TLV320AIC3107: 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/2859009

Essen Electronics

Tool/software:

Dear Sir,

Could you please tell me input impedance for diveder network,at 0.47uF coupling capacitor.

divider from 5V RMS to 0.5V RMS.

0 Daveon Douglas 6 months ago

Hi,

Our codec expert is out of office until Tuesday. Please be patient as responses will be delayed

0 Essen Electronics 6 months ago in reply to Daveon Douglas

Dear Sir,

Audio requirement details are as given below-

Signal name : Audio signal

Signal type : Analog stereo

Frequency : 300Hz to 3.5 KHz

Signal voltage : 0.4 to 5Vrms across 10K

Input impedance : 10KΩ

No of channels : 2

0 Daveon Douglas 6 months ago in reply to Essen Electronics

Hi,

Our codec expert is out of office until Tuesday. Please be patient as responses will be delayed

0 Jeff McPherson 5 months ago in reply to Daveon Douglas

Hi,

You can use the formula you have linked to to calculate input impedance. For your case you will need

Req = Rin* (1 + 2g)/(1+g)

The variable g is the analog PGA gain calculated in linear terms:

g = 10000 * 2^floor(G/6)/Rin

where G is the programmed analog PGA gain programmed (in dB) and Rin is the value of the programmed input resistor
and assumes Rin = Rcm.

where R1||R2<<Req and R1 and R2 form the resistor divider prior to the AC coupling cap.

Thank you and best regards,
Jeff McPherson

Audio forum