TS2007

Application information

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4.10

Output filter considerations

The TS2007 is designed to operate without an output filter. However, due to very sharp

transients on the TS2007 output, EMI radiated emissions may cause some standard

compliance issues.

These EMI standard compliance issues can appear if the distance between the TS2007

outputs and loudspeaker terminal are long (typically more than 50mm, or 100mm in both

directions, to the speaker terminals). As the PCB layout and internal equipment device are

different for each configuration, it is difficult to provide a one-size-fits-all solution.

However, to decrease the probability of EMI issues, there are several simple rules to follow:

●

Reduce, as much as possible, the distance between the TS2007 output pins and the

speaker terminals.

●

Use a ground plane for “shielding” sensitive wires.

●

Place, as close as possible to the TS2007 and in series with each output, a ferrite bead

with a rated current of minimum 2.5A and impedance greater than 50

Ω at frequencies

above 30MHz. If, after testing, these ferrite beads are not necessary, replace them by a

short-circuit.

●

Allow extra footprint to place, if necessary, a capacitor to short perturbations to ground

(see Figure 51).

Figure 51.

Ferrite chip bead placement

In the case where the distance between the TS2007 output and the speaker terminals is too

long, it is possible to have low frequency EMI issues due to the fact that the typical operating

frequency is 280kHz. In this configuration, it is necessary to use the output filter represented

in Figure 1 on page 4 as close as possible to the TS2007.

to speaker

about 100pF

gnd

Ferrite chip bead

From TS2007 output