MAX4284 Maxim, MAX4284 Datasheet - Page 13

• Manufacturer Part Number: MAX4284
• Description: The MAX4174/MAX4175/MAX4274/MAX4275 GainAmp family combines a low-cost rail-to-rail op amp with precision internal gain-setting resistors and VCC/2 biasing
• Manufacturer: Maxim

Common op-amp configurations include both nonin-
verting and inverting amplifiers. Figures 5–8 show vari-
ous single and dual-supply circuit configurations.
Single-supply systems benefit from a midsupply bias
on the noninverting input (provided internally on
MAX4175/MAX4275), as this produces a quiescent DC
level at the center of the rail-to-rail output stage signal
swing. For dual-supply systems, ground-referenced
signals may be DC-coupled into the inverting or non-
inverting inputs.
Figure 4. Single-Supply, DC-Coupled Inverting Amplifier with
Negative Input Voltage
Figure 5. Dual-Supply, DC-Coupled Inverting Amplifier
V
IN
V
IN
R
G
R
G
______________________________________________________________________________________
GainAmp Signal Coupling
R
V
F
R
MAX4281
CC
V
MAX4174
V
F
CC
EE
and Configurations
V
V
CC
OUT
V
=
OUT
GainAmps/Open-Loop Op Amps
SOT23, Rail-to-Rail, Fixed-Gain
-R
R
= - V
F
G
(V
IN
IN
(
)
R
R
F
G
)
Internal resistor biasing of the V
ples power-supply noise directly to the op amp’s nonin-
verting input. To minimize high-frequency power-supply
noise coupling, add a 1µF to 0.1µF capacitor from IN+
to ground to create a lowpass filter (Figure 6). The low-
pass filter resulting from the internal bias resistors and
added capacitor can help eliminate higher frequency
power-supply noise coupling through the noninverting
input.
Figure 6. Single-Supply, AC-Coupled Inverting Amplifier
Figure 7. Dual-Supply, AC-Coupled Noninverting Amplifier
0.1 F
V
V
IN
IN
IN_+ Filter on MAX4175/MAX4275
R
R
B
B
R
R
G
G
V
CC
R
V
V
F
CC
EE
R
MAX4175
F
MAX4174
CC
/ 2 bias options cou-
V
OUT
V
OUT
=
V
= V
CC
2
IN
- V
(
1+
IN
R
R
(
F
G
R
R
)
F
G
13
)