LT6551
1
DESCRIPTION
Demonstration circuit 866 is a Quad Video Amplifier fea-
turing the LT6551. The Demo Circuit is designed to oper-
ate from a single pow er supply from 4.5V to 12V. The
inputs and outputs are ac-coupled and include 75
Ω
ter-
minations for video cables. The LT6551 has a fixed volt-
age-gain of tw o, thus w ith a terminated output cable, the
net gain is nominally unity.
Design files for this circuit board are available. Call
the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT and
Pow erPath are trademarks of Linear Technology Corporation.
PERFORMANCE SUMMARY
Specification s are at T
A
= 25°C
SYM BO L PAR AM ETER
CO NDITION S
M IN
TYP
M AX
UN ITS
V+
Input Supply Range
4.5
5
12.0
V
Z
IN
Input Impedance
ac-coupled
75
Ω
Z
OUT
Output Impedance
ac-coupled
75
Ω
A
Gain
Output terminated into 75
Ω
Output terminated into hi-Z
0
+6
dB
dB
BW
Bandw idth
-3dB, small-signal
60
M Hz
Crosstalk
10M Hz
65
dB
V
IN
Input signal sw ing
V+= 5V, no output clipping
V+= 9V, no output clipping
±0.8
±1.5
V
V
I
S
Pow er Supply Current
V+= 5V, no signal
40
m
Α
OPERATING PRINCIPLES
DC866 provides four identical channels of w ideband sig-
nal amplification suitable for driving H DTV or high-
resolution R G B video display cables. Each amplifier sec-
tion of the LT6551 provides a fixed gain of 2, and w ith
series “back-termination” at the outputs (included on the
board), results in unity gain transmission of a video sig-
nal to a destination load, w ith frequency response show n
in Figure 2.
Each input is terminated to analog ground to properly
load the input signal cable. AC-coupling is provided for
both inputs and outputs, along w ith biasing circuitry, to
provide single-supply operation. Figure 3 show s the typi-
cal crosstalk betw een adjacent channels.
Figure 4 show s the material list of the components used
by DC866, and Figure 5 show s the electrical interconnec-
tion.
DEMO CIRCUIT 866
QUICK START GUIDE
LT6551
Quad Video Amplifier
