MAXIM MAX4063_11

19-2753; Rev 1; 6/11
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
The MAX4063 is a differential-input microphone preamplifier optimized for high-performance, portable applications. The device features two selectable inputs,
differential outputs, adjustable gain, an integrated lownoise bias source, and a low-power shutdown mode.
Two input paths provide both differential and singleended microphone sensing. The high-noise rejection of
the differential input is ideally suited to an internal microphone 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.
The differential and single-ended inputs have independent, adjustable gains that are set with a single external
resistor. Differential outputs provide a full-scale signal of
up to 6VP-P from a single 3V supply, optimizing the
dynamic range of the amplified signal. A complete shutdown mode reduces the supply current to only 0.3µA
and disables the microphone bias for the ultimate in
power savings.
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 TQFN
(4mm x 4mm x 0.8mm) and 14-pin TSSOP packages.
Applications
Notebook Audio Systems
Tablet PCs
Features
o
o
o
o
o
o
o
o
o
o
o
2.4V to 5.5V Single-Supply Operation
Differential Inputs and Outputs
Adjustable Gain
High 95dB PSRR
High 79dB CMRR
Low-Noise, Integrated Microphone Bias
750µA Supply Current
0.3µA Shutdown Current
±4kV ESD Protection (AUX_IN)
THD+N: 0.05% at 1kHz
Available in Space-Saving Packages
14-Pin TSSOP
16-Pin TQFN (4mm x 4mm x 0.8mm)
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX4063ETE+
-40°C to +85°C
16 TQFN-EP*
MAX4063EUD+
-40°C to +85°C
14 TSSOP
*EP = Exposed pad.
+Denotes a lead(pB)-free/RoHS-compliant package.
Typical Operating Circuit
2.4V TO 5.5V
PDA Audio Systems
Signal Conditioning
3
Pin Configurations
6
VCC
SHDN
INT/AUX 2
12 AUX_IN
ADJ
+
14 G1
G2 1
INT/AUX
2
13 N.C.
SHDN
3
12 AUX_IN
OUT 4
MAX4063
MAX4063
5 BIAS
7
OUT 4
VBIAS
OUT 8
11 GND
BIAS 5
10 IN-
VCC 6
9
IN+
ADJ 7
8
OUT
9 IN+
10 ING1 G2
14 1
TSSOP
GND
11
RG
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX4063
General Description
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC to GND). .................................-0.3V to +6V
Any Other Pin to GND ................................-0.3V to (VCC + 0.3V)
Duration of Short Circuit to GND or VCC ....................Continuous
Continuous Input Current (any pin) ................................ ±10mA
Continuous Power Dissipation (TA = +70°C)
14-Pin TSSOP (derate 10.0mW/°C above +70°C) .....796.8mW
16-Pin TQFN (derate 25.0mW/°C above +70°C) ........2000mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
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.
ELECTRICAL CHARACTERISTICS
(VCC = 3V, VGND = 0V, VSHDN = VCC, VINT/AUX = 0V, RG = 11.11kΩ, RL = 100kΩ to 1.5V, RBIAS = ∞, VOUT is measured between
OUT and OUT. TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1 and 2)
PARAMETER
SYMBOL
Supply Voltage Range
VCC
Supply Current
ICC
Output Common-Mode Voltage
