MAXIM MAX4060, MAX4061, MAX4062 Technical data

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 com­mon-mode rejection ratios, making them ideal for low­noise applications in portable audio systems.

The MAX4060/MAX4062 are capable of switching their
output between the differential input and a single­ended 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 shut­down 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 sup­ply and the MAX4061/MAX4062 operate from 2.4V to

5.5V. All devices are specified over the extended oper­ating 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

o 2.4V to 5.5V Single-Supply Operation
o Adjustable Gain or Fixed-Gain Options
o High PSRR (86dB at 1kHz)
o High CMRR (70dB at 1kHz)
o Low Input-Referred Noise
o Integrated Microphone Bias
o 750µA Supply Current
o 0.3µA Shutdown Current
o ±4kV ESD Protection (AUX_IN)
o Rail-to-Rail Outputs
o THD+N: 0.04% at 1kHz
o Available 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

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

BIAS

8

AUX_IN

2.4V TO 5.5V

4
V

x10

CC

MAX4060

INT/AUX

PART

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 —

TEMP

RANGE

PIN­PACKAGE

TOP

MARK

BIAS

5

IN+

6

IN-

x10

V

BIAS

GND

7

BIAS

OUT

1

2

BIAS

3

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, V

GND

= 0V, V

SHDN

= VCC, V

INT/AUX

= 0V, RG= 11.11kΩ,

RL= 100kΩ to 1.5V, R

BIAS

= ∞, TA= T

MIN

to T

MAX

, 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 (VCCto GND). .................................-0.3V to +6V

Any Other Pin to GND ................................-0.3V to (V

CC

+ 0.3V)

Duration of Short Circuit to GND or V

CC

....................Continuous

Continuous Input Current (any pin) ................................ ±10mA

Continuous Power Dissipation (T

A

= +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

Supply Voltage Range V

Supply Current I

Output Common-Mode Voltage V

Slew Rate SR AV = 10V/V ±1 V/µs

Supply Current in Shutdown I

Output Short-Circuit Current I

DIFFERENTIAL INPUT (V

Input Offset Voltage V

Common-Mode Input Voltage
Range

Maximum Differential Input
Voltage

Small-Signal Bandwidth BW

Input Resistance R

Input Resistance Match R

Input Noise-Voltage Density e

RMS Output Noise Voltage V

= 0V for MAX4060/MAX4062, default for MAX4061)

INT/AUX

CC

CC

OCM

SHDN

SC

OS

V

CM

V

DIFFMAXAV

-3dB

IN

MATCH

n

NRMS

Inferred from
PSRR test

V

= 0V, MAX4061 0.001 1 µA

SHDN

To GND 30

To V

CC

= 1V/V, MAX4061/MAX4062 1 V

Either differential input 100 kΩ

AV = 10V/V, f = 1kHz 100

AV = 100V/V, f = 1kHz, MAX4061/MAX4062
only

AV = 10V/V, BW = 22Hz to 22kHz 125 µV

MAX4061/MAX4062 2.4 5.5

MAX4060 4.5 5.5

1.25 1.5 1.75 V

12V

0.75 1.2 mA

30

±0.1 ±5mV

600 kHz

1%

20

V

mA

nV/√Hz

RMS

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, V

GND

= 0V, V

SHDN

= VCC, V

INT/AUX

= 0V, RG= 11.11kΩ,

R

L

= 100kΩ to 1.5V, R

BIAS

= ∞, TA= T

MIN

to T

MAX

, 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

AV = 10V/V, f = 1kHz, V

OUT

= 0.7V

RMS

,

BW = 22Hz to 22kHz

%

RG = open 1

1.3

RG = 11.11kΩ

10

1V < VCM < 2V,
V

OUT

= 0.7V

RMS

,

RG = 1.01kΩ

Differential Gain A

VDIFF

1V < VCM < 2V, V

OUT

= 0.7V

RMS

, MAX4060

V/V

Common-Mode Rejection Ratio CMRR VCM = 500mV

P-P

, f = 1kHz 70 dB

TA = +25°C

89

TA = T

MIN

to T

MAX

Power-Supply Rejection Ratio PSRR

V

CC

= 5V ±100mV, f = 1kHz 86

dB

AUXILIARY INPUT (MAX4060/MAX4062, INT/AUX = VCC)

Small-Signal Bandwidth

kHz

Input Resistance R

IN

kΩ

Input Noise-Voltage Density e

n

f = 1kHz 45

nV/√Hz

RMS Output Noise Voltage V

NRMS

BW = 22Hz to 22kHz

μV

RMS

Total Harmonic Distortion
Plus Noise

f = 1kHz, BW = 22Hz to 22kHz

%

TA = +25°C

90

Power-Supply Rejection Ratio PSRR

T

A

= T

MIN

- T

MAX

dB

Voltage Gain A

VAUX

V

OUT

= 0.7V

RMS

V/V

BIAS OUTPUT (MAX4060/MAX4062)

