Maxim MAX9812, MAX9813L Datasheet

General Description

The MAX9812/MAX9813 are single/dual-input, 20dB
fixed-gain microphone amplifiers. They offer tiny pack­aging and a low-noise, integrated microphone bias,
making them ideal for portable audio applications such
as notebook computers, cell phones, and PDAs. These
amplifiers feature a 500kHz bandwidth, Rail-to-Rail®
outputs, an industry-leading 100dB power-supply rejec­tion ratio, and a very low 0.015% THD+N. Power-saving
features include very low 230µA supply current and a
total shutdown mode that cuts the combined supply
and BIAS currents to only 100nA.

The MAX9812 is a single amplifier in a 6-pin SC70
package (2mm x 2.1mm) and the MAX9813 is a dual­input amplifier available in an 8-pin SOT23 (3mm x
3mm) package. The MAX9813 has two inputs allowing
two microphones to be multiplexed to a single output.

The MAX9812/MAX9813 are offered in two grades. The
MAX9812L/MAX9813L are optimized for 3.3V supply
operation (2.7V to 3.6V). The MAX9812H/MAX9813H are
PC2001 compliant and are optimized for 5V operation
(4.5V to 5.5V). Both devices are specified over the -40°C
to +85°C extended operating temperature range.

Applications

Notebook Computers

PDAs

Smart Phones

Car Kit Adapters

Digital Cameras

Video Tape Recorders

Features

♦ PC2001 Compliant
♦ 100dB at 217Hz Power-Supply Rejection Ratio
♦ Very Low 230µA Quiescent Current
♦ Low 0.015% THD+N
♦ Available in Two Versions

MAX9812L/MAX9813L—2.7V to 3.6V
MAX9812H/MAX9813H—4.5V to 5.5V

♦ Internal Low-Noise Microphone Bias Supply

2.3V for MAX9812L/MAX9813L

4.0V for MAX9812H/MAX9813H

♦ 100nA Low-Power Shutdown Mode
♦ Rail-to-Rail Outputs
♦ 20dB Fixed Gain
♦ Available in Tiny 6-Pin SC70 (2mm x 2.1mm) and

8-Pin SOT23 (3mm x 3mm) Packages

♦ Extended Temperature Range -40°C to +85°C

MAX9812/MAX9813

Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain

Microphone Amplifiers with Integrated Bias

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2840; Rev 0; 4/03

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, Selector Guide, and Typical Operating
Circuits appear at end of data sheet.

PART TEMP RANGE

PIN­PACKAGE VCC (V)

MAX9812LEXT-T -40°C to +85°C 6 SC70-6 2.7 to 3.6

MAX9812HEXT-T -40°C to +85°C 6 SC70-6 4.5 to 5.5

MAX9813LEKA-T -40°C to +85°C 8 SOT23-8 2.7 to 3.6

MAX9813HEKA-T -40°C to +85°C 8 SOT23-8 4.5 to 5.5

MAX9812

20dB

REFERENCE

2.3V (L VERSION)

4.0V (H VERSION)

IN

BIAS

OUT

SHDN

V

CC

GND

MAX9813

20dB

IN1/IN2

REFERENCE

2.3V (L VERSION)

4.0V (H VERSION)

IN2

IN1

BIAS

OUT

SHDN

V

CC

GND

Simplified Block Diagrams

Rail-to-Rail is a trademark of Nippon Motorola Ltd.

MAX9812/MAX9813

Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain
Microphone Amplifiers with Integrated Bias

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= 3.3V, I

BIAS

= 500µA (MAX9812L/MAX9813L), VCC= 5V, I

BIAS

= 800µA (MAX9812H/MAX9813H), GND = 0V, RL= open,

SHDN = V

CC

, TA= T

MIN

to T

MAX

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

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.

(All voltages referenced to GND)
V

CC

........................................................................-0.3V to +6.0V

All Other Pins..............................................-0.3V to (V

CC

+ 0.3V)

Continuous Current (IN, SHDN, IN1, IN2, IN1/IN2)...........±20mA

OUT, BIAS Short-Circuit Duration (to GND or V

CC

) ...Continuous

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW

8-Pin SOT23 (derate 8.9mw/°C above +70°C) ............714mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Junction Temperature......................................................+150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GENERAL

