Philips TDA3508 Datasheet

INTEGRATED CIRCUITS
DATA SH EET
TDA3508
Video control combination circuit with automatic cut-off control
Product specification Supersedes data of April 1993 File under Integrated Circuits, IC02
1996 Oct 25
Philips Semiconductors Product specification
Video control combination circuit with automatic cut-off control

FEATURES

Capacitive coupling of the colour difference and luminance input signals with black level clamping in the input stages
Linear saturation control acting on the colour difference signals
(GY) and RGB matrix
Linear transmission of inserted signals
Equal black levels for inserted and matrixed signals
Three identical channels for the RGB signals
Linear contrast and brightness controls, operating on
both the inserted and matrixed RGB signals
Peak beam current limiting input
Clamping, horizontal and vertical blanking of the three
input signals controlled by a 3-level sandcastle pulse
Three DC gain controls for the RGB output signals (white point adjustment)
Emitter-follower outputs for driving the RGB output stages
Input for automatic cut-off control with compensation for leakage current of the picture tube.
TDA3508

GENERAL DESCRIPTION

The TDA3508 is an integrated circuit which performs video control functions in a PAL/SECAM decoder for negative colour difference signals (RY) and (BY).
The required input signals are luminance and colour difference and a 3-level sandcastle pulse for control purposes. Linear RGB signals can be inserted from an external source. RGB output signals are available for driving the video output stages. The circuit provides automatic cut-off control of the picture tube.

ORDERING INFORMATION

TYPE
NUMBER
TDA3508 DIP28 plastic dual in-line package; 28 leads (600 mil) SOT117-1
NAME DESCRIPTION VERSION
PACKAGE
1996 Oct 25 2
Philips Semiconductors Product specification
Video control combination circuit with
TDA3508
automatic cut-off control

QUICK REFERENCE DATA

All voltages referenced to pin 24 (ground).
SYMBOL PARAMETER MIN. TYP. MAX. UNIT
V
P
I
P
V
15(p-p)
V
18(p-p)
V
17(p-p)
V
12,13,14(b-w)
V
10
V
20
V
19
V
16
T
amb
supply voltage (pin 6) 12.0 V supply current 95 mA composite video input signal (pin 15) (peak-to-peak value) 0.45 V
(BY) colour difference input signal (pin 18)
1.33 V
(peak-to-peak value)
(RY) colour difference input signal (pin 17)
1.05 V
(peak-to-peak value) inserted RGB signals (black-to-white value)
1.0 V
(pins 12, 13 and 14) 3-level sandcastle pulse (pin 10)
level 1 2.5 V level 2 4.5 V
level 3 8.0 V control voltage for brightness (pin 20) 1.0 3.0 V control voltage for contrast (pin 19) 2.0 4.3 V control voltage for saturation (pin 16) 2.0 4.3 V operating ambient temperature 0 70 °C
1996 Oct 25 3
Philips Semiconductors Product specification
Video control combination circuit with automatic cut-off control

BLOCK DIAGRAM

green
CONTROL
CONTROL
BRIGHTNESS
BRIGHTNESS
CONTROL
CONTRAST
(b-w)
879
13 1214
red
CONTROL
BRIGHTNESS
CONTROL
CONTRAST
blue
CONTROL
BRIGHTNESS
CONTROL
CONTRAST
clamping pulse
4.5 V
SOURCE
CURRENT
TRESHOLD
DETECTOR
TDA3508
control
voltage
brightness
19 20
contrast control
voltage (2 to 4.3 V)
25
control input
for peak beam
current limiting
(1 to 3 V)
signal insertion 1 V
3 x SIGNAL SWITCH
R
MATRIX
(RY)
CONTROL
SATURATION
17 CLAMPING
11
SIGNAL
SWITCHES
DRIVER FOR
(1 V)
G
Y
(GY)
4.4 V
MATRIX
(GY)
MATRIX
Y
B
MATRIX
(BY)
CONTROL
SATURATION
18
CLAMPING
Y
clamping pulse
CLAMPING
15
Y
AMPLIFIER
10 dB
(part A)
TDA3508
246
16
2.9 V
input for signal
switching voltage
P
V
(+12 V)
saturation
(2 to 4.3 V)
control voltage
MSA736
handbook, full pagewidth
Fig.1 Block diagram (continued in Fig.2).
(RY) (1.05 Vp-p)
1996 Oct 25 4
(BY) (1.33 Vp-p)
composite
video
signal
(0.45 Vp-p)
Philips Semiconductors Product specification
Video control combination circuit with automatic cut-off control
storage capacitors
for cut-off
control
2428
red 1
CONTROLLED
OUTPUT
STAGE
2 V B/W
CONTROLLED
OUTPUT
STAGE
2 V B/W
green 3
5 blue
CONTROLLED
OUTPUT
STAGE
2 V B/W
R G B
control current
(3x)
TDA3508
MSA737
L
input for
voltage derived
from leakage
current of R
and cut-off
currents
(R or G or B)
26
+
(part B)
TDA3508
22 2123
(0 to 12 V)
white point adjustment
CONTROL
AMPLIFIER
INSERTION
PULSE
CURRENT
OF BLACK
MEASURING
BLANKING
red
&
V/I
CONVERTER
COMPARATOR
MR
CONTROL
AMPLIFIER
OF BLACK
INSERTION
PULSE
CURRENT
MEASURING
BLANKING
green
&
V/I
CONVERTER
COMPARATOR
MG
CONTROL
AMPLIFIER
OF BLACK
INSERTION
PULSE
CURRENT
MEASURING
BLANKING
blue
&
V/I
CONVERTER
COMPARATOR
MB
line 21 (1)
line 22 (1)
line 23 (1)
H + V
clamping
pulse
CIRCUIT
CLAMPING
SWITCHING AND
clamping
lines 21 to 23 (1)
lines 21 (1)
&
PULSE
FORMER
COUNTER
H + V
H
DETECTOR
SANDCASTLE
pulse
storage of leakage
current information
2.5 V
4.5 V
0
8 V
10 27
sandcastle
pulse
handbook, full pagewidth
Fig.2 Block diagram (continued from Fig.1).
1996 Oct 25 5
(1) After start of vertical blanking pulse.
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