National Semiconductor LMV1089 Technical data

October 24, 2008

LMV1089
Dual Input, Clarisound™ Far Field Noise Suppression
Microphone Amplifier with Automatic Calibration
Capability

LMV1089 Dual Input, Clarisound™ Far Field Noise Suppression Microphone Amplifier with

Automatic Calibration Capability

General Description

The LMV1089 is a fully analog dual differential input, differ­ential output, microphone array amplifier designed to reduce
background acoustic noise, while delivering superb speech
clarity in voice communication applications.

The LMV1089 preserves near-field voice signals within 4cm
of the microphones while rejecting far-field acoustic noise
greater than 50cm from the microphones. Up to 20dB of far­field rejection is possible in a properly configured and cali­brated system.

Part of the Powerwise™ family of energy efficient solutions,
the LMV1089 consumes only 1.1mA of supply current pro­viding superior performance over DSP solutions consuming
greater than ten times the power.

A quick calibration during the manufacturing test process of
a product containing the LMV1089 compensates the entire
microphone system. This calibration compensates for mis­match in microphone gain and frequency response, as well
as acoustical path variances. The LMV1089 stores the cali­bration coefficients in the on-chip EEPROM. The calibration
is initiated by an I2C command or by a logic pin control.

The dual microphone inputs and the processed signal output
are differential to provide excellent noise immunity. The mi­crophones are biased with an internal low-noise bias supply.

Key Specifications

Far Field Noise Suppression Electrical 33dB

■

Supply voltage 2.7V to 5.5V

■

Supply current 1.1mA (typ)

■

Standby current

■

Signal-to-Noise Ratio (A-weighted) 65dB (typ)

■

Total Harmonic Distortion + Noise 0.1% (typ)

■

PSRR (217Hz) 96dB (typ)

■

0.7μA (typ)

Features

Low power consumption

■

Shutdown function

■

No added processing delay

■

Differential outputs

■

Automatic calibration

■

Adjustable 6 - 48dB gain

■

Excellent RF immunity

■

Space-saving 36–bump micro SMD package

■

Applications

Headset and Boom microphones

■

Mobile and handheld two-way radios

■

Bluetooth and other powered headsets

■

Hand-held voice microphones

■

Equalized stereo microphone preamplifier

■

30047240

FIGURE 1.

