1998 Dec 16

33

Philips Semiconductors

Preliminary specification

TDA9321H

27. All frequency variations are referenced to 3.58 or 4.43 MHz carrier frequency. All oscillator specifications are

insensitive to the spurious responses of the crystal. As long as the resonance resistance of the third overtone is

higher than that of the fundamental frequency the oscillator will operate at the correct frequency. The typical crystal

parameters for the crystal series are:

The minimum detuning range can only be specified if both the IC and the crystal tolerances are known and therefore

the figures regarding catching range are only valid for the specified crystal series. In this figure tolerances of the

crystal with respect to the nominal frequency, motional capacitance and ageing have been taken into account and

have been counted for gaussic addition. Whenever different typical crystal parameters are used the following

equation might be helpful for calculating the impact on the tuning capabilities:

Detuning range =

The resulting detuning range should be corrected for temperature shift and supply voltage deviation of both the IC

and the crystal. To guarantee a catching range of

±300 Hz on 4.43 MHz the minimum motional capacitance of the

crystal must have a value 13.2 fF or higher. For a catching range of 250 Hz with the 3.58 MHz crystal the minimum

motional capacitance must have a value of 9 fF. The actual series capacitance in the application should be

28. The hue control is active for NTSC on the demodulated colour difference signals and for PALplus on the demodulated

helper signal.

29. This parameter indicates the bandwidth of the complete chrominance circuit including the chrominance band-pass

filter. The bandwidth of the low-pass filter of the demodulator is approximately 1 MHz.

30. This delay is partially caused by the low-pass filter at the sync separator input.

31. The internal luminance signal (signal which is derived from the incoming CVBS or Y/C signals) has a separate gain

−1 and +2 dB) which

can be used to get an optimal input signal amplitude for the feature box.

32. The slicing level is independent of sync pulse amplitude. The given percentage is the distance between the slicing

level and the black level (back porch). When the amplitude of the sync pulse exceeds the value of 350 mV the sync

separator will slice the sync pulse at a level of 175 mV above top sync. The maximum sync pulse amplitude is 4 V

(peak-to-peak value).

33. To obtain a good performance for both weak signal and VCR playback the time constant of the first control loop is

noise detector and the time constant is switched to the slow mode when too much noise is present in the signal. In the

fast mode during the vertical retrace time the phase detector current is increased 50% so that phase errors due to

head-switching of the VCR are corrected as soon as possible. Switching between the two modes can be automatic

The circuit contains a video identification circuit which is independent of the first control loop. This identification circuit

can be used to close or open the first control loop when a video signal is present or not present on the input. This

enables a stable On Screen Display (OSD) when just noise is present at the input. The coupling of the video

C

mot

1

C

p

C

s

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+

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