TDA7512F Datasheet, PDF (43/45 Pages) STMicroelectronics – FM car-radio tuner IC with intelligent selectivity system (ISS)

TDA7512F
Appendix B Application notes
Application notes
Following items are important to get highest performance of TDA7512F in application:
1. In order to avoid leakage current from PLL loop filter input to ground a guardring is
recommended around loop filter PIN’s with PLL reference voltage potential.
2. Distance between Xtal and VCO input PIN 18 should be far as possible and Xtal
package should get a shield versus ground.
3. Blocking of VCO supply should be near at PIN 16 and PIN 17.
4. Wire lenght to FM mixer1 input and output should be symetrically and short.
5. FM demodulator capacitance at PIN 44 should be sense connected as short as
possible versus demodulator ground at PIN 47.
6. With respect to THD capacitive coupling from PIN 20 to VCO should be avoided.
Capacitance at PIN 20 has be connected versus VCC2 ground.
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