Ultra-Low-Distortion, Single-Supply,

300MHz Op Amps with Enable

12

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5

-5

0.1M

1M

10M

100M

1G

-3

FREQUENCY (Hz)

-1

1

3

2

0

-2

-4

4

Figure 3a. MAX4268 Small-Signal Gain vs. Frequency

Without Isolation Resistor

5

-5

0.1M

1M

10M

100M

1G

-3

FREQUENCY (Hz)

-1

1

3

2

0

-2

-4

4

Figure 3b. MAX4269 Small-Signal Gain vs. Frequency

Without Isolation Resistor

4

-6

0.1M

1M

10M

100M

1G

-4

FREQUENCY (Hz)

-2

0

2

1

-1

-3

-5

3

Figure 3c. MAX4270 Small-Signal Gain vs. Frequency

Without Isolation Resistor

5

-5

0.1M

1M

10M

100M

1G

-3

FREQUENCY (Hz)

-1

1

3

2

0

-2

-4

4

Ω

Ω

Ω

Figure 4a. MAX4268 Small-Signal Gain vs. Frequency

With Isolation Resistor

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 over load makes the MAX4265–

MAX4270 ideally suited for use as buffer amplifiers in

high-speed ADC applications.

Low-Power Disable Mode

The MAX4265–MAX4270 feature an active-high enable

pin that can be used to save power and place the out-

puts in a high-impedance state. Drive EN_ with logic

the dual versions (MAX4268/MAX4269/MAX4270),

each individual op amp is enabled separately, allowing

the devices to be used in a multiplex configuration. The

supply current in low-power mode is reduced to 1.6mA

per device. Enable time is typically 100ns, and disable

time is typically 750µs.

20

15

10

5

0

060

20

40

80

100

120

MAX4268

MAX4269

MAX4270

Figure 2. MAX4268/MAX4269/MAX4270 Isolation Resistance

vs. Capacitive Load