Datasheet
MAX4412/MAX4413
Low-Cost, Low-Power, Ultra-Small, 3V/5V, 500MHz
Single-Supply Op Amps with Rail-to-Rail Outputs
10 ______________________________________________________________________________________
Inverting and Noninverting Configurations
Select the gain-setting feedback (R
F
) and input (R
G
)
resistor values that best fit the application. Large resis-
tor values increase voltage noise and interact with the
amplifier’s input and PC board capacitance. This can
generate undesirable poles and zeros and decrease
bandwidth or cause oscillations. For example, a nonin-
verting gain-of-two configuration (R
F
= R
G
) using 1kΩ
resistors, combined with 1.8pF of amplifier input capac-
itance and 1pF of PC board capacitance, causes a
pole at 114MHz. Since this pole is within the amplifier
bandwidth, it jeopardizes stability. Reducing the 1kΩ
resistors to 100Ω extends the pole frequency to
1.14GHz, but could limit output swing by adding 200Ω
in parallel with the amplifier’s load resistor.
Note: For high-gain applications where output offset
voltage is a consideration, choose R
S
to be equal to the
parallel combination of R
F
and R
G
(Figures 3a and 3b):
Video Line Driver
The MAX4412/MAX4413 are designed to minimize dif-
ferential gain error and differential phase error to 0.01%/
0.03° respectively, making them ideal for driving video
loads.
Active Filters
The low distortion and high bandwidth of the
MAX4412/MAX4413 make them ideal for use in active
filter circuits. Figure 4 is a 15MHz lowpass, multiple-
feedback active filter using the MAX4412.
GAIN
R
R
=
2
1
R
S
R
F
R
G
R
F
R
G
=
×
+
V
OUT
V
OUT
= [1+ (R
F
/ R
G
)] V
IN
IN
R
F
R
0
R
G
R
S
Figure 3a. Noninverting Gain Configuration
V
OUT
IN
R
S
R
F
R
O
R
G
V
OUT
= (R
F
/ R
G
) V
IN
Figure 3b. Inverting Gain Configuration
V
OUT
V
IN
R
BIN
R
ISO
R
F
C
L
R
G
Figure 1. Driving a Capacitive Load Through an Isolation
Resistor
Figure 2. Isolation Resistance vs. Capacitive Load
10
16
14
12
18
20
22
24
26
28
30
0 400200 600 800 1000
ISOLATION RESISTANCE vs.
CAPACITIVE LOAD
MAX4412 toc29
C
LOAD
(pF)
R
ISO
(Ω)