MAX4061ETA-T Maxim Integrated, MAX4061ETA-T Datasheet - Page 8

• Manufacturer Part Number: MAX4061ETA-T
• Description: Microphone Preamplifiers
• Manufacturer: Maxim Integrated

Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
The MAX4060/MAX4061/MAX4062 are differential micro-
phone preamplifiers providing high-quality audio, opti-
mized for use in computer and mobile applications.
These devices feature rail-to-rail outputs, very high
power-supply rejection, and common-mode rejection,
making them ideal for low-noise applications. The
MAX4060/MAX4061/MAX4062 are particularly effective
when layout constraints force the microphone amplifier to
be physically remote from the ECM microphone and/or
the rest of the audio circuitry.
The MAX4060/MAX4062 are capable of switching their
output between the differential input and an inverting
single-ended input. INT/AUX selects either the differen-
tial input or single-ended auxiliary input. In addition, the
MAX4060 has an internal bias generator to bias the
microphone in either differential or single-ended
modes. The MAX4061 includes a complete 0.3µA shut-
8
MAX4060
_______________________________________________________________________________________
—
—
—
—
—
1
2
3
4
5
6
7
8
MAX4061
PIN
—
—
—
—
—
3
4
5
6
7
1
2
8
Detailed Description
MAX4062
10
—
—
—
2
3
5
6
7
8
9
1
4
INT/AUX
AUX_IN
NAME
SHDN
BIAS
GND
BIAS
OUT
V
IN+
IN-
G2
G1
EP
CC
Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low
to select internal or high to select auxiliary microphone input.
Amplifier Output. OUT is high impedance when in shutdown mode.
External Electret Microphone Capsule Bias Output. BIAS has a greater than
2kΩ output impedance.
Power Supply. Bypass the V
Noninverting Differential Amplifier Input. AC-couple the audio signal into IN+.
Inverting Differential Amplifier Input. AC-couple the audio signal into IN-.
Ground
Single-Ended Input for Auxiliary Microphone. AC-couple the audio signal into
AUX_IN.
Gain-Selectable Input. Connect an external resistor between G1 and G2 to set
the gain for the differential amplifier. (See Adjustable Differential-Gain Setting
section.)
Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low for
shutdown mode.
External Electret Microphone Capsule Bias Output. Bypass BIAS with 1µF
capacitor to ground.
Gain-Selectable Input. Connect an external resistor between G1 and G2 to set
the gain for the differential amplifier.
Exposed Pad (TDFN Only). Internally connected to GND. Connect to a large
ground plane to minimize thermal performance. Not intended as an electrical
connection point.
down mode for ultimate power savings. The differential
gain of the MAX4061/MAX4062 is set with a single
resistor connected between the G1 and G2 pins. The
MAX4060 has a fixed gain of 10V/V.
The main microphone input is a low-noise, differential
input structure. This is an almost essential element
when faced with amplification of low-amplitude analog
signals in digitally intense environments such as note-
book PCs or PDAs. Used correctly, the advantages
over a single-ended solution are:
• Better power-supply noise rejection.
• Less degradation from noise in PC board ground
• The microphone and preamplifier can be placed
planes.
physically further apart, easing PC board layout
restrictions.
CC
to GND with a 0.1µF capacitor.
FUNCTION
Pin Description
Differential Input