User guide

30 DS679F1
CS42L51
The MICBIAS series resistor must be selected based on the requirements of the particular microphone
used. The MICBIAS output pin is selected using the MICBIAS_SEL bit.
Software
Controls:
“Interface Control (Address 04h)” on page 52, “MIC Control (Address 05h)” on page 53.
fc
1
2π 50 kΩ()1 µF()
----------------------------------------------- 3 . 1 8 H z==
MICIN1
MICIN2
Σ
+
+
MICBIAS
18
17
20
//
//
Figure 9. MIC Input Mix w/Common Mode Rejection
Full-Scale Differential Input Level (MICMIX=1)
= (AINxA - AINxB) = 3.6 V
PP
= 1.27 V
RMS
AINxA
AINxB
2.15 V
1.25 V
0.35 V
2.5 V
2.15 V
1.25 V
0.35 V
VA
Figure 10. Differential Input