
Microphone Amplifier with AGC and
Low-Noise Microphone Bias
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD = 3.3V, SHDN = VDD, CCT = 470nF, CCG = 2F, GAIN = VDD, TA = TMIN to TMAX, unless otherwise specified. Typical values are
at TA = +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VDD to GND ..............................................................-0.3V to +6V
All Other Pins to GND.................................-0.3V to (VDD + 0.3V)
Output Short-Circuit Duration.....................................Continuous
Continuous Current (MICOUT, MICBIAS).......................±100mA
All Other Pins ....................................................................±20mA
Continuous Power Dissipation (TA = +70°C)
14-Pin TDFN-EP
(derate 16.7mW/°C above +70°C) ........................1481.5mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Bump Temperature (soldering) Reflow............................+235°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GENERAL
Operating Voltage
VDD
Guaranteed by PSRR test
2.7
5.5
V
Supply Current
IDD
3.1
6
mA
Shutdown Supply Current
ISHDN
0.01
1
A
Input-Referred Noise Density
en
BW = 20kHz, all gain settings
30
nV/
√Hz
Output Noise
BW = 20kHz
430
VRMS
BW = 22Hz to 22kHz
(500mVRMS output signal)
61
Signal-to-Noise Ratio
SNR
A-weighted
64
dB
Dynamic Range
DR
(Note 2)
60
dB
fIN = 1kHz, BW = 20Hz to 20kHz,
RL = 10k
Ω, VTH = 1V (threshold = 2VP-P),
VIN = 0.5mVRMS, VCT = 0V
0.04
Total Harmonic Distortion Plus
Noise
THD+N
fIN = 1kHz, BW = 20Hz to 20kHz,
RL = 10k
Ω, VTH = 0.1V (threshold =
200mVP-P), VIN = 30mVRMS, VCT = 2V
0.2
%
Amplifier Input BIAS
VIN
1.14
1.23
1.32
V
Maximum Input Voltage
VIN_MAX
1% THD
100
mVP-P
Input Impedance
ZIN
100
k
Ω
GAIN = VDD
39.5
40
40.5
GAIN = GND
49.5
50
50.6
Maximum Gain
A
GAIN = unconnected
59.5
60
60.5
dB
GAIN = VDD
18.7
20
20.5
GAIN = GND
29.0
30
30.8
Minimum Gain
GAIN = unconnected
38.7
40
40.5
dB
Maximum Output Level
VOUT_RMS
1% THD+N, VTH = MICBIAS
0.707
VRMS
Regulated Output Level
AGC enabled, VTH = 0.7V
1.26
1.40
1.54
VP-P
AGC Attack Time
tATTACK
CCT = 470nF (Note 3)
1.1
ms
A/R = GND
1:500
A/R = VDD
1:2000
Attack/Release Ratio
A/R
A/R = unconnected
1:4000
ms/ms
MAX9814
2
Maxim Integrated