MAX8989EVKIT+

MAX8989 Evaluation Kit Evaluates: MAX8989 General Description The MAX8989 evaluation kit (EV kit) is a fully assembled and tested circuit for evaluating the MAX8989 step-down converter with linear bypass regulator. The EV kit operates from a 2.7V to 5.5V power supply or battery. The output regulates to twice the voltage at REFIN (0.2V to 1.7V) and provides up to 2.5A drive capability. Features S PA Step-Down Converter 25µs (typ) Settling Time for 0.4V to 3.2V OutputVoltage Change Dynamic Output-Voltage Setting from 0.4V to VIN 85mI PFET and 100% Duty Cycle for Low Dropout 2MHz Switching Frequency Low Output-Voltage Ripple 2% Output-Voltage Accuracy Over Load, Line, and Temperature Tiny External Components Component List DESIGNATION QTY C1, C2, C4, C5, C6 5 4.7FF 20%, 6.3V X5R ceramic capacitors (0603) TDK C1608X5R0J475M C3 1 1000pF Q5%, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H102J C7 0 Not installed, ceramic capacitor (0603) JU1 1 2-pin header, 0.1in JU2 1 3-pin header, 0.1in 1 4.7FH Q20%, 252mI, 850mA inductor, 1.2mm (max) height (2520) TOKO 1239AS-H-4R7N=P2 (DFE252012C) U1 1 PWM step-down converter (9 WLP, 0.5mm pitch) Maxim MAX8989EWL+ — 2 Shunts, 2-position — 1 PCB: MAX8989 EVALUATION KIT+ L1 DESCRIPTION S 2.5A Output-Current Capability S Simple Logic On/Off Control S Low 0.1µA Shutdown Current S 2.7V to 5.5V Supply Voltage Range S Thermal-Overload Protection S Proven PCB Layout S Fully Assembled and Tested Ordering Information PART TYPE MAX8989EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component Suppliers SUPPLIER PHONE WEBSITE Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com TDK Corp. 847-803-6100 www.component.tdk.com TOKO America, Inc. 847-297-0070 www.tokoam.com Note: Indicate that you are using the MAX8989 when contacting these component suppliers. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com. 19-5745; Rev 0; 1/11 MAX8989 Evaluation Kit Evaluates: MAX8989 Quick Start • MAX8989 EV kit 10) Turn on the power supply and voltage reference. 11) Install the shunt on jumper JU1. Recommended Equipment 12) With the voltmeter, verify that the voltage from OUT to PGND2 is approximately twice the reference voltage. • 2.7V to 5.5V power supply or battery capable of delivering 2.5A Detailed Description of Hardware • Voltage reference or power supply capable of providing 0.2V to 1.7V (must be able to sink and source up to 1mA) The MAX8989 output regulates to twice the voltage at REFIN and provides up to 2.5A drive capability. REFIN must connect to an external reference supply between 0.2V and 1.7V. Connect the ground of the reference supply to the AGND PCB pad. Do not use AGND as a power-ground connection. • Voltmeter • Load (resistor or electronic load) Procedure Enable The EV kit is fully assembled and tested. Follow the steps below to verify board operation: Enable/shutdown control is provided by jumper JU1. For normal operation, place a shunt on the pins of JU1. For low-power shutdown mode, remove the shunt from JU1. In shutdown mode, the step-down regulator and LDO are off, reducing the supply current to 0.1µA (typ). 1) Preset the power supply to 3.7V. 2) Preset the voltage reference between 0.2V and 1.7V. 3) Turn off the power supply and reference. Do not turn on the power supply until all connections are completed. To drive the enable input from an external logic source, remove the shunt on JU1. Connect the logic signal to pin 2 of JU1. Connect the signal ground to AGND. Refer to the Electrical Characteristics section in the MAX8989 IC data sheet for the required logic levels. 4) Remove the shunt from jumper JU1. 5) Connect the positive power-supply terminal to the EV kit PCB pad labeled IN. Skip Mode 6) Connect the negative power-supply terminal to the EV kit PCB pad labeled GND1. The device has an optional skip mode. To enable skip mode, connect pins 2-3 of jumper JU2. Skip mode provides the highest possible efficiency during light-load conditions, reducing the no-load supply current to 115µA (typ). Skip mode is only active when the output voltage is less than 1V. 7) Connect the positive voltage-reference terminal to the EV kit PCB pad labeled REFIN. 8) Connect the negative voltage-reference terminal to the EV kit PCB pad labeled AGND. 9) Connect the load from OUT to GND2. To prevent the device from entering skip mode, connect pins 1-2 of JU2. Table 1. Jumper Settings (JU1, JU2) JUMPER 2   SHUNT POSITION OPEN 1-2 JU1 Shutdown mode Output enabled 2-3 — JU2 — Forced-PWM operation Skip mode enabled for light loads with VOUT < 1V Maxim Integrated MAX8989 Evaluation Kit Evaluates: MAX8989 Figure 1. MAX8989 EV Kit Schematic Maxim Integrated   3 MAX8989 Evaluation Kit Evaluates: MAX8989 1.0” 1.0” Figure 2. MAX8989 EV Kit Component Placement Guide— Component Side Figure 3. MAX8989 EV Kit PCB Layout—Component Side (Layer 1) 1.0” Figure 4. MAX8989 EV Kit PCB Layout—Inner Layer 2 4   Maxim Integrated MAX8989 Evaluation Kit Evaluates: MAX8989 1.0” Figure 5. MAX8989 EV Kit PCB Layout—Inner Layer 3 Maxim Integrated 1.0” Figure 6. MAX8989 EV Kit PCB Layout—Solder Side (Layer 4)   5 MAX8989 Evaluation Kit Evaluates: MAX8989 Revision History REVISION NUMBER REVISION DATE 0 1/11 DESCRIPTION Initial release PAGES CHANGED — Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 6 ©  2011 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 Maxim Integrated Products, Inc. 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