© 2008 National Semiconductor Corporation 300472 www.national.com

Typical Application

LMV1089

30047201

www.national.com 2

FIGURE 2. Typical Dual Microphone Far Field noise Cancelling Application

Connection Diagrams

LMV1089

36–Bump micro SMD package

Top View

30047230

Order Number LMV1089RL

See NS Package Number RLA36TTA

36–Bump micro SMD Marking

Top View

X = Plant Code

YY = Date Code

30047231

micro SMD Package View

Bottom View

TT = Die Tracability

ZA2 = LMV1089RL

Ordering Information

Order Number Package

Package Drawing

Number

Device Marking Transport Media

LMV1089RL 36 Bump µSMD RLA36TTA XYYTTZA2 250 units on tape and reel

LMV1089RLX 36 Bump µSMD RLA36TTA XYYTTZA2 1000 units on tape and reel

30047233

3 www.national.com

TABLE 1. Pin Name and Function

LMV1089

Bump Number Pin Name Pin Function Pin Type

A1 NC No connect No Connect

A2 T7

Auxiliary Control Manual Calibration = GND Auto Calibration = V

DD

Digital Input

A3 PE Program Enable EEPROM Digital Input

A4 MIC2– microphone 2 negative input Analog Input

A5 MIC2+ microphone 2 positive input Analog Input

A6 Mic Bias Microphone Bias Analog Output

B1 NC No Connect No Connect

B2 NC No Connect No Connect

B3 T5 Float (do not connect to GND) Production Test

B4 GND amplifier ground Ground

B5 M1_UNP microphone 1 unprocessed output Analog Output

B6 MIC1+ microphone 1 positive input Analog Input

C1 NC No Connect No Connect

C2 NC No Connect No Connect

C3 GB0 default Post Amp Gain 0 Digital Input

C4 GA0 default Pre Amp Gain 0 Digital Input

C5 GND amplifier ground Ground

C6 MIC1– amplifier ground Analog Input

D1 ADR I2C Address select Digital Input

D2 NC No Connect No Connect

D3 GND amplifier ground Ground

D4 GA1 default Pre Amp Gain 1 Digital Input

D5 M2_UNP microphone 2 unprocessed output Analog Output

D6 REF reference voltage de-coupling Analog Reference

E1 SCL I2C clock Digital Input

E2 GB1 default Post Amp Gain 1 Digital Input

E3 NC No Connect No Connect

E4 OUT+ positive optimized audio output Analog Output

E5 LPF+ Low Pass Filter for positive output Analog Input

E6 EN chip enable Digital Input

F1 SDA I2C data Digital Input/Output

F2

F3

I2CV

V

DD

DD

I2C power supply

Supply

power supply Supply

F4 OUT- negative optimized audio output Analog Output

F5 LPF- Low Pass Filter for negative output Analog Input

F6 CAL calibration enable Digital Input

www.national.com 4

LMV1089

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage 6.0V
Storage Temperature -85°C to +150°C
Power Dissipation (Note 3) Internally Limited
ESD Rating (Note 4) 2000V
ESD Rating (Note 5) 200V
Junction Temperature (T

Mounting Temperature

) 150°C

JMAX

235°C

Thermal Resistance

 θJA (microSMD)

70°C/W

Soldering Information See AN-112 “microSMD Wafers Level
Chip Scale Package.”

Operating Ratings (Note 2)

Supply Voltage

I2CV

DD

Supply Voltage (Note 8)
Temperature Range −40°C to 85°C

T

≤ TA ≤ T

MIN

MAX

2.7V ≤ V

DD

≤ 5.5V

1.7V ≤ I2CVDD ≤ 5.5V

−40°C ≤ TA ≤ +85°C

Infrared or Convection (20 sec.)

Electrical Characteristics 3.3V (Note 1)

Unless otherwise specified, all limits guaranteed for TJ = 25°C, VDD = 3.3V, VIN = 18mV
(Note 8), Pre Amp gain = 20dB, Post Amp gain = 6dB, RL = 100kΩ, and CL = 4.7pF, C

Symbol Parameter Conditions

SNR Signal-to-Noise Ratio

f = 1kHz, V

f = 1kHz, VIN = 18mV

= 18mV

IN

P-P

, A-Weighted

P-P

voice band (300 – 3400Hz)

Input Referred Noise level A-weighted 5

e

N

VINMaximum Input Signal THD+N < 1%, Pre Amp Gain = 6dB 910 870 mV

Maximum AC Output Voltage

V

OUT

f = 1kHz, Differential Out+, Out-

THD+N < 1%

DC Level at Outputs Out+, Out- 800 mV

THD+N Total Harmonic Distortion + Noise Differential Out+ and Out- 0.1 0.2 % (max)

Z

Input Impedance 155

IN

Z

Z

Output Impedance 300

OUT

Load Impedance (Out+, Out-) R

LOAD

C

LOAD

LOAD

AMMicrophone Preamplifier Gain Range

Microphone Preamplifier Gain Adjustment

A

MR

A

P

A

PR

A

CR

A

MD

X

Talk

T

CAL

FFNS

SNRI

Resolution

Post Amplifier Gain Range Pass Through Mode and Summing Mode 6 – 18 dB

Post Amplifier Gain Resolution 3

Gain Compensation Range ±3 dB

Maximum Gain Matching Difference After
Calibration

Crosstalk Attenuation between Mic1 and Mic2 Measured at M1_UNP and M2_UNP 52 41 dB (min)

Calibration Duration 790

Far Field Noise Suppression Electrical

E

Signal-to-Noise Ratio Improvement Electrical

E

f = 1kHz 2

f = 300Hz
f = 1kHz
f = 3kHz

f = 1kHz (See Test Method)
f = 300Hz (See Test Method)

f = 1kHz (See Test Method)
f = 300Hz (See Test Method)

Input Referred, Input AC grounded

PSRR Power Supply Rejection Ratio

RIPPLE

f

RIPPLE

= 217Hz (V

= 1kHz (V

RIPPLE

RIPPLE

= 100mV

= 100mV

f

CMRR Common Mode Rejection Ratio f = 1kHz 60 dB

, f = 1kHz, EN = VDD, pass through mode

P-P

= 10nF

REF

LMV1089

Typical

(Note 6)

Limits

(Note 7)

(Limits)

63 dB

65 dB

1.2 1.1

10

6 – 36

1.75

2.25

0.5

V

RMS

120
190

kΩ (min)

kΩ (max)

kΩ (min)

100

pF (max)

dB (min)

dB (max)

2.6

3.4

dB (min)

dB (max)

dB

0.25

0.5

ms (max)

27

dBV

33

24

dBV

28

P-P

P-P

)

)

96 85 dB (min)

91 80 dB (min)

Units

μV

RMS

P-P

(min)

Ω

dB

dB
dB

dBV

dBV

(min)

