200kHz, 4µA, Rail-to-Rail

I/O Op Amps with Shutdown

10

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Power-Supply Considerations

The MAX9910–MAX9913 are optimized for single 1.8V

to 5.5V supply operation. A high amplifier power-supply

rejection ratio of 95dB (typ) allows the devices to be

powered directly from a battery, simplifying design and

extending battery life.

Power-Up Settling Time

The MAX9910–MAX9913 typically require 5µs after

power-up. Supply settling time depends on the supply

voltage, the value of the bypass capacitor, the output

impedance of the incoming supply, and any lead resis-

tance or inductance between components. Op-amp

settling time depends primarily on the output voltage

and is slew-rate limited. Figure 3 shows the MAX991_ in

a noninverting voltage follower configuration with the

input held at midsupply. The output settles in approxi-

Characteristics for power-up settling time).

Shutdown Mode

The MAX9911/MAX9913 feature active-low shutdown

inputs. The MAX9911/MAX9913 enter shutdown in 2µs

(typ) and exit in 30µs (typ). The amplifiers’ outputs are

in a high-impedance state in shutdown mode. Drive

SHDN low to enter shutdown. Drive SHDN high to

enable the amplifier. The MAX9913 dual-amplifier fea-

tures separate shutdown inputs. Shut down both ampli-

fiers for the lowest quiescent current.

Power-Supply Bypassing and Layout

to ground, as close to the pin as possible.

Good layout techniques optimize performance

by decreasing the amount of stray capacitance and

inductance to the op amps’ inputs and outputs.

Minimize stray capacitance and inductance by placing

external components close to the IC.

Figure 1. Rail-to-Rail Output Voltage Range

RAIL-TO-RAIL OUTPUT VOLTAGE RANGE

200

µs/div

IN_

3V

3V

0V

0V

1V/div

OUT_

1V/div

Figure 2. Using a Resistor to Isolate a Capacitive Load from

the Op Amp

MAX9910–

MAX9913

≈ 1V/V

Figure 3. Power-Up Test Configuration

MAX991_

100k

Ω

100k

Ω

OUT

IN-

IN+

0V

5.5V