Cirrus Logic CS42L51 - Manual (Page 30)

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
2
π 50 kΩ ( ) 1 µF ( )
----------------------------------------------- 3.18 Hz = =
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