Microphone Amplifier with AGC and
Low-Noise Microphone Bias
Typical Application Circuit/Functional Diagram
VDD
CBIAS
0.47µF
BIAS
MICBIAS
RMICBIAS
2.21kΩ
MICIN
LNA
CIN
0.1µF
CT
CCT
470nF
CG
CCG
2.2µF
SHDN
VDD
CBYPASS
1µF
MAX9814
REF
AGC
VGA
A/R
TH
VDD
GAIN
MICBIAS
R1
150kΩ
R2
100kΩ
COUT
MICOUT
ROUT
GND
*THE DEVICE HAS BEEN CONFIGURED WITH AN ATTACK TIME OF 1.1ms, 40dB GAIN, AND AN ATTACK-AND-RELEASE RATIO OF 1:500.
10 ______________________________________________________________________________________