Evaluates: MAX9937 MAX9937 Evaluation Kit General Description Procedure The MAX9937 evaluation kit (EV kit) is an assembled and The MAX9937 EV kit is fully assembled and tested. Follow tested PCB used to evaluate the MAX9937 current-sense the steps below to verify board operation. Caution: Do amplifier, designed for unidirectional high-side current- not turn on power supplies until all connections are sense applications. The EV kit can be used to dem- completed. onstrate the applicability of the MAX9937 to withstand 1) Set the input power supply to 12V and connect the transients, such as load-dump protection, reverse-battery positive terminal to the VBAT PCB pad. Connect the protection, and filtering for EMI. ground of the power supply to the GND PCB pad. 2) Set the VCC power supply to 5V and connect the Features positive terminal to the VCC PCB pad. Connect the Reverse-Battery and Load-Dump Protection ground of the VCC supply to the GND pad. -20V to +40V 3) Set the electronic load to sink 2A. +4V to +28V Input Common-Mode Range 4) Connect the electronic loads positive terminal to the +2.7V to +5.5V Supply Range LOAD pad. Connect the loads ground to the GND Flexible EMI Filtering PCB pad. Lead(Pb)-Free and RoHS Compliant 5) Connect the DVM across the VOUT PCB pad and the GND pad. Fully Assembled and Tested 6) Turn on the 5V power supply. Quick Start 7) Turn on the 12V power supply. Recommended Equipment 8) Adjust the electronic load current (I ) between 0A LOAD Before beginning, the following equipment is needed: and 2A and verify that V is proportional to V OUT SENSE according to the following equation: 12V, 2A power supply (VBAT) 5V power supply (VCC) R2 VV OUT SENSE R3 Electronic load capable of sinking 2A Digital voltmeter (DVM) where V = I x R1. SENSE LOAD Ordering Information PART TYPE MAX9937EVKIT+ EV Kit *Denotes lead(Pb)-free and RoHS compliant. 19-4406 Rev 1 5/15 =Evaluates: MAX9937 MAX9937 Evaluation Kit Detailed Description of Hardware Component List The MAX9937 EV kit evaluates the MAX9937 DESIGNATION QTY DESCRIPTION unidirectional high-side current-sense amplifier, which 1F 10%, 50V X7R ceramic features a 4V to 28V input common-mode voltage range capacitor (1206) that is independent of supply voltage (VCC = 2.7V to C1 1 Murata GRM31MR71H105KA 5.5V). The MAX9937 monitors the current through a TDK C3216X7R1H105K current-sense resistor by converting the sense voltage to a voltage output (V ). Gain is set by the ratio of an output OUT C2, C4 0 Not installed, capacitors (0603) resistor (R2) and an input resistor (R3). High-side current 0.01F 10%, 50V X7R ceramic monitoring with the MAX9937 does not interfere with the capacitor (0603) ground path of the load, making it useful for a variety of C3 1 Murata GRM188R71H103K battery/ECU-monitoring applications. TDK C1608X7R1H103K The MAX9937 EV kit produces an output voltage (V ) OUT 0.05 1%, 0.5W current-sense given by the following equations: R1 1 resistor (1206) V I R IRC LRC-LR1206LF-01-R050-F SENSE LOAD SENSE R2 R2 1 20k 1% resistor (0603) VV OUT SENSE R3 R3, R4 2 1k 1% resistor (1206) where I is the current load applied to the device and Current-sense amplifier (5 SC70) LOAD U1 1 R is the current-sense resistor R1 (e.g., I Maxim MAX9937AXK+ SENSE LOAD = 2A, R = 0.05, R2 = 20k, R3 = 1k, and SENSE 1 PCB: MAX9937 EVALUATION KIT+ V = 2V). OUT Overvoltage Protection Component Suppliers The MAX9937 EV kit provides a 1k resistor at each of the SUPPLIER PHONE WEBSITE RSP and RSN inputs to demonstrate the reverse-battery and load-dump protection capabilities of the MAX9937 IRC, Inc. 361-992-7900 www.irctt.com IC. The normal operating V and V range is 4V to RSP RSN Murata Americas 770-436-1300 www.murataamericas.com 28V, but the robust input ESD structure allows the input TDK Corp. 847-803-6100 www.component.tdk.com common-mode voltages to exceed this range for short Note: Indicate that you are using the MAX9937 when contacting periods of time. these component suppliers. Short-duration overvoltages on the battery line (VBAT to LOAD) are isolated from the RSP and RSN pins of the MAX9937 by the use of input resistors R3 and R4. The input ESD clamp structure is designed so the device can withstand short-duration (< 1s) overvoltages up to 40V when using resistors R3 and R4 of 500 or greater. The circuit can also withstand a reverse-battery voltage of -20V. During reverse-battery conditions, size R3 and R4 input resistors to withstand their expected power dissipations. Refer to the Input Common-Mode Voltages > 28V and < 0V section in the MAX9937 IC data sheet for a more detailed description. EMI Filtering The MAX9937 EV kit provides two uninstalled capacitor pads (C2 and C4), which the user can populate to improve performance in the presence of input commonmode volt- age and input differential-voltage transients. Refer to the Flexible EMI Filtering section in the MAX9937 IC data sheet for a more detailed description. Maxim Integrated 2 www.maximintegrated.com = =