Smallest-size (1.6 x 0.8 mm) noise filter added to line-up of radiation noise suppression components for audio lines
-NFZ18SM(NFZ_S Series)-

音声ライン向け放射ノイズ対策部品に最小サイズ (1.6×0.8mm) をラインアップ -NFZ18SM (NFZ_S) シリーズ-



Murata has now added the NFZ18SM series, the smallest size now available, to its NFZ_S series of noise filters that are specifically designed and manufactured for audio line applications and suppress radiation noise with no adverse effects on the sound quality (*1).


Full-digital speakers (*2) are currently attracting a great deal of attention as systems that enable a higher sound quality and higher efficiency (one-eighth of the power consumption) than conventional class D amplifiers to be achieved. The finished product manufacturers in a wide variety of markets have expressed an interest in these products and have started to use them in headphones, speakers, AV navigation systems for vehicles and other such products: as such, high hopes are pinned on their future use in smartphones and tablets as well. As noise filters ideally suited to audio lines that are exemplified by these applications, Murata has been offering its NFZ_S series as a product line-up, but in response to the intensified demand for ever-smaller sizes, the company has now launched a 0603 size component that is the smallest model in the series.



・The new noise filters come in the 0603 size, and achieve an impressively high rated current that exceeds 1A.
・Evaluations performed in actual products and in combination with Y capacitors have revealed that the noise filters combine a radiation noise suppression effect that satisfies the CISPR22 standard (*3) with a THD+N performance on a par with the shorted status even with an applied voltage of 0.5W.
・Only one model is being released at the present time, but Murata will consider creating products with different impedance levels if there is demand.


Radiation noise suppression in the audio lines of filter-less class D amplifiers, full digital speakers and other such products

Parts List

NFZ18SM121SN10# (#: package code)
  For more details click here.


Electric characteristics

*1: When applied Rated current to the Products, self temperature rise shall be limited to 40℃ max.

External Size



Mass Production



*1: Sound quality: The distortion factor expressed as THD+N (total harmonic distortion plus noise) is used as the indicator to evaluate sound quality. This factor is an indicator for indicating as a percentage of the extent to which all the undesirable noises except for the audio signals that represent the sound we expect to hear, and the lower the distortion factor, the better the sound quality.
*2: Full digital speakers: Unlike regular speakers (to which analog signals supporting the changes in the amplitude of the audio signals are input), these are digitally driven speakers to which digital signals are input.
*3: CISPR22: This refers to the standard that regulates emissions for information technology equipment (ITE) defined by the CISPR (Special international committee on radio interference).

Murata in Brief

Murata Manufacturing Co., Ltd. is a worldwide leader in the design, manufacture and sale of ceramic-based passive electronic components & solutions, communication modules and power supply modules. Murata is committed to the development of advanced electronic materials and leading edge, multi-functional, high-density modules. The company has employees and manufacturing facilities throughout the world. For more information, visit Murata's website at