SAA4963T Philips, SAA4963T Datasheet - Page 5

• Manufacturer Part Number: SAA4963T
• Description: Integrated NTSC comb filter
• Manufacturer: Philips

Philips Semiconductors
FUNCTIONAL DESCRIPTION
Functional requirements
The NTSC comb filter processes the video standard
NTSC M. For SVHS signals the input signals are
bypassed to the output without processing by selecting the
SVHS mode.
A sync separation circuit is incorporated to generate
control signals for the internal clock processing. With a
sync compression of up to 12 dB (see Fig.5) the sync
separator works properly.
The IC is controlled via the pin SVHS (pin 2) which forces
the IC into the SVHS mode (bypass) if the comb filter
function is not desired. It is possible to select the following
modes:
The mode changes from SVHS to COMB and vice versa
are always performed asynchronously with respect to the
vertical blanking interval.
Pin description
FSC (
Input for the reference frequency f
“Characteristics”). For SVHS signals the signal
performance can be increased by switching the input
signal at FSC off.
SVHS (
Input signal that controls the operation mode. An internal
low-pass filter suppresses the subcarrier frequencies.
Thus applications are supported where the operation
mode (COMB or SVHS) is controlled by the DC level of the
FSC input signal at pin 1. For those applications the SVHS
input can be externally connected to FSC (pin 1).
Table 1 SVHS function
1997 Mar 03
LOW
HIGH
SVHS
COMB-mode: Luminance and chrominance comb filter
function active, if SVHS mode not active
SVHS-mode: No IC function active, all clocks inactive,
C
bypassed to Y
(pin 2).
Integrated NTSC comb filter
ext
PIN
(pin 7) is bypassed to C
PIN
1)
COMB
SVHS (PLL and clock processing stopped)
2)
O
(pin 11). This mode is forced via SVHS
SELECTED MODE
O
(pin 9) and Y
sc
(see note 3 of Chapter
ext
(pin 14) is
5
The PLL and the clock processing are always stopped if
the selected level for SVHS is applied to SVHS
(independent of the vertical pulse).
V
Supply voltages.
AGND, OGND, DGND
16
Ground connection. AGND is used as signal reference for
all analog input and output signals.
C
Input for an external chrominance signal which is
correlated with the external VBS signal in SVHS-mode.
C
Chrominance output signal. This output delivers the comb
filtered chrominance from the CVBS signal in
COMB-mode or the external chrominance signal from the
input C
In COMB-mode the output is delayed by an additional
processing delay.
Table 2 C
REFDL (
Decoupling capacitor for the delay line reference voltage.
Y
VBS output signal. This output delivers the comb filtered
luminance signal (including synchronization pulses) in
COMB-mode or the external (C)VBS signal from the input
Y
the output is delayed by an additional processing delay.
Table 3 Y
COMB
SVHS
COMB
SVHS
MODE
CCA
O
ext
ext
O
AND
(
MODE
(
PIN
PIN
if the IC is forced into SVHS-mode. In COMB-mode
(
, V
PIN
ext
17)
CCO
11)
9)
PIN
7)
if the IC is forced into the SVHS-mode.
comb filtered chrominance signal
external chrominance signal from C
O
O
, V
10)
output signal
output signal
DDD
comb filtered luminance signal
external (C)VBS signal from Y
AND
C
V
AND
O
CCPLL
Y
OUTPUT SIGNAL
O
PLLGND (
OUTPUT SIGNAL
(
PINS
Preliminary specification
4, 6, 15
PINS
SAA4963
5, 8,
AND
ext
ext
input
input
18)