About THS4521 Audio Application Issue

Jacky Wang(QD)

Other Parts Discussed in Thread: THS4521, DAC902, TPA6211A1

Hi all,

A customer who uses THS4521 for audio amplifier application encounters some problems, the schematic in below:

Audio signal generated from DAC902, and feeds into THS4521, the output of THS4521 connected to the TPA6211 to driver the speaker.

The problem customer met is that the output volume of the speaker is very small, but if you remove the THS4521 circuit, the volume of the speaker will be larger than before.

So anyone can give some comments to dig out what's the root cause for this case?

Thanks!

over 11 years ago

0 Luke LaPointe over 11 years ago

TI__Genius 13335 points

Jacky,

It could be an output drive limitation.The maximum linear output current on a 5V supply is 55mA into a 50Ω load, or 75.6mW. If you start decreasing this load, the power drops accordingly.

Although the TPA6211A1 has high input impedance (40kΩ), if there is some sort of line termination, that would have a big impact on the ability to drive the next stage.

What is the load seen by the THS4521?

Thanks,
Luke