CONDITIONS
Inferred from PSRR test
VOCM
MIN
TYP
MAX
5.5
V
0.75
1.1
mA
1.5
1.75
2.4
1.25
SR
AV = 20V/V
±1
Supply Current in Shutdown
I SHDN
V SHDN = 0V
0.001
Output Short-Circuit Current
ISC
Slew Rate
To GND
30
To VCC
30
UNITS
V
V/µs
1
µA
mA
DIFFERENTIAL INPUT (VINT/AUX = 0V)
±1
Input Offset Voltage
VOS
TA = +25°C
Common-Mode Input Voltage Range
VCM
Inferred from CMRR test
Maximum Differential Input Voltage
Small-Signal Bandwidth
Input Resistance
Input Resistance Match
VDIFFMAX AV = 2V/V
BW-3dB
RIN
mV
2
V
1
V
600
kHz
100
kΩ
1
%
AV = 20V/V, f = 1kHz
70
AV = 200V/V, f = 1kHz
12
VNRMS
AV = 20V/V, BW = 22Hz to 22kHz
225
µVRMS
THD+N
AV = 20V/V, f = 1kHz, VOUT = 0.7VRMS,
BW = 22Hz to 22kHz
0.05
%
AVDIFF
1V < VCM < 2V,
VOUT = 0.7VRMS
en
RMS Output Noise Voltage
Total Harmonic Distortion Plus Noise
Common-Mode Rejection Ratio
CMRR
Power-Supply Rejection Ratio
PSRR
2
Either differential input
RMATCH
Input Noise-Voltage Density
Differential Gain
1
RG = open
RG = 11.11kΩ
RG = 1.01kΩ
VCM = 500mVP-P, f = 1kHz
nV/√Hz
2
19.2
20
20.8
V/V
200
70
TA = +25°C
95
TA = TMIN - TMAX
85
VCC = 5V ±100mV, f = 1kHz
86
_______________________________________________________________________________________
dB
dB
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
(VCC = 3V, VGND = 0V, VSHDN = VCC, VINT/AUX = 0V, RG = 11.11kΩ, RL = 100kΩ to 1.5V, RBIAS = ∞, VOUT is measured between
OUT and OUT. TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1 and 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
AUXILIARY INPUT (INT/AUX = VCC)
Small-Signal Bandwidth
BW-3dB
Input Resistance
RIN
Input Noise-Voltage Density
en
230
100
kΩ
200
nV/√Hz
620
µVRMS
0.007
%
f = 1kHz
RMS Output Noise Voltage
VNRMS
BW = 22Hz to 22kHz
Total Harmonic Distortion Plus Noise
THD+N
f = 1kHz, BW = 22Hz to 22kHz
kHz
TA = +25°C
80
100
TA = TMIN - TMAX
72
-19.5
-20
2
2.2
Power-Supply Rejection Ratio
PSRR
Voltage Gain
AVAUX
VOUT = 0.7VRMS
Output Voltage
VOUT
IBIAS = 0.5mA to GND
Output Resistance
ROUT
IBIAS = 0.5mA to GND
16
20
dB
-20.5
V/V
30
Ω
BIAS OUTPUT
Output Noise Voltage
VNRMS
IBIAS = 0.5mA to GND, BW = 22Hz to 22kHz
Power-Supply Rejection Ratio
PSRR
IBIAS = 0.5mA, VCC = 3V + 100mVP-P,
f = 1kHz
IBIAS = 0.5mA to GND, VCC = 2.4V to 5.5V
60
V
µVRMS
74
dB
71
DIGITAL INPUTS (SHDN and INT/AUX)
Input Leakage Current
IIN
±1
VIN = 0V or VCC
0.7 ✕ VCC
µA
Input Voltage High
VINH
V
Input Voltage Low
VINL
Shutdown Enable Time
tON
10
µs
Shutdown Disable Time
tOFF
10
µs
0.3 ✕ VCC
V
Note 1: All specifications are 100% tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed
by design, not production tested.
Note 2: MAX4063 requires a 1µF capacitor from BIAS to ground and a 10pF capacitor from ADJ to OUT.
_______________________________________________________________________________________
3
MAX4063
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = 3V, AV = 20V/V, RL ≥ 100kΩ to 1.5V, VSHDN = VCC, VOUT is measured between OUT and OUT. TA = +25°C, unless otherwise
noted.)
