tda8374bh NXP Semiconductors, tda8374bh Datasheet - Page 44

• Manufacturer Part Number: tda8374bh
• Description: Tda837x Family I?c-bus Controlled Economy Pal/ntsc And Ntsc Tv-processors
• Manufacturer: NXP Semiconductors

Philips Semiconductors
39. At a chrominance input voltage of 660 mV (p-p) [colour bar with 75% saturation i.e. burst signal amplitude
40. The ACL function is available in the NTSC devices and is active in the PAL/NTSC devices when NTSC signals are
41. All frequency variations are referenced to 3.58 or 4.43 MHz carrier frequency. All oscillator specifications are
42. The (R
43. This parameter indicates the bandwidth of the complete chrominance circuit including the chrominance band-pass
44. The sub-carrier output signal can be used as reference signal of external comb filter ICs (all ICs) and as a reference
45. At nominal setting of the gain control. When this amplitude is exceeded the signal will be clipped.
46. When the reproduction of 4 : 3 pictures on a 16 : 9 picture tube is realized by means of a reduction of the horizontal
47. Signal-to-noise ratio (S/N) is specified as a peak-to-peak signal with respect to RMS noise (bandwidth 5 MHz).
1997 Jul 01
I
and NTSC TV-processors
2
300 mV (p-p)] the dynamic range of the ACC is +6 and 20 dB.
received. The ACL circuit reduces the gain of the chroma amplifier for input signals with a chroma-to-burst ratio which
exceeds a value of 3.0.
measured with the Philips crystal series 9922 520 with a series capacitor of 18 pF. The oscillator circuit is rather
insensitive to the spurious responses of the crystal. As long as the resonance resistance of the 3rd overtone is higher
than that of the fundamental frequency the oscillator will operate at the correct frequency. Typical parameters for the
above mentioned crystals are as follows:
a) Load resonance frequency f
b) Motional capacitance C
c) Parallel capacitance C
The minimum detuning range can only be specified if both the IC and the crystal tolerances are known and the figures
given are therefore valid for the specified crystal series. In this figure tolerances of the crystal with respect to nominal
frequency, motional capacitance and ageing have been taken into account and have been counted for gaussian
addition. Whenever different typical crystal parameters are used the following equation might be helpful for
calculating the impact on the detuning capabilities:
The detuning range divided by
The resulting detuning range should be corrected for temperature shift and supply deviation of both the IC and the
crystal. The actual series capacitance in the application should be C
on and off chip. For 3-norma applications with 2 crystals connected to one pin the maximum parasitic capacitance of
the crystal pin should not exceed 15 pF.
ratio
The output signal amplitudes of the TDA8373 and TDA8377A have twice the value. This is necessary to compensate
for the gain of the baseband delay line (TDA4665). The matrixing to the required signals is realized in the control part.
filter. The bandwidth of the low-pass filter of the demodulator is approximately 1 MHz.
signal for the SECAM decoder TDA8395 (only TDA8374 and TDA8375). In the latter types the output signal is
continuously available when PAL or NTSC signals are detected. When the system identifies a SECAM signal the
reference signal is only present in the vertical retrace period. This to prevent interference between the reference
signal and the SECAM input signal. For comb filter applications the DC load on this pin should be limited to 50 A to
avoid problems with SECAM identification.
scan amplitude, the edges of the picture may be slightly disturbed. This effect can be prevented by adding additional
blanking to the RGB signals. This blanking pulse is derived from the horizontal oscillator and is directly related to the
incoming video signal (independent of the flyback pulse). The additional blanking overlaps the normal blanking signal
with approximately 1 s on both sides. This blanking is activated with the HBL bit (only in the TDA8375 and
TDA8377).
C-bus controlled economy PAL/NTSC
-------------------- -
R Y
B Y
–
–
Y) and (B
=
1.78
.
Y) signals are demodulated with a phase difference of the reference carrier of 90 and a gain
par
mot
= 5 pF for both crystals.
= 20.6 fF (4.43 MHz crystal) or 14.7 fF (3.58 MHz crystal).
0
------------------------------ -
1
= 4.433619 or 3.579545 MHz (C
+
C
C
---------- -
mot
C
par
L
2
44
L
= 20 pF).
L
= 18 pF to account for parasitic capacitances
TDA837x family
Preliminary specification