MCP6002-E/SL Microchip Technology, MCP6002-E/SL Datasheet - Page 7

• Manufacturer Part Number: MCP6002-E/SL
• Description: 1 MHz Bandwidth Low Power Op Amp
• Manufacturer: Microchip Technology

3.0
The MCP6001/2/4 family of op amps is manufactured
using Microchip’s state-of-the-art CMOS process and
is specifically designed for low cost, low power and
general-purpose applications. The low supply voltage,
low quiescent current and wide bandwidth makes the
MCP6001/2/4 ideal for battery-powered applications.
This device has high phase margin, which makes it
stable for larger capacitive load applications.
3.1
The MCP6001/2/4 op amp is designed to prevent
phase reversal when the input pins exceed the supply
voltages. Figure 3-1 shows the input voltage exceeding
the supply voltage without any phase reversal.
FIGURE 3-1:
No Phase Reversal.
The input stage of the MCP6001/2/4 op amp uses two
differential input stages in parallel; one operates at low
common mode input voltage (V
high V
V
The
V
proper operation.
Input voltages that exceed the input voltage range
(V
sive current to flow into or out of the input pins. Current
beyond ±2 mA can cause reliability problems. Applica-
tions that exceed this rating must be externally limited
with a resistor, as shown in Figure 3-2.
CM
CM
2003 Microchip Technology Inc.
SS
up to 300 mV above V
= V
- 0.3V to V
-1
6
5
4
3
2
1
0
CM
Input
0.E+00
SS
APPLICATION INFORMATION
Rail-to-Rail Input
. With this topology, the device operates with
- 300 mV and V
1.E-05
Offset
DD
2.E-05
V
OUT
+ 0.3V at 25°C) can cause exces-
3.E-05
V
The MCP6001/2/4 Shows
IN
Time (10 µs/div)
Voltage
4.E-05
DD
5.E-05
DD
and 300 mV below V
+ 300 mV to ensure
CM
6.E-05
is
) and the other at
7.E-05
measured
8.E-05
V
G = +2 V/V
DD
= 5.0V
9.E-05
1.E-04
SS
at
.
FIGURE 3-2:
Resistor (R
3.2
The output voltage range of the MCP6001/2/4 op amp
is V
R
Refer to Figure 2-14 for more information.
3.3
Driving large capacitive loads can cause stability prob-
lems for voltage feedback op amps. As the load capac-
itance increases, the feedback loop’s phase margin
decreases, and the closed loop bandwidth is reduced.
This produces gain peaking in the frequency response,
with overshoot and ringing in the step response. A unity
gain buffer (G = +1) is the most sensitive to capacitive
loads, but all gains show the same general behavior.
When driving large capacitive loads with these op
amps (e.g., > 100 pF when G = +1), a small series
resistor at the output (R
feedback loop’s phase margin (stability) by making the
output load resistive at higher frequencies. It does not,
however, improve the bandwidth.
FIGURE 3-3:
stabilizes large capacitive loads.
To select R
(or step response overshoot) on the bench (or with the
MCP6001/2/4 Spice macro model). If the response is
reasonable, you do not need R
R
reasonable.
L
ISO
V
= 10 k
DD
IN
V
at 1 k
IN
- 25 mV (min.) and V
Rail-to-Rail Output
Capacitive Loads
R
R
IN
IN
ISO
is connected to V
IN
–
+
MCP600X
and modify its value until the response is
, check the frequency response peaking
).
------------------------------------------------------------------------------ -
R
V
--------------------------------------------------------------------------- -
Maximum expected V
IN
SS
–
MCP6001/2/4
Minimum expected V
Input Current Limiting
Output resistor, R
ISO
–
+
MCP600X
2 mA
2 mA
in Figure 3-3) improves the
SS
R
DD
+ 25 mV (max.) when
ISO
ISO
/2 and V
C
IN
. Otherwise, start
L
DS21733D-page 7
–
V
IN
DD
ISO
DD
V
V
OUT
= 5.5V.
OUT