GT4122 Video Multiplier
DATA SHEET
FEATURES
• broadcast quality video multiplier
• 30 MHz at -1.0 dB video and control channel bandwidth
• one external frequency compensation adjustment
• ultra low differential gain and differential phase,
(typically 0.01 % and 0.01 deg.)
• external DC offset and span trims
• 20 pin PDIP and SOIC packaging
APPLICATIONS
•
Production switcher video mixers
•
Linear Keyers
PIN CONNECTIONS
TOP VIEW
TOP VIEW
-V
S
+V
S
COMP
C
OS1
C
OS2
S1
V
REF
S2
V
C
GND
10
11
PIN 1
20
OUT
B
OS2
-IN B
+IN B
B
OS1
A
OS2
-IN A
+IN A
A
OS1
R
EXT
DESCRIPTION
The GT4122 multiplier is a monolithic dual-channel,
broadcast quality video mixer.
Featuring two wideband video inputs and a single control
input, the GT4122 achieves high quality video mixing of
the two video input signals to a single output by implementing
the function:
V
OUT
= V
A
• V
C
+ V
B
(1 - V
C
)
where V
C
is the control input voltage, which may be
varied continuously over the control range and V
A
and V
B
are the video input signals.
The GT4122 operates with power supply voltages of
±
10
volts and typically draws 24 mA of current. The GT4122
is available in a 20 pin DIP and 20 pin SOIC packaging.
An Application Note entitled ‘Using the GT4122 and
GT4124 Video Mixer ICs’ (Gennum Document 520-44) is
available from Gennum Corporation.
ORDERING INFORMATION
Part No.
GT4122 - CDF
GT4122 - CKF
Package Type
20 PDIP
20 SOIC
Temperature
0° to 70°C
0° to 70°C
20 PIN DIP / SOIC
+
IN A
-
IN A
A
OS1
A
OS2
+
AMP 1
PIN DESIGNATION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
-V
S
negative supply voltage
+V
S
positive supply voltage
COMPoutput freq'y comp'n R-C
C
OS1
control input offset adjust
C
OS2
control input offset adjust
S1
span adjust
V
REF
0.5volt reference input
S2
span adjust
V
C
control signal input
GND ground
R
EXT
current setting resistor
A
OS1
A black level adjust (OFFSET)
+IN A A video + input signal
-IN A A video - signal input
A
OS2
A black level adjust (OFFSET)
B
OS1
B black level adjust (OFFSET)
+IN B B video + signal input
-IN B B video - signal input
B
OS2
B black level adjust (OFFSET)
OUT multiplier output
XA
V
CA
=0.5 + V
K
COMP
-
+
Σ1
AMP 4
OUT
+
+
AMP 2
+
IN B
-
IN B
B
OS1
R
EXT
XB
BIAS
-
+
V
CB
=0.5 - V
K
-
V
K
Σ2
+
+
V
K
Σ3
AMP 3
-
A
K
+
B
OS2
V
REF
V
C
S1
S2
C
OS2
C
OS1
-
V
S
V
NOM
+
+
0.5V
+
V
NOM
+
V
S
GND
-
-
Device Function: V
OUT
= V
INA
• [V
NOM
+ A
K
(V
C
- V
REF
)] + V
INB
• [V
NOM
- A
K
(V
C
- V
REF
)]
FUNCTIONAL BLOCK DIAGRAM
Document No. 520 - 25 - 4
Revision Date: January 1994.
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946
Japan Branch: A-302, Miyamae Village, 2-10-42 Miyamae, Suginami-ku, Tokyo 168, Japan
tel. (03) 3334-7700
fax: (03) 3247-8839
GENNUM [ GENNUM CORPORATION ]