I

BIAS

= 0.8mA to GND, MAX4060 2

Output Voltage V

OUT

I

BIAS

= 0.5mA to GND, MAX4062 2

V

I

BIAS

= 0.8mA to GND, MAX4060

(T

A

= +25°C)

2

kΩ

Output Resistance R

OUT

I

BIAS

= 0.5mA to GND, MAX4062

(T

A

= +25°C)

22 40 Ω

I

BIAS

= 0.8mA to GND, BW = 22Hz to

22kHz, MAX4060

50

Output Noise Voltage V

NRMS

I

BIAS

= 0.5mA to GND, BW = 22Hz to

22kHz, MAX4062

20

μV

RMS

THD+N

BW

-3dB

THD+N

0.04

1.13

9.6

MAX4061/MAX4062

96 100 104

9.6 10.0 10.4

72

60

200

100

385

0.05

2.2

2.2

65

50

-10.7 -10 -9.3

2.5

10.4

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, V

GND

= 0V, V

SHDN

= VCC, V

INT/AUX

= 0V, RG= 11.11kΩ,

R

L

= 100kΩ to 1.5V, R

BIAS

= ∞, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)

Note 1: All specifications are 100% tested at TA= +25°C. Specification limits over temperature (TA= T

MIN

to T

MAX

) are guaranteed

by design, not production tested.

Note 2: MAX4062 requires a 1μF capacitor from BIAS to ground.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Power-Supply Rejection Ratio PSRR

DIGITAL INPUTS ( S HD N for M AX 4061 and INT /AU X for M AX 4060/M AX 4062)

Input Leakage Current I

Input-Voltage High V

Input-Voltage Low V

Shutdown Enable Time t

Shutdown Disable Time t

IN

INH

INL

ON

OFF

MAX4060

M AX 4062

VIN = 0V or V

MAX4061 10 μs

MAX4061 10 μs

CC

I

= 0.8mA to GND,

BIAS

= 4.5V to 5.5V

V

CC

I

= 0.8mA, VCC = 5V

BIAS

+ 100mV

I

= 0.5mA to GND,

BIAS

= 2.4V to 5.5V

V

CC

I

= 0.5mA, VCC = 3V

BIAS

+ 100mV

, f = 1kHz

P-P

, f = 1kHz

P-P

50 80

50 74

0.7 x
V

CC

70

71

0.3 x

dB

±1μA

V

V

CC

V

MAX4060/MAX4061/MAX4062

Differential Microphone Preamplifiers with

Internal Bias and Complete Shutdown

_______________________________________________________________________________________

5

Typical Operating Characteristics

(VCC= 3V (MAX4061/MAX4062), VCC= 5V for MAX4060, AV= 10V/V, RL≥ 100kΩ to 1.5V, SHDN = VCC(MAX4061 only),
T

A

= +25°C, unless otherwise noted.)

3

0

-3

-6

GAIN (dB)

-9

-12

-15
10 1M

SUPPLY CURRENT vs. SUPPLY VOLTAGE

0.9

0.8

0.7

0.6

0.5

0.4

0.3

SUPPLY CURRENT (mA)

0.2

0.1

0

2.0 5.5

GAIN vs. FREQUENCY

VCC = 5V

AV = 10V/V
NO LOAD

SUPPLY VOLTAGE (V)

(NO LOAD)

FREQUENCY (Hz)

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (DIFF INPUT)

0

-20

MAX4060 toc01

-40

-60

PSRR (dB)

-80

-100

100k10k1k100

-120
10 1M

AV = 10V/V

AV = 100V/V

100k10k1k100

FREQUENCY (Hz)

MAX4060 toc02

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

100

MAX4060 toc04

10

1

0.1

0.01

SHUTDOWN SUPPLY CURRENT (nA)

5.04.53.5 4.03.02.5

0.001

-40 85

TEMPERATURE (°C)

603510-15

MAX4060 toc05

SUPPLY CURRENT vs. TEMPERATURE

1.0

0.8

0.6

0.4

SUPPLY CURRENT (mA)

0.2

VCC = 5V

0

-40

TEMPERATURE (°C)

OUTPUT-VOLTAGE HIGH

vs. TEMPERATURE

1000

VOH = VCC - V

100

(mV)

OH

V

10

1

-40 85

OUT

I

= 2.5mA

LOAD

TEMPERATURE (°C)

I

LOAD

VCC = 3V

80655035205-10-25

= 50μA

603510-15

MAX4060 toc03

MAX4060 toc06

OUTPUT-VOLTAGE LOW

vs. TEMPERATURE

1000

I

= 2.5mA

100

(mV)

