LT1675 Datasheet, PDF (1/16 Pages) Linear Technology – 250MHz, Triple and Single RGB Multiplexer with Current Feedback Amplifiers

LT1675/LT1675-1
250MHz, Triple and Single
RGB Multiplexer with Current Feedback Amplifiers
FEATURES
s _{100MHz Pixel Switching}
s _{– 3dB Bandwidth: 250MHz}
s _{Small 16-Pin SSOP Package}
s _{Channel Switching Time: 2.5ns}
s _{Expandable to Larger Arrays}
s _{Drives Cables Directly}
s _{High Slew Rate: 1100V/µs}
s _{Low Switching Transient: 50mV}
s _{Shutdown Supply Current: 0mA}
s _{Output Short-Circuit Protected}
U
APPLICATIONS
s _{RGB Switching}
s _{Workstation Graphics}
s _{Pixel Switching}
s _{Coaxial Cable Drivers}
s _{High Speed Signal Processing}
DESCRIPTION
The LT^®1675 is a high speed RGB multiplexer designed for
pixel switching and fast workstation graphics.
Included on chip are three SPDT switches and three
current feedback amplifiers. The current feedback ampli-
fiers drive double-terminated 50Ω or 75Ω cables and are
configured for a fixed gain of 2, eliminating six external
gain setting resistors. The SPDT switches are designed to
be break-before-make to minimize unwanted signals cou-
pling to the input.
The LT1675-1 is a single version with two inputs, a single
output and is ideal for a single channel application such as
video sync.
The key to the LT1675 fast switching speed is Linear
Technology’s proprietary high speed bipolar process. This
MUX can toggle between sources in excess of 100MHz,
has a slew rate over 1000V/µs and has a –3dB bandwidth
of 250MHz. The speed and ease of use of the LT1675 make
it ideal for high performance PCs, workstations and pro-
fessional video monitors. The input-referred switching
transient is only 50mV_P-P and lasts just 5ns, making it
virtually undetectable. Power supply requirements are
±4V to ±6V and power dissipation is only 300mW on ±5V,
or 100mW for the LT1675-1. The expandable feature uses
the disable pin to reduce the power dissipation to near
0mW in the off parts.
Unlike competitive solutions that are in bulky high pin
count packages, the LT1675 is in a 16-lead narrow body
SSOP. This small footprint, the size of an SO-8, results in
a very clean high performance solution. The LT1675-1 is
available in the tiny MSOP and the SO-8.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
High Speed RGB MUX
RED 1
+1
75Ω
GREEN 1
+1
75Ω
BLUE 1
+1
75Ω
RED 2
+1
75Ω
GREEN 2
+1
75Ω
BLUE 2
+1
75Ω
LT1675
V⁺
75Ω ^CABLE
+2
V_{OUT RED}
75Ω
75Ω ^CABLE
+2
V_{OUT GREEN}
75Ω
75Ω ^CABLE
+2
V_{OUT BLUE}
75Ω
V^–
SELECT RGB1/RGB2
ENABLE
1675 TA01
Select Pin Switches Inputs at 100MHz
3V
SELECT
LOGIC
PIN 10
0V
1V
RED
OUT
0V
1V/DIV
500mV/DIV
RED 1 = 0V, RED 2 = 1V, R_L = 100Ω
MEASURED BETWEEN 50Ω BACK TERMINATION AND 50Ω LOAD
1675 TA02
1