TDK MAF1005G noise suppression filter cuts spurious cellular signals by up to 50 dB

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.