General Description
The MAX4060/MAX4061/MAX4062 are differential-input
microphone preamplifiers optimized for notebook and
PDA audio systems. These devices feature adjustable
gain with excellent power-supply rejection and com-
mon-mode rejection ratios, making them ideal for low-
noise applications in portable audio systems.
The MAX4060/MAX4062 are capable of switching their
output between the differential input and a single-
ended auxiliary microphone amplifier input. In addition,
the MAX4060/MAX4062 have a low-noise microphone
bias generator. The differential gain of the
MAX4061/MAX4062 is set with a single resistor. The
MAX4060 has a fixed gain of 10V/V and is PC99/2001
compliant. The MAX4061 includes a complete shut-
down mode. In shutdown, the supply current is
reduced to 0.3µA and the current to the microphone
bias is cut off for ultimate power savings.
The MAX4060 operates from a 4.5V to 5.5V single sup-
ply and the MAX4061/MAX4062 operate from 2.4V to
5.5V. All devices are specified over the extended oper-
ating temperature range, -40°C to +85°C. The
MAX4060/MAX4061 are available in tiny 8-pin TDFN
(3mm x 3mm x 0.8mm) and 8-pin µMAX®packages.
The MAX4062 is available in a 10-pin µMAX package.
Applications
Features
o2.4V to 5.5V Single-Supply Operation
oAdjustable Gain or Fixed-Gain Options
oHigh PSRR (86dB at 1kHz)
oHigh CMRR (70dB at 1kHz)
oLow Input-Referred Noise
oIntegrated Microphone Bias
o750µA Supply Current
o0.3µA Shutdown Current
o±4kV ESD Protection (AUX_IN)
oRail-to-Rail Outputs
oTHD+N: 0.04% at 1kHz
oAvailable in Space-Saving Packages
8-Pin TDFN (MAX4060/MAX4061)
8-Pin µMAX (MAX4060/MAX4061)
10-Pin µMAX (MAX4062)
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
________________________________________________________________
Maxim Integrated Products
1
BIAS
BIAS
AUX_IN
8
IN-
IN+
6
5
4
VCC
2.4V TO 5.5V
MAX4060
INT/AUX 1
OUT 2
GND
7
BIAS
3
VBIAS
x10
BIAS
x10
Typical Operating Circuit
Ordering Information
19-2408; Rev 3; 4/11
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.
Pin Configurations and Selector Guide appear at end of
data sheet.
*
EP = Exposed pad.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Notebook Audio
Systems
Tablet PCs
PDA Audio Systems
USB Audio Peripherals
AES-42-Compliant
Microphones
Signal Conditioning
PART TEMP
RANGE
PIN-
PACKAGE
TOP
MARK
MAX4060ETA+ -40°C to +85°C 8 TDFN-EP* ABY
MAX4060EUA+ -40°C to +85°C 8 µMAX —
MAX4061ETA+ -40°C to +85°C 8 TDFN-EP* ABZ
MAX4061EUA+ -40°C to +85°C 8 µMAX —
MAX4062EUB+ -40°C to +85°C 10 µMAX —
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC = 3V for MAX4061/MAX4062, VCC = 5V for MAX4060, VGND = 0V, VSHDN = VCC, VINT/AUX = 0V, RG= 11.11kΩ,
RL= 100kΩto 1.5V, RBIAS = ∞, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)
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.
