MCP617-I/SN Microchip Technology, MCP617-I/SN Datasheet - Page 18

• 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

MCP616/7/8/9
4.8
In applications where low input bias current is critical,
Printed Circuit Board (PCB) surface leakage effects
need to be considered. Surface leakage is caused by
humidity, dust or other contamination on the board.
Under low humidity conditions, a typical resistance
between nearby traces is 10
cause 5 pA of current to flow, which is greater than the
MCP616/7/8/9
(1 pA, typical).
The easiest way to reduce surface leakage is to use a
guard ring around sensitive pins (or traces). The guard
ring is biased at the same voltage as the sensitive pin.
An example is shown below in
FIGURE 4-8:
for Inverting Gain.
1.
2.
DS21613C-page 18
Non-inverting Gain and Unity Gain Buffer:
a)
b)
Inverting Gain and Transimpedance gain (con-
vert current to voltage, such as photo detectors)
amplifiers:
a)
b)
PCB Surface Leakage
Connect the non-inverting pin (V
input with a wire that does not touch the
PCB surface.
Connect the guard ring to the inverting input
pin (V
common mode input voltage.
Connect the guard ring to the non-inverting
input pin (V
to the same reference voltage as the op
amp (e.g., V
Connect the inverting pin (V
with a wire that does not touch the PCB
surface.
Guard Ring
IN
–). This biases the guard ring to the
family’s
IN
DD
+). This biases the guard ring
Example Guard Ring Layout
/2 or ground).
V
bias
12
IN
– V
Ω. A 5V difference would
Figure
IN
current
+
IN
4-8.
–) to the input
V
SS
IN
+) to the
at
25°C
4.9
4.9.1
The MCP616/7/8/9 op amps are well suited to
amplifying small signals produced by low-impedance
sources/sensors. The low offset voltage, low offset
current and low noise fit well in this role.
shows a typical pre-amplifier connected to a low-
impedance source (V
FIGURE 4-9:
For the best noise and offset performance, the source
resistance R
resistances at the inputs are equal to minimize the
offset voltage caused by the input bias currents
(Section 4.2 “DC Offsets”). In this circuit, the DC gain
is 10 V/V, which will give a typical bandwidth of 19 kHz.
4.9.2
The two-op amp instrumentation amplifier shown in
Figure 4-10
of two input voltages, level-shifting it and gaining it to
the output. This configuration is best suited for higher
gains (i.e., gain > 3 V/V). The reference voltage (V
is typically at mid-supply (V
environment.
FIGURE 4-10:
Instrumentation Amplifier.
The key specifications that make the MCP616/7/8/9
family appropriate for this application circuit are low
input bias current, low offset voltage and high common-
mode rejection.
V
V
REF
S
V
V
2
1
V
V OUT
Application Circuits
10 kΩ
DD
R
R
HIGH GAIN PRE-AMPLIFIER
/2
TWO OP AMP INSTRUMENTATION
AMPLIFIER
serves the function of taking the difference
S
1
S
=
needs to be less than 15 kΩ. The DC
(
11.0 kΩ
V 1 V 2
R
R
–
MCP617
G
S
2
High Gain Pre-amplifier.
Two-Op Amp
and R
R
½
© 2008 Microchip Technology Inc.
) 1
G
⎛
⎜
⎝
+
R
R 1
------
R 2
S
DD
MCP616
).
2
/2) in a single-supply
+
100 kΩ
2R 1
--------- -
R G
R
F
⎞
⎟
⎠
R
MCP617
+
1
V REF
½
Figure 4-9
V
V
OUT
OUT
REF
)