SA1787 Datasheet, PDF (15/19 Pages) Silan Microelectronics Joint-stock – SINGLE-CHIP TUNER IC FOR CAR RADIOS

Pilot canceller adjustment (pins 17 and 18)
SA1787
Figure 10
The pilot canceller signal waveform (pin 19) is a 19 kHz signal that not contains third harmonic as shown in figure
10. Since this signal has the same phase as the pilot signal, no capacitor is required between pin 18 and ground.
Since it has no third harmonic component, excellent pilot cancellation can be acquired in both the left and right
channels by adjusting with a variable resistor.
Separation adjustment (pin 19)
Figure 11
The separation is adjusted by modifying the input level to the subdecoder with the variable resistor connected to
pin 19. Since only the sub-modulation level is changed by changing the variable resistor setting, the monaural
(main) output level is not changed. Furthermore, degradation of high band separation in the decoder can be
avoided if the impedance of the external capacitor (C) in the subchannel frequency band (23 to 53 kHz) is made
sufficiently smaller than the variable resistor.
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http://www.silan.com.cn
REV:1.0
2008.08.29
Page 15 of 19