Oscillator controls (FSEL, OSEL)

TDA7479

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Oscillator controls (FSEL, OSEL)

Three different crystal frequencies can be used. The adoption of the internal clock divider to

the external crystal is achieved via the input pin FSEL. See the following table for reference:

A special mode is introduced to reduce EMI. With pin OSEL connected to GND the internal

oscillator is switched off and an external sinusoidal frequency could be applied on OSCIN.

The peak to peak voltage of this signal can be reduced down to 60mV.

In this mode the frequency selection via FSEL is still active.

Suggested values of C1 and C2 are shown in the following table:

Table 6.

Crystal frequencies

Crystal

FSEL (pin configuration)

4.332MHz

8.664MHz

17.328MHz

connected to GND or open connected to Vs external resistor of 100K to Vs

Table 7.

C1 and C2 value

Crystal

C1

C2

4.332MHz

8.664MHz

17.328MHz

27pF

27pF

27pF

47pF

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