GB4551 Datasheet, PDF (1/5 Pages) Gennum Corporation – Video Buffer with Strobed DC Restore

GB4551 Video Buffer with
Strobed DC Restore
DATA SHEET
FEATURES
• accurate clamping to within ±1mV
• ultra low differential gain (0.03% typ.)
and differential phase (0.03^o typ.)
• wideband unity gain, can typically be flattened to
±0.1dB at 30MHz
• can be configured as a gain stage with reduced
bandwidth.
• drives 100pF loads
• convenient 8 pin SIP packaging
PIN CONNECTIONS
GB4551
1 2 3 4 5 67 8
Pin No.
1
2
3
4
5
6
7
8
GB4551
+IN
V_CC
STB
GND
C_X
V_EE
- IN
OUT
Function
non-inverting input
positive power supply
strobe
ground
external capacitor
negative power supply
inverting input
output
ORDERING INFORMATION
Part Number
GB4551-CSA
Package Type
8 Pin SIP
Temperature Range
0 to 70^o C
DESCRIPTION
The GB4551 is a high performance video buffer with DC
restore primarily used for accurate back porch clamping.
The circuit features a wideband differential amplifier that
can be configured as a gain stage. The output signal
voltage is limited to +2V above the clamp level in order to
prevent damage to crosspoints or other circuits connected
to the output.
The clamping action occurs when the STROBE (STB)
input is taken to ground. A typical application would be for
DC restoration during the back porch period. In this case
the negative-going back porch pulse would be derived
from an external sync separator circuit.
The GB4551 will operate from ± 9V to ±12V power supplies
and will directly interface with Gennum’s video crosspoint
switches. The 8 pin SIP package is ideally suited for
space restricted board layouts.
APPLICATIONS
• Input buffering and DC restoration to crosspoint switches
• Accurate back porch video signal clamping
• Inter-circuit buffering and DC restoration.
CX
+IN
500
30k
+
–IN
-
(+2V OUTPUT CLAMP)
10k
+
12pF
-
10k
STROBE
VEE
7mA
NOM.
VCC
All resistors in ohms, all capacitors in microfarads unless otherwise stated.
SIMPLIFIED CIRCUIT DIAGRAM
OUT
GND
Document No. 520 - 52 - 2
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone] fax: [phone]
Japan Branch: B-201 Miyamae Village, 2-10-42 Miyamae, Suginami-ku Tokyo 168, Japan tel. [phone] fax: [phone]