AD8182AN Analog Devices Inc, AD8182AN Datasheet - Page 8

• Manufacturer Part Number: AD8182AN
• Description: IC MULTIPLEXER DUAL 2X1 14DIP
• Manufacturer: Analog Devices Inc

Specifications of AD8182AN

• Rohs Status: RoHS non-compliant
• Function: Multiplexer
• Circuit: 2 x 2:1
• Voltage Supply Source: Dual Supply
• Voltage - Supply, Single/dual (±): ±4 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 14-DIP (0.300", 7.62mm)

AD8180/AD8182
APPLICATIONS
Multiplexing two RGB Video Sources
A common video application requires two RGB sources to be
multiplexed together before the selected signal is applied to a
monitor. Typically one source would be the PC’s normal output,
the second source might be a specialized source such as MPEG
video. Figure 23 shows how such a circuit could be realized
using the AD8180 and AD8182 and three current feedback op
amps. The video inputs to the multiplexers are terminated with
75
of the applied signals.
Because all three multiplexers are permanently active, the
ENABLE pins are tied permanently low. The three SELECT
pins are tied together and this signal is used to select the source.
In order to drive a 75
multiplexer outputs are buffered using the AD8001 current feed-
back op amp. A gain of two compensates for the signal halving by
the AD8001 output back termination resistor so that the system
has an overall gain of unity.
If lower speed and crosstalk can be tolerated, either of the triple
op amps, AD8013 or AD8073, can replace the three AD8001 op
amps in the above circuit. Because both devices have bandwidths
in the 100 MHz to 140 MHz range at a gain of +2, these ampli-
fiers will dominate the frequency response of the circuit.
R
R
resistors. This has the effect of halving the signal amplitude
COMPUTER
GRAPHICS
MPEG
G
G
B
B
75
75
75
back terminated load (R
75
75
75
+V
+V
S
S
0.1 F
0.1 F
10 F
10 F
Figure 23. Multiplexing Two Component Video Sources
+
+
1
2
3
4
1
2
3
4
5
6
7
+1
+1
+1
+1
+1
+1
L
DECODER
DECODER
DECODER
AD8180
AD8182
= 150 ), the
14
13
12
11
10
8
7
6
5
9
8
ENABLE A
ENABLE
10 F
–8–
0.1 F
10 F
With no signal present, the total quiescent current of the cir-
cuit in Figure 23 is 25.6 mA (3.8 mA + 6.8 mA + 3 5 mA), or
about 8.5 mA per channel. If either the AD8013 or AD8073
are used, the quiescent current will decrease to about 6.5 mA
per channel.
To reduce power consumption further, three AD8011 single
op amps can be used. With a quiescent current of 1 mA, this
will reduce the per channel quiescent current to about 4.5 mA.
Op Amp Comments
AD8001 Highest Bandwidth, 440 MHz (G = +2), I
AD8011 Lower Power Consumption, Bandwidth (G = +2) =
AD8013 Triple Op Amp, Bandwidth (G = +2) = 140 MHz,
AD8073 Lower Power Triple Op Amp, Bandwidth (G = +2) =
+
0.1 F
+
ENABLE B
R
TERM
Table II. Amplifier Options for RGB Multiplexer
–V
–V
SELECT
S
S
210 MHz, I
I
100 MHz, I
SY
= 3.4 mA
681
681
681
SY
SY
AD8001
AD8001
AD8001
= 1 mA
= 3.5 mA
+V
–V
+V
–V
+V
–V
S
S
S
S
S
S
681
681
681
0.1 F
0.1 F
0.1 F
0.1 F
10 F
10 F
0.1 F
0.1 F
10 F
10 F
10 F
10 F
+
+
+
+
+
+
75
75
75
R
G
B
SY
MONITOR
= 5 mA
REV. B