TLV320AIC3106: Input Impedance & Output Impedance

Hi,

For input impedance and your question on input signal see section 10.3.7 of the datasheet and this post.

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/773059/faq-tlv320aic-codecs-how-do-i-calculate-the-input-impedance-of-an-tlv320aic-device

For output impedance, we don't specify/measure but when powered up the line outputs should be on the order of 100 Ohms and the high power outputs should be less than 1 Ohm. When these outputs are in High-Z, they should be greater that 50 k Ohms. This would be over the full audio band.

See audio DAC load condition for each output driver.

Regards.

Hello, 

Thank you for your response. It seems that the TLV320 series are all very similar. So reading through lots of different datasheets to gather some information has been helpful. (on a side note, these codecs are really cool!). 

So in the TLV320AIC3204 there is this section on the Output. 

9.3.2.4 Line Outputs
The stereo line level drivers on LOL and LOR pins can drive a wide range of line level resistive impedances in
the range of 600Ω to 10kΩ. The output common modes of line level drivers can be configured to equal either the
analog input common-mode setting or to 1.65V. With output common-mode setting of 1.65V and DRVdd_HP
supply at 3.3V the line-level drivers can drive up to 1Vrms output signal. The line-level drivers can drive out a
mixed combination of DAC signal and attenuated ADC PGA signal. Signal mixing is register-programmable.

Which is good news.

I have another problem though. In the link you sent here: e2e.ti.com/.../faq-tlv320aic-codecs-how-do-i-calculate-the-input-impedance-of-an-tlv320aic-device

Analog Input Connection With Pull-down Resistor

Each analog input is capable of handling signal amplitude of 0.5Vrms. 
If the input signal source can drive signals higher than the maximum value, 
an external resistor divider network as shown below should be used to attenuate 
the signal to less than 0.5Vrms before connecting the signal to the device. 
The resistor values of the network should be chosen to provide desired 
attenuation as well as to satisfy the following equation:

R1||R2<<Req

So the inputs of the device only accept .5 VRMS? So does this mean if someone where to set the output of a TLV320 into the input of a TLV320 will it kill the chip? I also have experience with the PCM5242 and that has 2.1VRMS outputs. So could that also cause issues if directly connected to the input of a TLV320?

I'm using the chip as a front end for an instrument which accepts line inputs... I want to be sure that I can plug pretty much anything into it and obviously not cause any damage. Can you please expand on this? The EVM does not have the described input PAD... which is not a problem but I'm just thinking I should probably add the LPF on the inputs as suggested which will also lower the VRMS?

Sorry for my confusion. I'm not sure about these things I've been thinking about them for a few days and I wanted to post my question to you ASAP. If I think of anything else I'll reply later today. Thank you!

Thanks for your help!

Jay