MAX4063 [MAXIM]
Differential Microphone Preamplifier with Internal Bias and Complete Shutdown; 差分麦克风前置放大器，内部偏置并可完全关断
| 型号： | MAX4063 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Differential Microphone Preamplifier with Internal Bias and Complete Shutdown |
| 文件： | 总15页 (文件大小：403K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2753; Rev 0; 1/03
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
General Description
Features
o 2.4V to 5.5V Single-Supply Operation
The MAX4063 is a differential-input microphone preampli-
fier optimized for high-performance, portable applica-
tions. The device features two selectable inputs,
differential outputs, adjustable gain, an integrated low-
noise bias source, and a low-power shutdown mode.
Two input paths provide both differential and single-
ended microphone sensing. The high-noise rejection of
the differential input is ideally suited to an internal micro-
phone where system noise and long-run PC board traces
can degrade low-level signals. The single-ended input
provides a simple connection to an external microphone.
o Differential Inputs and Outputs
o Adjustable Gain
o High 95dB PSRR
o High 79dB CMRR
o Low-Noise, Integrated Microphone Bias
o 750µA Supply Current
o 0.3µA Shutdown Current
o
4ꢀV ꢁSD Protection ꢂAꢃUXINꢄ
o THD+N: 0.05% at 1ꢀHz
o Available in Space-Saving Pacꢀages
14-Pin TSSOP
The differential and single-ended inputs have indepen-
dent, adjustable gains that are set with a single external
resistor. Differential outputs provide a full-scale signal of
up to 6V
from a single 3V supply, optimizing the
P-P
16-Pin Thin QFN ꢂ4mm x 4mm x 0.8mmꢄ
dynamic range of the amplified signal. A complete shut-
down mode reduces the supply current to only 0.3µA
and disables the microphone bias for the ultimate in
power savings.
Ordering Information
PART
TꢁMP RANGꢁ
PIN-PACKAGꢁ
The MAX4063 operates from 2.4V to 5.5V and is specified
over the extended -40°C to +85°C operating temperature
range. The MAX4063 is available in both 16-pin thin QFN
(4mm x 4mm x 0.8mm) and 14-pin TSSOP packages.
MAX4063ETE*
MAX4063EUD
-40°C to +85°C
-40°C to +85°C
16 Thin QFN-EP**
14 TSSOP
*Future product—contact factory for availability.
**EP = Exposed paddle.
Applications
Notebook Audio Systems
Tablet PCs
Typical Operating Circuit
2.4V TO 5.5V
PDA Audio Systems
6
Signal Conditioning
V
CC
3
2
7
INT/AUX
ADJ
SHDN
Pin Configurations
12
AUX_IN
4
8
MAX4063
OUT
G2
INT/AUX
SHDN
OUT
1
2
3
4
5
6
7
14 G1
5
BIAS
V
13 N.C.
12 AUX_IN
11 GND
10 IN-
BIAS
OUT
MAX4063
9
IN+
IN-
BIAS
V
9
8
IN+
CC
10
ADJ
OUT
G1 G2
14
GND
11
1
TSSOP
R
G
Pin Configurations continued at end of data sheet.
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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.
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
ABSOLꢃTꢁ MAUIMꢃM RATINGS
Supply Voltage (V
to GND). .................................-0.3V to +6V
16-Pin Thin QFN (derate 16.9mW/°C above +70°C) ..1349mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
CC
Any Other Pin to GND ................................-0.3V to (V
+ 0.3V)
CC
Duration of Short Circuit to GND or V ....................Continuous
CC
Continuous Input Current (any pin) ................................ 10mA
Continuous Power Dissipation (T = +70°C)
A
14-Pin TSSOP (derate 9.1mW/°C above +70°C) ..........667mW
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.
