Digital microphones output digital signals instead of typical analog signals. The basic shape of the product is square or circular, and its appearance is similar to that of a typical electret microphone. Digital microphones output digital signals instead of typical analog signals.
The basic shape of the product is square or circular, and its appearance is similar to that of a typical electret microphone. Its basic structure is: a transducer used to generate analog signals representing acoustic signals (usually completed by an electret diaphragm and its back electrode); A single bit modulator analog-to-digital converter with a sampling rate greater than 1 generates a data output signal by modulating the analog signal in the form of a bitstream.
The advantage of digital microphones is their strong
anti-interference ability, which eliminates the need for
built-in high-frequency filtering capacitors and filtering
circuits like traditional microphones. Due to its inherent
characteristics, digital microphones are not subject to
interference and influence from computers, networks, and RF
magnetic field signal sources. Therefore, there is no need to
use shielded wires when connecting, which can effectively
utilize the limited space of related products.
Most digital microphones are electret capacitor microphones, a
technology that has existed for decades. The working principle
is to use a polymer material vibration film with charge
isolation. Compared with the polymer diaphragm of ECM, the
performance of MEMS microphones is very stable at different
temperatures, unaffected by temperature, vibration, humidity,
and time. Due to its strong heat resistance, MEMS microphones
can withstand high temperature reflow soldering at 260 ° C
without any changes in performance. This can even save audio
tuning costs during the manufacturing process, as there is
almost no change in sensitivity before and after assembly.
Let's take a look at the working parameters of digital
microphones.
Working voltage: DC voltage range from 1.6V to 2.9V;
Current consumption: less than 100A, power consumption in
energy-saving mode is less than 75A;
Distortion: At a sound pressure level of 115dB, the total
harmonic distortion is less than 10%.
Unlike traditional microphones, digital microphones are just a
simple field-effect transistor conversion amplifier circuit, but
integrate application functions such as preamplifiers, sleep
mode, stereo input, etc. Integrated MEMS patented technology,
supporting standard automatic selection and pasting equipment,
compliant with lead-free specifications, compatible with
industrial lead-free soldering (260 ° C reflow soldering for
30 seconds).
