19-4520; Rev 0; 3/09 MAX9940 Evaluation Kit The MAX9940 evaluation kit (EV kit) is an assembled and tested PCB used to evaluate the MAX9940 highvoltage signal-line protector for microcontroller ports. The MAX9940 EV kit demonstrates that microcontroller ports are protected against high-voltage faults. The EV kit comes with a MAX9940AXK+ installed. Features o Output Connection to 1-Wire(R) Device (DS2413) o Pushbutton that Initiates High-Voltage Fault o Lead(Pb)-Free and RoHS Compliant o Proven PCB Layout o Fully Assembled and Tested Ordering Information PART TYPE MAX9940EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component List DESIGNATION QTY C1, C7, C9 3 10F 10%, 16V X5R ceramic capacitors (0805) KEMET C0805C106K4PACTU 3 0.1F 10%, 16V X7R ceramic capacitors (0603) TDK C1608X7R1C104K 1 1F 10%, 16V X5R ceramic capacitor (0603) TDK C1608X5R1C105K C5, C6 2 10pF 5%, 50V C0G ceramic capacitors (0603) Murata GRM1885C1H100J D1 1 Green LED (0603) D2, D3, D4 3 Red LEDs (0603) D5 0 Not installed, Schottky diode (3 SOT23) Fairchild BAT54C H1 0 Not installed, 2 x 5-pin JTAG header JU1 1 3-pin header R1 1 2k 5% resistor (0603) C2, C3, C4 C8 DESIGNATION DESCRIPTION QTY DESCRIPTION R2, R3 2 220 5% resistors (0603) R4 1 3k 5% resistor (0603) R5 0 Not installed, resistor (0603) SW1, SW2, SW3 3 Pushbutton switches U1 1 High-voltage signal-line protector (5 SC70) Maxim MAX9940AXK+ U2 1 Microcontroller (68 QFN-EP*) Maxim MAXQ2000-RAX+ U3 1 LDO regulator (5 SC70) Maxim MAX8511EXK25+ U4 1 Addressable switch (6 TSOC) Maxim DS2413P+ Y1 1 16MHz crystal Hong Kong X'tals SSM1600000E18FAF -- 1 Shunt -- 1 PCB: MAX9940 Evaluation Kit+ *EP = Exposed pad. Component Suppliers SUPPLIER PHONE WEBSITE Hong Kong X'tals Ltd. 852-35112388 KEMET Corp. 864-963-6300 www.hongkongcrystal.com www.kemet.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 MAX9940 when contacting these component suppliers. 1-Wire 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: MAX9940 General Description Evaluates: MAX9940 MAX9940 Evaluation Kit Quick Start Detailed Description of Hardware Recommended Equipment The MAX9940 EV kit is an assembled and tested PCB used to evaluate the MAX9940 high-voltage signal-line protector for microcontroller ports. The MAX9940 EV kit demonstrates that microcontroller ports are protected against high-voltage faults. * 3.3V DC power supply * 28V DC power supply Procedure The MAX9940 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) Connect the 3.3V DC power supply to the VCC and GND pads on the EV kit. 2) Connect the 28V DC power supply to the FAULT and GND pads on the EV kit. 3) Verify that a shunt is installed in the 1-2 position on jumper JU1. START Pushbutton Press the START pushbutton (SW2) to start communicating with the DS2413, dual-channel addressable switch. The on-board microcontroller commands the DS2413 to continuously blink the green LED for 30 cycles. STOP Pushbutton Press the STOP pushbutton (SW3) to stop communicating with the DS2413. The green LED should stop blinking if the STOP pushbutton is pressed. If JU1 is in the 2-3 position, then the MAX9940 is also disabled. 4) Turn on both supplies. 5) Press the START pushbutton (SW2) momentarily and observe as the green LED (D1) continuously turns on and off every 500ms for 30 cycles. 6) While the green LED is still blinking, press the FAULT pushbutton (SW1) and observe as the red LEDs (D2, D3, and D4) turn on. Once SW1 is deactivated, the red LEDs turn off and the green LED continues blinking until it reaches the end of its sequence. FAULT Pushbutton Press the FAULT pushbutton (SW1) while the microcontroller is communicating with the DS2413. The red LEDs indicate that a voltage is applied to the EXT pin of the MAX9940. The absolute maximum voltage of the DATA signal of the microcontroller (U2) is specified to be (VDDIO + 0.5)V, i.e., 3.8V. When the MAX9940 detects a voltage greater than (VCC + 0.3)V, it automatically turns off, presenting the high voltage fault signal on its EXT pin from appearing on the DATA signal line, thus protecting the microcontroller from damage. Table 1. VCC Selection (JU1) SHUNT POSITION DESCRIPTION 1-2* Connects the MAX9940 to the +3.3V supply. Before changing shunt positions, press the STOP pushbutton (SW3). 2-3 Enables the MAX9940 using the MAXQ2000's GPIO pin, which is used for power saving. Power is only applied when the START pushbutton (SW2) is pressed. Power is disabled when the MAXQ2000 is done communicating with the DS2413. Before changing shunt positions, press the STOP pushbutton (SW3). Note: The MAX9940 can withstand fault voltages even when its VCC = 0. *Default position. 2 _______________________________________________________________________________________ MAX9940 Evaluation Kit Evaluates: MAX9940 Figure 1a. MAX9940 EV Kit Schematic (Sheet 1 of 2) _______________________________________________________________________________________ 3 Evaluates: MAX9940 MAX9940 Evaluation Kit Figure 1b. MAX9940 EV Kit Schematic (Sheet 2 of 2) 4 _______________________________________________________________________________________ MAX9940 Evaluation Kit Evaluates: MAX9940 Figure 2. MAX9940 EV Kit Component Placement Guide-- Component Side Figure 3. MAX9940 EV Kit PCB Layout--Component Side Figure 4. MAX9940 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 _____________________ 5 (c) 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. 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