May 2005
LMV1015 Analog Series:
Built-in Gain IC’s for High Sensitivity 2-Wire
Microphones
General Description
Features
The LMV1015 is an audio amplifier series for small form
factor electret microphones. This 2-wire portfolio is designed
to replace the JFET amplifier. The LMV1015 series is ideally
suited for applications requiring high signal integrity in the
presence of ambient or RF noise, such as in cellular com-
munications. The LMV1015 audio amplifiers are guaranteed
to operate over a 2.2V to 5.0V supply voltage range with
fixed gains of 15.6 dB and 23.8 dB. The devices offer excel-
lent THD, gain accuracy and temperature stability as com-
pared to a JFET microphone.
(Typical LMV1015-15, 2.2V supply, RL = 2.2 kΩ, C = 2.2 µF,
VIN = 18 mVPP, unless otherwise specified)
n Supply voltage
n Supply current
n Signal to noise ratio (A-weighted)
n Output voltage noise (A-weighted)
n Total harmonic distortion
n Voltage gain
— LMV1015-15
— LMV1015-25
2V - 5V
<
180 µA
60 dB
−89 dBV
0.09%
15.6 dB
23.8 dB
−40˚C to 85˚C
The LMV1015 series enables a two-pin electret microphone
solution, which provides direct pin-to-pin compatibility with
the existing older JFET market.
n Temperature range
n Large Dome 4-Bump micro SMD package with improved
adhesion technology.
National Semiconductors built-in gain families are offered in
extremely thin space saving 4-bump micro SMD packages
(0.3 mm maximum). The LMV1015XR is designed for 1.0
mm ECM canisters and thicker. These extremely miniature
packages have the Large Dome Bump (LDB) technology.
This micro SMD technology is designed for microphone
PCBs requiring 1 kg adhesion criteria.
Applications
n Cellular phones
n Headsets
n Mobile communications
n Automotive accessories
n PDAs
n Accessory microphone products
Schematic Diagram
Built-In Gain Electret Microphone
20128902
20128901
© 2005 National Semiconductor Corporation
DS201289
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