OL

V

10

1

-40 85

LOAD

I

TEMPERATURE (°C)

LOAD

= 50μA

603510-15

MAX4060 toc07

(mV)

OH

V

OUTPUT-VOLTAGE HIGH

vs. LOAD CURRENT

(mV)

OL

V

300

250

200

150

100

50

0

175

VOH = V

- V

CC

150

125

100

75

50

25

0

05

OUT

MAX4060 toc08

VCC = 3V

4321

LOAD CURRENT (mA)

OUTPUT-VOLTAGE LOW

vs. LOAD CURRENT

05

MAX4060 toc09

VCC = 3V

4321

LOAD CURRENT (mA)

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≥ 100kΩ to 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

I

BIAS

= 800μA

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DIFF INPUT)

MAX4060 toc11

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

0.001
10 100k

V

OUT

= 2.26V

P-P

VCC = 5V

VCC = 3V

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

V

OUT

= 2.26V

P-P

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT AMPLITUDE

(DIFF INPUT, V

CC

= 3V)

MAX4060 toc13

OUTPUT VOLTAGE (V

P-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

(DIFF INPUT, V

CC

= 5V)

MAX4060 toc14

OUTPUT VOLTAGE (V

P-P

)

THD+N (%)

3.02.52.01.51.00.5

0.01

0.1

1

10

0.001
0 3.5

f = 10kHz

f = 1kHz

BW = 22kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT AMPLITUDE

(AUX INPUT, V

CC

= 3V)

MAX4060 toc15

OUTPUT VOLTAGE (V

P-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, V

CC

= 5V)

MAX4060 toc16

OUTPUT VOLTAGE (V

P-P

)

THD+N (%)

3.02.52.01.51.00.5

0.01

0.1

1

10

0.001
0

3.5

f = 10kHz

f = 1kHz

BW = 22kHz

MAX4060 toc17

FREQUENCY (Hz)

(nV/√Hz)

10k1k100

100

200

300

400

500

600

700

800

0

10 100k

INPUT-REFERRED NOISE

vs. FREQUENCY (DIFF INPUT)

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

Typical Operating Characteristics (continued)

(VCC= 3V (MAX4061/MAX4062), VCC= 5V for MAX4060, AV= 10V/V, RL≥ 100kΩ to 1.5V, SHDN = VCC(MAX4061 only),
T

A

= +25°C, unless otherwise noted.)

MAX4062

MIC BIAS OUTPUT NOISE

VCC = 5V
BW = 22Hz TO 22kHz

100ms/div

MAX4060 toc19

SMALL-SIGNAL TRANSIENT RESPONSE

FOR AUX INPUT

MAX4060 toc21

5μV/div

INPUT
5mV/div

SMALL-SIGNAL TRANSIENT RESPONSE

FOR DIFF INPUT

10μs/div

MAX4060 toc20

LARGE-SIGNAL TRANSIENT RESPONSE

FOR DIFF INPUT

MAX4060 toc22

INPUT
5mV/div

OUTPUT
50mV/div

INPUT
100mV/div

OUTPUT
1V/div

OUTPUT
50mV/div

10μs/div

10μs/div

LARGE-SIGNAL TRANSIENT RESPONSE

FOR AUX INPUT

10μs/div

MAX4060 toc23

INPUT
200mV/div

OUTPUT
1V/div

OUTPUT OVERDRIVEN

DIFFERENTIAL INPUT

10μs/div

MAX4060 toc24

INPUT
500mV/div

OUTPUT
1V/div

MAX4060/MAX4061/MAX4062

Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown

8 _______________________________________________________________________________________

Pin Description

Detailed Description

The MAX4060/MAX4061/MAX4062 are differential micro­phone preamplifiers providing high-quality audio, opti­mized 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 differen­tial 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 note­book 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.

PIN

MAX4060 MAX4061 MAX4062

1—2INT/AUX

2 3 3 OUT Amplifier Output. OUT is high impedance when in shutdown mode.

3 — — BIAS

445VCCPower 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

—11G2

—2—SHDN

— — 4 BIAS

—810G1

———EP

NAME FUNCTION

Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low
to select internal or high to select auxiliary microphone input.

External Electret Microphone Capsule Bias Output. BIAS has a greater than
2kΩ output impedance.

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.

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 sys­tem. 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 11.11kΩ resistor 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= V

OUT

/ (V

IN+

- V

IN-

)

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 single­ended 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:

C

IN

= 1 / (2πf

CUTRIN

)

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 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 differ-

BIAS

IN-

IN+

6

5

4
V

CC

2.4V TO 5.5V

MAX4060

INT/AUX

1

OUT

2

GND

7

BIAS

3

V

BIAS

BIAS

x10

BIAS

8

AUX_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 ______________________________________________________________________________________

Figure 1. MAX4062 with Auxiliary Input Configuration

ential inputs and to set the lower 3dB point (f

CUT

) 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
VINas an AC signal:

CMRR(dB) = A

DM

/ A

CM

where ADMis the differential gain, ACMis the common­mode 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).

