General Description
The MAX4073 evaluation kit (EV kit) is an assembled
and tested PCB used to evaluate the MAX4073 high-
side current-sense amplifier, which is designed for low-
cost, compact, current-sense applications. The EV kit
has a 2V to 28V input common-mode sense-voltage
range that is independent of the supply voltage. The EV
kit comes assembled with the MAX4073F IC (internal
gain = 50V/V), but can also evaluate the MAX4073T/
MAX4073H (internal gains of 20/100, respectively) ICs.
Features
oHigh-Side Current Sensing
oMultiple Fixed Gains Available
20V/V (MAX4073T)
50V/V (MAX4073F)
100V/V (MAX4073H)
o3V to 28V Operating Supply (VCC)
o2V to 28V Common-Mode Range Independent of
Supply Voltage
oLead(Pb)-Free and RoHS Compliant
oFully Assembled and Tested
Evaluates: MAX4073F/MAX4073H/MAX4073T
MAX4073 Evaluation Kit
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Maxim Integrated Products
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19-4527; Rev 0; 3/09
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, C5 2
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
C2, C4, C7, C8 0 Not installed, capacitors (0603)
C3, C6 2
1µF ±10%, 50V X7R ceramic
capacitors (0805)
Murata GRM21BR71H105K
TDK C2012X7R1H105K
RS+, RS- 2 Test points
DESIGNATION QTY DESCRIPTION
R1 1
0.07Ω ±1% current-sense resistor
(1206)
Vishay/Dale WSL1206R0700FEB
R2, R3 0 Not installed, resistors—short
(PC trace) (0603)
U1 1
High-side current-sense amplifier
(5 SC70)
Maxim MAX4073FAXK+
— 1 PCB: MAX4073 Evaluation Kit+
SUPPLIER PHONE WEBSITE
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
TDK Corp. 847-803-6100 www.component.tdk.com
Vishay 402-564-3131 www.vishay.com
PART TYPE
MAX4073EVKIT+ EV Kit
+
Denotes lead(Pb)-free and RoHS compliant.
Note: Indicate that you are using the MAX4073 when contacting these component suppliers.
Evaluates: MAX4073F/MAX4073H/MAX4073T
MAX4073 Evaluation Kit
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Quick Start
Recommended Equipment
• 12V, 1A power supply (VBAT)
• 5V power supply (VCC)
• Electronic load capable of sinking 1A
• Digital voltmeter (DVM)
Procedure
The MAX4073 EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on power supplies until all
connections are completed.
1) Set the input power supply to 12V. Connect the
ground of the power supply to the GND pad and
connect the positive terminal to the VSOURCE pad.
2) Set the VCC power supply to 5V. Connect the
ground of the VCC supply to the GND pad and con-
nect the positive terminal to the VCC pad.
3) Set the electronic load to sink 1A.
4) Connect the electronic load’s ground to the GND
pad. Connect the load’s positive terminal to the
LOAD pad.
5) Connect the DVM across the OUT pad and the
GND pad.
6) Turn on the 5V power supply.
7) Turn on the 12V power supply.
8) Adjust the electronic load current (ISENSE) between
0A and 1A and verify that VOUT is proportional to
VSENSE according to the following equation:
VOUT = AVx VSENSE
where VSENSE = ISENSE x R1 and AVis the gain of
the device (50V/V for MAX4073F).
Detailed Description of Hardware
The MAX4073 EV kit is a current-sense amplifier that
measures the load current and provides an analog volt-
age output. The EV kit is installed with a MAX4073FAXK+,
which has a gain of 50V/V. With the installed current-
sense resistor (RSENSE) value of 0.07Ω, and a full-scale
ISENSE of 1A, the full-scale VSENSE is set to 70mV. The
VOUT is given by:
VOUT =A
Vx RSENSE x ISENSE
where ISENSE is the load current and AV is the gain of
the device. Set the full-scale output range by selecting
RSENSE and the appropriate gain version of the
MAX4073.
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 the OUT pad. Like all differential
amplifiers, the output voltage has two components of
error (an offset error and a gain error). The offset error
affects accuracy at low currents and the gain error
affects accuracy at large currents—both errors affect
accuracy at intermediate currents. By minimizing both
offset and gain errors, accuracy is optimized over a
wide dynamic range.
Evaluating Other Gain Versions
The MAX4073 EV kit can be used to evaluate other gain
versions of the MAX4073 (20V/V, 100V/V = T, H suffix).
Replace U1 with a different version of the MAX4073
and refer to
Table 1. Recommended Component
Values
in the MAX4073 IC data sheet for additional
information.
Evaluates: MAX4073F/MAX4073H/MAX4073T
MAX4073 Evaluation Kit
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Figure 1. MAX4073 EV Kit Schematic
Evaluates: MAX4073F/MAX4073H/MAX4073T
MAX4073 Evaluation Kit
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.
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_____________________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.
Figure 2. MAX4073 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX4073 EV Kit PCB Layout—Component Side
Figure 4. MAX4073 EV Kit PCB Layout—Solder Side
