MAX4270 Maxim, MAX4270 Datasheet - Page 14

• Manufacturer Part Number: MAX4270
• Description: The MAX4265–MAX4270 ultra-low distortion, voltage-feed-back op amps are capable of driving a 100Ω load while maintaining ultra-low distortion over a wide bandwidth
• Manufacturer: Maxim

Ultra-Low-Distortion, +5V,
400MHz Op Amps with Disable
be maintained using an amplifier with very low output
impedance at high frequencies. The combination of
high speed, fast slew rate, low noise, and a low and
stable distortion overload makes the MAX4265–
MAX4270 ideally suited for use as buffer amplifiers in
high-speed ADC applications.
The MAX4265–MAX4270 feature an active-low disable
mode that can be used to save power and place the
outputs in a high-impedance state. Drive DISABLE_ with
logic levels, or connect DISABLE_ to V
operation. In the dual versions (MAX4268/ MAX4269/
MAX4270), each individual op amp is disabled sepa-
rately, allowing the devices to be used in a multiplex
configuration. The supply current in low-power mode is
reduced to 1.6mA per amplifier. Enable time is typically
100ns, and disable time is typically 750µs.
Figure 3c. MAX4270 Small-Signal Gain vs. Frequency
Without Isolation Resistor
14
Figure 3a. MAX4268 Small-Signal Gain vs. Frequency
Without Isolation Resistor
______________________________________________________________________________________
-1
-2
-3
-4
-5
-6
-1
-2
-3
-4
-5
4
3
2
1
0
5
4
3
2
1
0
0.1M
0.1M
1M
1M
FREQUENCY (Hz)
Low-Power Disable Mode
FREQUENCY (Hz)
10M
10M
C
C
C
C
L
L
L
L
= 10pF
= 7.3pF
= 2.2pF
= 7.3pF
C
C
L
L
= 15pF
100M
100M
= 5.1pF
CC
1G
1G
for normal
Figure 2. MAX4265–MAX4270 Isolation Resistance vs.
Capacitive Load
Figure 4a. MAX4268 Small-Signal Gain vs. Frequency
With Isolation Resistor
Figure 3b. MAX4269 Small-Signal Gain vs. Frequency
Without Isolation Resistor
-1
-2
-3
-4
-5
5
4
3
2
1
0
20
15
10
-1
-2
-3
-4
-5
5
4
3
2
1
0
5
0
0.1M
0.1M
0
MAX4265/MAX4268
MAX4266/MAX4269
20
MAX4267/MAX4270
1M
1M
40
FREQUENCY (Hz)
FREQUENCY (Hz)
C
LOAD
10M
10M
60
C
L
(pF)
= 2.2pF
C
R
C
R
C
C
R
ISO
L
L
ISO
L
ISO
L
C
= 10pF
= 10pF
= 7.3pF
= 10pF
80
L
= 15Ω
= 18Ω
= 12Ω
100M
= 5.1pF
100M
100
1G
120
1G