MCP6271 Microchip Technology, MCP6271 Datasheet - Page 16

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

MCP6271/2/3/4/5
4.8.3.6
Figure 4-14 is a second-order Sallen-Key low-pass
filter with Chip Select. Use the Filterlab
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 4-14:
Low-Pass Filter with an Extra Pole-Zero Pair and
Chip Select.
DS21810D-page 16
V
IN
R
4
R
Second-Order Sallen-Key with an
Extra Pole-Zero Pair
R
C
3
2
1
C
Second-Order Sallen-Key
R
2
A
1
3
MCP6275
, R
R
CS
5
5
and R
®
software from
C
B
3
6
.
R
6
V
OUT
4.8.3.7
The low-pass filter shown in Figure 4-15 does not
require external capacitors and uses only three exter-
nal resistors; the op amp’s GBWP sets the corner fre-
quency. R
is used to set the Q. To avoid gain-peaking in the
frequency response, Q needs to be low (lower values
need to be selected for R
bandwidth varies greatly over temperature and
process. This configuration, however, provides a low-
cost solution for applications with high bandwidth
requirements.
FIGURE 4-15:
Low-Pass Filter with Chip Select.
V
V
REF
IN
R
2
1
and R
Capacitorless Second-Order
Low-Pass filter with Chip Select
A
2
are used to set the circuit gain. R
MCP6275
Capacitorless Second-Order
R
 2004 Microchip Technology Inc.
3
CS
3
). Note that the amplifier
R
B
1
V
OUT
3