MAX8989 Evaluation Kit Evaluates: MAX8989 General Description Features The MAX8989 evaluation kit (EV kit) is a fully assembled S PA Step-Down Converter and tested circuit for evaluating the MAX8989 step-down 25s (typ) Settling Time for 0.4V to 3.2V Output- Voltage Change converter with linear bypass regulator. The EV kit oper- ates from a 2.7V to 5.5V power supply or battery. The Dynamic Output-Voltage Setting from 0.4V to V output regulates to twice the voltage at REFIN (0.2V to IN 1.7V) and provides up to 2.5A drive capability. 85mI PFET and 100% Duty Cycle for Low Dropout 2MHz Switching Frequency Component List Low Output-Voltage Ripple 2% Output-Voltage Accuracy Over Load, Line, DESIGNATION QTY DESCRIPTION and Temperature 4.7FF 20%, 6.3V X5R ceramic C1, C2, C4, C5, Tiny External Components 5 capacitors (0603) C6 S 2.5A Output-Current Capability TDK C1608X5R0J475M S Simple Logic On/Off Control 1000pF Q5%, 50V C0G ceramic C3 1 capacitor (0402) S Low 0.1A Shutdown Current Murata GRM1555C1H102J S 2.7V to 5.5V Supply Voltage Range Not installed, ceramic capacitor S Thermal-Overload Protection C7 0 (0603) S Proven PCB Layout JU1 1 2-pin header, 0.1in S Fully Assembled and Tested JU2 1 3-pin header, 0.1in 4.7FH Q20%, 252mI, 850mA inductor, 1.2mm (max) L1 1 height (2520) Ordering Information TOKO 1239AS-H-4R7N=P2 (DFE252012C) PART TYPE MAX8989EVKIT+ EV Kit PWM step-down converter U1 1 (9 WLP, 0.5mm pitch) +Denotes lead(Pb)-free and RoHS compliant. Maxim MAX8989EWL+ 2 Shunts, 2-position PCB: MAX8989 EVALUATION 1 KIT+ 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 19-5745 Rev 0 1/11 at 1-888-629-4642, or visit Maxims website at www.maximintegrated.com.MAX8989 Evaluation Kit Evaluates: MAX8989 10) Turn on the power supply and voltage reference. Quick Start 11) Install the shunt on jumper JU1. Recommended Equipment 12) With the voltmeter, verify that the voltage from OUT to MAX8989 EV kit 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 The MAX8989 output regulates to twice the voltage at providing 0.2V to 1.7V (must be able to sink and REFIN and provides up to 2.5A drive capability. REFIN source up to 1mA) must connect to an external reference supply between Voltmeter 0.2V and 1.7V. Connect the ground of the reference supply to the AGND PCB pad. Do not use AGND as a Load (resistor or electronic load) power-ground connection. Procedure Enable The EV kit is fully assembled and tested. Follow the steps Enable/shutdown control is provided by jumper JU1. For below to verify board operation: normal operation, place a shunt on the pins of JU1. For 1) Preset the power supply to 3.7V. low-power shutdown mode, remove the shunt from JU1. 2) Preset the voltage reference between 0.2V and 1.7V. In shutdown mode, the step-down regulator and LDO are off, reducing the supply current to 0.1A (typ). 3) Turn off the power supply and reference. Do not turn on the power supply until all connections are com- To drive the enable input from an external logic source, pleted. remove the shunt on JU1. Connect the logic signal to pin 2 of JU1. Connect the signal ground to AGND. Refer to 4) Remove the shunt from jumper JU1. the Electrical Characteristics section in the MAX8989 IC 5) Connect the positive power-supply terminal to the data sheet for the required logic levels. EV kit PCB pad labeled IN. Skip Mode 6) Connect the negative power-supply terminal to the The device has an optional skip mode. To enable skip EV kit PCB pad labeled GND1. mode, connect pins 2-3 of jumper JU2. Skip mode pro- 7) Connect the positive voltage-reference terminal to vides the highest possible efficiency during light-load the EV kit PCB pad labeled REFIN. conditions, reducing the no-load supply current to 115A 8) Connect the negative voltage-reference terminal to (typ). Skip mode is only active when the output voltage is the EV kit PCB pad labeled AGND. less than 1V. 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) SHUNT POSITION JUMPER OPEN 1-2 2-3 JU1 Shutdown mode Output enabled JU2 Forced-PWM operation Skip mode enabled for light loads with V < 1V OUT 2 Maxim Integrated