MAX9922 MAX9923 MAX9923T MAX9923H MAX9923F MAX9922/MAX9923 MAX9922EVKIT - Datasheet Archive
MAX9922 Evaluation Kit The MAX9922 evaluation kit (EV kit) is a fully assembled and tested PCB used to evaluate the MAX9922 and
19-4487; Rev 0; 3/09 MAX9922 MAX9922 Evaluation Kit The MAX9922 MAX9922 evaluation kit (EV kit) is a fully assembled and tested PCB used to evaluate the MAX9922 MAX9922 and MAX9923 MAX9923 ultra-precision, high-side current-sense amplifiers. An ultra-low offset voltage (VOS) of 10µV (max) allows accurate measurement of currents at both extremes of sense voltages (VSENSE), from 10mV to 100mV. The EV kit has a 1.9V to 28V input commonmode sense voltage range that is independent of the 2.85V to 5.5V VDD supply. The MAX9922 MAX9922 EV kit comes assembled with the MAX9922 MAX9922 IC with adjustable gain, but can also evaluate the MAX9923 MAX9923 ICs with fixed gains of 25V/V (MAX9923T MAX9923T), 100V/V (MAX9923H MAX9923H), and 250V/V (MAX9923F MAX9923F). The MAX9922/MAX9923 MAX9922/MAX9923 are capable of both unidirectional and bidirectional operation. Features o Bidirectional or Unidirectional Current Sensing o Shutdown Logic Input Control o Multiple Gains Available Adjustable (MAX9922 MAX9922) 25V/V (MAX9923T MAX9923T) 100V/V (MAX9923H MAX9923H) 250V/V (MAX9923F MAX9923F) o 2.85V to 5.5V Supply Range (VDD) o 1.9V to 28V Input Common-Mode Range Independent of VDD o Lead(Pb)-Free and RoHS Compliant o Fully Assembled and Tested Ordering Information PART TYPE MAX9922EVKIT MAX9922EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component List COMPONENT C1 C2, C7 C3, C4, C5, C8 C6 QTY 1 2 DESCRIPTION 4.7µF ±10%, 6.3V X5R ceramic capacitor (0603) Murata GRM188R70J475K GRM188R70J475K TDK C1608X5R0J475K C1608X5R0J475K 0.1µF ±10%, 25V X7R ceramic capacitors (0603) TDK C1608X7R1E104K C1608X7R1E104K Murata GRM188R71E104K GRM188R71E104K 0 1 QTY R2 1 249k ±0.1% resistor (0603) R3 1 1k ±0.1% resistor (0603) JU1, JU2 2 2-pin headers JU3 1 3-pin header R1 1 DESCRIPTION R4 1 100k ±5% resistor (0603) R5, R6 2 1k ±5% resistors (0603) R7, R8, R9 0 Not installed, resistors-short PC trace (0603) SHDN 1 Test point Keystone 5000 U1 1 High-side current-sense amplifier (10 µMAX®) Maxim MAX9922EUB MAX9922EUB+ Not installed, capacitors (0603) 1000pF ±10%, 50V X7R ceramic capacitor (0603) Murata GRM1885C1H102J GRM1885C1H102J TDK C1608X7R1H102K C1608X7R1H102K COMPONENT - 3 Shunts - 1 PCB: MAX9922/3 MAX9922/3 Evaluation Kit+ 0.1 ±1% current-sense resistor (1206) IRC LRC-LR1206LF-01-R100-F LRC-LR1206LF-01-R100-F µMAX is a registered trademark of Maxim Integrated Products, Inc. _ 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: MAX9922/MAX9923 MAX9922/MAX9923 General Description Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 MAX9922 MAX9922 Evaluation Kit Component Suppliers SUPPLIER PHONE WEBSITE IRC, Inc. 361-992-7900 www.irctt.com Keystone Electronics Corp. 209-796-2032 www.keyelco.com Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the MAX9922 MAX9922 when contacting these component suppliers. Quick Start Detailed Description of Hardware Recommended Equipment The MAX9922 MAX9922 EV kit is a current-sense amplifier that measures the load current and provides an analog voltage output. The EV kit comes assembled with the MAX9922 MAX9922 IC, which allows adjustable gain with a pair of external resistors (R2 and R3) between OUT, FB, and REF. The EV kit is configured for bidirectional current sensing. The output voltage (VOUT) is given by the following equation: · 12V, 100mA power supply (VSOURCE) · 3.3V power supply (VDD) · Electronic load capable of sinking 100mA · Digital voltmeter (DVM) Procedure The MAX9922 MAX9922 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. R2 VOUT = RSENSE × 1 + × ISENSE + VREF R3 1) Verify that all jumpers (JU1, JU2, and JU3) are in their default positions, as shown in Tables 1, 2, and 3. where RSENSE = 0.1, ISENSE = load current, and VREF = VDD/2. For unidirectional operation, the output voltage (VOUT) is given by the following equation: 2) Set the input power supply to 12V. Connect the ground of the power supply to the PGND pad, and connect the positive terminal to the VSOURCE pad. R2 VOUT = RSENSE × 1 + × ISENSE R3 3) Set the VDD power supply to 3.3V. Connect the ground of the VDD supply to the GND pad and connect the positive terminal to the VDD pad. 4) Set the electronic load to sink 100mA. 5) Connect the load's ground to the GND pad. Connect the electronic load's positive terminal to the LOAD pad. 6) Connect the DVM across the VOUT pad and the GND pad. 7) Turn on the 3.3V power supply. 