LMV1012 Analog Series Pre-Amplified IC鈥檚 for High Gain 2-Wire Microphones
August 2004
LMV1012 Analog Series:
Pre-Amplified IC鈥檚 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
L
= 2.2 k鈩? C = 2.2 碌F,
V
IN
= 18 mV
PP
, unless otherwise specified)
n
Supply voltage
2V - 5V
<
180 碌A
n
Supply current
n
Signal to noise ratio (A-weighted)
60 dB
n
Output voltage noise (A-weighted)
鈭?9 dBV
n
Total harmonic distortion
0.09%
n
Voltage gain
鈥?LMV1012-07
7.8 dB
鈥?LMV1012-15
15.6 dB
鈥?LMV1012-20
20.9 dB
鈥?LMV1012-25
23.8 dB
n
Temperature range
鈭?0藲C to 85藲C
n
Offered in 4-bump micro SMD packages
Applications
n
n
n
n
n
n
Cellular phones
Headsets
Mobile communications
Automotive accessories
PDAs
Accessory microphone products
Schematic Diagram
Built-In Gain Electret Microphone
20058702
20058701
漏 2004 National Semiconductor Corporation
DS200587
www.national.com