250 MHz, 10 ns Switching
Multiplexers w/Amplifier
a
AD8170/AD8174
FUNCTIONAL BLOCK DIAGRAM
AD8170
FEATURES
Fully Buffered Inputs and Outputs
Fast Channel Switching: 10 ns
Internal Current Feedback Output Amplifier
High Output Drive: 50 mA
Flexible Gain Setting via External Resistor(s)
High Speed
SELECT
1
2
3
4
8
7
6
5
V
OUT
–V
+V
GND
IN
–V
S
S
IN1
IN0
+1
+1
250 MHz Bandwidth, G = +2
1000 V/s Slew Rate
Fast Settling Time of 15 ns to 0.1%
Low Power: < 10 mA
Excellent Video Specifications (RL = 150 ⍀, G = +2)
Gain Flatness of 0.1 dB Beyond 80 MHz
0.02% Differential Gain Error
AD8174
+1
+V
14
13
12
1
2
3
4
IN0
GND
IN1
S
V
OUT
–V
IN
+1
+1
+1
2
GND
IN2
11 SD
0.05؇ Differential Phase Error
Low Crosstalk of –78 dB @ 5 MHz
High Disable Isolation of –88 dB @ 5 MHz
High Shutdown Isolation of –92 dB @ 5 MHz
Low Cost
ENABLE
10
9
5
6
7
A1
A0
–V
S
8
IN3
2
Fast Output Disable Feature for Connecting Multiple
Devices (AD8174 Only)
Shutdown Feature Reduces Power to 1.5 mA (AD8174 Only)
APPLICATIONS
The AD8174 offers a high speed disable feature allowing the
output to be put into a high impedance state for cascading
stages so that the off channels do not load the output bus.
Additionally, the AD8174 can be shut down (SD) when not in
use to minimize power consumption (IS = 1.5 mA). These
products will be offered in 8-lead and 14-lead PDIP and SOIC
packages.
Pixel Switching for “Picture-In-Picture”
LCD and Plasma Displays
Video Routers
PRODUCT DESCRIPTION
The AD8170(2:1) and AD8174(4:1) are very high speed
buffered multiplexers. These multiplexers offer an internal
current feedback output amplifier whose gain can be pro-
grammed via external resistors and is capable of delivering 50
mA of output current. They offer –3 dB signal bandwidth of
250 MHz and slew rate of greater than 1000 V/µs. Additionally,
the AD8170 and AD8174 have excellent video specifications
with low differential gain and differential phase error of 0.02%
and 0.05° and 0.1 dB flatness out to 80 MHz. With a low 78
dB of crosstalk and better than 88 dB isolation, these devices are
useful in many high speed applications. These are low power
devices consuming only 9.7 mA from a ±5 V supply.
0
V
= 50mV rms
IN
G = +2
–1
–2
–3
–4
–5
–6
–7
–8
–9
R
R
R
= 499Ω (AD8170R)
F
F
L
= 549Ω (AD8174R)
= 100Ω
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
1M
10M
100M
1G
FREQUENCY – Hz
Figure 1. Small Signal Frequency Response
REV. 0
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otherwise under any patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 1996