ꢁLꢁCTRICAL CHARACTꢁRISTICS
(V
= 3V, GND = 0V, SHDN = V
INT/AUX = 0V, R = 11.11kΩ, R = 100kΩ to 1.5V, R
= ∞, V
is measured between OUT
OUT
CC
CC,
G
L
BIAS
and OUT. T = T
to T
, unless otherwise noted. Typical values are at T = +25°C.) (Notes 1 and 2)
MAX A
A
MIN
PARAMꢁTꢁR
Supply Voltage Range
Supply Current
SYMBOL
CONDITIONS
Inferred from PSRR test
MIN
TYP
MAU
5.5
ꢃNITS
V
V
2.4
CC
CC
I
0.75
1.5
1
1.1
mA
V
Output Common-Mode Voltage
Slew Rate
V
1.25
1.75
OCM
SR
A = 20V/V
V
V/µs
µA
Supply Current in Shutdown
I
V
= 0V
SHDN
0.001
30
1
2
SHDN
To GND
To V
Output Short-Circuit Current
I
mA
SC
30
CC
DIFFꢁRꢁNTIAL INPꢃT ꢂINT/AꢃU = 0Vꢄ
Input Offset Voltage
V
T
= +25°C
A
1
mV
V
OS
Common-Mode Input Voltage Range
V
Inferred from CMRR test
1
CM
Maximum Differential Input Voltage
Small-Signal Bandwidth
Input Resistance
V
A = 2V/V
V
1
V
DIFFMAX
BW
R
600
100
1
kHz
kΩ
%
-3dB
IN
Either differential input
Input Resistance Match
R
MATCH
A = 20V/V, f = 1kHz
70
V
Input Noise-Voltage Density
RMS Output Noise Voltage
e
nV/√Hz
n
A = 200V/V, f = 1kHz
V
12
V
A = 20V/V, BW = 22Hz to 22kHz
V
225
µV
RMS
NRMS
A = 20V/V, f = 1kHz, V
V
BW = 22Hz to 22kHz
= 0.7V
,
OUT
RMS
Total Harmonic Distortion Plus Noise
THD+N
0.05
%
R
R
R
= open
2
20
200
70
95
85
86
G
G
G
1V < V
< 2V,
CM
Differential Gain
A
= 11.11kΩ
= 1.01kΩ
19.2
20.8
V/V
dB
dB
VDIFF
V
= 0.7V
RMS
OUT
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
CMRR
PSRR
V
= 500mV , f = 1kHz
CM P-P
T
T
= +25°C
A
A
= T
- T
MIN
MAX
V
= 5V 100mV, f = 1kHz
CC
2
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Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
ꢁLꢁCTRICAL CHARACTꢁRISTICS ꢂcontinuedꢄ
(V
= 3V, GND = 0V, SHDN = V
INT/AUX = 0V, R = 11.11kΩ, R = 100kΩ to 1.5V, R
= ∞, V
is measured between OUT
CC
CC,
G
L
BIAS
OUT
and OUT. T = T
to T
, unless otherwise noted. Typical values are at T = +25°C.) (Notes 1 and 2)
MAX A
A
MIN
PARAMꢁTꢁR
AꢃUILIARY INPꢃT ꢂINT/AꢃU = V
Small-Signal Bandwidth
Input Resistance
SYMBOL
CONDITIONS
MIN
TYP
MAU
ꢃNITS
ꢄ
CC
BW
R
230
100
kHz
kΩ
-3dB
IN
Input Noise-Voltage Density
RMS Output Noise Voltage
e
f = 1kHz
BW = 22Hz to 22kHz
THD+N f = 1kHz, BW = 22Hz to 22kHz
200
nV/√Hz
n
V
620
µV
RMS
NRMS
Total Harmonic Distortion Plus Noise
0.007
100
%
T
T
= +25°C
80
72
A
A
Power-Supply Rejection Ratio
PSRR
dB
V/V
= T
- T
MIN
MAX
Voltage Gain
A
V
= 0.7V
-19.5
-20
-20.5
30
VAUX
OUT
RMS
BIAS OꢃTPꢃT
Output Voltage
V
I
I
I
I
= 0.5mA to GND
2
2.2
16
20
74
V
OUT
BIAS
BIAS
BIAS
BIAS
Output Resistance
Output Noise Voltage
R
OUT
= 0.5mA to GND
Ω
V
= 0.5mA to GND, BW = 22Hz to 22kHz
µV
NRMS
RMS
= 0.5mA to GND, V
= 2.4V to 5.5V
60
CC
Power-Supply Rejection Ratio
PSRR
dB
I
= 0.5mA, V
= 3V + 100mV
,
BIAS
CC
P-P
71
f = 1kHz
DIGITAL INPꢃTS ꢂSHDN and INT/AꢃUꢄ
Input Leakage Current
Input Voltage High
I
V
= 0V or V
CC
1
µA
V
IN
IN
✕
V
0.7
V
CC
INH
✕
Input Voltage Low
V
0.3
V
V
INL
ON
CC
Shutdown Enable Time
Shutdown Disable Time
t
10
10
µs
µs
t
OFF
Note 1: All specifications are 100% tested at T = +25°C. Specification limits over temperature (T = T
to T
) are guaranteed
MAX
A
A
MIN
by design, not production tested.
