MAX4493_08 Datasheet, PDF (7/15 Pages) Maxim Integrated Products – SC70, Low-Power, General-Purpose, Dual-Supply, Rail-to-Rail Op Amps

SC70, Low-Power, General-Purpose,
Dual-Supply, Rail-to-Rail Op Amps
MAX4493
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4
1
3
5
2
PIN
MAX4494
1
2
3
7
6
5
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8
4
MAX4495
1
2
3
7
6
5
8
9
10
14
13
12
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4
11
Applications Information
Rail-to-Rail Output Stage
The MAX4493/MAX4494/MAX4495 output stage can
drive up to 1kΩ and still swing within 200mV of the rails.
Capacitive-Load Stability
Driving large capacitive loads can cause instability in
many op amps. The MAX4493/MAX4494/MAX4495 are
INPUT
MAX4493
R_ISO
OUTPUT
C_L
Pin Description
NAME
FUNCTION
OUTA
INA-
INA+
OUTB
INB-
INB+
OUTC
INC-
INC+
OUTD
IND-
IND+
OUT
IN+
IN-
V_CC
V_EE
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
stable with capacitive loads up to 300pF. The
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:
Full-Power Bandwidth
[ ] ^{FPBW(Hz) =}
SR
π V_{OUTp−p(max)}
Figure 1. Capacitive Load Driving Circuit
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