2.4V TO 5.5V

5

V

x10

CC

V

BIAS

MAX4062

2

INT/AUX

3

OUT

G1

10

1

G2

GND

8

100k

Ω

R

BIAS

BIAS

4

C

BIAS

9

AUX_IN

6

IN+

7

IN-

MAX4060/MAX4061/MAX4062

Differential Microphone Preamplifiers with

Internal Bias and Complete Shutdown

______________________________________________________________________________________ 11

MAX4061/MAX4062

The MAX4062 has a lower bias voltage and low-imped­ance outputs (optimum electret bias resistor can then
be set externally). This gives a low-noise, flexible solu­tion that can run from 2.4V to 5.5V, suitable for hand­held 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 per­formance. 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 rec­ommended.

Applications Information

Shutdown Mode

The MAX4061 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 MAX4060 operates from a 4.5V to 5.5V single sup­ply 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.

Figure 2. MAX4060 Used for Biasing a Microphone

4.5V TO 5.5V

4

V

CC

MICROPHONE

INPUT

8

AUX_IN

x10

MAX4060

BIAS

3

5

IN+

6

IN-

V

R

BIAS

BIAS

INT/AUX

x10

GND

7

OUT

1

2

MAX4060/MAX4061/MAX4062

Differential Microphone Preamplifiers with
Internal Bias and Complete Shutdown

12 ______________________________________________________________________________________

Figure 3. MAX4062 Used to Bias a Microphone Connected to the Auxiliary Input and the Differential Input

2.4V TO 5.5V

5

V

CC

4

BIAS

V

0.1μF

BIAS

MAX4062

2.2kΩ

2.2kΩ

0.1μF

11kΩ

0.1μF

0.1μF

AUX_IN9

G1

10

R

G

1

G2

6

IN+

7

IN-

x10

INT/AUX

GND

8

OUT

2

3

MAX4060/MAX4061/MAX4062

Differential Microphone Preamplifiers with

Internal Bias and Complete Shutdown

______________________________________________________________________________________ 13

Figure 4. Remote Differential Microphone Bias Network Optimizes Noise Rejection in Long-Run, PC Board Traces

Pin Configurations

2.2μF

2.2μF

2.2kΩ

V

DD

1kΩ

1kΩ

1kΩ

1kΩ

0.1μF

0.1μF

11kΩ

0.1μF

0.1μF

2.4V TO 5.5V

5

V

CC

4

BIAS

V

BIAS

9

AUX_IN

G1

10

R

G

1

G2

6

IN+

7

IN-

x10

GND

8

MAX4062

INT/AUX

OUT

2

3

TOP VIEW

INT/AUX

OUT

BIAS

V

1

2

MAX4060

3

4

CC

µMAX/TDFN

8

AUX_IN

7

GND

6

IN-

EP*

5

IN+

*CONNECT EP TO GND (TDFN ONLY).

SHDN

OUT

G2

CC

1

2

MAX4061

3

4

µMAX/TDFN

EP*

8

G1

7

GND

6

IN-

5

IN+V

INT/AUX

OUT

1

G2

2

MAX4062

3

4

5

CC

µMAX

10

9

8

7

6

G1

AUX_IN

GND

IN-BIAS

IN+V

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

Chip Information

PROCESS: BiCMOS

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

8

3

6

5

AUX_IN

BIAS

IN+

IN-

4.5V TO 5.5V

x10

V

BIAS

x10

4

V

CC

MAX4060

GND

7

INT/AUX

OUT 2

1

2.4V TO 5.5V

4
V

CC

SHDN

2

5

IN+

IN-

6

G1
8

MAX4061

3

OUT

G2
1

GND

7

8

4

6

7

AUX_IN

BIAS

IN+

IN-

V

BIAS

2.4V TO 5.5V

x10

G1

10

5

V

CC

G2

1

MAX4062

INT/AUX

GND

OUT

8

2

3

PRODUCT*

AUXILIARY

INPUT

DIFF INPUT

GAIN

SINGLE-ENDED

INPUT

GAIN (dB)

MICROPHONE

MAX4060 ✔ 20dB 20 ✔ — 4.5 to 5.5

MAX4061 — ADJ — — ✔ 2.4 to 5.5

MAX4062 ✔ ADJ 20 ✔ — 2.4 to 5.5

BIAS

SHUTDOWN

MODE

SUPPLY

VOLTAGE

(V)

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

3 4/11 Added exposed pad information to Pin Description and Pin Configurations sections 8, 13

REVISION

DATE

DESCRIPTION

PAGES

CHANGED