Note 2: MAX4063 requires a 1µF capacitor from BIAS to ground and a 10pF capacitor from ADJ to OUT.
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3
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Typical Operating Characteristics
(V
noted.)
= 3V, A = 20V/V, R ≥ 100kΩ to 1.5V, SHDN = V , V
is measured between OUT and OUT. T = +25°C, unless otherwise
CC
V
L
CC OUT A
GAIN vs. FREQUENCY
(NO LOAD)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (DIFF INPUT)
SUPPLY CURRENT vs. TEMPERATURE
0
-20
1.0
0.8
0.6
0.4
0.2
0
V
V
= 5V
CC
= 2V/V
9
6
A
V
= 5V
CC
V
CC
= 3V
-40
3
-60
A
= 20V/V
V
0
-80
-3
-6
-9
-100
-120
-140
A
= 200V/V
100k
V
NO LOAD
20 35 50 65 80
TEMPERATURE (°C)
10
100
1k
10k
100k
1M
10
100
1k
10k
1M
-40 -25 -10
5
FREQUENCY (Hz)
FREQUENCY (Hz)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
V
vs. TEMPERATURE
OH
SUPPLY CURRENT vs. SUPPLY VOLTAGE
100
10
1000
100
10
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
I
= 2.5mA
LOAD
1
0.1
I
= 50µA
LOAD
0.01
0.001
NO LOAD
1
-40
-15
10
35
60
85
-40
-15
10
35
60
85
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
V
vs. LOAD CURRENT
V
vs. LOAD CURRENT
OL
V
vs. TEMPERATURE
OH
OL
350
300
250
200
150
100
50
400
350
300
250
200
150
100
50
1000
100
10
V
= V - V
CC OUT
OH
I
= 2.5mA
LOAD
V
= 3V
CC
V
= 3V
CC
I
= 50µA
LOAD
0
0
1
0
1
2
3
4
5
0
1
2
3
4
5
-40
-15
10
35
60
85
LOAD CURRENT (mA)
LOAD CURRENT (mA)
TEMPERATURE (°C)
4
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Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Typical Operating Characteristics (continued)
(V
noted.)
= 3V, A = 20V/V, R ≥ 100kΩ to 1.5V, SHDN = V , V
is measured between OUT and OUT. T = +25°C, unless otherwise
CC
V
L
CC OUT A
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY (DIFF INPUT)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY (AUX INPUT)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (DIFF INPUT)
1
1
0.1
10
BW = 22Hz TO 22kHz
V
OUT
= 4.5V
P-P
V
= 4.5V
P-P
OUT
1
0.1
3V
3V
0.1
f = 1kHz
5V
5V
0.01
0.01
0.01
0.001
f = 10kHz
0.001
10
0.001
100
1k
10k
100k
10
100
1k
FREQUENCY (Hz)
10k
100k
0
1
2
3
4
5
6
FREQUENCY (Hz)
OUTPUT VOLTAGE (V
)
P-P
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (DIFF INPUT)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (AUX INPUT)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (AUX INPUT)
10
10
10
BW = 22Hz TO 22kHz
BW = 22Hz TO 22kHz
BW = 22Hz TO 22kHz
V
CC
= 5V
V
= 5V
V
= 5V
CC
CC
1
1
1
f = 1kHz
f = 1kHz
f = 1kHz
0.1
0.1
0.1
f = 10kHz
0.01
0.001
0.01
0.001
0.01
0.001
f = 10kHz
f = 10kHz
0
1
2
3
4
5
6
0
1
2
3
4
5
6
0
1
2
3
4
5
6
OUTPUT VOLTAGE (V
)
OUTPUT VOLTAGE (V
)
OUTPUT VOLTAGE (V
)
P-P
P-P
P-P
SMALL-SIGNAL TRANSIENT RESPONSE
INPUT-REFERRED NOISE
vs. FREQUENCY (DIFF INPUT)
FOR DIFF INPUT
MIC BIAS OUTPUT NOISE
MAX4063 toc18
MAX4063 toc17
400
350
300
250
200
150
100
50
V
= 5V
CC
BW = 22Hz TO 22kHz
DIFF
INPUT
5mV/div
20µV/div
DIFF
OUTPUT
50mV/div
0
10µs/div
10
100
1k
10k
100k
100ms/div
FREQUENCY (Hz)
_______________________________________________________________________________________
5
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Typical Operating Characteristics (continued)
(V
noted.)