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)
8-Pin TDFN (derate 24.4mW/°C above +70°C) ......1951.2mW
8-Bump µMAX (derate 4.8mW/°C above +70°C) .....387.8mW
10-Bump µMAX (derate 8.8mW/°C above +70°C) ..707.3mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX4061/MAX4062 2.4 5.5
Supply Voltage Range VCC Inferred from
PSRR test MAX4060 4.5 5.5 V
Supply Current ICC 0.75 1.2 mA
Output Common-Mode Voltage VOCM 1.25 1.5 1.75 V
Slew Rate SR AV = 10V/V ±1 V/µs
Supply Current in Shutdown I SHDN V SHDN = 0V, MAX4061 0.001 1 µA
To GND 30
Output Short-Circuit Current ISC To VCC 30 mA
DIFFERENTIAL INPUT (VINT/AUX = 0V for MAX4060/MAX4062, default for MAX4061)
Input Offset Voltage VOS ±0.1 ±5mV
Common-Mode Input Voltage
Range VCM 12V
Maximum Differential Input
Voltage VDIFFMAX AV = 1V/V, MAX4061/MAX4062 1 V
Small-Signal Bandwidth BW-3dB 600 kHz
Input Resistance RIN Either differential input 100 kΩ
Input Resistance Match RMATCH 1%
AV = 10V/V, f = 1kHz 100
Input Noise-Voltage Density enAV = 100V/V, f = 1kHz, MAX4061/MAX4062
only 20 nV/√Hz
RMS Output Noise Voltage VNRMS AV = 10V/V, BW = 22Hz to 22kHz 125 µVRMS
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 3V for MAX4061/MAX4062, VCC = 5V for MAX4060, VGND = 0V, VSHDN = VCC, VINT/AUX = 0V, RG= 11.11kΩ,
RL= 100kΩto 1.5V, RBIAS = ∞, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Total Harmonic Distortion
Plus Noise
THD+N
AV = 10V/V, f = 1kHz, VOUT = 0.7VRMS,
BW = 22Hz to 22kHz
0.04
%
RG = open 1
1.13
1.3
RG = 11.11kΩ
9.6
10
10.4
1V < VCM < 2V,
VOUT = 0.7VRMS,
MAX4061/MAX4062
RG = 1.01kΩ
96 100 104
Differential Gain AVDIFF
1V < VCM < 2V, VOUT = 0.7VRMS, MAX4060
9.6 10.0 10.4
V/V
Common-Mode Rejection Ratio CMRR VCM = 500mVP-P, f = 1kHz 70 dB
TA = +25°C
72
89
TA = TMIN to TMAX
60
Power-Supply Rejection Ratio PSRR
VCC = 5V ±100mV, f = 1kHz 86
dB
AUXILIARY INPUT (MAX4060/MAX4062, INT/AUX = VCC)
Small-Signal Bandwidth
BW-3dB 200
kHz
Input Resistance RIN
100
kΩ
Input Noise-Voltage Density enf = 1kHz 45
nV/√Hz
RMS Output Noise Voltage VNRMS BW = 22Hz to 22kHz
385
μVRMS
Total Harmonic Distortion
Plus Noise
THD+N
f = 1kHz, BW = 22Hz to 22kHz
0.05
%
TA = +25°C
65
90
Power-Supply Rejection Ratio PSRR TA = TMIN - TMAX
50
dB
Voltage Gain AVAUX VOUT = 0.7VRMS
-10.7 -10 -9.3
V/V
BIAS OUTPUT (MAX4060/MAX4062)
IBIAS = 0.8mA to GND, MAX4060 2
2.2
Output Voltage VOUT IBIAS = 0.5mA to GND, MAX4062 2
2.2
V
IBIAS = 0.8mA to GND, MAX4060
(TA = +25°C) 2
2.5
kΩ
Output Resistance ROUT IBIAS = 0.5mA to GND, MAX4062
(TA = +25°C) 22 40 Ω
IBIAS = 0.8mA to GND, BW = 22Hz to
22kHz, MAX4060 50
Output Noise Voltage VNRMS IBIAS = 0.5mA to GND, BW = 22Hz to
22kHz, MAX4062 20
μVRMS
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 3V for MAX4061/MAX4062, VCC = 5V for MAX4060, VGND = 0V, VSHDN = VCC, VINT/AUX = 0V, RG= 11.11kΩ,
RL= 100kΩto 1.5V, RBIAS = ∞, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
IBIAS = 0.8mA to GND,
VCC = 4.5V to 5.5V 50 80
MAX4060
IBIAS = 0.8mA, VCC = 5V
+ 100mVP-P, f = 1kHz 70
IBIAS = 0.5mA to GND,
VCC = 2.4V to 5.5V 50 74
Power-Supply Rejection Ratio PSRR
M AX 4062
IBIAS = 0.5mA, VCC = 3V
+ 100mVP-P, f = 1kHz 71
dB
DIGITAL INPUTS ( S HD N for M AX 4061 and INT /AU X for M AX 4060/M AX 4062)
Input Leakage Current IIN VIN = 0V or VCC ±1μA
Input-Voltage High VINH 0.7 x
VCC V
Input-Voltage Low VINL 0.3 x
VCC V
Shutdown Enable Time tON MAX4061 10 μs
Shutdown Disable Time tOFF MAX4061 10 μs
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: MAX4062 requires a 1μF capacitor from BIAS to ground.
