MCP6271 Microchip Technology, MCP6271 Datasheet - Page 15

• Manufacturer Part Number: MCP6271
• Description: 170 uA, 2 MHz Rail-to-Rail Op Amp
• Manufacturer: Microchip Technology

FIGURE 4-10:
Configuration.
4.8.3.3
Figure 4-11 shows op amp A configured as a difference
amplifier with Chip Select. In this configuration, it is
recommended that well-matched resistors (e.g., 0.1%)
be used to increase the Common Mode Rejection Ratio
(CMRR). Op amp B can be used to provide additional
gain and isolate the load from the difference amplifier.
FIGURE 4-11:
4.8.3.4
Figure 4-12 uses an active compensator (op amp B) to
compensate for the non-ideal op amp characteristics
introduced at higher frequencies. This circuit uses
op amp B as a unity-gain buffer to isolate the integration
capacitor C
with a low-impedance source. Since both op amps are
matched very well, they provide a high-quality
integrator.
 2004 Microchip Technology Inc.
V
V
IN2
IN1
R
V
4
IN
R
R
R
2
2
1
1
from op amp A and drives the capacitor
Difference Amplifier
Inverting Integrator with Active
Compensation and Chip Select
R
A
3
R
A
1
MCP6275
Cascaded Gain Circuit
Difference Amplifier Circuit.
MCP6275
CS
R
CS
R
4
2
R
R
B
1
3
B
V
V
OUT
OUT
FIGURE 4-12:
Compensation.
4.8.3.5
Figure 4-13 is a second-order multiple feedback low-
pass filter with Chip Select. Use the FilterLab
from Microchip to determine the R and C values for
op amp A’s second-order filter. Op amp B can be used
to add a pole-zero pair using C
FIGURE 4-13:
Feedback Low-Pass Filter with an Extra Pole-
Zero Pair.
V
IN
V
IN
R
C
3
2
R
MCP6271/2/3/4/5
1
R
Second-Order MFB with an extra
pole-zero pair
2
R
R
5
4
R
A
1
C
1
Integrator Circuit with Active
Second-Order Multiple
C
CS
A
1
MCP6275
3
MCP6275
, R
CS
R
6
6
B
and R
DS21810D-page 15
C
R
B
3
7
7
.
®
V
software
OUT
V
OUT