= 3V, A = 20V/V, R ≥ 100kΩ to 1.5V, SHDN = V , V
is measured between OUT and OUT. T = +25°C, unless otherwise
CC
V
L
CC OUT
A
LARGE-SIGNAL TRANSIENT RESPONSE
SMALL-SIGNAL TRANSIENT RESPONSE
FOR DIFF INPUT
FOR AUX INPUT
MAX4063 toc20
MAX4063 toc19
DIFF
INPUT
S/E
INPUT
5mV/div
100mV/div
DIFF
OUTPUT
2V/div
DIFF
OUTPUT
100mV/div
10µs/div
10µs/div
LARGE-SIGNAL TRANSIENT RESPONSE
FOR AUX INPUT
OUTPUT OVERDRIVEN
MAX4063 toc22
MAX4063 toc21
S/E
INPUT
100mV/div
DIFF
INPUT
500mV/div
DIFF
OUTPUT
2V/div
DIFF
OUTPUT
2V/div
10µs/div
10µs/div
6
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Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Pin Description
PIN
NAMꢁ
G2
FꢃNCTION
TSSOP
QFN
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).
1
15
Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low to select
differential in or high to select auxiliary in.
2
16
INT/AUX
Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low for shutdown
mode.
3
4
5
6
7
1
2
3
4
5
SHDN
OUT
Amplifier Output. OUT is high impedance when in shutdown mode.
External Electret Microphone Capsule Bias Output. Bypass BIAS with a 1µF capacitor to
ground.
BIAS
V
Power Supply. Bypass the V
to GND with a 0.1µF capacitor.
CC
CC
Adjustable Gain Select for AUX_IN (see Auxiliary Input-Gain Adjustment section). Connect
a 10pF capacitor between OUT and ADJ.
ADJ
8
7
9
OUT
IN+
Complementary Amplifier Output. OUT is high impedance in shutdown mode.
Noninverting Differential Amplifier Input. AC-couple the audio signal into IN+.
Inverting Differential Amplifier Input. AC-couple the audio signal into IN-.
Ground
9
10
11
12
13
10
IN-
11
GND
AUX_IN
N.C.
12
Single-Ended Input for Auxiliary Microphone. AC-couple the audio signal into AUX_IN.
No Connection. Not internally connected.
6, 8, 14
Gain-Selectable Input. Connect an external resistor between G1 and G2 to set the gain for
the differential amplifier.
14
13
G1
external components. The MAX4063 has a complemen-
Detailed Description
tary output allowing CODECs and other devices with
differential inputs to be optimally driven (see Functional
Diagram). The MAX4063 includes a 0.3µA shutdown
mode for ultimate power savings. The differential gain
of the MAX4063 is set with a single resistor connected
between the G1 and G2 pins. The MAX4063 has an
internal default gain of 20V/V on the AUX_IN input. The
AUX_IN gain can be increased with a single external
resistor (see the Differential-Gain Adjustment and
Auxiliary Input-Gain Adjustment sections).
The MAX4063 is a differential microphone pre-
amplifier providing high-quality amplification, optimized
for use in computer and mobile applications. This device
features adjustable gain, very high power-supply rejec-
tion (95dB), and common-mode rejection (79dB), making
it ideal for low-noise applications. The MAX4063 provides
a differential input stage, making the device particularly
effective when layout constraints force the microphone
amplifier to be physically remote from the ECM micro-
phone.