MAX9812L/MAX9813L 2.7 3.6

Supply Voltage Range V

CC

MAX9812H/MAX9813H

Inferred from
PSRR test

4.5 5.5

V

Supply Current I

CC

I

BIAS

= 0 230 400 µA

Shutdown Supply Current I

CC_SHDN

SHDN = GND 0.1 1 µA

MAX9812L/MAX9813L 1.35 1.5 1.65

Amplifier Output Bias Voltage V

OUT_DC

MAX9812H/MAX9813H 2.25 2.5 2.75

V

Input Resistance R

IN

85 kΩ

Voltage Gain A

V

19 20 21 dB

DC 90 100

f = 217Hz 100

f = 1kHz 100

Power-Supply Rejection Ratio PSRR

OUT

Input referred, TA = +25°C

f = 10kHz 90

dB

RL = 10kΩ to VCC/2

V

CC

-

0.1

V

OH

RL = 1kΩ to VCC/2

V

CC

-

0.25V

VCC -

0.1V

RL = 10kΩ to VCC/2 0.1

Output Voltage Swing

V

OL

RL = 1kΩ to VCC/2 0.1 0.25

V

Output Short-Circuit Current I

OUT_SC

Sinking or sourcing 3 12 24 mA

Small-Signal -3dB Bandwidth BW V

OUT

= 10mV

P-P

400 kHz

Output Capacitive-Load Stability C

L

No sustained oscillations 50 pF

Output Impedance Z

OUT

f = 1kHz 0.5 Ω

Output Slew Rate SR V

OUT

= 1V step 1 V/µs

MAX9812/MAX9813

Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain

Microphone Amplifiers with Integrated Bias

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 3.3V, I

BIAS

= 500µA (MAX9812L/MAX9813L), VCC= 5V, I

BIAS

= 800µA (MAX9812H/MAX9813H), GND = 0V, RL= open,

SHDN = V

CC

, TA= T

MIN

to T

MAX

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

Note 1: All specifications are 100% tested at T

A

= +25°C. Temperature limits are guaranteed by design.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Amplifier Input Voltage-Noise
Density

e

n

Inputs at AC GND f = 1kHz 40 nV/√Hz

Total Integrated Input Noise V

n

22Hz to 22kHz BW, inputs at AC GND 5 µV

RMS

1kHz 75

Off-Isolation

Input referred, MAX9813
only

10kHz 60

dB

V

OUT

= 1V

P-P

(L version)

0.04

Total Harmonic Distortion Plus
Noise

THD+N

f = 1kHz, R

L

= 10kΩ to

V

CC

/2, BW = 22Hz to

22kHz

V

OUT

= 4V

P-P

(H version)

0.015

%

BIAS

MAX9812L/MAX9813L 2.1 2.30 2.55

Bias Output Voltage Range V

BIAS

MAX9812H/MAX9813H 3.6 4.0 4.4

V

Bias Output Resistance R

BIAS

0.1 Ω

DC, TA = +25°C7080

f = 217Hz 80

f = 1kHz 75

Power-Supply Rejection Ratio
(V

CC

to BIAS)

PSRR

BIAS

f = 10kHz 55

dB

BIAS Current Limit I

BIAS_SC

BIAS short to GND 5 22 50 mA

BIAS Capacitive-Load Stability C

BIAS

No sustained oscillations 50 pF

Total Integrated BIAS Noise V

n

22Hz to 22kHz BW 29 µV

RMS

DIGITAL INPUTS (SHDN, IN1/IN2)

Logic-Low Threshold V

IL

0.8 V

Logic-High Threshold V

IH

2.0 V

Logic Input Current I

IN

SHDN = GND or V

CC

±1µA

Shutdown Enable Time t

SHDN_ON

95% of settled value 10 ms

Shutdown Disable Time t

SHDN_OFF

50 µs

IN1/IN2 Select Time t

SEL

10 µs

MAX9812/MAX9813

Tiny, Low-Cost, Single/Dual-Input, Fixed-Gain
Microphone Amplifiers with Integrated Bias

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VCC= 3.3V (MAX9812L/MAX9813L), VCC= 5V (MAX9812H/MAX9813H), GND = 0V, RL= 10kΩ to VCC/2, SHDN = VCC, TA= +25°C,
unless otherwise noted.)

-20

0

-10

20

10

30

40

10 1k 10k100 100k 1M 10M

GAIN vs. FREQUENCY

MAX9812 toc01

FREQUENCY (Hz)

OUTPUT VOLTAGE GAIN (dB)

RL = OPEN
V

OUT

= 10mV

P-P

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX9812 toc02

FREQUENCY (Hz)

PSRR (dB)

10k1k10010 100k

-150

-80

-90

-100

-110

-120

-130

-140

-60

-70

-40

-50

-30

-10

-20

0

V

RIPPLE

= 200mV

P-P

INPUT REFERRED

POWER-SUPPLY REJECTION RATIO

(V

CC

TO BIAS) vs. FREQUENCY

MAX9812 toc03

FREQUENCY (Hz)

PSRR (V

CC

TO BIAS) (dB)

10k1k100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100
10 100k

V

RIPPLE

= 200mV

P-P

200

210

205

220

215

230

225

235

245

240

250

-40 -10 5 20-25 35 50 65 80

SUPPLY CURRENT

vs. TEMPERATURE

MAX9812 toc04

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

MAX9812H

MAX9812L

100

140

120

180

160

220

200

240

280

260

300

2.0 2.8 3.2 3.62.4 4.0 4.4 4.8 5.65.2 6.0

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9812 toc05

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

MAX9812L

MAX9812H

0.05

0.07

0.06

0.09

0.08

0.11

0.10

0.12

0.14

0.13

0.15

-40 -10 5 20-25 35 50 65 80

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

MAX9812 toc06

TEMPERATURE (°C)

SHUTDOWN SUPPLY CURRENT (µA)

2.27

2.28

2.29

2.30

2.31

2.32

2.33

-40 -10-25 5 2035506580

V

BIAS

vs. TEMPERATURE

MAX9812 toc07

TEMPERATURE (°C)

V

BIAS

(L VERSION) (V)

3.97

3.98

3.99

4.00

4.01

4.02

4.03

3.96

V

BIAS

(H VERSION) (V)

MAX9812H

MAX9812L

2.2997

2.2998

2.2999

2.3000

2.3001

2.3002

0 0.8 1.00.4 0.60.2 1.2 1.4 1.6 1.8 2.0

V

BIAS

vs. I

BIAS

MAX9812 toc08

I

BIAS

(mA)

V

BIAS

(L VERSION) (V)

MAX9812H

MAX9812L

3.9998

3.9999

4.0000

4.0001

4.0002

V

BIAS

(H VERSION) (V)