TELEFUNKEN Semiconductors
TDA4455
Preliminary Information
Rev. A1: 08.05.1995
1 (12)
Multistandard VIF Amplifier and PLL Demodulator
Application
Monolithic integrated circuit for vision IF signal processing in multistandard TV and VTR sets.
Description
This multistandard video IF processing circuit with PLL
picture carrier regeneration gives a high performance of
linear video demodulation.
With two IF inputs (Pins 12 and Pins 1718), it is
possible to select between two signal sources. The input
selector switch (Pin 16) works independent from the
standard switch (Pin 11).
The IF signal is internally fed via a 3-stage controlled
wideband amplifier to the video demodulator and the
phase detector. The phase detector compares the phase of
IF signal (0
) with the output signal of the VCO (90
) and
sets the VCO frequency accordingly. A lock detector
switches the PLL loop filter according to the state of the
PLL (locked-PLL slow, unlocked-PLL fast).
A second output of the VCO (0
) provides the reference
carrier for the video demodulator. The polarity of the
demodulator can be inverted by the standard switch
(Pin 11), so that negative or positive modulated IF signals
are always available with the same polarity at the demo-
dulator output. The demodulated video signal is filtered,
amplified and fed via an interference limiter to the video
output (Pin 7).
The standard switch also determines the clamp level of
the video amplifier and the required IF-AGC mode. In the
standard B/G mode the sync peak value is the criterion for
a fast charge and discharge. In the standard L mode on the
other hand, fast AGC action is achieved by charging at
peak white level and discharging by the averaged video
signal (time constant on Pin 8). The response level for
discharge has a hysteresis. In the D2MAC mode a similar
function is applied to achieve the AGC, but with different
threshold levels.
An overload detector prevents the PLL becoming
unlocked by large IF input signals.
To achieve a delayed tuner-AGC action, the current out-
put (Pin 4) can be adjusted with a resistor at Pin 3.
Features
D Suitable for standard B/G, L and D2MAC, processes
negative and positive modulated IF-signals with equal
polarity of the output signal
D Two IF-inputs, for switching between two signal
sources (e.g., two tuners and two SAW-filters)
D High performance video demodulator with PLL
picture carrier regeneration
D Extended video bandwidth (12 MHz) for the demodu-
lation of amplitude modulated MAC-signals
D Standard B/G: AGC acting on the sync peak pulse
D Standard L: fast AGC acting on peak white level with
average value controlled capacitor discharge and
reference hysteresis
D D2MAC: fast AGC acting on peak level with
controlled capacitor discharge
D Output for delayed tuner-AGC, take over point
adjustable
D High input sensitivity
D Ultra white and ultra black limiting
D Supply voltage range 6.8 to 13 V
D Low power consumption
D ESD protection
Package Options
Case: 18-pin DIL plastic
TELEFUNKEN Semiconductors
TDA4455
Preliminary Information
Rev. A1: 08.05.1995
2 (12)
Block Diagram
90
0
Interference
rejection
Video
VCO
R
O
Video
output
7
Lock
detector
B/G
L
D2MAC
V
S
15
B/G
D2MAC
L
3
6
IF AGC
5
8
14
Average
(only L, D2MAC)
13
12
10
9
16
Loop filter
VCO Tank
11 Standard switch
Input
selector
switch
=
+
17
18
1
2
IF Input 1
4
Tuner AGC
93 7502
Tuner AGC
take over
Int. Ref
IF Input 2
Overload
detector
+/
Pin Description
Pin
Symbol
Function
1, 2
IF input 1
3
Tuner AGC adjustment (turn
over point)
4
Delayed tuner AGC current
5, 14
Ground
6
IF AGC time constant
7
Video output
8
Video averaging for standard L
and D2MAC
Pin
Symbol
Function
9, 10
VCO circuit
11
Standard switch
12
PLL loop filter
13
PLL time constant switch
15
Supply voltage
16
Input selector switch
17, 18
IF input 2
TELEFUNKEN Semiconductors
TDA4455
Preliminary Information
Rev. A1: 08.05.1995
3 (12)
Absolute Maximum Ratings
reference point Pin 4, unless otherwise specified
Parameters
Symbol
Value
Unit
Supply voltage