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
_______________________________________________________________________________________
5
MAX4060 toc01
FREQUENCY (Hz)
GAIN (dB)
100k10k1k100
-12
-9
-6
-3
0
3
-15
10 1M
GAIN vs. FREQUENCY
(NO LOAD)
VCC = 5V
MAX4060 toc02
FREQUENCY (Hz)
PSRR (dB)
100k10k1k100
-100
-80
-60
-40
-20
0
-120
10 1M
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (DIFF INPUT)
AV = 100V/V
AV = 10V/V
SUPPLY CURRENT vs. TEMPERATURE
MAX4060 toc03
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
80655035205-10-25
0.2
0.4
0.6
0.8
1.0
0
-40
VCC = 3V
VCC = 5V
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4060 toc04
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.04.53.5 4.03.02.5
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0
2.0 5.5
AV = 10V/V
NO LOAD
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX4060 toc05
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (nA)
603510-15
0.01
0.1
1
10
100
0.001
-40 85
OUTPUT-VOLTAGE HIGH
vs. TEMPERATURE
MAX4060 toc06
TEMPERATURE (°C)
VOH (mV)
603510-15
10
100
1000
1
-40 85
ILOAD = 2.5mA
ILOAD = 50μA
VOH = VCC - VOUT
OUTPUT-VOLTAGE LOW
vs. TEMPERATURE
MAX4060 toc07
TEMPERATURE (°C)
VOL (mV)
603510-15
10
100
1000
1
-40 85
ILOAD = 2.5mA
ILOAD = 50μA
OUTPUT-VOLTAGE HIGH
vs. LOAD CURRENT
MAX4060 toc08
LOAD CURRENT (mA)
VOH (mV)
4321
25
50
75
100
125
150
175
0
05
VOH = VCC - VOUT
VCC = 3V
OUTPUT-VOLTAGE LOW
vs. LOAD CURRENT
MAX4060 toc09
LOAD CURRENT (mA)
VOL (mV)
4321
50
100
150
200
250
300
0
05
VCC = 3V
Typical Operating Characteristics
(VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV= 10V/V, RL≥100kΩto 1.5V, SHDN = VCC (MAX4061 only),
TA= +25°C, unless otherwise noted.)
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV= 10V/V, RL≥100kΩto 1.5V, SHDN = VCC (MAX4061 only),
MAX4060
MIC BIAS VOLTAGE vs. TEMPERATURE
MAX4060 toc10
TEMPERATURE (°C)
MIC BIAS VOLTAGE (V)
6035-15 10
2.125
2.150
2.175
2.200
2.225
2.250
2.275
2.300
2.100
-40 85
IBIAS = 800μA
MAX4060 toc12
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
0.001
10 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (AUX INPUT)
VCC = 3V
VCC = 5V
VOUT = 2.26VP-P
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE
(DIFF INPUT, VCC = 3V)
MAX4060 toc13
OUTPUT VOLTAGE (VP-P)
THD+N (%)
2.52.01.51.00.5
0.01
0.1
1
10
0.001
0 3.0
f = 10kHz
f = 1kHz
BW = 22kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT AMPLITUDE
(AUX INPUT, VCC = 5V)
MAX4060 toc16
OUTPUT VOLTAGE (VP-P)
THD+N (%)
3.02.52.01.51.00.5
0.01
0.1
1
10
0.001
03.5
f = 10kHz
f = 1kHz
BW = 22kHz
MAX4060
MIC BIAS OUTPUT NOISE
MAX4060 toc18
100ms/div
5μV/div
VCC = 5V
BW = 22Hz TO 22kHz
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
_______________________________________________________________________________________
7
MAX4062
MIC BIAS OUTPUT NOISE
MAX4060 toc19
100ms/div
5μV/div
VCC = 5V
BW = 22Hz TO 22kHz
SMALL-SIGNAL TRANSIENT RESPONSE
FOR DIFF INPUT
MAX4060 toc20
10μs/div
INPUT
5mV/div
OUTPUT
50mV/div
LARGE-SIGNAL TRANSIENT RESPONSE
FOR DIFF INPUT
MAX4060 toc22
10μs/div
INPUT
100mV/div
OUTPUT
1V/div
SMALL-SIGNAL TRANSIENT RESPONSE
FOR AUX INPUT
MAX4060 toc21
10μs/div
INPUT
5mV/div
OUTPUT
50mV/div
OUTPUT OVERDRIVEN
MAX4060 toc24
10μs/div
INPUT
500mV/div
OUTPUT
1V/div
DIFFERENTIAL INPUT
LARGE-SIGNAL TRANSIENT RESPONSE
FOR AUX INPUT
MAX4060 toc23
10μs/div
INPUT
200mV/div
OUTPUT
1V/div
Typical Operating Characteristics (continued)
(VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV= 10V/V, RL≥100kΩto 1.5V, SHDN = VCC (MAX4061 only),
TA= +25°C, unless otherwise noted.)