Differential Input
The main microphone amplifier is a low-noise, differen-
tial input structure. This is an almost essential element
when faced with amplification of low-amplitude analog
signals in digitally intense environments such as note-
The MAX4063 is capable of switching its output
between the differential input and an inverting single-
ended input. INT/AUX selects either the differential
input or single-ended auxiliary input. In addition, the
MAX4063 has an integrated microphone bias source,
simplifying system design and eliminating the need for
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7
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Functional Diagram
2.4V TO 5.5V
6
BIAS
V
CC
MAX4063
AUX_IN
12
INT/AUX 2
7
ADJ
14 G1
OUT
4
BIAS
R
G
1
9
G2
OUT
8
5
IN+
10
3
IN-
BIAS
V
CC
V
BIAS
SHDN
SHDN
GND
11
book PCs or PDAs. Used correctly, the advantages
over a single-ended solution are:
Hence, an 11.11kΩ resistor yields a gain of 20V/V, or
26dB. Leaving the pins unconnected results in a gain of
2V/V. Gain is defined as:
•
•
Better power-supply noise rejection.
Less degradation from noise in PC board ground
planes.
For differential out:
VOUT − VOUT
•
The microphone and preamplifier may be placed
physically further apart, easing PC board layout
restrictions.
AVD
=
V
− V
IN+
IN-
The resistor can be either fixed or variable, allowing the
use of a digitally controlled potentiometer to alter the
gain under software control.
Differential-Gain Adjustment
The MAX4063 allows the user to alter the differential
gain to optimize the signal-to-noise ratio (SNR) of their
system. The gain is set by a single external resistor
Auxiliary Input-Gain Adjustment
The MAX4063 provides an option to increase the
AUX_IN (see Figure 3). To increase the gain, connect
(R ) connected between the G1 and G2 pins:
G
resistor R
between the ADJ and AUX_IN pins. R
is
ADJ
ADJ
200kΩ
calculated from the following formula:
R
=
G
A
− 2
VD
2MΩ
AVAUX − 20
RADJ
=
(to increase the gain)
where A is the required voltage gain.
V
8
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Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
2.4V TO 5.5V
6
V
CC
100kΩ
R
BIAS
BIAS
5
V
BIAS
C
BIAS
MAX4063
12
AUX_IN
2
7
INT/AUX
ADJ
OUT
14 G1
4
8
1
9
G2
OUT
IN+
10
3
IN-
V
CC
SHDN
SHDN
GND
11
Figure 1. MAX4063 with Auxiliary Input Configuration
where:
compared to the input resistance of the amplifier—this is
usually most noticeable at low frequencies. One way to
avoid the need for matched or tight tolerance capaci-
tors is to deliberately oversize the values on the differ-
VOUT − VOUT
AVAUX
=
VAUX_IN
ential inputs and to set the lower 3dB point (f
) of the
CUT
amplifier by sizing the output capacitor appropriately.
R
ADJ
is placed between AUX_IN and ADJ.
The input impedance matching on the differential input
is typically 1%, allowing input capacitor matching to be
effective at improving low-frequency PSRR.
Input Capacitors
The two differential microphone inputs and the single-
ended auxiliary input of the MAX4063 have on-chip
bias components, allowing the user to AC-couple any
signals into the input. The input resistance is 100kΩ
(typ), so the capacitor size may be chosen accordingly
to define the LF rolloff desired. This can be calculated
as:
Common-Mode Rejection Ratio
The common-mode rejection ratio (CMRR) refers to the
amount of rejection that the amplifier is capable of pro-
viding to any signal applied equally to the IN+ and IN-
inputs. In the case of amplifying low-level microphone
signals in noisy digital environments, it is a key figure of
merit. In audio circuits, this is generally measured for
C
IN
= 1 / (2πf
R )
CUT IN
This assumes a low source impedance is driving the
inputs.
V
IN
as an AC signal:
CMRR(dB) = A
/ A
DM
CM
A further consideration for the differential input is the
effect of these series input capacitors on low-frequency,
common-mode rejection. Any mismatch in the values of
these two capacitors degrades the CMRR at frequen-
cies where the impedance of the capacitor is significant
where A
is the differential gain, A
is the common-
DM
mode gain.
CM
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9
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Input voltages should be sufficiently small such that the
2.4V TO 5.5V
output is not clipped in either differential or common-
mode application. The topology used in the MAX4063
6
means that the CMRR actually improves at higher dif-
V
CC
ferential gains—another advantage of using differential
sensing.