8) Turn on the 12V power supply. 9) Adjust the electronic load current (ISENSE) between 0A and 100mA and verify that VOUT is proportional to VSENSE according to the following equation: R2 VOUT = RSENSE × 1 + × ISENSE + VREF R3 Shutdown Input Control The MAX9922 MAX9922 EV kit features 2-pin jumper JU1 to control the logic shutdown input. For normal operation, remove the shunt from jumper JU1 to drive SHDN high. To place the device in shutdown mode, drive SHDN low by placing a shunt across the JU1 pins. Table 1 summarizes jumper JU1's function. Table 1. Jumper JU1 Function (SHDN) SHUNT POSITION SHDN PIN MODE Installed Connected to GND Shutdown mode Not installed* Connected to VDD through pullup resistor R4 Normal operation *Default position. where RSENSE = R1 and VREF = VDD/2. 2 _ MAX9922 MAX9922 Evaluation Kit SHUNT POSITION REF PIN OPERATION Installed Connected to GND Unidirectional Not installed* Set to VDD/2 Bidirectional *Default position. Table 3. Jumper JU3 Function (RSB) SHUNT POSITION RSB PIN HIGH SIDE 1-2* Connected to VSOURCE VSOURCE 2-3 Connected to LOAD LOAD *Default position. External Reference The MAX9922 MAX9922 EV kit features 2-pin jumper JU2 to support both unidirectional and bidirectional operation. For unidirectional current-sense applications, connect the REF input to GND by placing a shunt across JU2. For bidirectional operation, connect REF to a reference voltage. By default, the EV kit provides a VDD/2 voltagedivider when the shunt on JU2 is not installed. In this mode, VOUT equals VREF when VSENSE equals 0mV. Table 2 summarizes jumper JU2's function. Current-Sense Amplifier Supply Input The MAX9922 MAX9922 EV kit features 3-pin jumper JU3 to select the current-sense amplifier voltage supply (VRSB) input. The VRSB pad can be connected to either side of the current-sense resistor by changing the shunt position of JU3. Place a shunt across pins 1-2 if the VSOURCE pad is being used to power VRSB. Place a shunt across pins 2-3 if the LOAD pad is being used to power VRSB. Table 3 summarizes jumper JU3's function. Input Differential Signal Range The MAX9922/MAX9923 MAX9922/MAX9923 feature a proprietary input structure optimized for small differential signals as low as 10mV full scale for high efficiency or 100mV full scale for high dynamic range. For best linearity and accuracy, do not exceed VSENSE of ±150mV. With a 0.1 sense resistor installed, the EV kit is optimized for a 100mA full-scale load current and a 10mV full-scale sense voltage. For other load-current applications, choose the appropriate sense resistor according to the following equation: VSENSE_FULL_SCALE RENSE = ILOAD_FULL_SCALE In applications monitoring a high current, ensure that RSENSE is able to dissipate its own I2R loss. If the resistor's power dissipation is exceeded, its value may drift, or fail altogether. Evaluating the MAX9923T/MAX9923H/ MAX9923T/MAX9923H/ MAX9923F MAX9923F The MAX9922 MAX9922 EV kit can also be used to evaluate the MAX9923T/MAX9923H/MAX9923F MAX9923T/MAX9923H/MAX9923F ultra-precision, fixed-gain, high-side current-sense amplifiers. Leave the FB pin unconnected by uninstalling feedback resistors R2 and R3. Replace U1 with the MAX9923T MAX9923T, MAX9923H MAX9923H, or the MAX9923F MAX9923F. For bidirectional mode, the output voltage (V OUT ) is given by the following equation: VOUT = A V × RSENSE × ISENSE + VREF where RSENSE = 0.1, ISENSE = load current, VREF = VDD/2, and AV is the gain of the device. For unidirectional operation, the output voltage (VOUT) is given by the following equation: VOUT = A V × RSENSE × ISENSE _ 3 Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 Table 2. Jumper JU2 Function (REF) Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 MAX9922 MAX9922 Evaluation Kit Figure 1. MAX9922 MAX9922 EV Kit Schematic 4 _ MAX9922 MAX9922 Evaluation Kit Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 Figure 2. MAX9922 MAX9922 EV Kit Component Placement Guide-Component Side _ 5 Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 MAX9922 MAX9922 Evaluation Kit Figure 3. MAX9922 MAX9922 EV Kit Component PCB Layout-Component Side 6 _ MAX9922 MAX9922 Evaluation Kit Evaluates: MAX9922/MAX9923 MAX9922/MAX9923 Figure 4. MAX9922 MAX9922 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _ 7 © 2009 Maxim Integrated Products SPRINGER Maxim is a registered trademark of Maxim Integrated Products, Inc.