to Robert Clifton56

TI__Genius 11280 points

Hi Robert, Thank you for responding.

According to them the load the amplifier sees should be resistive at around 2-4 ohms, there will be some capacitance, but we try to design the transformer to make the impedance the amplifier sees look as resistive as possible.

Regards,

Mark

0 Robert Clifton56 over 6 years ago in reply to Mark Philip Felipe

TI__Mastermind 30720 points

Hi Mark,

Thank you for your patience. I'll test the TPA3221 today and get back to you with the results as well as the test conditions that were used!

Best Regards,

Robert Clifton

0 Robert Clifton56 over 6 years ago in reply to Robert Clifton56

TI__Mastermind 30720 points

Hi Mark,

To keep it short, I'm experiencing issues with my setup. I'll be able to get to it tomorrow however. Thank you for understanding.

Best Regards,

Robert Clifton

0 Robert Clifton56 over 6 years ago in reply to Robert Clifton56

TI__Mastermind 30720 points

Hi Mark,

Here's the bandwidth results. I used the TPA3220 instead of the TPA3221 but that should be fine since they have the same bandwidth performances.

Test Conditions:

Output Power = 5W

Load = 8ohms

LC Filter = 5.6uH/ 0.1uF

Gain = 18dB.

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/6/TPA3220EVM-Bandwidth.emf

Hope this answers your question!

Best Regards,

Robert Clifton

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TPA3221: Frequency Plot