Have in the sale activity before perhaps you still remember a few years so a word: Can be “ heard now? ”The equipment that designs today, from can apparel equipment assists device to the family, be asked increasingly environment of ” of “ listen respectfully. Equipment uses appropriate microphone to be able to be caught well and truly almost any sound, and two kinds of the most commonly used technologies when compose builds microphone are MEMS is mixed be stationed in extremely technology of system electric capacity. Although the working principle of these two kinds of technologies is similar, but in very multi-purpose still need to be in in the exemple this is both in make a choice. Considering this, we will review MEMS and halt extremely the fundamental of body condenser microphone, compare the distinction between two kinds of technologies, generalize the advantage of every kinds of solution.

 

MEMS microphone fundamental

MEMS microphone uses park printed circuit board (PCB) the MEMS that defends with machine lid (system of personal computer cable) package compose is built and become. Alveolus is made on crust, facilitating sound enters microphone, aperture is located in coping call coping port model, and aperture is located in PCB to call bottom port in-housely model. MEMS package design can be normally on semiconductor brilliant circle tectonic machinery brace up film and installation structure.

 

 

MEMS brace up film forms a capacitor, and acoustical pressing wave can be caused brace up velar motion. MEMS microphone contains circle of another semiconductor brilliant normally, use as frequency preamplifier, the metabolic capacitance of MEMS changeover is telegraphic date. If the user needs imitate to output signal, can offer the output of frequency preamplifier for its. If the user needs a number to output signal, join modulus converter on as located as frequency preamplifier same brilliant circle (ADC) . The current form that code of the number in MEMS microphone uses is pulse density modulation (PDM) , can mix only a clock and an alone data line communication. Data uses single bit code, simplified thereby the decipher of signal of the number in receiver.

 

 

Be stationed in extremely fundamental of body condenser microphone

Halt extremely body condenser microphone (the construction of ECM) pursues as follows be shown.

 

 

Halt extremely body brace up film (the stuff that has fixed surface charge) stand by electric conduction board to lie between open buy, and mix MEMS microphone is similar, also can form a capacitor, serve as dielectric with air gap. Change through what the voltage of capacitor is worth as capacitance and change, and the change of capacitance is be stationed in by shift extremely body brace up velar sound is pressed wave cause, ΔV= Q /ΔC. The JFET that capacitor voltage changes to wrap Fu by microphone crust has enlarge and buffer. JFET is used normally in all source configuration, and exterior application circuit uses exterior load resistor and lie between straight capacitance.

 

 

The distinction of different microphone technology

When undertaking choosing between ECM and MEMS microphone need considers a lot of factors. This kind of new technology has MEMS microphone a lot of advantage, consequently market share grows quickly continuously. For example, what the space suffers bounds application to be able to discover MEMS microphone is small enclose dimension to have appeal, and because an imitate and digital circuit hold concurrently in MEMS microphone structure, can reduce PCB area and package cost at the same time so. The output impedance of imitate MEMS microphone is relatively inferior, and the output of digital MEMS microphone suits the application in electric noise environment very much. In tall oscillatory environment technology of use MEMS microphone can reduce the harmful noise level that mechanical vibration causes. In addition, use semiconductor to make a technology and after joining frequency preamplifier, make make have the MEMS microphone that matchs to stabilize function feature with temperature cheek by jowl to become a possibility. Using MEMS microphone at array application, these ask function character of Yan Ke has an advantage especially. In product production process, MEMS microphone also can be mixed through collect place a machine to undertake be carryinged easily, and can be able to bear or endure suffer circumfluence to solder temperature curve.

 

Although MEMS microphone is gaining ground quickly, but still exist preferential choose halt extremely the application of body condenser microphone. A lot of traditional designs used ECM, what if the project is right,have a design consequently is simple upgrade, had better continue to use ECM. Can choose bring foot, electrical wiring, SMT, solder dish join ECM with bedspring contact applied circuit, provided additional design flexibility for the engineer thereby. If need is dustproof,mix moistureproof, have tall eyewinker to defend (IP) the ECM product of grade because oneself physics size is larger, be discovered more easily so. To wanting the project that wants inhomogenous space sensitivity, ECM product has inherent orientaton, can be one-way model also can be noise is eliminated model, and the working voltage range of ECM is wide, adjust loose to having so the product of voltage course, the likelihood is first selection solution.

 

The project that is you chooses proper microphone technology

The decision is used halt extremely body condenser microphone or MEMS microphone depend on your project requirement. Although because MEMS microphone has numerous and immanent advantage and gain ground continuously, but because ECM is had more extensive enclose and directional choice, still can use at all sorts of application so. No matter choose which kinds of technology, CUI can be developed ceaselessly and supply mixed microphone and product, the ” of project “ listen respectfully that helps you needs heard voice.