19-5757; Rev 0; 2/11 MAX44264 Evaluation Kit Evaluates: MAX44264 General Description The MAX44264 evaluation kit (EV kit) is a fully assembled and tested circuit board that contains all the components necessary to evaluate the MAX44264 IC, offered in a space-saving 0.9mm x 1.3mm, 6-bump wafer-level package (WLP). The device is a rail-to-rail micropower op amp, drawing only 750nA of supply current. The EV kit operates from a single 1.8V to 5.5V DC power supply. Features S 1.8V to 5.5V Single-Supply Operation S Jumper Selectable for Inverting, Noninverting, Differential, and Buffer Op-Amp Configurations S Demonstrates Super-Capacitor Charge Balancing Using the Op-Amp Buffer Configuration S Evaluates the Device in a 6-Bump WLP S Proven PCB Layout S Fully Assembled and Tested Ordering Information appears at end of data sheet. Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY JU2 1 3-pin header DESCRIPTION 2 0.22F -20% to +80%, 3.3V super capacitors (6.8mm) R1, R6 0 1 1FF Q10%, 6.3V X5R ceramic capacitor (0603) Murata GRM188R60J105K Not installed, resistors (0603) R1 is short (PC trace) and R6 is open R2 1 0I Q5% resistor (0603) 1 0.1FF Q10%, 16V X5R ceramic capacitor (0603) Murata GRM188R61C104K R3, R4 2 2MI Q5% resistors (0603) R5 1 10I Q5% resistor (0603) C5 1 0.01FF Q10%, 16V X7R ceramic capacitor (0603) Murata GRM188R71C103K U1 1 Rail-to-rail op amp (6 WLP) Maxim MAX44264EWT+ (Top Mark: +CB) 3 Shunts (JU1, JU2, JU3) 0 Not installed, ceramic capacitor (0603) -- C6 JU1, JU3 2 2-pin headers -- 1 PCB: MAX44264 EVALUATION KIT C1, C2 C3 C4 Component Supplier SUPPLIER Murata Electronics North America, Inc. PHONE 770-436-1300 WEBSITE www.murata-northamerica.com Note: Indicate that you are using the MAX44264 when contacting this component supplier. __________________________________________________________________ Maxim Integrated Products 1 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. MAX44264 Evaluation Kit Evaluates: MAX44264 Quick Start Required Equipment * MAX44264 EV kit * 1.8V to 5.5V, 100mA DC power supply * Voltmeter Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. 1) To configure the EV kit as an op-amp buffer to balance super capacitors C1 and C2 charge, set jumpers JU1, JU2, and JU3 in their default positions, as shown in Table 1. 2) Set the power supply to provide 5V and then disable the power supply. 3) Connect the power-supply positive terminal to the VDD PCB pad. 4) Connect the power-supply ground to the GND PCB pad (nearest the VDD PCB pad). 5) Enable the power supply. 6) Verify that the OUT PCB pad is at 2.5V. Detailed Description of Hardware The MAX44264 EV kit contains the MAX44264 IC, which is a rail-to-rail micropower op amp with an ultra-low 750nA supply current designed in a 6-bump WLP. The EV kit operates from a single 1.8V to 5.5V DC power supply. Table 1. Default Shunt Positions JUMPER SHUNT POSITION DESCRIPTION JU1 Not installed IN- = OUT (through resistor R2) JU2 2-3 JU3 Installed IN+ = VDD/2 Default Application Circuit The EV kit comes preconfigured as a buffer used in a super-capacitor charge-balancing circuit. Super capacitors offer exceptional charge storage density and are widely used to prolong the life of weak batteries subject to high current-load pulses, or to buffer a weak energy source to a high-power load in energy-harvesting devices. In such applications, it is common to have a stack of super capacitors connected in series to achieve the desired working voltage. The EV kit demonstrates an active, super-capacitor charge-balancing circuit that distributes the charge equally across two series-connected super capacitors (C1 and C2), ensuring identical voltage across each capacitor. This circuit prevents overvoltage conditions from occurring across either of the super capacitors due to a difference in leakage currents and tolerance in the capacitor values. The IC's ultra-low power consumption of 750nA and CMOS inputs allow a