MCP6284 MICROCHIP [Microchip Technology], MCP6284 Datasheet - Page 16

• Manufacturer Part Number: MCP6284
• Description: 450 ?A, 5 MHz Rail-to-Rail Op Amp
• Manufacturer: MICROCHIP [Microchip Technology]

MCP6281/1R/2/3/4/5
FIGURE 4-11:
Configuration.
4.9.3.3
Figure 4-12
amplifier with Chip Select. In this configuration, it is
recommended to use well-matched resistors (e.g.,
0.1%) 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 4-12:
4.9.3.4
Figure 4-13
is buffered and has a Chip Select input. Op amp A is
configured as a non-inverting integrator. In this config-
uration, matching the impedance at each input is
recommended. R
at frequencies << 1/(2πR
integrator (it has a finite gain at DC). Op amp B is used
to isolate the load from the integrator.
DS21811E-page 16
V
V
IN2
IN1
R
V
4
IN
R
R
R
2
2
1
shows op amp A configured as a difference
shows a lossy non-inverting integrator that
Difference Amplifier
Buffered Non-inverting Integrator
R
A
3
R
F
A
1
is used to provide a feedback loop
MCP6285
Cascaded Gain Circuit
Difference Amplifier Circuit.
MCP6285
1
CS
C
CS
R
1
R
4
) and makes this a lossy
2
R
R
B
1
B
3
V
V
OUT
OUT
FIGURE 4-13:
Integrator with Chip Select.
4.9.3.5
Figure 4-14
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 low-impedance source. Since both op amps are
matched very well, they provide a higher quality
integrator.
FIGURE 4-14:
Compensation.
4.9.3.6
Figure 4-15
pass filter with Chip Select. Use the FilterLab
from Microchip to determine the R and C values for the
op amp A’s second-order filter. Op amp B can be used
to add a pole-zero pair using C
V
IN
R
V
1
IN
C
R
1
1
R
R
=
2
1
1
(
uses an active compensator (op amp B) to
is a second-order multiple feedback low-
R
from op amp A and drives the capacitor
Inverting Integrator with Active
Compensation and Chip Select
Second-Order MFB Low-Pass Filter
with an Extra Pole-Zero Pair
C
2
1
||
R
A
C
F
R
A
)C
C
2
F
1
2
Buffered Non-inverting
Integrator Circuit with Active
CS
© 2008 Microchip Technology Inc.
MCP6285
CS
MCP6285
3
, R
6
B
, and R
B
7
®
.
V
software
OUT
V
OUT