Two new amplifiers, lmv1012 and lmv1014, are introduced by National Semiconductor Corporation. The amplifier uses a new design to replace the existing microphone technology, so the audio performance is greatly improved. These two amplifiers can be built into 2-wire and 3-wire electret condenser microphone (ECM), which is the first “microphone amplifier” in the market. The low power consumption of these two amplifiers helps to prolong the battery life, and have stronger anti noise ability, which ensures that the microphone can perform better than JFET. They are most suitable for mobile phone microphone, mobile phone accessories, and other portable microphone applications.
Susan Inouye, senior information analyst at databeans Inc., Reno, nev., said: “it is expected that major manufacturers will switch to these two new chips to develop new products one after another. We believe that national semiconductor will establish its leading position in the mobile phone and other product markets. As mobile phone manufacturers continue to cut production costs, manufacturers are increasingly paying attention to the design of fewer components and more streamlined production processes. “
Kingly bang, marketing manager of bsecorporation, a famous microphone manufacturer in South Korea, said: “since the amplifier of national semiconductor can be directly installed in the electret condenser microphone, we can make full use of this advantage to develop more sensitive microphone, so as to greatly improve the sound effect of mobile phones and other communication equipment.”
Dennis swan, marketing manager of national semiconductor amplifier products division, said: “we have to design the circuit board carefully and cooperate with other necessary filter elements to give full play to the performance of the microphone. All along, the amplifier chips on the market are too large to be built into the increasingly miniaturized electret capacitor microphone. National Semiconductor clearly knows that with innovative circuit design and advanced packaging technology, the performance of the microphone, such as sensitivity, distortion rate and power supply, can be greatly improved to ensure that the electret capacitor microphone can play a higher performance and support a longer battery life. “
National Semiconductor’s lmv1012 is a 2-wire electret condenser microphone amplifier. With an internal gain of 17dbv, this chip is most suitable for mobile phone microphone. Lmv1012 amplifier also has other advantages, such as higher anti RF interference ability and lower distortion rate. The new generation electret condenser microphone with lmv1012 chip has only 0.1% total harmonic distortion rate, and the signal-to-noise ratio (SNR) can reach more than 55dB, while the power supply required is not more than 240ua. The high gain microphone with this chip is most suitable for mobile communication devices, automotive auxiliary devices, mobile phones and personal digital assistants.
Lmv1014 is a low current and low noise 3-wire electret condenser microphone amplifier. This product consumes no more than 40mA current, and the output impedance is as low as 200W. The PSRR of lmv1014 is more than 60dB, and the signal-to-noise ratio is more than 55dB. The chip is designed for applications with low power supply and strong noise immunity, including Bluetooth wireless communication products, microphone assisted products, handheld recording devices and personal digital assistants.
Both amplifier chips are fully compatible with existing electret capacitor microphone standards.
The lmv1012 chip is packaged in 4-ball MICROSMD and costs $0.39 per chip. The lmv1014 chip is also packaged in a 4-ball MICROSMD package, which costs $0.49 each.
Editor in charge: GT