MCP617-I/SN Microchip Technology, MCP617-I/SN Datasheet - Page 17

• Manufacturer Part Number: MCP617-I/SN
• Description: IC OPAMP 2.3V DUAL R-R 8SOIC
• Manufacturer: Microchip Technology

Specifications of MCP617-I/SN

• Slew Rate: 0.08 V/µs
• Operating Temperature: -40°C ~ 85°C
• Amplifier Type: General Purpose
• Number Of Circuits: 2
• Output Type: Rail-to-Rail
• Gain Bandwidth Product: 190kHz
• Current - Input Bias: 15nA
• Voltage - Input Offset: 150µV
• Current - Supply: 19µA
• Current - Output / Channel: 17mA
• Voltage - Supply, Single/dual (±): 2.3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Op Amp Type: General Purpose
• No. Of Amplifiers: 2
• Bandwidth: 190kHz
• Supply Voltage Range: 2.3V To 5.5V
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Number Of Channels: 2
• Voltage Gain Db: 120 dB
• Common Mode Rejection Ratio (min): 80 dB
• Input Offset Voltage: 0.15 mV
• Operating Supply Voltage: 3 V, 5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: Details

4.4
Driving large capacitive loads can cause stability
problems for voltage feedback op amps. As the load
capacitance 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, though all gains show the
same general behavior.
When driving large capacitive loads with these op
amps (e.g., > 60 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. The
bandwidth will be generally lower than the bandwidth
with no capacitive load.
FIGURE 4-5:
stabilizes large capacitive loads.
Figure 4-6
different capacitive loads and gains. The x-axis is the
normalized load capacitance (C
circuit’s noise gain. For non-inverting gains, G
Signal Gain are equal. For inverting gains, G
1+|Signal Gain| (e.g., -1 V/V gives G
FIGURE 4-6:
for Capacitive Loads.
After selecting R
resulting frequency response peaking and step
response overshoot. Modify R
response is reasonable. Bench evaluation and
simulations with the MCP616/7/8/9 SPICE macro
model are helpful.
© 2008 Microchip Technology Inc.
10,000
1,000
V
100
10k
100
IN
1k
1.E-11
Capacitive Loads
10p
gives recommended R
Normalized Load Capacitance; C
MCP61X
ISO
1.E-10
for your circuit, double-check the
100p
Output Resistor, R
Recommended R
ISO
in
G
G
N
N
Figure
R
= +1
t +2
C
ISO
L
L
ISO
/G
1.E-09
N
1n
’s value until the
), where G
N
4-5) improves the
ISO
= +2 V/V).
L
/G
ISO
N
values for
V
ISO
(F)
OUT
N
1.E-08
Values
and the
N
10n
is the
N
is
4.5
The MCP618 is a single op amp with Chip Select (CS).
When CS is pulled high, the supply current drops to
50 nA (typical) and flows through the CS pin to V
When this happens, the amplifier output is put into a
high-impedance state. By pulling CS low, the amplifier
is enabled. The CS pin has an internal 5 MΩ (typical)
pull-down resistor connected to V
the CS pins is left floating.
voltage and supply current response to a CS pulse.
4.6
With this family of operational amplifiers, the power
supply pin (V
bypass capacitor (i.e., 0.01 µF to 0.1 µF) within 2 mm
for good high-frequency performance. It may use a bulk
capacitor (i.e., 1 µF or larger) within 100 mm to provide
large, slow currents. This bulk capacitor is not required
and can be shared with other analog parts.
4.7
An unused op amp in a quad package (MCP619)
should be configured as shown in
circuits prevent the output from toggling and causing
crosstalk. Circuits A sets the op amp at its minimum
noise gain. The resistor divider produces any desired
reference voltage within the output voltage range of the
op amp; the op amp buffers that reference voltage.
Circuit B uses the minimum number of components
and operates as a comparator, but it may draw more
current.
FIGURE 4-7:
V
DD
¼ MCP619 (A)
V
R
R
REF
1
2
MCP618 Chip Select (CS)
Supply Bypass
Unused Op Amps
=
DD
V
V
DD
DD
for single supply) should have a local
MCP616/7/8/9
⋅
------------------ -
R
1
Unused Op Amps.
R
+
2
V
R
Figure 1-1
REF
2
SS
, so it will go low if
Figure
DS21613C-page 17
¼ MCP619 (B)
shows the output
V
4-7. These
DD
SS
.