Audio Sample Kit

TDK’s MEMS microphone, ESD notch filter, and noise suppression filter sample kit

Image of TDK's Audio Sample Kit TDK's audio solution sample kit provides noise suppression and ESD countermeasures for microphone lines without degrading sound signals.

As society trends towards the Internet of Things and connected devices, smart appliances and consumer electronics are on the rise, including smart (or AI) speakers. The difference between smart speakers and conventional ICT devices is that with smart speakers, a person's voice becomes an interface to connect them with the device and the speaker's key components are microphones, which also act as sound sensors. TDK provides various types of MEMS microphones for these applications, which have been developed by applying TDK semiconductor micro-fabrication technology.

Important points to consider when using MEMS microphones include circuit technology and noise countermeasures so signal waveforms are transmitted with no distortion. If high-frequency signals from communication waves intrude into microphone lines, undesired sound known as buzz or buzz noise may be heard from speakers. Since this had in the past become a serious problem in telephones that used the TDMA (time division multiple access) system, it is generally referred to as TDMA noise. TDK has developed the MAF series of noise suppression filters for audio lines as components for use in countermeasures against such problems. Using the MAF series in microphone lines makes it possible to prevent TDMA noise without degrading sound quality. ESD (electrostatic discharge) countermeasures are also important to prevent the intrusion of ESD from human bodies into circuits through holes in the microphones. TDK's AVRF series ESD notch filters exhibit high-level noise suppression effects and can protect circuits from electrostatic discharges. Figure 1 shows an example of noise countermeasures in microphone lines using MAF series noise suppression filters and AVRF series ESD Notch Filters and their effectiveness. It can be clearly seen that in filter circuits that use both MAF and AVRF series products together, the insertion loss in cellular bands is even larger than in circuits that use only MAF products.

AUDIO-1-KIT combines TDK InvenSense MEMS microphones with TDK brand's noise suppression filters (MAF series) and ESD notch filters (AVRF series) specifically designed to combat typical issues in audio lines including suppression of TDMA noise while offering additional benefits such as improving reception sensitivity in cellular or Wi-Fi® communication.

Figure 1: Noise countermeasures in microphone lines using the MAF series noise suppression filters and AVRF series ESD Notch Filters

Image of TDK's Audio Sample Kit

Figure 2: Example combinations of MAF noise suppression filters and AVRF ESD notch filters in microphone lines

Image of TDK's Audio Sample Kit

Features
  • Improvement in reception sensitivity of cellular and Wi-Fi communication
  • High sound quality as a result of low distortion due to low THD+N characteristics
  • Suppression of TDMA noise
  • Small signal degradation due to low resistance
  • Achievement of both ESD countermeasures and noise countermeasures

Applications

  • Noise suppression and ESD countermeasures for speaker and microphone lines

Additional Content Links

Audio Sample Kit

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
AUDIO MEMS AND FILTER KITAUDIO-1-KITAUDIO MEMS AND FILTER KIT4 - ImmediateView Details

Associated Parts: Microphones

ImageManufacturer Part NumberDescriptionTypeDirectionFrequency RangeAvailable QuantityView Details
MICROPHONE MEMS DIGITAL PDM OMNIICS-41350MICROPHONE MEMS DIGITAL PDM OMNIMEMS (Silicon)Omnidirectional50Hz ~ 40kHz4372 - ImmediateView Details
MICROPHONE MEMS ANALOG OMNIICS-40618MICROPHONE MEMS ANALOG OMNIMEMS (Silicon)Omnidirectional50Hz ~ 20kHz4898 - ImmediateView Details

Associated Parts: Ferrite Beads

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
FERRITE BEAD 200 OHM 0402 1LNMAF1005GAD152AT000FERRITE BEAD 200 OHM 0402 1LN45812 - ImmediateView Details
FERRITE BEAD 400 OHM 0402 1LNMAF1005GAD262AT000FERRITE BEAD 400 OHM 0402 1LN92452 - ImmediateView Details
NOISE SUPPRESSION FILTER FOR AUDMAF1005GWZ102AT000NOISE SUPPRESSION FILTER FOR AUD17655 - ImmediateView Details
NOISE SUPPRESSION FILTER FOR AUDMAF0603GWY551AT000NOISE SUPPRESSION FILTER FOR AUD29264 - ImmediateView Details

Associated Parts: EMI/RFI Filters

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
FOR AUDIO LINE, 39V, 6.8PF, 28VDAVRF101U6R8KT242FOR AUDIO LINE, 39V, 6.8PF, 28VD6625 - ImmediateView Details
ESD NOTCH FILTER 3.5VDC/1GHZAVRF060V600MT102ESD NOTCH FILTER 3.5VDC/1GHZ29628 - ImmediateView Details
ESD NOTCH FILTER 5.5VDC/1GHZAVRF060W650MT102ESD NOTCH FILTER 5.5VDC/1GHZ29630 - ImmediateView Details
ESD NOTCH FILTER 7VDC/2.4GHZAVRF060X100LT242ESD NOTCH FILTER 7VDC/2.4GHZ29129 - ImmediateView Details
ESD NOTCH FILTER 7VDC/2.7GHZAVRF060X8R2LT272ESD NOTCH FILTER 7VDC/2.7GHZ29790 - ImmediateView Details
ESD NOTCH FILTER 12VDC/2.1GHZAVRF061P160MT212ESD NOTCH FILTER 12VDC/2.1GHZ29201 - ImmediateView Details
Published: 2020-11-02