10

Maxim Integrated

MAX44244/MAX44245/MAX44248

36V, Precision, Low-Power, 90µA,

Single/Quad/Dual Op Amps

Pin Description

Detailed Description

The MAX44244/MAX44245/MAX44248 are high-precision

amplifiers with less than 2FV (typ) input-referred

offset and low input voltage-noise density at 10Hz.

1/f noise, in fact, is eliminated to improve the performance

in low-frequency applications. These characteristics are

achieved through an auto-zeroing technique that cancels

the input offset voltage and 1/f noise of the amplifier.

External Noise Suppression in EMI Form

These devices have input EMI filters to prevent effects

of radio frequency interference on the output. The EMI

filters comprise passive devices that present significant

higher impedance to higher frequency signals. See the

EMIRR vs. Frequency graph in the Typical Operating

Characteristics section for details.

High Supply Voltage Range

The devices feature 90µA current consumption per chan-

nel and a voltage supply range from either 2.7V to 36V

single supply or ±1.35V to ±18V split supply.

Applications Information

The devices feature ultra-high precision operational

amplifiers with a high supply voltage range designed

for load cell, medical instrumentation, and precision

instrument applications.

4–20mA Current-Loop Communication

Industrial environments typically have a large amount of

broadcast electromagnetic interference (EMI) from high-

voltage transients and switching motors. This combined

with long cables for sensor communication leads to

high-voltage noise on communication lines. Current-Loop

communication is resistant to this noise because the EMI

induced current is low. This configuration also allows for

low-power sensor applications to be powered from the

communication lines.

The Typical Operating Circuit shows how the device can

be used to make a current loop driver.

The circuit uses low-power components such as the

MAX44244 op amp, the 16-bit MAX5216 DAC, and the

high-precision 60µA-only MAX6033 reference. In this

PIN

NAME

FUNCTION

MAX44244

MAX44245

MAX44248

SOT23

µMAX

SO-14

TSSOP

SO-8

µMAX

1

6

1

1

1

1

OUTA

Channel A Output

2

4

11

11

4

4

Negative Supply Voltage

3

3

3

3

3

3

INA+

Channel A Positive Input

4

2

2

2

2

2

INA-

Channel A Negative Input

5

7

4

4

8

8

Positive Supply Voltage

—

—

5

5

5

5

INB+

Channel B Positive Input

—

—

6

6

6

6

INB-

Channel B Negative Input

—

—

7

7

7

7

OUTB

Channel B Output

—

—

8

8

—

—

OUTC

Channel C Output

—

—

9

9

—

—

INC-

Channel C Negative Input

—

—

10

10

—

—

INC+

Channel C Positive Input

—

—

12

12

—

—

IND+

Channel D Positive Input

—

—

13

13

—

—

IND-

Channel D Negative Input

—

—

14

14

—

—

OUTD

Channel D Output

—

1, 5, 8

—

—

—

—

N.C.

No Connection. Not internally

connected.