LT1195 LINER [Linear Technology], LT1195 Datasheet - Page 10

• Manufacturer Part Number: LT1195
• Description: Low Power, High Speed Operational Amplifier
• Manufacturer: LINER [Linear Technology]

LT1195
Send Color Video Over Twisted-Pair
With an LT1195 it is possible to send and receive color
composite video signals more than 1000 feet on a low cost
twisted-pair. A bidirectional “video bus” consists of the
LT1195 op amp and the LT1187 video difference amplifier.
A pair of LT1195s at TRANSMIT 1, is used to generate
differential signals to drive the line which is back-termi-
nated in its characteristic impedance. The LT1187,
twisted-pair receiver, converts signals from differential to
single-ended. Topology of the LT1187 provides for cable
compensation at the amplifier’s feedback node as shown.
In this case, 1000 feet of twisted-pair is compensated with
1000pF and 50
system from 750kHz to 4MHz. This bandwidth is adequate
to pass a 3.58MHz chrome subcarrier, and the 4.5MHz
sound subcarrier. Attenuation in the cable can be compen-
sated by lowering the gain set resistor R
2, another pair of LT1195s serve the dual function to
provide cable termination via low output impedance, and
generate differential signals for TRANSMIT 2. Cable termi-
nation is made up of 15 and 33 attentuator to reduce
the differential input signal to the LT1187. Maximum input
signal for the LT1187 is 760mV
10
A
PPLICATI
Response Through 1000 Feet of Twisted-Pair
1.5MHz Square Wave Input and Unequalized
O
to boost the 3dB bandwidth of the
U
S
I FOR ATIO
U
P-P
.
W
G
. At TRANSMIT
1195 A108
U
Response Through 1000 Feet of Twisted-Pair
Vector Plot of Standard Color Burst Through
1.5MHz Square Wave Input and Equalized
Multiburst Pattern Passed Through
1000 Feet of Twisted-Pair
1000 Feet of Twisted-Pair
1195 A111
1195 A110
1195 A109