Evaluates: MAX8627 19-0687 Rev 0 11/06 MAX8627 Evaluation Kit General Description Features The MAX8627 evaluation kit (EV kit) is a fully assembled 1MHz PWM Switching Frequency and tested circuit for evaluating the MAX8627 step-up True Shutdown Output converter. The MAX8627 EV kit operates from a 1.8V to 5.5V supply, and provides up to 1A output current from Up to 95% Efficiency its 5V output. The output voltage can be adjusted from 1.0A Guaranteed Output Current at V 3V IN 3V to 5V by changing a resistor on the board. Fast Soft-Start Eliminates Inrush Current Component List 20A (typ) Quiescent Current 0.1A Logic-Controlled Shutdown DESIGNATION QTY DESCRIPTION 22F 20%, 6.3V X5R ceramic Tiny 14-Pin, 3mm x 3mm TDFN IC Package C1C4 4 capacitors (1206) Fully Assembled and Tested TDK C3216X5R0J226M JU1 1 3-pin header 1H inductor L1 1 TOKO A918CY-1R0M (D62LCB) R1 1 2M 1% resistor (0402) R2 1 499k 1% resistor (0402) Ordering Information Not installed, (0402) PCB short R3 0 PART TEMP RANGE IC PACKAGE resistor MAX8627EVKIT 0C to +70C 14 TDFN (3mm x 3mm) R4 0 Not installed, (0402) resistor MAX8627ETD (14-pin TDFN, U1 1 3mm x 3mm) 1 Shunt, 2 position 1 MAX8627 EV kit PCB 3) Connect the positive power-supply lead to the EV Quick Start kit pad labeled BATT. Connect the power-supply Recommended Equipment ground to the EV kit pad labeled GND (located next 1.8V to 5.5V power supply capable of delivering 3A to BATT). Voltmeter 4) Connect the load between the EV kit pads labeled OUT and GND. Load (up to 1A) 5) Turn on the power supply. Procedure 6) Connect the voltmeter across the EV kit pads Follow the steps below to verify board operation. labeled OUT and GND to verify that the output volt- 1) Place the shunt across pins 2-3 of JU1 on the EV kit age is 5V. to enable the converter. 2) Set the power-supply voltage between 1.8V and 5.5V. Turn off the power supply. Do not turn on the power supply until all connections are completed. True Shutdown is a trademark of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX8627 Evaluation Kit resistor R1. Find the value of R1 from the following Table 1. JU1 Functions equation: SHUNT POSITION FUNCTION V OUT RR12 = x 1 1-2 Shutdown V FB 2-3 Enable Enable function is driven externally where the lower feedback resistor, R2, is 499k , and Open by a logic signal connected to the V is 1.01V. FB ON pad of the EV kit. Adjusting the Current Limit The MAX8627 EV kits current limit is set to the default Detailed Description of 3.5A. To set the current limit lower, cut the PCB trace shorting R3, and then install resistors R3 and R4. Refer Adjusting the Output Voltage to the MAX8627 data sheet for information on calculat- The default output voltage of the MAX8627 EV kit is 5V, ing these resistor values. but it can be adjusted between 3V and 5V by changing BATT 1.8V TO 5V C2 GND L1 22F C1 1H 4, 5 22F 8, 9 BATT LX LX POUT OUT 3 ON 5V JU1 3 6, 7 2 ON U1 POUT 1 C4 POUT 22F MAX8627 12 14 R1 AGND OUTS 2M R4 C3 OPEN ILIM 22F 13 2 ILIM FB R3 SHORT R2 GND 1 10, 11 499k GND PG Figure 1. MAX8627 EV Kit Schematic 2 Evaluates: MAX8627