MCP6283 MICROCHIP [Microchip Technology], MCP6283 Datasheet - Page 15

• Manufacturer Part Number: MCP6283
• Description: 450 UA, 5 MHz Rail-to-Rail Op Amp
• Manufacturer: MICROCHIP [Microchip Technology]

4.8.3.4
Figure 4-12 shows a lossy non-inverting integrator that
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/(2 R
integrator (it has a finite gain at DC). Op amp B is used
to isolate the load from the integrator.
FIGURE 4-12:
Integrator with Chip Select.
4.8.3.5
Figure 4-13 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 low-impedance source. Since both op amps are
matched very well, they provide a higher quality
integrator.
FIGURE 4-13:
Compensation.
 2004 Microchip Technology Inc.
V
IN
R
V
1
IN
C
R
1
1
R
R
=
2
1
1
R
from op amp A and drives the capacitor
Buffered Non-inverting Integrator
Inverting Integrator with Active
Compensation and Chip Select
C
2
1
F
R
A
C
F
is used to provide a feedback loop
R
A
C
2
F
C
1
2
Buffered Non-inverting
Integrator Circuit with Active
CS
1
MCP6285
C
1
) and makes this a lossy
CS
MCP6285
B
B
V
OUT
V
OUT
4.8.3.6
Figure 4-14 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 the
op amp A’s second-order filter. Op amp B can be used
to add a pole-zero pair using C
FIGURE 4-14:
Feedback Low-Pass Filter with an Extra
Pole-Zero Pair.
4.8.3.7
Figure 4-15 is a second-order Sallen-Key low-pass
filter with Chip Select. Use the FilterLab
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
FIGURE 4-15:
Low-Pass Filter with an Extra Pole-Zero Pair and
Chip Select.
V
V
IN
IN
R
R
C
4
3
2
MCP6281/2/3/4/5
R
R
Second-Order MFB Low-Pass Filter
with an Extra Pole-Zero Pair
Second-Order Sallen-Key Low-Pass
Filter with an Extra Pole-Zero Pair
R
3
C
2
R
R
2
1
5
4
R
1
C
Second-Order Multiple
Second-Order Sallen-Key
R
C
2
A
A
1
1
3
, R
MCP6285
3
MCP6285
, R
5
CS
R
and R
R
CS
6
6
5
and R
DS21811D-page 15
®
6
C
R
software from
.
B
C
B
3
7
7
R
3
.
6
®
software
V
V
OUT
OUT