TLV320AIC3100: Speaker & MIC Interface

Hi,

1. A series capacitor is not necessary. You can optionally include a coupling capacitor reduce out of band noise.

2. MICDETECT pin is primarily used for headset detection. Explained in detail with multiple configurations here: Headset Detection for TLV320AIC33 and TLV320AIC310x Family

Regards,

HI Deveon,

Thanks for your reply.

Could share the recommended low pass filter circuit between SPKER & TLV320AIC3100?

Mani Selvam P

Hi Mani,

Optionally as well,  At the output you can implement an LC filter with a cutoff frequency of 20kHz to attenuate switching and cut high frequency noise. You can use this calculator to determine component values (https://www.ti.com/tool/LCFILTER-CALC-TOOL)

Regards,

HI Deveon,

Thanks for your reply. 

As per the tool results L=45uH & C =0.7uF to the cut off frequency values of 20KHz.

What current rating of inductor to be selected?

How much current the CODEC will give to 8Ohm speaker when SPKR VDD=5V? This data is not in datasheet.

Mani Selvam P

HI Deveon,

Along with above request, Please clarify the below too.
As per EVM design (Doc Number : SLAU307), No LC filter is given between CODEC IC and Speaker. Please clarify.

Mani Selvam P

Hi Mani,

That is correct, a filter is not required at the output. You can optionally include an AC coupling cap (1uF is okay) or an LC filter. If you choose to add an LC filter

You can calculate the current drawn from the speaker with Po = V^2 / R and Pin = V*I.

 Po = 2^2 / 8 = 0.5W

I = 0.5W / 5V =0.1A derived from SPKVDD.

This is rough estimate and doesn't factor in efficiency and how device was configured.

Mani Selvam P Palanivel said:

What current rating of inductor to be selected?

If you choose to include an LC filter, Ideally, the saturation current rating of the inductor is at least as large as the Ipeakmax. This size makes sure that the inductor does not saturate, even during a short circuit on the output.

2.5A - 3A current rating should be okay.

Regards,