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
8 _______________________________________________________________________________________
Pin Description
PIN
MAX4060 MAX4061 MAX4062
NAME FUNCTION
1—2INT/AUX Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low
to select internal or high to select auxiliary microphone input.
2 3 3 OUT Amplifier Output. OUT is high impedance when in shutdown mode.
3 — — BIAS External Electret Microphone Capsule Bias Output. BIAS has a greater than
2kΩ output impedance.
445V
CC Power Supply. Bypass the VCC to GND with a 0.1µF capacitor.
5 5 6 IN+ Noninverting Differential Amplifier Input. AC-couple the audio signal into IN+.
6 6 7 IN- Inverting Differential Amplifier Input. AC-couple the audio signal into IN-.
7 7 8 GND Ground
8 — 9 AUX_IN Single-Ended Input for Auxiliary Microphone. AC-couple the audio signal into
AUX_IN.
—11G2
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—SHDN Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low for
shutdown mode.
— — 4 BIAS External Electret Microphone Capsule Bias Output. Bypass BIAS with 1µF
capacitor to ground.
—810G1
Gain-Selectable Input. Connect an external resistor between G1 and G2 to set
the gain for the differential amplifier.
———EP
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.
Detailed Description
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-
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.
Differential Input
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
planes.
• The microphone and preamplifier can be placed
physically further apart, easing PC board layout
restrictions.
MAX4060/MAX4061/MAX4062
Fixed Differential Gain (MAX4060)
The MAX4060 has an internal fixed gain of 10V/V for its
differential input. This feature simplifies design, reduces
pin count, footprint, and eliminates external gain-setting
resistors.
Adjustable Differential-Gain Setting
The MAX4061/MAX4062 allow the user to alter the gain
to optimize the signal-to-noise ratio (SNR) of their sys-
tem. The gain is set by a single external resistor (RG)
connected between the G1 and G2 pins, where:
RG= 100kΩ/ (AV- 1)
where AVis the required voltage gain.
Hence, an 11.11kΩresistor yields a gain of 10V/V, or
20dB. Leaving the pins unconnected results in a gain
of 1V/V. Gain for the MAX4061/MAX4062 is defined as:
AV= 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.
Input Capacitors
The two differential microphone inputs and the single-
ended auxiliary input of the MAX4060/MAX4061/
MAX4062 have on-chip bias components, allowing the
user to AC-couple any signals onto 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 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 frequen-
cies 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 capaci-
tors is to deliberately oversize the values on the differ-
BIAS
IN-
IN+
6
5
4
VCC
2.4V TO 5.5V
MAX4060
INT/AUX 1
OUT 2
GND
7
BIAS
3
VBIAS BIAS
x10
BIAS
8AUX_IN
x10
Functional Diagram
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
_______________________________________________________________________________________ 9
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
10 ______________________________________________________________________________________
AUX_IN
9
4
IN-
IN+
7
6
5
VCC
2.4V TO 5.5V
MAX4062
2
GND
8
VBIAS
G2
G1
BIAS
RBIAS
CBIAS
100kΩ
OUT 3
INT/AUX
10
1
x10
Figure 1. MAX4062 with Auxiliary Input Configuration
ential 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 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
VIN as an AC signal:
CMRR(dB) = ADM / ACM
where ADM is the differential gain, ACM is the common-
mode gain.
Input voltages are sufficiently small such that the output
is not clipped in either differential or common-mode
application. The topology used in the MAX4061/
MAX4062 means that the CMRR actually improves at
higher differential gains—another advantage of using
differential sensing.
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
MAX4060
The MAX4060 has a microphone bias voltage designed
to comply with the Microsoft/Intel PC99/2001 audio
standard. It features source impedance of greater than
2kΩ, and delivers more than 2V of bias when loaded
with a current of 800μA. This limits operation of this part
to supplies between 4.5V to 5.5V (see Figure 2).
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
______________________________________________________________________________________ 11
MAX4061/MAX4062
The MAX4062 has a lower bias voltage and low-imped-
ance outputs (optimum electret bias resistor can then
be set externally). This gives a low-noise, flexible solu-
tion that can run from 2.4V to 5.5V, suitable for hand-
held devices such as PDAs that typically have audio
power supplies in the 3V region (see Figure 3).
