MAX44265EVKIT# Maxim Integrated Products, MAX44265EVKIT# Datasheet - Page 2

• Manufacturer Part Number: MAX44265EVKIT#
• Description: Amplifier Modules & Development Tools MAX44265 Eval Kit
• Manufacturer: Maxim Integrated Products

Specifications of MAX44265EVKIT#

• Lead Free Status / Rohs Status: Details

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The EV kit is fully assembled and tested. Follow the steps
below to verify board operation:
1) Verify that the jumpers are in their default positions, as
2) Connect the positive terminal of the +5V supply to the
3) Connect the positive terminal of the precision voltage
4) Connect the DMM to monitor the voltage on the OUT
5) Turn on the +5V power supply.
6) Apply 100mV from the precision voltage source.
7) Apply 400mV from the precision voltage source. OUT
The MAX44265 EV kit provides a proven layout for the
MAX44265 low-power, MOS-input op amp. The device is
a single-supply op amp that is ideal for buffering sensor
signals. The Sallen-Key topology is easily accomplished
by changing and removing some components. The
Sallen-Key topology is ideal for buffering and filtering
sensor signals.
Table 1. Jumper Descriptions (JU1, JU2)
*Default position.
Detailed Description of Hardware
shown in Table 1.
VDD PCB pad and the negative terminal to the GND
PCB pad closest to VDD.
source to the IN+ PCB pad. Connect the negative
terminal of the precision voltage source to GND (GND
or IN- PCB pads).
PCB pad. With the 10kI feedback resistor (R5) and
1kI series resistor (R1), the gain is +11 (noninverting
configuration).
Observe the output at OUT on the DMM. OUT should
read approximately +1.1V.
should read approximately +4.4V.
MAX44265 EV kit
+5V, 10mA DC power supply (PS1)
Precision voltage source
Digital multimeter (DMM)
JUMPER
JU1
JU2
_________________________________________________________________ Maxim Integrated Products 2
SHUNT POSITION
Not installed
Required Equipment
Installed*
1-2*
2-3
Quick Start
Procedure
Connects the IN- PCB pad to GND.
Isolates the IN- PCB pad from GND.
Connects SHDN to VDD (normal operation).
Connects SHDN to GND (shutdown).
The device is a single-supply op amp that is ideal for
differential sensing, noninverting amplification, buffering,
and filtering. A few common configurations are detailed
in the next few sections.
The EV kit comes preconfigured as a noninverting ampli-
fier. The gain is set by the ratio of R5/R1. The EV kit comes
preconfigured for a gain of +11. For a voltage applied to
the IN+ PCB pad, the output voltage for the noninverting
configuration is given by the equation below:
where V
To configure the EV kit as a differential amplifier, replace R1,
R2, R
and R
mined by the matching of resistor ratios R1/R2 and R
where:
The Sallen-Key topology is ideal for filtering sensor
signals with a 2nd-order filter and acting as a buffer.
Schematic complexity is reduced by combining the filter
and buffer operations. The EV kit can be configured in
a Sallen-Key topology by replacing and populating a
few components. The Sallen-Key topology is typically
configured as a unity-gain buffer, which can be done
by replacing R1 and R5 with 0I resistors. The signal is
noninverting and applied to IN+. The filter component
pads are R2, R3, R4, and R8, where some have to be
populated with resistors and others with capacitors.
C3
C3
Evaluates: MAX44265
, and R5 with appropriate resistors. When R1 = R2
OS
= R5, the CMRR of the differential amplifier is deter-
V
OUT
= Input-referred offset voltage.
DESCRIPTION
V
=
OUT
Gain(V
Gain
=
(1
IN
+
=
+
R5
R1
R5
Op-Amp Configurations
R1
−
Noninverting Configuration
)(V
V
Sallen-Key Configuration
IN
=
IN
−
R
R2
) (1
+
C3
Differential Amplifier
+
+
V
+
OS
R5
R1
)
)V
OS
C3
/R5: