TDA7512 Datasheet, PDF (40/42 Pages) STMicroelectronics – AM/FM CAR RADIO TUNER IC WITH INTELLIGENT SELECTIVITY SYSTEM ISS

TDA7512
4.0 Application notes
Following items are important to get highest performance of TDA7512 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.
7. Wire lenght from AM mixer tank output to 9KHz ceramic filter input has to be short as possible.
40/42