tda8361 NXP Semiconductors, tda8361 Datasheet - Page 24

• Manufacturer Part Number: tda8361
• Description: Integrated Pal And Pal/ntsc Tv Processors
• Manufacturer: NXP Semiconductors

Philips Semiconductors
11. Measured with a source impedance of 75 , where:
12. To obtain a good noise immunity of the AGC circuit the AGC detector is gated during the sync pulse. This gating is
13. When the leakage current of the capacitor exceeds this value it will result in a reduced performance of the AGC
14. The AFC slope is directly related to the Q-factor of the demodulator tuned circuit. The given AFC steepness is
15. For positive modulated signals the FM sound demodulator for the sound is not required. This is because the sound
16. The sound IF input is combined with the AF volume control. The IF signal is internally AC coupled to the limiter
17. V
18. V
19. V
20. Audio attenuator at 20 dB; temperature range 10 to 50 C.
21. In the TDA8361 and TDA8362 the audio and CVBS switches are controlled via the chrominance input pin.
22. Signal with negative-going sync. Amplitude includes sync pulse amplitude.
23. This parameter is measured at nominal settings of the various control voltages.
24. Burst amplitude; for a colour bar with 75% saturation the chrominance signal amplitude is 660 mV (p-p).
25. Nominal contrast is specified as maximum contrast 3 dB. Nominal saturation as maximum 12 dB. The nominal
26. When the data blanking input pulse exceeds a level of 4 V the RGB outputs are blanked. In this condition it is possible
27. The 3 dB bandwidth of the circuit can be calculated by means of the following equation:
March 1994
Integrated PAL and PAL/NTSC TV
processors
switched off during the vertical retrace to avoid disturbances of the signal amplitude due to phase errors of the
incoming video signal which are caused by the head-switching of VCRs.
(amplitude variation during line or frame) but it will not result in a hang-up situation.
obtained with a Q-factor of 60. When a lower steepness is required this can be obtained by connecting an external
resistor to the AFC output (the output impedance is 50 k ). The AFC off-set is tested with a double sideband input
signal and with the reference tuned circuit tuned to minimum AGC voltage (optimum tuning for the demodulator).
signal is amplitude modulated. Therefore the TDA8362 can be switched to positive modulation via the de-emphasis
pin (pin 1). When switched to positive modulation the audio switch is set to ‘external’ so that the demodulated audio
signal can be supplied to the input. The option between AM sound and SCART audio signals is achieved by means
of an external switch.
amplifier. The volume control voltage must be supplied to this pin via a resistor.
FM: 70 Hz 50 kHz deviation
AM: 1 kHz at 30% modulation.
Table 1 lists the various possibilities.
When the DC voltage has a value between 3 and 5 V the switches are set to the S-VHS position. The chrominance
trap is then switched off and separate Y and chrominance signals have to be applied to the inputs (the audio switch
is set to external in this condition). The audio switch is also set to external when the IF amplifier is switched to positive
modulation (see also note 15).
brightness control voltage is 2.5 V.
to supply ‘On-Screen-Display’ signals to the outputs. This blanking overrules both the internal and external
RGB signals.
S/N = 20 log
f
–
I
I
I
3 dB
= 100 mV RMS; FM: 1 kHz, f = 50 kHz.
= 50 mV RMS, f = 4.5/5.5 MHz;
= 100 mV RMS, 5.5 MHz; FM: 1 kHz, 17.5 kHz deviation; 15 kHz bandwidth; audio attenuator at 6 dB.
=
f
osc
-------------------------------------------------------- -
V
1
V
m rms
–
O
------- -
2Q
(black-to-white)
1
B = 5 MHz
24
TDA8360; TDA8361; TDA8362
Objective specification