MAX4311ESD MAXIM [Maxim Integrated Products], MAX4311ESD Datasheet - Page 15

• Manufacturer Part Number: MAX4311ESD
• Description: High-Speed, Low-Power, Single-Supply, Multichannel, Video Multiplexer-Amplifiers
• Manufacturer: MAXIM [Maxim Integrated Products]

A correctly terminated transmission line is purely resis-
tive and presents no capacitive load to the amplifier.
Reactive loads decrease phase margin and may pro-
duce excessive ringing and oscillation (see Typical
Operating Characteristics ).
Another concern when driving capacitive loads origi-
nates from the amplifier’s output impedance, which
appears inductive at high frequencies. This inductance
Figure 10. High-Speed EV Board Layout—Component Side
Figure 11. High-Speed EV Board Layout—Solder Side
Multichannel, Video Multiplexer-Amplifiers
______________________________________________________________________________________
High-Speed, Low-Power, Single-Supply,
Driving Capacitive Loads
forms an L-C resonant circuit with the capacitive load,
which causes peaking in the frequency response and
degrades the amplifier’s phase margin.
Although the MAX4310–MAX4315 are optimized for AC
performance and are not designed to drive highly capaci-
tive loads, they are capable of driving up to 20pF without
oscillations. However, some peaking may occur in the fre-
quency domain (Figure 6). To drive larger capacitive
loads or to reduce ringing, add an isolation resistor
between the amplifier’s output and the load (Figure 7).
The value of R
capacitive load (Figure 8). Figure 9 shows the
MAX4310–MAX4315 frequency response with the isola-
tion resistor and a capacitive load. With higher capaci-
tive values, bandwidth is dominated by the RC network
formed by R
itself is much higher. Also note that the isolation resistor
forms a divider that decreases the voltage delivered to
the load.
Table 2. Input Control Logic
SHDN
SHDN
SHDN
0
1
1
0
1
1
1
1
0
1
1
1
1
1
1
1
1
ISO
A2
A2
A2
—
—
—
—
—
—
—
—
X
0
0
0
0
1
1
1
1
ISO
and C
A1
A1
A1
—
—
—
depends on the circuit’s gain and the
MAX4310/MAX4313
MAX4311/MAX4314
X
0
0
1
1
MAX4312/MAX4315
X
0
0
1
1
0
0
1
1
L
A0
A0
A0
; the bandwidth of the amplifier
X
0
1
X
0
1
0
1
X
0
1
0
1
0
1
0
1
CHANNEL SELECTED
CHANNEL SELECTED
CHANNEL SELECTED
None, High-Z Output
None, High-Z Output
None, High-Z Output
0
1
0
1
2
3
0
1
2
3
4
5
6
7
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