Datasheet

Detailed Description
Featuring a maximized ratio of gain bandwidth to supply
current, low operating supply voltage, low input bias cur-
rent, and rail-to-rail inputs and outputs, the MAX9914–
MAX9917 are an excellent choice for precision or gen-
eral-purpose low-current, low-voltage, battery-powered
applications. These CMOS devices consume an ultra-low
20μA (typ) supply current and a 200μV (typ) offset volt-
age. For additional power conservation, the MAX9914/
MAX9917 feature a lowpower shutdown mode that
reduces supply current to 1nA (typ), and puts the ampli-
fiers’ output in a highimpedance state. These devices are
unity-gain stable with a 1MHz gain-bandwidth product
driving capacitive loads up to 30pF. The capacitive load
can be increased to 100pF when the amplifier is config-
ured for a 10V/V gain.
Rail-to-Rail Inputs and Outputs
The MAX9914–MAX9917 amplifiers all 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 supply rails, with
excellent common-mode rejection.
The MAX9914–MAX9917 are capable of driving the out-
put to within 5mV of both supply rails with a 100kΩ load.
These devices can drive a 5kΩ load with swings to within
60mV of the rails. Figure 1 shows no clipping at the output
voltage swing of the MAX9914–MAX9917 configured as a
unity-gain buffer powered from a single 3V supply.
Low Input Bias Current
The MAX9914–MAX9917 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 1GΩ).
Applications Information
Driving Capacitive Loads
The MAX9914–MAX9917 amplifiers are unity-gain stable
for loads up to 30pF. However, the capacitive load can be
increased to 100pF when the amplifier is configured for a
minimum gain of 10V/V.
Applications that require greater capacitive drive capabil-
ity should use an isolation resistor between the output and
the capacitive load (Figure 2). Also, in unity-gain applica-
tions with relatively small R
L
(about 5kΩ), the capacitive
load can be increased up to 100pF.
PIN
NAME FUNCTION
MAX9914 MAX9915 MAX9916 MAX9917
1 1 — — IN+ Noninverting Amplier Input
2 2 4 4 V
SS
Negative Supply Voltage
3 3 — — IN- Inverting Amplier Input
4 4 — — OUT Amplier Output
5 6 8 10 V
DD
Positive Supply Voltage
— 5 — —
SHDN
Shutdown
— — 1 1 OUTA Amplier Output Channel A
— — 2 2 INA- Inverting Amplier Input Channel A
— — 3 3 INA+ Noninverting Amplier Input Channel A
— — — 5
SHDNA
Shutdown Channel A
— — — 6
SHDNB
Shutdown Channel B
— — 5 7 INB+ Noninverting Amplier Input Channel B
— — 6 8 INB- Inverting Amplier Input Channel B
— — 7 9 OUTB Amplier Output Channel B
MAX9914–MAX9917 1MHz, 20μA, Rail-to-Rail
I/O Op Amps with Shutdown
www.maximintegrated.com
Maxim Integrated │ 9
Pin Description