5 www.national.com

V

BM

e

LMV1089

VBM

I

BM

I

DDQ

I

DD

I

SD

I

DDCP

Microphone Bias Supply Voltage

10nF capacitor on V

pin A-Weighted, 10nF cap at V

REF

Total available Microphone Bias Current

Supply Quiescent Current VIN = 0V

Supply Current

Shut Down Current

Supply Current during Calibration and
Programming

I

BIAS

VIN = 25mV
mode

EN pin = GND

Calibrating or Programming EEPROM 30 40 mA (max)

IDDI2C I2C supply current I2C Idle Mode

T

ON

T

OFF

Turn On Time

Turn Off Time

= 1mA

pin 10

REF

both inputs, Noise cancelling

P-P

2.0

1.85

2.15

V (min)

V (max)

μV

RMS

1.2 mA (min)

1.1 1.5 mA (max)

1.1 mA

0.7 1

μA (max)

25 100 nA (max)

40 ms (max)

60 ms (max)

www.national.com 6

Electrical Characteristics 5.0V (Note 1)

Unless otherwise specified, all limits guaranteed for TJ = 25°C, VDD = 5V, VIN = 18mV
Pre Amp gain = 20dB, Post Amp gain = 6dB, RL = 100kΩ, and CL = 4.7pF.

Symbol Parameter Conditions

SNR Signal-to-Noise Ratio

f = 1kHz, V

f = 1kHz, VIN = 18mV

= 18mV

IN

P-P

, A-Weighted

P-P

voice band (300 – 3400Hz)

e

Input Referred Noise level A-weighted 5

N

VINMaximum Input Signal f = 1kHz, THD+N < 1% 918 870 mV

Maximum AC Output Voltage

V

OUT

f = 1kHz, THD+N < 1%
between differential output

DC Output Voltage 800 mV

THD+N

FFNS

SNRI

Total Harmonic Distortion + Noise f = 1kHz VIN = 18mV

Z

Input Impedance 155

IN

Z

Output Impedance 300

OUT

AMMicrophone Preamplifier Gain Range

Microphone Preamplifier Gain Adjustment

A

MR

Resolution

A

Post Amplifier Gain Range

P

Post Amplifier Gain Adjustment Resolution

A

PR

A

Gain Compensation Range f = 1kHz ±3 dB

CR

Maximum Gain Matching Difference After

A

MD

Calibration

T

Calibration Duration 790 ms (max)

CAL

Far Field Noise Suppression Electrical

E

Signal-to-Noise Ratio Improvement Electrical

E

f = 1kHz 6 – 36 dB

f = 1kHz 2

f = 1kHz Pass Through Mode and Summing
Mode

f = 1kHz 3

f = 300Hz
f = 2kHz
f = 3kHz

f = 1kHz (See Test Method)
f = 300Hz (See Test Method)

f = 1kHz (See Test Method)
f = 300Hz (See Test Method)

P-P

Input Referred, Input AC grounded

PSRR Power Supply Rejection Ratio

RIPPLE

f

RIPPLE

= 217Hz (V

= 1kHz (V

RIPPLE

RIPPLE

= 100mV

= 100mV

f

CMRR Common Mode Rejection Ratio f = 1kHz 62 dB

V

Microphone Bias Supply Voltage

BM

10nF capacitor on V

e

VBM

I

Total Available Microphone Bias Current

BM

I

Supply Quiescent Current VIN = 0V

DDQ

Supply Current during Calibration and

I

DDCP

Programming

I

Supply Current

DD

I

Shut Down Current EN pin = GND 1.6

SD

T

Turn On Time

ON

T

Turn Off Time

OFF

pin A-Weighted 10

REF

I

= 1mA

BIAS

Calibrating or Programming EEPROM 30 40 mA (max)

VIN = 25mV

both inputs, Noise cancelling

P-P

mode

, EN = VDD, pass through mode (Note 8),

P-P

LMV1089

Typical Limit

(Limits)

(Note 6) (Note 7)

63 dB

65 dB

1.2 1.1

V

RMS

0.1 0.2 % (max)

120
190

1.75

2.25

kΩ (min)

kΩ (max)

dB (min)

dB (max)

6 – 18 dB

2.6

3.4

dB (min)

dB (max)

0.5

0.25

0.5

27

dBV

33

24

dBV

27

P-P

P-P

)

)

96 85 dB (min)

91 80 dB (min)

2.0 V

1.2 mA (min)

1.1 1.5 mA (max)

1.1 mA (max)

40 ms (max)

60 ms (max)

Units

μV

P-P

dBV

dBV

μV

LMV1089

RMS

(min)

(min)

Ω

dB
dB
dB

RMS

μA

7 www.national.com

Digital Interface Characteristics (Notes 1, 8)

Unless otherwise specified, all limits guaranteed for TJ = 25°C, I2CVDD within the Operating Rating (Note 8)

LMV1089

Symbol Parameter Conditions

V

V

ts

th

ts

PEC

th

PEC

Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability
and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in
the Recommended Operating Conditions is not implied. The Recommended Operating Conditions indicate conditions at which the device is functional and the
device should not be operated beyond such conditions. All voltages are measured with respect to the ground pin, unless otherwise specified.

