tda8376ah NXP Semiconductors, tda8376ah Datasheet - Page 30

• Manufacturer Part Number: tda8376ah
• Description: I2c-bus Controlled Pal/ntsc Tv Processors
• Manufacturer: NXP Semiconductors

Philips Semiconductors
16. Conditions: frequency is 50 Hz; normal mode; VS = 1FH.
17. The E-W output current range of the TDA8376A is higher than that of the TDA8376 because of the horizontal zoom
18. The TDA8376A has a zoom adjustment possibility for the vertical and horizontal deflection. For this reason an extra
19. At a chrominance input voltage of 660 mV (p-p) [colour bar with 75% saturation i.e. burst signal amplitude
20. All frequency variations are referenced to a 3.58 or 4.43 MHz carrier frequency. All oscillator specifications are
21. The (R Y) and (B Y) signals are demodulated with a phase difference of the reference carrier of 90 and a gain
22. The subcarrier output signal can be supplied to the TDA8395 but it can also be used as drive signal for external comb
23. At nominal setting of the gain control. When this amplitude is exceeded the peak-white limiting circuit will reduce the
24. Signal-to-noise ratio (S/N) is specified as peak-to-peak signal with respect to RMS noise (bandwidth 5 MHz).
25. This is a current input. The indicated value of the nominal bias current is obtained at the nominal setting of the gain
1996 Jan 26
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function of the TDA8376A. The output range percentages mentioned for E-W control parameters are based on the
assumption that 400 A variation in E-W output current is equivalent to 20% variation in picture width.
DAC has been added in the vertical amplitude control which controls the vertical scan amplitude between 75 to 138%
of the nominal scan. At an amplitude of 106% of the nominal scan the output current is limited and the blanking of
he RGB outputs is activated. This is illustrated in Fig.21. In addition to the variation of the vertical amplitude the
vertical slope control range is also increased. This allows variation of the position of the bottom part of the picture
independent of the upper part. The nominal scan height must be adjusted at a position of 19H of the vertical ‘zoom’
DAC.
300 mV (p-p)] the dynamic range of the ACC is +6 and 20 dB.
measured with the Philips crystal series 9922 520 with a series capacitance of 18 pF. The oscillator circuit is rather
insensitive to the spurious responses of the crystal. Provided 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 crystals are:
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 in are therefore valid for the specified crystal series. In this, tolerances of the crystal with respect to nominal
frequency, motional capacitance and ageing have been taken into account and have been counted for by gaussic
addition. Whenever different typical crystal parameters are used the following equation might be helpful for
calculating the impact on the detuning capabilities:
Detuning range:
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-normal applications with two crystals connected to one pin the maximum parasitic capacitance
of the crystal pin should not exceed 15 pF.
ratio
filters. For this reason the signal is continuously available at the output. Only when SECAM has been identified the
subcarrier signal is available only during the vertical retrace time. This is to avoid cross-talk between the SECAM
input signal and the subcarrier signal. An external DC load on this pin is not allowed because this current will disturb
the reliability of the communication between the TDA8376/TDA8376A and the TDA8395.
contrast. The control voltage is generated via the external capacitor connected to the beam-current limiting input.
(white point) control. The actual value of the bias current depends on the gain control setting of each channel. As a
result the ‘black-current’ of each gun is adapted to the white point setting so that the background colour will follow
the white point adjustment.
C-bus controlled PAL/NTSC TV processors
----------------------- -
–
–
R Y
B Y
–
–
=
------------------------- -
1.78
1
+
C
C
------ -
C
M
. The matrixing to the required signals is achieved in the control part.
0
L
0
2
M
= 5 pF for both crystals.
= 20.6 fF (4.43 MHz crystal) or 14.7 fF (3.58 MHz crystal)
0
(C
L
= 20 pF) = 4.433619 or 3.579545 MHz
30
L
= 18 pF to account for parasitic capacitances
TDA8376; TDA8376A
Objective specification