MCP6232-E/SNG Microchip Technology, MCP6232-E/SNG Datasheet - Page 13

• Manufacturer Part Number: MCP6232-E/SNG
• Description: 1.8V, 200KHz DUAL LOW-COST CMOS OPERATIONAL AMPLIFIER, -40C to +125C, 8-SOIC 150mil, TUBE
• Manufacturer: Microchip Technology

4.7.2
In analog circuit design, the PCB parasitic capacitance
can compromise the circuit behavior;
a typical scenario. If the input of an amplifier sees
parasitic capacitance of several picofarad (C
which includes the common mode capacitance of 6 pF,
typical), and large R
of the circuit will include a zero. This parasitic zero
introduces gain-peaking and can cause circuit
instability.
FIGURE 4-9:
Capacitance at the Input.
One solution is to use smaller resistor values to push
the zero to a higher frequency. Another solution is to
compensate by introducing a pole at the point at which
the zero occurs. This can be done by adding C
parallel with the feedback resistor (R
selected so that the ratio C
of R
© 2008 Microchip Technology Inc.
V
V
F
AC
DC
:R
G
.
C
COMPENSATING FOR THE
PARASITIC CAPACITANCE
R
PARA
G
F
and R
Effect of Parasitic
MCP623X
+
–
PARA
R
C
G
F
F
, the frequency response
:C
C
F
F
is equal to the ratio
=
F
Figure 4-9
). C
C
PARA
F
V
needs to be
OUT
•
R
------ -
R
shows
G
F
PARA
F
in
,
MCP6231/1R/1U/2/4
DS21881D-page 13