MCP6273T-E/SL Microchip Technology, MCP6273T-E/SL Datasheet - Page 14

• Manufacturer Part Number: MCP6273T-E/SL
• Description: 170 uA, 2 MHz Rail-to-Rail Op Amp
• Manufacturer: Microchip Technology

MCP6271/2/3/4/5
FIGURE 3-11:
Configuration.
3.8.3.3
Figure 3-12 shows op amp A configured as a difference
amplifier with chip select. In this configuration, it is
recommended that well-matched resistors (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 3-12:
3.8.3.4
Figure 3-13 uses an active compensator (op amp B) to
compensate for the non-ideal characteristics intro-
duced at higher frequency integration. The alternative
is to use a passive element (such as a resistor) for com-
pensation. However, the quality of compensation would
not be constant since the AC characteristics of an
amplifier vary over temperature and process. This
circuit uses op amp B as a unity-gain buffer to isolate
the integration capacitor C
the capacitor with a low-impedance source. Since both
amplifiers are matched very well, it provides a higher
quality of integration.
DS21810C-page 14
V
V
IN2
IN1
R
V
4
IN
R
R
R
2
2
1
Difference Amplifier
Integrator with Active Compensation
and a Chip Select
R
A
3
R
A
1
MCP6275
Cascaded Gain Circuit
Difference Amplifier Circuit.
MCP6275
CS
1
R
CS
from op amp A and drives
R
4
2
R
R
B
1
3
B
V
V
OUT
OUT
FIGURE 3-13:
Compensation.
3.8.3.5
Figure 3-14 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 3-14:
Feedback Low-Pass Filter with an Extra Pole-
Zero Pair and Chip Select.
V
IN
V
IN
R
C
3
2
R
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
CS
C
 2004 Microchip Technology Inc.
A
1
MCP6275
3
and R
MCP6275
CS
R
6
B
6
.
C
B
3
®
V
software
OUT
V
OUT