STA335ML

Applications

Doc ID 17638 Rev 4

15/20

Figure 12.

Filterless output configuration

The filterless application is more critical in terms of EMI. It is quite important to follow the

suggestions below:

●

Tracks from amplifier to speaker should be as short as possible.

●

Ferrite beads can be used (instead of coils) to improve EMI performance.

–

Ferrite beads must have a low impedance in the audio band and high impedance

at high frequencies.

–

Place ferrite beads as close as possible to the IC.

–

Ferrite filters must reduce EMI above 1 MHz.

–

FCC and CE authorities test radiated emission above 30 MHz.

Figure 13.

Filterless output configuration with snubber network

The presence of snubber networks reduce the EMI. The snubber networks should be placed

as close as possible to the IC.

OUT1A

OUT1B

OUT2A

OUT2B

Right

Left

OUT1A

330 pF

22 R

OUT1B

OUT2A

330 pF

22 R

OUT2B

Right

Left