MAX4494AKA-T Maxim, MAX4494AKA-T Datasheet - Page 7

• Manufacturer Part Number: MAX4494AKA-T
• Description: SC70 / Low-Power / General-Purpose / Dual-Supply / Rail-to-Rail Op Amps
• Manufacturer: Maxim

The MAX4493/MAX4494/MAX4495 output stage can
drive up to 1kΩ and still swing within 200mV of the rails.
Driving large capacitive loads can cause instability in
many op amps. The MAX4493/MAX4494/MAX4495 are
stable with capacitive loads up to 300pF. The
Figure 1. Capacitive Load Driving Circuit
MAX4493
INPUT
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—
—
—
—
—
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4
1
3
5
2
MAX4493
Applications Information
_______________________________________________________________________________________
Capacitive-Load Stability
Rail-to-Rail Output Stage
MAX4494
PIN
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1
2
3
7
6
5
8
4
SC70, Low-Power, General-Purpose,
R
ISO
Dual-Supply, Rail-to-Rail Op Amps
C
L
MAX4495
OUTPUT
—-
10
14
13
12
—
—
11
1
2
3
7
6
5
8
9
4
Capacitive-Load Stability graph in the Typical
Operating Characteristics gives the stable operation
region for capacitive versus resistive load. Stability with
higher capacitive loads can be improved by adding an
isolation resistor in series with the op-amp output, as
shown in Figure 1. This resistor improves the circuit’s
phase margin by isolating the load capacitor from the
amplifier’s output. As seen in the Typical Operating
Characteristics, driving capacitive loads with an isola-
tion resistor exhibits some overshoot, but no oscillation.
The FPBW is given by:
NAME
OUTA
OUTB
OUTC
OUTD
INA+
INB+
INC+
IND+
INA-
INB-
INC-
IND-
OUT
V
V
IN+
IN-
CC
EE
FPBW Hz
Channel A Output
Channel A Inverting Input
Channel A Noninverting Input
Channel B Output
Channel B Inverting Input
Channel B Noninverting Input
Channel C Output
Channel C Inverting Input
Channel C Noninverting Input
Channel D Output
Channel D Inverting Input
Channel D Noninverting Input
Output
Noninverting Input
Inverting Input
Positive Supply
Negative Supply
(
)
=
π
[
V
OUTp p
Full-Power Bandwidth
SR
FUNCTION
−
Pin Description
(max)
]
7