By Jim Harrison

Audio cables and circuit boards are susceptible to EMI from cellular
transmissions. Earphones, speakers, and microphones in smartphones, tablets,
and portable game consoles with a cellular connection can all be experiencing
some sounds that don’t belong.

The new MAF1005GAD noise suppression filters features a high
attenuation of cellular bands from 700 MHz to 2.5 GHz. They can suppress the
spurious emissions from these bands by up to 50 dB. The tiny 1.0 x 0.5 x 0.5-mm
filters do this without causing any degradation of audio signals. They feature
a DC resistance of 0.55 to 1.30 ohms typical and use newly developed low-distortion ferrite materials.


The devices three versions, -152A, -262A, and -352A, are
rated for 400-, 300-, and 270-mA DC with typical Z at 900 MHz of 1.5, 2.6, and 3.5
kΩ, respectively. Impedance at 1.7 GHz is 1.2, 2.0, 2.4 kΩ. Operating temperature
is a wide −55°C to 125°C.