MCP6284-E/SN Microchip Technology, MCP6284-E/SN Datasheet - Page 14

• Manufacturer Part Number: MCP6284-E/SN
• Description: 450 uA, 5 MHz Rail-to-Rail Op Amp
• Manufacturer: Microchip Technology

MCP6281/2/3/4/5
3.8.3.4
Figure 3-13 shows a buffered non-inverting integrator
with chip select. Op amp A is configured as a non-
inverting integrator. In this configuration, matching the
impedance at each input is recommended. R
to provide a feedback loop at frequencies << 1/(2 RC).
Op amp B is used to isolate the load from the integrator.
FIGURE 3-13:
Integrator with Chip Select Circuit.
3.8.3.5
Figure 3-14 uses an active compensator (op amp B) to
compensate for the non-ideal characteristics introduced
at higher frequency integration. The alternative is to use
a passive element such as a resistor for compensation.
However, the quality of compensation would not be
constant since the AC characteristics of an amplifier
varies over temperature and process. This circuit uses
op amp B as a unity-gain buffer to isolate the integration
capacitor C
with low impedance source. Since both amplifiers are
matched very well, it provides higher quality of
integration.
FIGURE 3-14:
Compensation.
DS21811C-page 14
V
IN
V
IN
R
1
R
R
1
1
1
from op amp A and drives the capacitor
Buffered Non-inverting Integrator
Integrator with Active Compensation
and a Chip Select
C
1
A1
C
R
A
1
C
f
1
Buffered Non-inverting
Integrator Circuit with Active
CS
MCP6285
CS
MCP6285
B
A2
V
f
OUT
is used
V
OUT
3.8.3.6
Figure 3-15 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 3-15:
Feedback Low-Pass Filter with an Extra Pole-
Zero Pair and a Chip Select.
3.8.3.7
Figure 3-16 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 3-16:
Low-Pass Filter with an Extra Pole-Zero Pair and
a Chip Select.
V
V
IN
IN
R
R
C
4
3
2
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
 2004 Microchip Technology Inc.
A
A
1
1
3
MCP6285
and R
MCP6285
3
and R
CS
R
R
CS
6
5
5
.
6
®
.
C
software from
C
B
B
3
3
®
software
V
V
OUT
OUT