LMV1012 Analog Series:

Pre-Amplified IC’s for High Gain 2-Wire Microphones

General Description

The LMV1012 is an audio amplifier series for small form

factor electret microphones. This 2-wire portfolio is designed

to replace the JFET amplifier currently being used. The

LMV1012 series is ideally suited for applications requiring

high signal integrity in the presence of ambient or RF noise,

such as in cellular communications. The LMV1012 audio

amplifiers are guaranteed to operate over a 2.2V to 5.0V

supply voltage range with fixed gains of 7.8 dB, 15.6 dB,

20.9 dB, and 23.8 dB. The devices offer excellent THD, gain

accuracy and temperature stability as compared to a JFET

microphone.

The LMV1012 series enables a two-pin electret microphone

solution, which provides direct pin-to-pin compatibility with

the existing JFET market.

The devices are offered in extremely thin space saving

4-bump micro SMD packages. The LMV1012XP is designed

for 1.0 mm canisters and thicker ECM canisters. These

extremely miniature packages are designed for electret con-

denser microphones (ECM) form factor.

Features

(Typical LMV1012-15, 2.2V supply, R

Ω, C = 2.2 µF,

V

n

Supply voltage

2V - 5V

n

Supply current

n

Signal to noise ratio (A-weighted)

60 dB

n

Output voltage noise (A-weighted)

−89 dBV

n

Total harmonic distortion

0.09%

n

Voltage gain

— LMV1012-07

7.8 dB

— LMV1012-15

15.6 dB

— LMV1012-20

20.9 dB

— LMV1012-25

23.8 dB

n

Temperature range

−40˚C to 85˚C

n

Offered in 4-bump micro SMD packages

Applications

n

Cellular phones

n

Headsets

n

Mobile communications

n

Automotive accessories

n

PDAs

n

Accessory microphone products

Schematic Diagram

20058701

Built-In Gain Electret Microphone

20058702

August 2004

© 2004 National Semiconductor Corporation

DS200587

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