MAX17498BB Evaluates: MAX17498B in a Evaluation Kit Step-Up (Boost) Configuration General Description Features The MAX17498BB evaluation kit (EV kit) is a fully assem- 4.5V to 10V Input Range bled and tested surface-mount circuit board to evaluate Output Voltage: 24V at 100mA the MAX17498B peak-current-mode controller in a step- 500kHz Switching Frequen cy up (boost) configuration. The EV kit output is configured for 24V output voltage, which can supply up to 100mA of Integrated n-Channel MOSFET current. The input voltage range is from 4.5V to 10V. Efficiency Up to 94.2% The EV kit features a 500kHz fixed frequency for optimum Resistor-Programmable UVLO/OVI Threshold efficiency and component size. High efficiency up to 94.2% Open-Drain Power-Good Signal (PGOOD) is achieved using a boost converter, providing an output Low-Cost Boost Converter Design power up to 2.4W. Proven PCB Layout Fully Assembled and Tested Ordering Information appears at end of data sheet. Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION 40V, 1A Schottky diode 10F 20%, 25V aluminum D1 1 (SOD123) electrolytic capacitor C1 1 Central Semi CMMSH1-40 (4.3mm x 4.3mm) Panasonic EEE-FK1E100R 56H, 0.75A inductor L1 1 (6mm x 6mm) 2.2F 10%, 10V X7R ceramic Coilcraft LPS6235-563ML C2 1 capacitor (0805) Murata GRM21BR71A225K R1 1 43.2k 1% resistor (0402) 0.1F 10%, 16V X7R ceramic R2 1 71.5k 0.1% resistors (0402) C3 1 capacitor (0402) R3 1 374k 1% resistor (0402) Murata GRM155R71C104K R4 1 20k 1% resistor (0402) 270pF 5%, 50V C0G ceramic R5 1 2.37k 1% resistor (0402) C4 1 capacitor (0402) R6, R8 2 0 5% resistors (0402) Murata GRM1555C1H271J R7 0 Not installed, resistor (0402) 47000pF 10%,16V X7R R9 1 10k 5% resistor (0402) C5 1 ceramic capacitor (0402) Murata GRM155R71C473K Peak-current-mode, boost U1 1 regulator (16 TQFN-EP*) 2.2F 10%, 50V X7R ceramic Maxim MAX17498BATE+ C6 1 capacitor (1206) Murata GRM31CR71H225K PCB: MAX17498BB 1 EVALUATION KIT 1F 10%, 25V X7R ceramic *EP = Exposed pad. C7 1 capacitor (0805) Murata GRM21BR71E105K 19-6580 Rev 0 1/13MAX17498BB Evaluates: MAX17498B in a Evaluation Kit Step-Up (Boost) Configuration Component Suppliers SUPPLIER PHONE WEBSITE Coilcraft, Inc. 847-639-6400 www.coilcraft.com Central Semiconductor Corp 631-435-1110 www.centralsemi.com Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com Panasonic Corp 800-344-2112 www.panasonic.com Note: Indicate that you are using the MAX17498BATE+ when contacting these component suppliers. switch. This PWM controller varies the duty cycle to Quick Start compensate for the variation in input voltage and the Required Equipment output load to maintain a constant output voltage. The MAX17498BB EV kit duty cycle determines the on/off duration of the internal switch. The duty cycle is controlled by the feedback loop 4.5V to 10V, 600mA DC power supply consisting of voltage-divider resistors (R3, R4), internal Voltmeter error amplifier, compensation components (R5, C3, C4), and the PWM comparator insid e the device. VOUT Setup Procedure The EV kit is fully assembled and tested. Follow the steps The EV kit sets the peak inductor current-limit threshold to below to verify board operation : 864mA using resistor R1. Capacitor C5 sets VOUT soft- start to 5.7ms. 1) Conn ect the positive lead of the DC voltmeter to the VOUT PCB pad. Current Limit 2) Conn ect the negative lead of the DC voltmeter to the Resistor R1 sets the EV kits inductor peak-current limit to PGND PCB pad. 864mA. The device turns off its internal switch when the peak current reaches the current limit. To reconfigure the 3) Set the DC power-supply output to 5V. Disable the peak current limit to a different value, use the following power supply. equation to choose a new value for R1: 4) Conn ect the power-supply positive terminal to the VIN PCB pad. R1=50I k PK 5) Conn ect the power-supply negative terminal to the where I is the peak inductor current in amps. PGND PCB pad. PK 6) Enable the power supply. Undervoltage Lockout and Overvoltage Protection 7) Verify that VOUT is 24V throughout the 4.5V to 10V input voltage range. The EV kit features a UVLO and OVI circuit that prevent operation below the programmed input-supply startup Detailed Description voltage and above the overvoltage threshold. Resistors The MAX17498BB EV kit provides a proven design to R6R8 set the undervoltage and overvoltage thresh- olds. With 0 resistors in the place of R6 and R8, the evaluate the MAX17498B high -efficiency step-up DC-DC converter in a space-saving 16-pin TQFN package. The undervoltage threshold is set at 4.5V (typ) and the over- voltage detection is disabled. To reconfigure the UVLO EV kit is configured for a 24V output voltage that can supply up to 100mA of current. The EV kit features a and OVI voltages, refer to the Startup Voltage and Input Overvoltage-Protection Setting (EN/UVLO, OVI) section 500kHz fixed switching frequency for optimum efficiency and component size. in the MAX1749 8B IC data sheet This EV kit uses the device, a peak-current-mode, pulse- EN/UVLO and OVI PCB pads are available for monitoring the voltages present at the respective inputs. width modulati ng (PWM) regulator with an integrated Maxim Integrated 2 www.maximintegrated.com