PSRR (dB)
0
AV = 20V/V
-80
-3
-100
-6
-120
-9
-140
AV = 200V/V
VCC = 3V
0.6
0.4
0.2
NO LOAD
100
1k
10k
100k
1M
0
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
0.7
0.6
0.5
0.4
0.3
0.2
20
35
50
65
80
VOH vs. TEMPERATURE
100
1000
10
ILOAD = 2.5mA
100
1
VOH (mV)
0.8
5
TEMPERATURE (°C)
MAX4063 toc05
MAX4063 toc04
0.9
-40 -25 -10
1M
MAX4063 toc06
10
SUPPLY CURRENT (mA)
-60
SHUTDOWN SUPPLY CURRENT (nA)
GAIN (dB)
-40
3
VCC = 5V
0.8
SUPPLY CURRENT (mA)
-20
6
1.0
MAX4063 toc02
VCC = 5V
AV = 2V/V
SUPPLY CURRENT vs. TEMPERATURE
0
MAX4063 toc01
9
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (DIFF INPUT)
MAX4063 toc03
GAIN vs. FREQUENCY
(NO LOAD)
0.1
10
ILOAD = 50µA
0.01
0.1
NO LOAD
0.001
2.5
3.0
3.5
4.0
4.5
5.0
1
-40
5.5
-15
10
35
60
85
-15
MAX4063 toc07
400
ILOAD = 2.5mA
60
85
350
VOH = VCC - VOUT
300
VCC = 3V
250
250
VOL (mV)
VOH (mV)
100
35
VOL vs. LOAD CURRENT
350
300
10
TEMPERATURE (°C)
VOH vs. LOAD CURRENT
VOL vs. TEMPERATURE
1000
200
VCC = 3V
200
150
150
10
100
100
50
50
ILOAD = 50µA
0
0
1
-40
-15
10
35
TEMPERATURE (°C)
4
-40
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX4063 toc09
2.0
MAX4063 toc08
0
VOL (mV)
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
60
85
0
1
2
3
LOAD CURRENT (mA)
4
5
0
1
2
3
LOAD CURRENT (mA)
_______________________________________________________________________________________
4
5
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
10
MAX4063 toc11
VOUT = 4.5VP-P
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (DIFF INPUT)
1
MAX4063 toc10
1
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY (AUX INPUT)
VOUT = 4.5VP-P
BW = 22Hz TO 22kHz
1
3V
3V
0.1
MAX4063 toc12
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY (DIFF INPUT)
5V
THD+N (%)
THD+N (%)
THD+N (%)
0.1
0.01
5V
f = 1kHz
0.1
0.01
0.01
0.001
100
1k
10k
0.001
100k
10
100
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (DIFF INPUT)
BW = 22Hz TO 22kHz
VCC = 5V
THD+N (%)
0.1
0.01
0.001
1
2
3
4
5
6
3
4
5
6
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (AUX INPUT)
BW = 22Hz TO 22kHz
VCC = 5V
10
BW = 22Hz TO 22kHz
VCC = 5V
1
f = 1kHz
0.1
f = 10kHz
0.1
f = 1kHz
0.01
f = 10kHz
0.001
0.001
0
2
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE (AUX INPUT)
0.01
f = 10kHz
1
OUTPUT VOLTAGE (VP-P)
1
f = 1kHz
THD+N (%)
0
100k
THD+N (%)
1
10k
FREQUENCY (Hz)
10
MAX4063 toc13
10
1k
MAX4063 toc14
10
f = 10kHz
MAX4063 toc15
0.001
0
1
2
3
4
5
0
6
1
2
3
4
5
6
OUTPUT VOLTAGE (VP-P)
OUTPUT VOLTAGE (VP-P)
OUTPUT VOLTAGE (VP-P)
INPUT-REFERRED NOISE
vs. FREQUENCY (DIFF INPUT)
MIC BIAS OUTPUT NOISE
SMALL-SIGNAL TRANSIENT RESPONSE
FOR DIFF INPUT
MAX4063 toc16
400
INPUT-REFERRED NOISE (nV/√Hz)
MAX4063
Typical Operating Characteristics (continued)
(VCC = 3V, AV = 20V/V, RL ≥ 100kΩ to 1.5V, VSHDN = VCC, VOUT is measured between OUT and OUT. TA = +25°C, unless otherwise
noted.)
350
MAX4063 toc18
MAX4063 toc17
VCC = 5V
BW = 22Hz TO 22kHz
DIFF
INPUT
5mV/div
300
250
200
20µV/div
DIFF
OUTPUT
50mV/div
150
100
50
0
10
100
1k
10k
100k
100ms/div
10µs/div
FREQUENCY (Hz)
_______________________________________________________________________________________
5
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Typical Operating Characteristics (continued)
(VCC = 3V, AV = 20V/V, RL ≥ 100kΩ to 1.5V, VSHDN = VCC, VOUT is measured between OUT and OUT. TA = +25°C, unless otherwise
noted.)
