200kHz, 4µA, Rail-to-Rail

I/O Op Amps with Shutdown

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9

Detailed Description

Featuring a maximized ratio of GBW to supply current,

low operating supply voltage, low input bias current,

and rail-to-rail inputs and outputs, the MAX9910–

MAX9913 are an excellent choice for precision or gen-

eral-purpose, low-current, low-voltage, battery-powered

applications. These CMOS devices consume an ultra-

low 4µA (typ) supply current and a 200µV (typ) offset

voltage. For additional power conservation, the

MAX9911/MAX9913 feature a low-power shutdown

mode that reduces supply current to 1nA (typ), and

puts the amplifiers’ output in a high-impedance state.

These devices are unity-gain stable with a 200kHz

GBW product, driving capacitive loads up to 30pF. The

capacitive load can be increased to 250pF when the

amplifier is configured for a 10V/V gain.

Rail-to-Rail Inputs and Outputs

All of the MAX9910–MAX9913 amplifiers have a parallel-

connected n- and p-channel differential input stage that

allows an input common-mode voltage range that

extends 100mV beyond the positive and negative sup-

ply rails, with excellent common-mode rejection.

The MAX9910–MAX9913 are capable of driving the out-

put to within 5mV of both supply rails with a 100k

Ω

load. These devices can drive a 5k

Ω load with swings

to within 60mV of the rails. Figure 1 shows the output

voltage swing of the MAX9910–MAX9913 configured as

a unity-gain buffer powered from a single 3V supply.

Low Input Bias Current

The MAX9910–MAX9913 feature ultra-low 1pA (typ)

input bias current. The variation in the input bias current

is minimal with changes in the input voltage due to very

high input impedance (in the order of 1G

Ω).

Applications Information

Driving Capacitive Loads

The MAX9910–MAX9913 amplifiers are unity-gain sta-

ble for loads up to 30pF. However, the capacitive load

can be increased to 250pF when the amplifier is config-

ured for a minimum gain of 10V/V. Applications that

require greater capacitive-drive capability should use

an isolation resistor between the output and the capaci-

tive load (Figure 2). Also, in unity-gain applications with

Ω), the capacitive

load can be increased up to 200pF.

PIN

MAX9910

MAX9911

MAX9912

MAX9913

NAME

FUNCTION

11

——

IN+

Noninverting Amplifier Input

224

4

Negative Supply Voltage

33

——

IN-

Inverting Amplifier Input

44

——

OUT

Amplifier Output

568

10

Positive Supply Voltage

—5

—

—

SHDN

Shutdown

——

11

OUTA

Amplifier Output Channel A

——

22

INA-

Inverting Amplifier Input Channel A

——

33

INA+

Noninverting Amplifier Input Channel A

———

5

SHDNA

Shutdown Channel A

———

6

SHDNB

Shutdown Channel B

——

57

INB+

Noninverting Amplifier Input Channel B

——

68

INB-

Inverting Amplifier Input Channel B

——

79

OUTB

Amplifier Output Channel B

Pin Description