19-1950; Rev 1; 4/01
Low-Cost, Micropower, SC70/SOT23-8, Microphone
Preamplifiers with Complete Shutdown
General Description
Features
The MAX4465–MAX4469 are micropower op amps opti-
mized for use as microphone preamplifiers. They pro-
vide the ideal combination of an optimized gain
bandwidth product vs. supply current, and low voltage
operation in ultra-small packages. The MAX4465/
MAX4467/MAX4469 are unity-gain stable and deliver a
200kHz gain bandwidth from only 24µA of supply cur-
rent. The MAX4466/MAX4468 are decompensated for a
minimum stable gain of +5V/V and provide a 600kHz
gain bandwidth product. In addition, these amplifiers
®
o +2.4V to +5.5V Supply Voltage Operation
o Versions with 5nA Complete Shutdown Available
(MAX4467/MAX4468)
o Excellent Power-Supply Rejection Ratio: 112dB
o Excellent Common-Mode Rejection Ratio: 126dB
o High A
: 125dB (R = 100kΩ)
L
VOL
o Rail-to-Rail Outputs
feature Rail-to-Rail outputs, high A
plus excellent
VOL,
o Low 24µA Quiescent Supply Current
power-supply rejection and common-mode rejection
ratios for operation in noisy environments.
o Gain Bandwidth Product:
200kHz (MAX4465/MAX4467/MAX4469)
The MAX4467/MAX4468 include a complete shutdown
mode. In shutdown, the amplifiers’ supply current is
reduced to 5nA and the bias current to the external
microphone is cut off for ultimate power savings. The
single MAX4465/MAX4466 are offered in the ultra-small
5-pin SC70 package, while the single with shutdown
MAX4467/MAX4468 and dual MAX4469 are available in
the space-saving 8-pin SOT23 package.
600kHz A ≥ 5 (MAX4466/MAX4468)
V
o Available in Space-Saving Packages
5-Pin SC70 (MAX4465/MAX4466)
8-Pin SOT23 (MAX4467/MAX4468/MAX4469)
Ordering Information
PART
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
5 SC70-5
MAX4465EXK-T
MAX4465EUK-T
MAX4466EXK-T
MAX4466EUK-T
Applications
5 SOT23-5
5 SC70-5
Microphone Preamplifiers
Hearing Aids
5 SOT23-5
Cellular Phones
Ordering Information continued at end of data sheet.
Voice-Recognition Systems
Digital Dictation Devices
Headsets
Typical Operating Circuit
Portable Computing
V
CC
Pin Configurations
SHDN
R
BIAS
MIC_BIAS
IN+
TOP VIEW
C
R
BIAS
R
DC
1
2
3
5
V
CC
IN+
GND
IN-
R
BIAS
OUT
MAX4465
MAX4466
C
IN
IN
IN-
MAX4467
MAX4468
C
BYPASS
4
OUT
R
DC
GND
SC70/SOT23
MICROPHONE
CAPSULE
Pin Configurations continued at end of data sheet.
R
FB
MAX4467/MAX4468 TYPICAL OPERATING CIRCUIT WITH
COMPLETE SHUTDOWN
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
________________________________________________________________ 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.