LARGE-SIGNAL TRANSIENT RESPONSE
FOR DIFF INPUT
SMALL-SIGNAL TRANSIENT RESPONSE
FOR AUX INPUT
MAX4063 toc20
MAX4063 toc19
DIFF
INPUT
100mV/div
S/E
INPUT
5mV/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
6
10µs/div
_______________________________________________________________________________________
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
PIN
NAME
FUNCTION
TSSOP
TQFN
1
15
G2
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).
2
16
INT/AUX
Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low to select
differential in or high to select auxiliary in.
3
1
SHDN
4
2
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.
Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low for shutdown
mode.
5
3
BIAS
6
4
VCC
Power Supply. Bypass the VCC to GND with a 0.1µF capacitor.
7
5
ADJ
Adjustable Gain Select for AUX_IN (see Auxiliary Input-Gain Adjustment section). Connect
a 10pF capacitor between OUT and ADJ.
8
7
OUT
Complementary Amplifier Output. OUT is high impedance in shutdown mode.
9
9
IN+
Noninverting Differential Amplifier Input. AC-couple the audio signal into IN+.
10
10
IN-
Inverting Differential Amplifier Input. AC-couple the audio signal into IN-.
11
11
GND
12
12
AUX_IN
13
6, 8, 14
N.C.
14
13
G1
Gain-Selectable Input. Connect an external resistor between G1 and G2 to set the gain for
the differential amplifier.
—
—
EP
Exposed Pad (TQFN Only). Internally connected to GND. Connect to a large ground plane
to maximize thermal performance. Not intended as an electrical connection point.
Ground
Single-Ended Input for Auxiliary Microphone. AC-couple the audio signal into AUX_IN.
No Connection. Not internally connected.
Detailed Description
The MAX4063 is a differential microphone preamplifier providing high-quality amplification, optimized
for use in computer and mobile applications. This device
features adjustable gain, very high power-supply rejection (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 microphone.
The MAX4063 is capable of switching its output
between the differential input and an inverting singleended 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
external components. The MAX4063 has a complementary 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).
Differential Input
The main microphone amplifier 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-
_______________________________________________________________________________________
7
MAX4063
Pin Description
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
MAX4063
Functional Diagram
2.4V TO 5.5V
BIAS
6
VCC
MAX4063
12 AUX_IN
INT/AUX 2
ADJ 7
14 G1
OUT 4
BIAS
RG
1 G2
OUT 8
9 IN+
10 IN-
BIAS
VCC
5
VBIAS
3 SHDN
SHDN
GND
11
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
planes.
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:
For differential out:
• The microphone and preamplifier may be placed
physically further apart, easing PC board layout
restrictions.
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
(RG) connected between the G1 and G2 pins:
RG =
200kΩ
A VD − 2
where AV is the required voltage gain.
8
A VD =
VOUT − VOUT
VIN+ − VIN-
The resistor can be either fixed or variable, allowing the
use of a digitally controlled potentiometer to alter the
gain under software control.
Auxiliary Input-Gain Adjustment
The MAX4063 provides an option to increase the
AUX_IN (see Figure 3). To increase the gain, connect
resistor RADJ between the ADJ and AUX_IN pins. RADJ is
calculated from the following formula:
RADJ =
2MΩ
(to increase the gain)
AVAUX − 20
_______________________________________________________________________________________
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
MAX4063
2.4V TO 5.5V
6
100kΩ
VCC
RBIAS
5 BIAS
VBIAS
CBIAS
MAX4063
12 AUX_IN
INT/AUX 2
7
ADJ
14 G1
OUT 4
1 G2
OUT 8
9 IN+
10 INVCC
3 SHDN
SHDN
GND
11
Figure 1. MAX4063 with Auxiliary Input Configuration
where:
AVAUX =
VOUT − VOUT
VAUX_IN
RADJ is placed between AUX_IN and ADJ.
Input Capacitors
The two differential microphone inputs and the singleended 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:
CIN = 1 / (2πfCUTRIN)
This assumes a low source impedance is driving the
inputs.
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 frequencies where the impedance of the capacitor is significant
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 capacitors is to deliberately oversize the values on the differential inputs and to set the lower 3dB point (fCUT) of the
amplifier by sizing the output capacitor appropriately.
The input impedance matching on the differential input
is typically 1%, allowing input capacitor matching to be
effective at improving low-frequency PSRR.
