Document
LMV1012 Analog Series Pre-Amplified IC’s for High Gain 2-Wire Microphones
August 2004
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 condenser microphones (ECM) form factor.
Features
(Typical LMV1012-15, 2.2V supply, RL = 2.2 kΩ, C = 2.2 µF, VIN = 18 mVPP, unless otherwise specified) n Supply voltage 2V - 5V < 180 µA 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 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
© 2004 National Semiconductor Corporation
DS200587
www.national.com
LMV1012 Analog Series
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Body Model Machine Model Supply Voltage VDD - GND 5.5V 2500V 250V
Storage Temperature Range Junction Temperature (Note 6) Mounting Temperature Infrared or Convection (20 sec.)
−65˚C to 150˚C 150˚C max 235˚C
Operating Ratings (Note 1)
Supply Voltage Temperature Range 2V to 5V −40˚C to 85˚C
(Note 3) Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VDD = 2.2V, VIN = 18 mV, RL = 2.2 kΩ and C = 2.2 µF. Boldface limits apply at the temperature extremes. Symbol IDD Parameter Supply Current VIN = GND Conditions LMV1012-07 LMV1012-15 LMV1012-20 LMV1012-25 SNR Signal to Noise Ratio f = 1 kHz, VIN = 18 mV, A-Weighted LMV1012-07 LMV1012-15 LMV1012-20 LMV1012-25 VIN Max Input Signal f = 1 kHz and THD+N < 1% LMV1012-07 LMV1012-15 LMV1012-20 LMV1012-25 VOUT Output Voltage VIN = GND LMV1012-07 LMV1012-15 LMV1012-20 LMV1012-25.