Original question:
Hi Team,
A customer designs a E-call with TLV320AIC3104-Q1 , But I am not sure about the SCH. Could you please help to double check? Thanks a lot!
Function:Realize single end microphone output, differential SPK output function.
Note: MIC IN input pseudo-differential signal (actually single end)
Amelie,
The input pins 10,11,14 and 16 can be tied together and then have connected to a 0.47uf Cap to GND.
the mic bias circuit is a little confusing, they seem to be using an external 8V supply, but have the micBIAS pin set up as backup? There should be no capacitor on the micbias pin.
R127 goes from the BCLK line to the MCLK pin. This is not necessary. The BCLK can be selected as the PLL input, but the customer should note the constraints of the PLL:
These constraints can be impossible to meet with BCLK in certain scenarios. for example in I2S mode, when FS = 8khz and the word length is 16bits, BCLK will be 256khz, There is no way to meet the PLL constraints. Customer should already be aware of this, but just in case...
The customer should use a passive LPF on the LINE DIFF output if they are connecting to a CLASS D amplifier. See the section 2.4 in Application report below:
Regarding the Microphone. can you explain the Pseudo differential? The inputs on the TLV320AIC3104 can be set up for SE if the customer would prefer SE.
best regards,
-Steve Wilson