2
7
INT/AUX
ADJ
MAX4063
MICROPHONE
INPUT
Auxiliary Input
The auxiliary input is a single-ended input intended to
be used with a jack-socket type microphone input
(Figure 1). Internal DC-bias components (as on the
main inputs) allow the input signal to be AC-coupled.
Mechanically switched jack sockets can be used in
conjunction with the INT/AUX select pin, allowing the
auxiliary microphone input to be automatically selected
when a jack socket is inserted.
12
5
AUX_IN
BIAS
V
4
8
OUT
BIAS
V
CC
SHDN
IN+
3
9
OUT
SHDN
Microphone Bias Voltage
On the MAX4063 thin QFN package, connect the
exposed paddle (backside of PRS) to the ground
plane. The MAX4063 has an integrated low-noise, low-
output impedance bias voltage. An optimum electret
bias resistor can be set externally. This gives a low-
noise, flexible solution that can run from 2.4V to 5.5V,
which is suitable for hand-held devices such as PDAs
that typically have audio power supplies in the 3V
region (Figure 2).
10
IN-
G1 G2
14
GND
11
1
Figure 2. MAX4063 Used for Biasing a Microphone
Applications Information
Output
Shutdown Mode
The MAX4063 features a low-power, complete shut-
down mode. When SHDN goes low, the supply current
drops to 0.3µA, the output enters a high-impedance
state, and the bias current to the microphone is
switched off. Driving SHDN high enables the amplifier.
SHDN should not be left floating.
DC Bias
In shutdown mode, the bias voltage is disabled. OUT
and OUT have a low-noise, DC-bias voltage indepen-
dent of the power supplies, resulting in superior PSRR
performance. The MAX4063 outputs are high imped-
ance when the part is in shutdown mode.
Differential Output
The MAX4063 features a differential output stage (OUT
and OUT), allowing optimum performance when con-
nected to ADCs and CODECs with differential inputs.
This differential output is particularly useful in designs
where the microphone preamplifier is mounted some
distance away from the CODEC/ADC, as the low-imped-
ance, differential line provides excellent noise rejection
and immunity (Figure 4).
Power Supplies and Layout
The MAX4063 operates from a 2.4V to 5.5V single sup-
ply. Bypass the power supply with a 0.1µF capacitor to
ground. In systems where analog and digital grounds
are available, the MAX4063 should be connected to the
analog ground.
10 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
2.4V TO 5.5V
6
V
CC
R
ADJ
MAX4063
7
ADJ
0.1µF
2.2kΩ
12 AUX_IN
BIAS
5
10pF
V
BIAS
1µF 14 G1
4
OUT
R
G
11kΩ
1µF
1
9
G2
2.2kΩ
OUT
INT/AUX
SHDN
8
2
3
0.1µF
0.1µF
IN+
V
CC
10
IN-
SHDN
GND
11
Figure 3. MAX4063 Used to Bias a Microphone Connected to the Auxiliary Input and the Differential Input
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 11
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
2.4V TO 5.5V
6
V
CC
MAX4063
ADJ
7
V
CC
12
5
AUX_IN
BIAS
10pF
V
BIAS
1kΩ
1kΩ
1µF
14 G1
1µF
4
OUT
ADC
11.1kΩ
2.2µF
1
9
G2
1µF
OUT
8
2
0.1µF
IN+
INT/AUX
0.1µF
10
3
IN-
V
CC
1kΩ
1kΩ
SHDN
SHDN
GND
11
2.2µF
Figure 4. Using the MAX4063 with Differential Input/Differential Output Configuration
12 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Simplified Block Diagram
2.4V TO 5.5V
6
V
CC
MAX4063
INT/AUX
2
7
12
AUX_IN
ADJ
OUT
4
8
SHDN
IN+
3
9
SHDN
OUT
10 IN-
5
BIAS
V
BIAS
G1
14
G2 GND
11
1
Chip Information
Pin Configurations (continued)
TRANSISTOR COUNT: 351
PROCESS: BiCMOS
TOP VIEW
16 15 14 13
SHDN
OUT
1
2
3
4
12 AUX_IN
11 GND
10 IN-
MAX4063
BIAS
V
9
IN+
CC
5
6
7
8
THIN QFN
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 13
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/pacꢀages.)
PACKAGE OUTLINE
12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
A
PACKAGE OUTLINE
12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
A
14 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/pacꢀages.)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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