General Description
The MAX4173 evaluation kit (EV kit) is a fully assembled
and tested surface-mount PCB that contains a
MAX4173TEUT+. The MAX4173 is a high-side, current-
sense amplifier with an input common-mode voltage
range that extends from 0 to 28V. The current-sense
amplifier provides an analog voltage output proportion-
al to the load current flowing through an external sense
resistor.
The 20V/V gain version of the MAX4173 (MAX4173TEUT+)
and a 150mΩsense resistor are installed on the board.
Other gain versions of the MAX4173 can be evaluated
by replacing the MAX4173TEUT+ with a MAX4173FEUT+
(50V/V) or a MAX4173HEUT+ (100V/V) and a user-sup-
plied, external sense resistor. The user can easily
match the full-scale sense voltage to the required out-
put-voltage range.
Features
oReal-Time Current Monitoring
oWide 0 to 28V Input Common-Mode Range
Independent of Operating Supply Voltage
o±0.5% Full-Scale Accuracy
oLead(Pb)-Free and RoHS Compliant
oFully Assembled and Tested
Evaluates: MAX4173
MAX4173 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4465; Rev 0; 2/09
Component List
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
Component Suppliers
DESIGNATION QTY DESCRIPTION
C1 1
0.1μF ±10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H104K
C2 1
4.7μF ±10%, 50V X7R ceramic
capacitor (1210)
Murata GRM32ER71H475K
C3, C4, C5 0 Not installed, ceramic capacitors
(1210)
C6 0
Not installed, ceramic capacitor
(0603)
R1 1
0.15 ±1%, current-sense resistor
(1206)
IRC LR1206LF-R150-F
DESIGNATION QTY DESCRIPTION
R2, R3, R4 0 Not installed, resistors—short
(PC trace) (0603)
RS+, RS- 2 Binding posts
TP1 1 Multipurpose test point, orange
TP2, TP4, TP6 3 Multipurpose test points, black
TP3, TP5 2 Multipurpose test points, red
U1 1
High-side current-sense amplifier
(6 SOT23)
Maxim MAX4173TEUT+
— 1 PCB: MAX4173 Evaluation Kit+
SUPPLIER PHONE WEBSITE
IRC, Inc. 361-992-7900 www.irctt.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
PART TYPE
MAX4173EVKIT+ EV kit
+
Denotes lead(Pb)-free and RoHS compliant.
Note: Indicate that you are using the MAX4173 when contacting these component suppliers.
Evaluates: MAX4173
MAX4173 Evaluation Kit
2 _______________________________________________________________________________________
Quick Start
Recommended Equipment
• One 12V, 2A power supply
• One electronic load capable of sinking 1A
• Two digital voltmeters (DVMs)
Procedure
The MAX4173 EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on the power supply or the
electronic load until all connections are completed.
1) Set the power supply to 12V and connect the posi-
tive terminal to test point TP3 (VCC) on the EV kit.
Connect the ground of the power supply to test
point TP4 (GND) on the EV kit.
2) Connect the positive terminal of the 12V power sup-
ply to binding post RS+ on the EV kit.
3) Set the electronic load to sink 1A.
4) Connect the positive terminal of the electronic load
to binding post RS- on the EV kit.
5) Connect the negative terminal of the electronic load
to the ground of the power supply.
6) Connect a voltmeter across test point TP5 (RS+)
and test point TP6 (RS-).
7) Connect the second voltmeter across test points
TP1 (OUT) and TP2 (GND).
8) Turn on the power supply.
9) Turn on the electronic load.
10) Verify that the first DVM reading is approximately
150mV and the second DVM is approximately 3V.
11) Adjust the electronic load current to between 1A
and 0A and verify that the reading of the second
DVM is approximately 20 times the reading of the
first DVM.
Detailed Description of Hardware
The MAX4173 IC is a current-sense amplifier that mea-
sures the load current and provides an analog voltage
output. The full-scale VSENSE is set to 150mV. The full-
scale ISENSE is set at 1A. They can be changed by
replacing current-sense resistor R1 to another appropri-
ate value.
Applying the VCC Power Supply and the
Load Power Supply
The MAX4173 EV kit is installed with a MAX4173TEUT+,
which has a gain of 20V/V. The current-sense resistor
value is 0.15Ω. The VOUT is given by:
VOUT = VSENSE x AV= ISENSE x 0.15 x 20
where VSENSE is the sense voltage, ISENSE is the load
current, and AVis the gain of the device.
Normal operating VCC is from 3V to 28V. RS+ and RS-
range is 0 to 28V.
Measuring the Load Current
The load current is measured as a voltage drop
(VSENSE) across an external sense resistor. This volt-
age is then amplified by the current-sense amplifier and
presented at its OUT pin.
The MAX4173 EV kit, which is assembled with the
MAX4173TEUT+, is designed with a full-scale sense
voltage drop of 150mV. For a typical 1A full-scale load
current, this results in the use of a 0.15Ωsense resistor
on the MAX4173 EV kit using the following equation:
For different full-scale sense voltage and full-scale
load-current arrangements, the equation above can be
used to determine the appropriate current-sense-
resistor values. Refer to the
Recommended Component
Values
section in the MAX4173 IC data sheet for further
guidance.
Evaluating the
MAX4173FEUT+/MAX4173HEUT+
The MAX4173 EV kit can also be used to evaluate other
gain versions of the MAX4173 (20V/V, 50V/V, 100V/V =
T, F, H suffix, respectively). Replace U1 with a different
version of the MAX4173 and refer to the
Recommended
Component Values
section in the MAX4173 IC data
sheet for additional information.
RV
I
SENSE FULL SCALE
LOAD FULL SCALE
1=__
__
Evaluates: MAX4173
MAX4173 Evaluation Kit
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Figure 1. MAX4173 EV Kit Schematic
Figure 2. MAX4173 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX4173 EV Kit PCB Layout—Component Side
Figure 4. MAX4173 EV Kit PCB Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4
___________________
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX4173
MAX4173 Evaluation Kit
