Single/Dual/Quad, Low-Cost, Single-Supply

7MHz, Rail-to-Rail Op Amps

6

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Detailed Description

Rail-to-Rail Output Stage

The MAX4484/MAX4486/MAX4487 can drive a 2k

Ω

load and still swing within 50mV of the supply rails.

Figure 1 shows the output swing of the MAX4484 con-

Driving Capacitive Loads

Driving a capacitive load can cause instability in many

op amps, especially those with low quiescent current.

The MAX4484/MAX4486/MAX4487 are unity-gain stable

for a range of capacitive loads up to 100pF. Figure 2

shows the response of the MAX4484 with an excessive

capacitive load. Adding a series resistor between the

output and the load capacitor (Figure 3) improves the

circuit’s response by isolating the load capacitance

from the op amp’s output.

Applications Information

Power Supplies and Layout

The MAX4484/MAX4486/MAX4487 operates from a sin-

gle +2.7V to +5.5V power supply. Bypass the power

supply with 0.1µF capacitor to ground.

Good layout techniques optimize performance by

decreasing the amount of stray capacitance at the op

amp’s inputs and outputs. To decrease stray capaci-

tance, minimize trace lengths by placing external com-

ponents close to the op amp’s pins. Use surface-mount

components for best results.

Pin Description

PIN

MAX4484

MAX4486

MAX4487

NAME

FUNCTION

3

——

IN-

Inverting Amplifier Input

1

——

IN+

Noninverting Amplifier Input

4

——

OUT

Amplifier Output

—

2

2

INA-

Inverting Amplifier Input (Channel A)

—

3

3

INA+

Noninverting Amplifier Input (Channel A)

—

1

1

OUTA

Amplifier Output (Channel A)

—

6

6

INB-

Inverting Amplifier Input (Channel B)

—

5

5

INB+

Noninverting Amplifier Input (Channel B)

—

7

7

OUTB

Amplifier Output (Channel B)

——

9

INC-

Inverting Amplifier Input (Channel C)

——

10

INC+

Noninverting Amplifier Input (Channel C)

——

8

OUTC

Amplifier Output (Channel C)

——

13

IND-

Inverting Amplifier Input (Channel D)

——

12

IND+

Noninverting Amplifier Input (Channel D)

——

14

OUTD

Amplifier Output (Channel D)

2

4

11

Negative Power-Supply Voltage

584

Positive Power-Supply Voltage