Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain
Microphone Amplifiers with Integrated Bias
VDD
0.1µF
VDD
220kΩ
0.1µF
IN1/IN2 VCC
0.1µF
0.1µF
OUT
IN1
22kΩ
2.2kΩ
MAX9813
IN2
CODEC
1µF
15kΩ
0.68µF
0.68µF 15kΩ
HPF
VDD
BIAS
SVDD
PVDD
0.047µF 27.4kΩ
GAINLB
GAINLA
33.2kΩ
15kΩ
OUTL+
INL1
OUTL-
INL2
0.68µF 15kΩ
MAX9760
INR1
2.2kΩ
0.1µF
BIAS GND SHDN
0.68µF 15kΩ
HPF
INR2
VDD
1kΩ 1kΩ 10kΩ
MICROCONTROLLER
SCL
SDA
ADD
INT
SHDN
OUTR-
OUTR+
GAINRA
GAINRB
15kΩ
33.2kΩ
27.4kΩ
0.047µF
47kΩ
HPS
220µF
10kΩ
220µF
10kΩ
VDD
680kΩ
Figure 1. Typical Application Circuit
8 _______________________________________________________________________________________