Note 2: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes. Typical specifications are estimations only and are not guaranteed.

Note 3: The maximum power dissipation must be de-rated at elevated temperatures and is dictated by T
allowable power dissipation is P
150°C and the typical θJA for this microSMD package is 70°C/W and for the LLP package θJA is 64°C/W Refer to the Thermal Considerations section for more
information.

Note 4: Human body model, applicable std. JESD22-A114C.

Note 5: Machine model, applicable std. JESD22-A115-A.

Note 6: Typical values represent most likely parametric norms at TA = +25°C, and at the Recommended Operation Conditions at the time of product

characterization and are not guaranteed.

Note 7: Datasheet min/max specification limits are guaranteed by test, or statistical analysis.

Note 8: The voltage at I2CVDD must not exceed the voltage on VDD.

Logic High Input Level

IH

Logic Low Input Level

IL

CAL Setup Time 2 ms

CAL

CAL Hold time until calibration is

CAL

finished

PE Setup Time 2 ms

PE Hold until calibration is finished 790 ms (min)

= (T

DMAX

– TA) / θJA or the number given in the Absolute Maximum Ratings, whichever is lower. For the LMV1089, T

JMAX

EN, TM, SCL, SDA, ADR, CAL, PE

GA0, GA1, GB0, GB1

EN, TM, SCL, SDA, ADR, CAL, PE

GA0, GA1, GB0

790 ms (min)

, θJC, and the ambient temperature TA. The maximum

JMAX

Typical

(Note 6)

LMV1089

(Note 7)

0.75xI2CV

0.6xV

0.25xI2CV

0.4xV

Limit

DD

DD

DD

DD

Units

(Limits)

V (min)

V (max)

=

JMAX

www.national.com 8

Test Methods

LMV1089

30047212

FIGURE 3. FFNSE, NFSLE, SNRIE Test Circuit

FAR FIELD NOISE SUPPRESSION (FFNSE)

For optimum noise suppression the far field noise should be
in a broadside array configuration from the two microphones
(see Figure 15). Which means the far field sound source is
equidistance from the two microphones. This configuration
allows the amplitude of the far field signal to be equal at the
two microphone inputs, however a slight phase difference
may still exist. To simulate a real world application a slight
phase delay was added to the FFNSE test. The block diagram
from Figure 3 is used with the following procedure to measure
the FFNSE.

1.

A sine wave with equal frequency and amplitude
(25mV
generator, the phase of Mic 2 is delayed by 1.1° when

) is applied to Mic1 and Mic2. Using a signal

P-P

compared with Mic1.

2.

Measure the output level in dBV (X)

3.

Mute the signal from Mic2

4.

Measure the output level in dBV (Y)

5.

FFNSE = Y - X dB

NEAR FIELD SPEECH LOSS (NFSLE)

For optimum near field speech preservation, the sound
source should be in an endfire array configuration from the

two microphones (see Figure 16). In this configuration the
speech signal at the microphone closest to the sound source
will have greater amplitude than the microphone further away.
Additionally the signal at microphone further away will expe­rience a phase lag when compared with the closer micro­phone. To simulate this, phase delay as well as amplitude
shift was added to the NFSLE test. The schematic from Figure
3 is used with the following procedure to measure the NF­SLE.

1.

A 25mV
applied to Mic1 and Mic2 respectively. Once again, a

and 17.25mV

P-P

(0.69*25mV

P-P

) sine wave is

P-P

signal generator is used to delay the phase of Mic2 by

15.9° when compared with Mic1.

2.

Measure the output level in dBV (X)

3.

Mute the signal from Mic2

4.

Measure the output level in dBV (Y)

5.

NFSLE = Y - X dB

SINGLE TO NOISE RATIO IMPROVEMENT ELECTRICAL
(SNRIE)

The SNRIE is the ratio of FFNSE to NFSLE and is defined as:
SNRIE = FFNSE - NFSL

E

9 www.national.com