Datasheet LT1203, LT1205 (Analog Devices) - 8

LT1203/LT1205
O U U W U APPLICATI S I FOR ATIO CMOS MUX Channel-to-Channel Switching Transient
only 10mVP-P. A photo of the switching transients from a CMOS MUX shows glitches to be 50 times larger than on the LT1203. Also shown is the output of the LT1203 OUTPUT switching on and off a 2MHz sinewave cleanly and without 1V/DIV abnormalities.
Pixel Switching
INPUT 1V/DIV The multiplexers are fabricated on LTC's Complementary Bipolar Process to attain fast switching speed, high band- LOGIC width, and a wide supply voltage range compatible with CONTROL traditional video systems. Channel-to-channel switching time and Enable time are both 25ns, therefore delay is the LT1203/05 • AI02 RS = 50Ω NOTE: 50 TIMES LARGER THAN LT1203 TRANSIENT same when switching between channels or between ICs. To demonstrate the switching speed of the LT1203/LT1205
LT1203 Switching Inputs
the RGB MUX of Figure 1 is used to switch RGB Worksta- tion inputs with a 22ns pixel width. Figure 2a is a photo LOGIC showing the Workstation output and RGB MUX output. (PIN 5) The slight rise time degradation at the RGB MUX output is due to the bandwidth of the LT1260 current feedback amplifier used to drive the 75Ω cable. In Figure 2b, the OUTPUT (PIN 7) LT1203 switches to an input at zero at the end of the first pixel and removes the following pixels. LT1203/05 • AI03 CHANNEL 1 = 0V CHANNEL 2 = 2MHz SINEWAVE J8 ENABLE V+ V – GND J7 C4 LOGIC 4.7µF + + R11 R10 C3 1.5k 1.5k 4.7µF 16 J1 1 – R16 RED 1 1 16 15 75Ω +1 J9 R J2 2 15 2 RED R1 + 14 RED 2 75Ω 3 14 R7* 3 +1 R12 13 J3 4 13 10k R2 LT1205 1.5k 4 – R17 GREEN 1 75Ω 5 12 12 75Ω +1 J10 G J4 6 11 5 GREEN R3 + GREEN 2 75Ω 7 10 R8* R13 6 11 +1 8 9 10k 1.5k R4 7 R18 75Ω C2 + R14 10 75Ω J5 J11 0.1µF 1.5k B BLUE 1 8 BLUE 1 8 – +1 9 J6 2 7 R15 R5 LT1203 LT1260 BLUE 2 1.5k 75Ω 3 6 +1 R9* 4 5 10k R6 LT1203/05 • F01 75Ω C1 *OPTIONAL 0.1µF
Figure 1. RGB MUX
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