Evaluates: MAX4080/MAX4081 19-3102 Rev 0 12/07 MAX4080 Evaluation Kit General Description Features The MAX4080 evaluation kit (EV kit) is a fully assembled Real-Time Current Monitoring and tested surface-mount printed-circuit board (PCB) Wide 4.5V to 76V Input Common-Mode Range that contains a MAX4080SAUA (8-pin MAX ) IC. The Independent of Operating Supply Voltage MAX4080 is a high-side, current-sense amplifier with an input common-mode voltage range that extends from Bidirectional or Unidirectional I SENSE 4.5V to 76V. The current-sense amplifier provides an 0.1% Full-Scale Accuracy analog voltage output proportional to the load current flowing through an external sense resistor. 8-Pin MAX Package The EV kit can also be used to evaluate the MAX4081, Fully Assembled and Tested which is a bidirectional version of the current-sense amplifier. The MAX4081s single output pin continuously Ordering Information monitors the transition from charge to discharge and avoids the need for a separate polarity output pin. The PART TYPE MAX4081 requires an external reference to set the zero- MAX4080EVKIT+ EV Kit current output level (V = 0V). Charging current is SENSE +Denotes lead-free and RoHS-compliant. represented by an output voltage from V to V , REF CC while discharge current is given from V to GND. REF Component List All gain versions of the MAX4080 and MAX4081 are footprint-compatible and the MAX4080SAUA can easily DESIGNATION QTY DESCRIPTION be replaced by a MAX4080FAUA, MAX4080TAUA, 4.7F 10%, 100V X5R ceramic MAX4081FAUA, MAX4081TAUA, or MAX4081SAUA. C1 1 capacitor (2220) With a combination of three gain versions (5V/V, 20V/V, TDK C5750X5R2A475M 60V/V = F, T, S suffix) and a user-selectable, external sense resistor, the user can easily match the full-scale 0.1F 10%, 100V X5R ceramic load current to the required output-voltage range. C2 1 capacitor (1206) For maximum versatility, these parts can operate with TDK C3216X5R2A104K 76V input common-mode voltage at RS+ and RS- pins, Not installed, ceramic capacitors independent of operating supply voltage (V ) used. CC C3, C4, C5 0 (1206) These parts also allow a large differential voltage between RS+ and RS- pins for high reliability. High-side 0.1F 10%, 25V X5R ceramic current monitoring does not interfere with the ground C6, C7 2 capacitors (0603) path of the load being measured, making the TDK C1608X5R1E104K MAX4080/MAX4081 particularly useful in a wide range Not installed, ceramic capacitor of high-voltage systems. C8 0 (0603) JU1, JU2 2 3-pin headers 0.1 1% current-sense resistor R1 1 (1206) IRC LRC-LR1206LF-01-R100-F Not installed, resistorsshort (PC R2, R3, R4 0 trace) (0603) Maxim high-side, current-sense U1 1 amplifier with voltage output MAX4080SAUA+ (8-pin MAX) 2 Shunts MAX is a registered trademark of Maxim Integrated Products, 1 PCB: MAX4080 Evaluation Kit+ Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX4080 Evaluation Kit 9) Turn on the power supply. Component Suppliers 10) Turn on the electronic load. SUPPLIER PHONE WEBSITE 11) Verify that the first DVM reading is approximately IRC, Inc. 361-992-7900 www.irctt.com 100mV and the second DVM is approximately 6V. TDK Corp. 847-803-6100 www.component.tdk.com 12) Adjust the electronic load current to between 1A Note: Indicate that you are using the MAX4080 or MAX4081 and 0A and verify that the reading of the second when contacting these component suppliers. DVM is about 60 times the reading of the first DVM. Quick Start Detailed Description Recommended Equipment The MAX4080 EV kit is a current-sense amplifier that Before beginning, the following equipment is needed: measures the load current and provides an analog volt- age output. The full-scale V is set to 100mV. The SENSE One 12V, 1A power supply full-scale I is set at 1A. They can be changed by SENSE One electronic load capable of sinking 1A replacing current-sense resistor R1 to another appropri- Two digital voltmeters (DVMs) ate value. Procedure Applying the V Power Supply and the CC The MAX4080 EV kit is fully assembled and tested. Load Power Supply Follow the steps below to verify board operation. The EV kit is installed with a MAX4080SAUA, which has Caution: Do not turn on the power supply or the a gain of 60. The current-sense-resistor value is 0.1. electronic load until all connections are completed. The V is given by: OUT 1) MAX4081 only: Verify that a shunt is installed across pins 1-2 of jumper JU1. VV=A=I 01. 60 OUT SENSE V SENSE 2) MAX4081 only: Verify that a shunt is installed across pins 1-2 of jumper JU2. where V is the sense voltage, I is the load SENSE SENSE 3) Set the power supply to 12V and connect the posi- current, and A is the gain of the device. V tive terminal to the VCC pad. Connect the ground of Note: Output voltage is internally clamped not to the power supply to the GND pad closest to the exceed 18V. VCC pad. Normal operating V , V , and V range is CC SENSE+ SENSE- 4) Connect the VCC pad and the VSENSE+ pad. 4.5V to 76V. 5) Set the electronic load to sink 1A. Measuring the Load Current 6) Connect the electronic loads positive terminal to The load current is measured as a voltage drop the VSENSE- pad. Connect the loads ground to the (V ) across an external sense resistor. This volt- SENSE GND pad closest to the VCC pad. age is then amplified by the current-sense amplifier and 7) Connect a voltmeter across the VSENSE+ and presented at its OUT pin. Like all differential amplifiers, VSENSE- pads. (Note that this voltmeter measure- the output voltage has two components of error (an off- ment will not accurately reflect actual sense voltage set error and a gain error). The offset error affects accu- across the sense resistor due to voltage drop in the racy of measurement at low currents and a gain error trace and in the connectors. Accurate measurement affects output accuracy at large currentsboth errors of sense voltage across low-value sense resistors affect accuracy of measurement at intermediate cur- requires the use of 4-wire Kelvin-connected sense rents. By minimizing both offset and gain errors, accu- resistors. The EV kit board shows one example of rate measurements can be obtained from the good layout practice by which RS+ and RS- of the MAX4080/MAX4081 over a wide dynamic range. current-sense amplifier can connect to commonly available 2-wire sense resistors.) 8) Connect the second voltmeter across the VOUT pad and the closest GND pad. 2 Evaluates: MAX4080/MAX4081