1996 Jan 17

25

Philips Semiconductors

Preliminary specification

PAL/NTSC/SECAM decoder/sync processor

TDA9143

Notes to the characteristics

1. All frequency variations are referred to 3.58 MHz or 4.43 MHz carrier frequency. All oscillator specifications are

measured with the Philips crystal series 9920 520 0047x and 9920 520 0048x. The oscillator circuit is insensitive to

the spurious responses of the crystal. The typical crystal parameters for the crystals mentioned above are:

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

general specifications given for the subcarrier regeneration are therefore valid for the specified crystal series. In

the figure tolerances of the crystal with respect to nominal frequency, motional capacitance and ageing have been

taken into account and have been counted for by Gaussian addition.

Whenever different typical crystal parameters are used, the following equation might be helpful for calculating the

impact on the detuning capabilities:

e) Detuning range proportional to:

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

to account for parasitic capacitance on and off chip. For 3-norm applications with two crystals connected to one

pin, the maximum load capacitance of the crystal pin should not exceed 12 pF.

2. YD3 and YD2 are equal significant bits, both representing a 160 ns delay step. YD1 represents 80 ns and YD0

represents a 40 ns delay step.

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

4. The delay between the positive edge of VA and the first negative edge of HA (or positive edge of CLP) after VA is

34.5

µs for field 1 and 2.5 µs for field 2 (17 LLC pulses with or without

respectively).

5. The output signals of the demodulator are called

−(R−Y) and −(B−Y) in this specification. The colour difference input

and output signals of the YUV switch are called UV signals. However, these signals do not have the amplitude

correction factor of real UV signals. They are called UV signals and not

−(R−Y) and −(B−Y) to prevent confusion

between the colour difference signals of the demodulator and the colour difference signals of the YUV switch.

6. The maximum external clamping pulse width is the minimum available blanking level time of the supplied RGB

signals.

C

M

1

C

O

C

L

--------

+





---------------------------

1

2f

H

×

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