max9814etdt Maxim Integrated Products, Inc., max9814etdt Datasheet - Page 6

• Manufacturer Part Number: max9814etdt
• Description: Max9814 Microphone Amplifier With Agc And Low-noise Microphone Bias
• Manufacturer: Maxim Integrated Products, Inc.

Microphone Amplifier with AGC and
Low-Noise Microphone Bias
6
(V
T
TDFN UCSP
A
4, 11
DD
10
12
13
14
= +25°C, unless otherwise noted.)
1
2
3
5
6
7
8
9
_______________________________________________________________________________________
= 5V, C
500mV/div
PIN
V
MICOUT
A1
B2
A2
A3
A4
B4
C4
B3
C3
C2
C1
B1
—
0V
CT
= 470nF, C
MICBIAS
MICOUT
NAME
MICIN
SHDN
GAIN
HOLD AND RELEASE TIME
GND
BIAS
N.C.
V
A/R
CG
CT
TH
DD
CG
40ms/div
= 2.2µF, V
Timing Capacitor Connection. Connect a capacitor to CT to control the Attack and Release times of
the AGC.
Active-Low Shutdown Control
Amplifier DC Offset Adjust. Connect a 2.2µF capacitor to GND to ensure zero offset at the output.
No Connection. Connect to GND.
Power Supply. Bypass to GND with a 1µF capacitor.
Amplifier Output
Ground
Microphone Noninverting Input
Tri-Level Attack and Release Ratio Select. Controls the ratio of attack time to release time for the AGC
circuit.
A/R = GND: Attack/Release Ratio is 1:500
A/R = V
A/R = BIAS: Attack/Release Ratio is 1:4000
Tri-Level Amplifier Gain Control.
GAIN = V
GAIN = GND, gain set to 50dB.
GAIN = Unconnected, uncompressed gain set to 60dB.
Amplifier Bias. Bypass to GND with a 0.47µF capacitor.
Microphone Bias Output
AGC Threshold Control. TH voltage sets gain control threshold. Connect TH to MICBIAS to disable
the AGC.
DD
C
A/R = V
DD
CT
TH
: Attack/Release Ratio is 1:2000
= 47nF
, gain set to 40dB.
= V
DD
MICBIAS
Typical Operating Characteristics (continued)
x 0.4, GAIN = V
DD
(40dB), AGC disabled, no load, R
FUNCTION
500mV/div
V
MICOUT
0V
HOLD AND RELEASE TIME
100ms/div
Pin Description
C
A/R = UNCONNECTED
CT
= 47nF
L
= 10kΩ, C
OUT
= 1µF,