19-4527; Rev 0; 3/09 MAX4073 Evaluation Kit The MAX4073 evaluation kit (EV kit) is an assembled and tested PCB used to evaluate the MAX4073 highside current-sense amplifier, which is designed for lowcost, 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. Ordering Information PART TYPE MAX4073EVKIT+ Features o High-Side Current Sensing o Multiple Fixed Gains Available 20V/V (MAX4073T) 50V/V (MAX4073F) 100V/V (MAX4073H) o 3V to 28V Operating Supply (VCC) o 2V to 28V Common-Mode Range Independent of Supply Voltage o Lead(Pb)-Free and RoHS Compliant o Fully Assembled and Tested EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component List DESIGNATION QTY DESCRIPTION C1, C5 2 0.1F 10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H104K TDK C1608X7R1H104K C2, C4, C7, C8 0 Not installed, capacitors (0603) C3, C6 2 1F 10%, 50V X7R ceramic capacitors (0805) Murata GRM21BR71H105K TDK C2012X7R1H105K RS+, RS- 2 Test points DESIGNATION QTY DESCRIPTION R1 1 0.07 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+ Component Suppliers 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 Note: Indicate that you are using the MAX4073 when contacting these component suppliers. ________________________________________________________________ Maxim Integrated Products 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. 1 Evaluates: MAX4073F/MAX4073H/MAX4073T General Description Evaluates: MAX4073F/MAX4073H/MAX4073T MAX4073 Evaluation Kit Quick Start Detailed Description of Hardware Recommended Equipment The MAX4073 EV kit is a current-sense amplifier that measures the load current and provides an analog voltage output. The EV kit is installed with a MAX4073FAXK+, which has a gain of 50V/V. With the installed currentsense resistor (RSENSE) value of 0.07, and a full-scale ISENSE of 1A, the full-scale VSENSE is set to 70mV. The VOUT is given by: VOUT = AV x RSENSE x ISENSE * 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 connect 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 = AV x VSENSE where ISENSE is the load current and AV is the gain of the device. Set the full-scale output range by selecting R SENSE 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 voltage 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. where VSENSE = ISENSE x R1 and AV is the gain of the device (50V/V for MAX4073F). 2 _______________________________________________________________________________________ MAX4073 Evaluation Kit Evaluates: MAX4073F/MAX4073H/MAX4073T Figure 1. MAX4073 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX4073F/MAX4073H/MAX4073T MAX4073 Evaluation Kit 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 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 (c) 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.