TPA3116D2EVM: Frequency response does not match part datasheet - pole at 65 kHz

Christopher Hess

Part Number: TPA3116D2EVM

I am having an issue with the frequency response of this amplifier. I tested the frequency response using a 70 mV rms single ended input signal from 256Hz to 200kHz, with a 24V rail voltage at 1.2MHz switching frequency. I have also made a couple measurements using the exact configuration as used in Figure 12 of the datasheet and still observed this spike in gain. Gain begins to increase as low as 35kHz and peaked at around 65kHz at 45db. I have not made any modifications to the TPA3116D2EVM board, so the gain is set for 26 dB. What is causing this pole in the frequency response?

over 4 years ago

0 Yanming Gong over 4 years ago

TI__Mastermind 19030 points

Hi Hess,

The Figure 12 is test on BD mode, Fs is 400KHz.

Do you add AES17 filter on AP instrument? Can you share you test result picture to us?

Thanks!

Regards,

Derek

0 Christopher Hess over 4 years ago in reply to Yanming Gong

Prodigy 95 points

For my end application I would like to use a 24V rail with Fs = 1.2MHz in BD mode, so this is how I have taken most my measurements. However, I have also taken measurements with a 12V rail and Fs = 400kHz in BD mode as in Figure 12. I have made all my measurements just using an oscilloscope and have not used an AES17 filter.

Below is my collected data with the 24V rail and 1.2MHz Fs. I have also included a screenshot at 65k with channel 1 being the input signal and math being the differential output