Q: [TPA6201A1] pop up noise improvement for single ended application.

Dear experts,

I need your advice on this application.

when TPA6201A1 amp turns on , pop up noise of amp itself  is heard slightly .  this is single ended application based on datasheet.

Is there any way to minimize pop noise  in this case ?

 

A: Re: [TPA6201A1] pop up noise improvement for single ended application.

In general, the TPA6201A1 should have very good pop performance.  The main factor that can affect pop performance is the impedance matching on the input components.  For best pop performance, please ensure that the input resistors (R346 and R313) are matched well (ideally 1% or better) and that the input capacitors (C384 and C329) are matched well, too.  A mismatch in these values will cause differences in input ramp rates when the device turns on, which can cause a pop at the output.

Also, you may need to consider the output impedance of the source feeding the signal to the device (SPKOUT_N).  If the source feeding the signal has a high output impedance, this needs to be accounted for in the IN+ resistor.  For example, if the audio source has an output impedance of 1kOhm, then R313 should be made 20kOhm in the above schematic to account for this, and to maintain input impedance matching.

If the input components are matched well, increasing the BYP capacitor may slightly improve pop performance.  Increasing C339 from 1000nF to 2200nF will slow the turn on time of the amplifier, which may make any pop noise less noticeable.  However, in lab experiments I found that input component matching was a much more significant factor than the BYP cap value.