19-2840; Rev 0; 4/03
Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain
Microphone Amplifiers with Integrated Bias
General Description
The MAX9812/MAX9813 are single/dual-input, 20dB
fixed-gain microphone amplifiers. They offer tiny pack-
aging and a low-noise, integrated microphone bias,
making them ideal for portable audio applications such
as notebook computers, cell phones, and PDAs. These
amplifiers feature a 500kHz bandwidth, Rail-to-Rail®
outputs, an industry-leading 100dB power-supply rejec-
tion ratio, and a very low 0.015% THD+N. Power-saving
features include very low 230µA supply current and a
total shutdown mode that cuts the combined supply
and BIAS currents to only 100nA.
The MAX9812 is a single amplifier in a 6-pin SC70
package (2mm x 2.1mm) and the MAX9813 is a dual-
input amplifier available in an 8-pin SOT23 (3mm x
3mm) package. The MAX9813 has two inputs allowing
two microphones to be multiplexed to a single output.
The MAX9812/MAX9813 are offered in two grades. The
MAX9812L/MAX9813L are optimized for 3.3V supply
operation (2.7V to 3.6V). The MAX9812H/MAX9813H are
PC2001 compliant and are optimized for 5V operation
(4.5V to 5.5V). Both devices are specified over the -40°C
to +85°C extended operating temperature range.
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Features
PC2001 Compliant
100dB at 217Hz Power-Supply Rejection Ratio
Very Low 230µA Quiescent Current
Low 0.015% THD+N
Available in Two Versions
MAX9812L/MAX9813L—2.7V to 3.6V
MAX9812H/MAX9813H—4.5V to 5.5V
Internal Low-Noise Microphone Bias Supply
2.3V for MAX9812L/MAX9813L
4.0V for MAX9812H/MAX9813H
100nA Low-Power Shutdown Mode
Rail-to-Rail Outputs
20dB Fixed Gain
Available in Tiny 6-Pin SC70 (2mm x 2.1mm) and
8-Pin SOT23 (3mm x 3mm) Packages
Extended Temperature Range -40°C to +85°C
MAX9812/MAX9813
Ordering Information
PART
MAX9812LEXT-T
MAX9812HEXT-T
MAX9813LEKA-T
MAX9813HEKA-T
PIN-
TEMP RANGE PACKAGE
-40°C to +85°C 6 SC70-6
-40°C to +85°C 6 SC70-6
-40°C to +85°C 8 SOT23-8
-40°C to +85°C 8 SOT23-8
V
CC
(V)
2.7 to 3.6
4.5 to 5.5
2.7 to 3.6
4.5 to 5.5
Applications
Notebook Computers
PDAs
Smart Phones
Car Kit Adapters
Digital Cameras
Video Tape Recorders
Pin Configurations, Selector Guide, and Typical Operating
Circuits appear at end of data sheet.
Rail-to-Rail is a trademark of Nippon Motorola Ltd.
Simplified Block Diagrams
V
CC
V
CC
SHDN
BIAS
REFERENCE
2.3V (L VERSION)
4.0V (H VERSION)
BIAS
REFERENCE
2.3V (L VERSION)
4.0V (H VERSION)
SHDN
IN1
IN
20dB
OUT
IN2
20dB
OUT
IN1/IN2
MAX9812
GND
GND
MAX9813
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Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
DALLAS [ DALLAS SEMICONDUCTOR ]