V
s
6.8 to 13.0
V
Supply current
I
S
60
mA
Output current
I
out
5.0
mA
Maximum power dissipation
P
720
mW
Junction temperature
T
j
+125
C
Ambient temperature
T
amb
25 to +85
C
Storage temperature
T
stg
25 to +125
C
Thermal Resistance
Parameters
Symbol
Value
Unit
Junction ambient (when soldered to PCB)
R
thJA
60
K/W
External Voltage
Pin
Voltage range *)
1, 2
0
v Vpin v min (V
s
, 8 V)
3
0
v Vpin v V
s
4
0
v Vpin v min (V
s
, 10 V)
6
0
v Vpin v min (V
s
, 10 V)
7
0
v Vpin v 6 V
8
0
v Vpin v min (V
s
, 8 V)
9, 10
0
v Vpin v V
s
11
0
v Vpin v V
s
12
0
v Vpin v min (V
s
, 7.5 V)
13
0
v Vpin v V
s
15
6.8 V
v Vpin v V
s
16
0
v Vpin v V
s
17, 18
0
v Vpin v min (V
s
, 8 V)
*)
min(V
s
, xV): the lesser of the two values is the lower limit
TELEFUNKEN Semiconductors
TDA4455
Preliminary Information
Rev. A1: 08.05.1995
4 (12)
Electrical Characteristics
Vs = 8 V, T
amb
= 25
C, reference point Pin 5, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
DC-supply
Pin 15
Supply voltage
V
s
6.8
8.0
13.0
V
Supply current
I
s
50
60
mA
IF-amplifier
Pins 12 or Pins 1718
Input sensitivity
sync peak value, B/G
V
in
80
120
V
eff
Input impedance
R
in
1.2
k
W
Input capacitance
C
in
2
pF
IF-AGC
Pins 6 and 8
IF gain control range
G
v
60
66
dB
Response time, standard L
Note 1
t
AGC
10
sec
AGC capacitor
C
6
4,7
F
Average capacitor
C
8
68
nF
Tuner-AGC
Pins 3 and 4
Available tuner-AGC
current
I
4
4
mA
Automatic turn over point
G
v,tun
65
dB
PLL
Pins 910, 12, 13
see note 2
PLL capture range
Df
cap
1.5
MHz
VCO-tuning range
Df
vco
3.0
MHz
VCO-tuning sensitivity
Df / Du
3.0
4.5
kHz/mV
Video demodulator output
Pin 7
see note 3
Composite video output
signal standard B/G
Note 4
V
out
1.8
2.0
2.2
V
pp
Video output signal
standard L
Note 5
V
out
1.2
1.4
1.6
V
pp
Difference of the video
signals
Standard B/G and L
DV
out
10
%
Ultra white level,
standard B/G
Zero carrier level
V
7
4.2
V
Ultra black level, Stand. L
Zero carrier level
V
7
1.9
V
Supply voltage influence
on the ultra black level
(B /G)
DV/
V
0.5
%/V
Supply voltage influence
on the ultra black level (L)
DV/
V
0.5
%/V
Video bandwidth (3 dB)
B
12
MHz
Video frequency response
over the AGC range
DB
2.0
dB
Differential gain error
DG
3
%
Differential phase error
DF
3
deg
Video demodulator output
Pin 7
Sound chroma beat
(1.07 MHz intermodu-
lation) related to demodu-
lated auxiliary colour
carrier.
Picture carrier = 0 dB
Colour carrier = 6 dB
Sound carrier = 24 dB
a
IM
52
dB
TELEFUNKEN Semiconductors
TDA4455
Preliminary Information
Rev. A1: 08.05.1995
5 (12)
Unit
Max.
Typ.
Min.
Symbol
Test Conditions / Pins
Parameters
IF residual voltage
f = 38.9 MHz
f = 77.8 MHz
V
res1
V
res2
2
5
mV
mV
Upsetting factor of sync
pulse in the AGC range
DVsync
Vsync
3
%
Tilt of half picture
between black and white
Standard L
5
10
%
Ultra black limiting
threshold
Below sync level
DV
lim1
250
mV
Ultra white limiting
threshold
Above ultra white level
DV
lim2
500
mV
Standard switch
Pin 11
Control voltage B/G
Note 6
V
sw1
2.5
4.0
V
Control voltage L
V
sw2
0
1.5
V
Control voltage D2MAC
V
sw3
5.0
V
s
V
Input selector switch
Pin 16
Control voltage input 1
active
Note 7
5.0
V
S
V
Control voltage input 2
active
0
2.5
V
Notes
1.
A peak white value for at least 10
s must be trans-
mitted for each complete frame
2.
Loop filter: R1 = 500
W 1 k, C1 = 0.47 mF
Capacitor VCO circuit: C
VCO
= 27 47 pF
3.
Pin 7 unloaded
4.
Residual carrier: 10% carrier amplitude
5.
Blanking level: 30% carrier amplitude
6.
Without control voltage at Pin 11 standard B/G is
automatically selected
7.
Without control voltage at Pin 16 input 1 is auto-
matically active
Alignment of the VCO
1.
Apply 4.5 V to Pin 6, to disable the broadband
amplifier.
2.
Measure the dc-voltage at Pin 12 (phase detector).
3.
Apply a 38.9 MHz unmodulated carrier signal to the
IF input (Pins 12 or Pins 1718); adjust the input
level so that the AGC voltage at Pin 6 is between
2.0 V and 2.5 V.
4.
Adjust the VCO circuit until at Pin 12 is the same DC-
voltage as measured in step 2.
PDF 
ZIP