TDA8501 Datasheet, PDF (10/30 Pages) NXP Semiconductors – PAL/NTSC encoder

Philips Semiconductors
PAL/NTSC encoder
Preliminary specification
TDA8501
Fig.9 Nominal Y + SYNC signal level at pin 22
(PAL mode).
NTSC option with internal set-up generation
Pin 4 connected to ground or left open-circuit. The set-up
is generated internally and the input signals have the
values already specified in section Input stage. The set-up
is not suppressed during vertical sync.
NTSC option without internal set-up generation
Pin 4 connected to V_CC. This option places some
restrictions on the input signals as follows:
• if the output signal must be according to the NTSC
standard, the input signals must be generated with a
specific set-up level
• for R, G and B inputs a set-up level of 53 mV is required,
therefore the specified amplitude must be 753 mV
(peak-to-peak) instead of 700 mV (peak-to-peak)
• for U, V and Y inputs a set-up level for Y of 76 mV is
required, therefore the specified amplitude must be
1076 mV (peak-to-peak) (without sync) instead of 1 V
(peak-to-peak). This option, combined with U, V and Y
inputs, is not possible if V_CC is < 4.75 V.
Fig.10 Nominal Y +SYNC signal level at pin 22
(NTSC mode).
April 1993
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