Common-Mode Rejection Ratio
The common-mode rejection ratio (CMRR) refers to the
amount of rejection that the amplifier is capable of providing to any signal applied equally to the IN+ and INinputs. 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
VIN as an AC signal:
CMRR(dB) = ADM / ACM
where ADM is the differential gain, ACM is the commonmode gain.
Input voltages should be sufficiently small such that the
output is not clipped in either differential or common-
_______________________________________________________________________________________
9
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
mode application. The topology used in the MAX4063
means that the CMRR actually improves at higher differential gains—another advantage of using differential
sensing.
2.4V TO 5.5V
6
VCC
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.
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, lowoutput impedance bias voltage. An optimum electret
bias resistor can be set externally. This gives a lownoise, 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).
Output
DC Bias
In shutdown mode, the bias voltage is disabled. OUT
and OUT have a low-noise, DC-bias voltage independent of the power supplies, resulting in superior PSRR
performance. The MAX4063 outputs are high impedance when the part is in shutdown mode.
Differential Output
The MAX4063 features a differential output stage (OUT
and OUT), allowing optimum performance when connected 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-impedance, differential line provides excellent noise rejection
and immunity (Figure 4).
10
MAX4063
MICROPHONE
INPUT
INT/AUX 2
12 AUX_IN
ADJ
5 BIAS
VBIAS
7
OUT 4
VCC
3 SHDN
OUT 8
SHDN
9 IN+
10 ING1
G2
14
1
GND
11
Figure 2. MAX4063 Used for Biasing a Microphone
Applications Information
Shutdown Mode
The MAX4063 features a low-power, complete shutdown 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 unconnected.
Power Supplies and Layout
The MAX4063 operates from a 2.4V to 5.5V single supply. 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.
______________________________________________________________________________________
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
MAX4063
2.4V TO 5.5V
6
VCC
RADJ
MAX4063
0.1µF
ADJ 7
12 AUX_IN
5
2.2kΩ
1µF
BIAS
10pF
VBIAS
14 G1
OUT 4
1µF
RG
11kΩ
1 G2
2.2kΩ
0.1µF
OUT 8
9 IN+
INT/AUX 2
VCC
10 INSHDN
0.1µF
SHDN 3
GND
11
Figure 3. MAX4063 Used to Bias a Microphone Connected to the Auxiliary Input and the Differential Input
______________________________________________________________________________________
11
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
2.4V TO 5.5V
6
VCC
MAX4063
VCC
12 AUX_IN
5
1kΩ
ADJ 7
1µF
BIAS
10pF
VBIAS
14 G1
1µF
OUT 4
11.1kΩ
2.2µF
1 G2
1kΩ
0.1µF
OUT 8
ADC
1µF
9 IN+
INT/AUX 2
0.1µF
10 INVCC
1kΩ
3
SHDN
SHDN
GND
2.2µF
11
1kΩ
Figure 4. Using the MAX4063 with Differential Input/Differential Output Configuration
12
______________________________________________________________________________________
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
2.4V TO 5.5V
6
VCC
MAX4063
12 AUX_IN
INT/AUX 2
ADJ
7
OUT 4
3 SHDN
SHDN
OUT 8
9 IN+
10 INVBIAS
G1
14
Chip Information
BIAS 5
G2 GND
11
1
Pin Configurations (continued)
PROCESS: BiCMOS
14 SSOP
U14+1
21-0066
90-0113
16 TQFN
T1644+4
21-0139
90-0070
G1
13
12 AUX_IN
OUT 2
11 GND
MAX4063
BIAS 3
10 INEP*
VCC 4
5
6
7
8
N.C.
LAND
PATTERN NO.
14
OUT
OUTLINE NO.
15
N.C.
PACKAGE
CODE
16
+
ADJ
PACKAGE
TYPE
SHDN 1
N.C.
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
G2
INT/AUX
TOP VIEW
9
IN+
TQFN
*CONNECT EP TO GND.
______________________________________________________________________________________
13
MAX4063
Simplified Block Diagram
MAX4063
Differential Microphone Preamplifier with
Internal Bias and Complete Shutdown
Revision History
REVISION
NUMBER
REVISION
DATE
0
1/03
Initial release
6/11
Added EP information to Pin Description, updated power dissipation ratings,
updated Ordering Information and Pin Configuration for lead-free parts
1
DESCRIPTION
PAGES
CHANGED
—
1, 2, 7, 13
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.
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