powerefficient solution to the super-capacitor charge-balancing problem. Op-Amp Configurations While super-capacitor charge balancing is the featured application, the EV kit also provides flexibility to easily reconfigure the op amp into any of the four common circuit topologies: inverting amplifier, noninverting amplifier, differential amplifier, or buffer. Table 2 lists the JU1, JU2, and JU3 jumper settings for the various op-amp configurations. The configurations are described in the next few sections. Important Note: Remove super capacitors C1 and C2 when not demonstrating super-capacitor charge balancing in the four configurations detailed in the Noninverting Amplifier, Inverting Amplifier, Differential Amplifier, and Buffer Amplifier sections. Table 2. JU1, JU2, JU3 Jumper Functions (IN-, IN+, REF) OP-AMP CONFIGURATION Inverting Differential Noninverting SHUNT POSITION JU1 JU2 JU3 1-2 Not installed 2-3 Installed Installed Buffer Not installed Super-capacitor buffer Not installed __________________________________________________________________ Maxim Integrated Products 2 MAX44264 Evaluation Kit Evaluates: MAX44264 Noninverting Amplifier To configure the device as a noninverting amplifier, replace R2 and R6 with suitable resistors. Replace R3 with a short and remove C5 (follow the jumper settings listed in Table 2). The output voltage (VOUT) for the noninverting configuration is given by the following equation: R2 VOUT = 1 + (VIN+ + VOS ) R6 where: VOS = Input-referred offset voltage. VIN+ = Input voltage applied at the IN+ PCB pad. Inverting Amplifier To configure the device as an inverting amplifier, cut open the shorted PCB trace on R1. Replace R3 with a short and remove C5. Replace R1 and R2 with suitable gain resistors (follow the jumper settings listed in Table 2). An appropriate DC voltage (VDC) should be applied to the IN+ PCB pad to level shift the output voltage of the op amp if the applied input voltage (VIN-) at the IN- PCB pad is positive: R2 R2 VOUT = - VIN- + 1 + (VOS + VDC ) R1 R1 Differential Amplifier To configure the device as a differential amplifier, cut open the shorting PCB trace on R1. Replace R1-R4 with appropriate resistors. Remove C5 (follow the jumper settings listed in Table 2). Apply a reference voltage (VREF) to the REF PCB pad to level shift the output voltage of the op amp, if required. When R1 = R3 and R2 = R4, the CMRR of the differential amplifier is determined by the matching of ratios R1/R2 and R3/R4: R2 VOUT = GAIN(VIN+ - VIN- ) + 1 + VOS + VREF R1 where: GAIN = R2 R4 = R1 R3 Buffer Amplifier To configure the device as a standard unity-gain buffer, replace R3 with a short and remove C5: VOUT = VIN+ + VOS Important Note: Remove super capacitors C1 and C2 when not demonstrating super-capacitor charge balancing for the four configurations just listed. __________________________________________________________________ Maxim Integrated Products 3 MAX44264 Evaluation Kit Evaluates: MAX44264 Figure 1. MAX44264 EV Kit Schematic __________________________________________________________________ Maxim Integrated Products 4 MAX44264 Evaluation Kit Evaluates: MAX44264 1.0" Figure 2. MAX44264 EV Kit Component Placement Guide-- Component Guide 1.0" Figure 3. MAX44264 EV Kit PCB Layout--Component Side 1.0" Figure 4. MAX44264 EV Kit PCB Layout--Solder Side __________________________________________________________________ Maxim Integrated Products 5 MAX44264 Evaluation Kit Evaluates: MAX44264 Ordering Information PART TYPE MAX44264EVKIT# EV Kit #Denotes RoHS compliant. __________________________________________________________________ Maxim Integrated Products 6 MAX44264 Evaluation Kit Evaluates: MAX44264 Revision History REVISION NUMBER REVISION DATE 0 2/11 DESCRIPTION Initial release PAGES CHANGED -- 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 (c) 2011 Maxim Integrated Products 7 Maxim is a registered trademark of Maxim Integrated Products, Inc.