Datasheet

Power-Supply Considerations
The MAX9914–MAX9917 are optimized for single 1.8V
to 5.5V supply operation. A high amplifier power-supply
rejection ratio of 85dB (typ) allows the devices to be
powered directly from a battery, simplifying design and
extending battery life.
Power-Up Settling Time
The MAX9914–MAX9917 typically require 2μs after pow-
er-up. Supply settling time depends on the supply voltage,
the value of the bypass capacitor, the output imped-
ance of the incoming supply, and any lead resistance 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 mid-
supply. The output settles in approximately 3.5μs for V
DD
= 3V (see the Typical Operating Characteristics for the
Power-Up Settling Time graph).
Shutdown Mode
The MAX9915 and MAX9917 feature active-low shutdown
inputs. The MAX9915 and MAX9917 enter shutdown in
2μs (typ) and exit shutdown in 10μs (typ). The amplifiers’
outputs are high impedance in shutdown mode. Drive
SHDN low to enter shutdown. Drive SHDN high to enable
the amplifier. The MAX9917 dual amplifier features sepa-
rate shutdown inputs. Shut down both amplifiers for low-
est quiescent current.
Power-Supply Bypassing and Layout
Bypass V
DD
with a 0.1μF capacitor to ground as close to
the pin as possible to minimize noise.
Good layout techniques optimize performance by decreas-
ing the amount of stray capacitance and inductance to the
op amp’s inputs and outputs. Minimize stray capacitance
and inductance, by placing external components close to
the IC.
Figure 1. Rail-to-Rail Output Voltage Range
Figure 3. Power-Up Test Configuration
Figure 2. Using a Resistor to Isolate a Capacitive Load from
the Op Amp
RAIL-TO-RAIL OUTPUT VOLTAGE RANGE
200µs/div
3V
0V
3V
0V
IN_
1V/div
OUT_
1V/div
V
DD
= 3V
MAX9914–
MAX9917
R
ISO
C
L
R
L
A
V
= 1V/V
R
L
R
L
+ R
ISO
MAX991_
100kΩ
100kΩ
OUT
IN-
IN+
0V
5.5V
V
DD
V
SS
MAX9914–MAX9917 1MHz, 20μA, Rail-to-Rail
I/O Op Amps with Shutdown
www.maximintegrated.com
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