TPA1517: When add TPA1517，The sound is smaller。

user4883824

Prodigy 160 points

Part Number: TPA1517

Hi，

I use 5W/8ohm speaker in my system which supports 3W/4ohm，but The sound is smaller when add TPA1517。

over 7 years ago

0 Shawn Zheng over 7 years ago

TI__Mastermind 24835 points

Hi Xiaojian,

Let's take an example. A 1kHz sinewave is added on the input. With the two speaker, the input signal is the same, and the gain in TPA1517 is fixed, so the output voltage doesn't change. By Ohm law, the ouptut power is larger for the speaker with the smaller resistance.

For the speaker 5W/8ohm, 8Ohm is the resistance, and the 5W is the maximum power rating.

Best regards,

Shawn Zheng

0 user4883824 over 7 years ago in reply to Shawn Zheng

Prodigy 160 points

Hi Shawn Zheng，

I think it must be something wrong，pls see the picture。

0 Shawn Zheng over 7 years ago in reply to user4883824

TI__Mastermind 24835 points

Hi Xiaojian,
The gain on TAP1517 is 20dB, then the voice is supposed to be larger with it. Could you please show me the waveform on the input and output of TPA1517? Can you see the gain on the audio amplifier by comparing the waveforms? How much is the power supply on TPA1517? The maximum output power depends on the power supply voltage. Please refer to Figure19 in TPA1517 datasheet. If the power supply is low, the maximum output power can't be high. So what if you increase the power supply on TPA1517?

Best regards,
Shawn Zheng