MAX4412 Maxim, MAX4412 Datasheet - Page 10

• Manufacturer Part Number: MAX4412
• Description: The MAX4412 single and MAX4413 dual operational amplifiers are unity-gain-stable devices that combine high-speed performance, low supply current, and ultra-small packaging
• Manufacturer: Maxim

Select the gain-setting feedback (R
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
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
parallel combination of R
Low-Cost, Low-Power, Ultra-Small, 3V/5V, 500MHz
Single-Supply Op Amps with Rail-to-Rail Outputs
Figure 2. Isolation Resistance vs. Capacitive Load
10
Figure 1. Driving a Capacitive Load Through an Isolation
Resistor
______________________________________________________________________________________
Inverting and Noninverting Configurations
R
30
28
26
24
22
20
18
16
14
12
10
V
G
IN
R
0
BIN
ISOLATION RESISTANCE vs.
200
CAPACITIVE LOAD
F
400
C
and R
LOAD
R
F
(pF)
600
G
(Figures 3a and 3b):
F
S
800
F
= R
to be equal to the
) and input (R
R
ISO
1000
G
) using 1kΩ
C
V
L
OUT
G
)
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.
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.
Figure 3a. Noninverting Gain Configuration
Figure 3b. Inverting Gain Configuration
IN
IN
R
R
R
S
G
G
R
S
R S
GAIN
=
R F
R F
V
V
OUT
=
R
OUT
R
F
F
×
+
= [1+ (R
= (R
R
R
2
1
R G
R G
F
Video Line Driver
/ R
F
G
/ R
) V
G
IN
)] V
Active Filters
V
IN
OUT
V
OUT
R
O
R
0