In applications where the differential microphone is
placed some distance from the MAX4060/MAX4061/
MAX4062, using a remote differential bias scheme as
shown in Figure 4 can provide improved noise rejection.
Output
MAX4060/MAX4061 DC Bias
The output voltage has a DC-bias voltage independent
of the power supplies, resulting in superior PSRR per-
formance. The MAX4061 output is high impedance
when the part is in shutdown mode. AC-coupling the
output into the next audio stage (e.g., CODEC) is rec-
ommended.
Applications Information
Shutdown Mode
The MAX4061 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 unconnected.
Power Supplies and Layout
The MAX4060 operates from a 4.5V to 5.5V single sup-
ply and the MAX4061/MAX4062 operate 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 MAX4060/
MAX4061 should be connected to the analog ground.
IN-
IN+
6
5
4
VCC
4.5V TO 5.5V
MAX4060
INT/AUX 1
OUT 2
GND
7
x10
VBIAS
x10
BIAS
3
AUX_IN
MICROPHONE
INPUT 8
RBIAS
Figure 2. MAX4060 Used for Biasing a Microphone
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
12 ______________________________________________________________________________________
2.2kΩ
2.2kΩ
AUX_IN9
IN-
IN+
7
6
5
VCC
2.4V TO 5.5V
MAX4062
GND
8
G2
G1
0.1μF
0.1μF
1
10
RG
11kΩ
BIAS VBIAS
0.1μF
0.1μF
4
x10
OUT
INT/AUX 2
3
Figure 3. MAX4062 Used to Bias a Microphone Connected to the Auxiliary Input and the Differential Input
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
______________________________________________________________________________________ 13
2.2kΩ
1kΩ
AUX_IN
9
IN-
IN+
7
6
5
VCC
2.4V TO 5.5V
MAX4062
GND
8
G2
G1
0.1μF
0.1μF
1
10
RG
11kΩ
BIAS VBIAS
0.1μF
0.1μF
4
x10
OUT
INT/AUX 2
3
1kΩ
VDD
2.2μF
1kΩ
1kΩ
2.2μF
Figure 4. Remote Differential Microphone Bias Network Optimizes Noise Rejection in Long-Run, PC Board Traces
Pin Configurations
1
2
3
4
8
7
6
5
AUX_IN
GND
IN-
IN+
EP*
VCC
*CONNECT EP TO GND (TDFN ONLY).
BIAS
OUT
INT/AUX
MAX4060
µMAX/TDFN
1
2
3
4
8
7
6
5
G1
GND
IN-
IN+VCC
OUT
SHDN
G2
MAX4061
µMAX/TDFN
TOP VIEW
1
2
3
4
5
10
9
8
7
6
G1
AUX_IN
GND
IN-BIAS
OUT
INT/AUX
G2
MAX4062
µMAX
IN+VCC
EP*
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.
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
14 ______________________________________________________________________________________
Selector Guide
PRODUCT* AUXILIARY
INPUT
DIFF INPUT
GAIN
SINGLE-ENDED
INPUT
GAIN (dB)
MICROPHONE
BIAS
SHUTDOWN
MODE
SUPPLY
VOLTAGE
(V)
MAX4060 ✔20dB 20 ✔— 4.5 to 5.5
MAX4061 — ADJ — — ✔2.4 to 5.5
MAX4062 ✔ADJ 20 ✔— 2.4 to 5.5
Chip Information
PROCESS: BiCMOS
IN-
IN+
6
5
4
VCC
4.5V TO 5.5V
INT/AUX 1
OUT 2
GND
7
x10
VBIAS
x10
BIAS
3
AUX_IN
8
IN-
IN+
6
5
2
4
SHDN
VCC
2.4V TO 5.5V
OUT 3
GND
7
1
8
G1 G2 IN-
IN+
7
6
5
VCC
2.4V TO 5.5V
INT/AUX 2
OUT 3
GND
8
x10
VBIAS
BIAS
4
AUX_IN
8
1
10
G1 G2
MAX4061
MAX4062
MAX4060
Block Diagrams
*
See Block Diagrams.
PACKAGE
TYPE
PACKAGE
CODE
DOCUMENT
NO.
LAND PATTERN
NO.
8 TDFN T833+2 21-0137 90-0059
8 μMAX U8+1 21-0036 90-0092
10 μMAX U10+2 21-0061 90-0030
MAX4060/MAX4061/MAX4062
Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown
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.
15
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
3 4/11 Added exposed pad information to Pin Description and Pin Configurations sections 8, 13