Evaluates: MAX15462A MAX15462A Evaluation Kit General Description Quick Start The MAX15462A evaluation kit (EV kit) is a fully assembled Recommended Equipment and tested circuit board that demonstrates the perfor- MAX15462A EV kit mance of the MAX15462A 42V, 300mA ultra-small, high- 42V adjustable, 0.5A DC power supply efficiency, synchronous step-down converter. The EV kit operates over a wide 4.5V to 42V input voltage range, Electronic load up to 300mA and provides up to 300mA at the preset 3.3V output. Voltmeter The device features undervoltage-lockout, overcurrent protection, and thermal shutdown. The EV kit switches Procedure at a fixed frequency of 500kHz, and delivers a peak The EV kit is fully assembled and tested. Follow the steps efficiency of 90% with the supplied components. below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. The EV kit comes installed with the MAX15462AATA+ in an 8-pin (2mm x 2mm) lead(Pb)-free/RoHS-compliant 1) Verify that shunts are installed on jumpers JU1 and TDFN package. JU2 (EN/UVLO). 2) Verify that jumper JU3 (MODE PFM operation) is Features open. 4.5V to 42V Input Voltage Range 3) Set the electronic load to constant-current mode, 3.3V Output, 300mA Continuous Current 300mA, and disable the electronic load. Internal Compensation 4) Connect the electronic loads positive terminal to the EN/UVLO for On/Off Control and Programmable VOUT PCB pad. Connect the negative terminal to Input Undervoltage Lockout the GND PCB pad. 90% Peak Efficiency 5) Connect the voltmeter across the VOUT and GND PCB pads. 500kHz Fixed-Frequency PWM Operation 6) Set the power-supply output to 24V. Disable the PFM or Forced-PWM Mode of Operation power supply. Hiccup Mode Overcurrent Protection 7) Connect the 24V power-supply output to the VIN Open-Drain RESET Output PCB pad. Connect the supply ground to the GND Thermal Shutdown PCB pad. Proven PCB Layout 8) Turn on the power supply and verify that VOUT is at 3.3V with respect to GND. Fully Assembled and Tested 9) Enable the electronic load and verify that VOUT is at 3.3V with respect to GND. Ordering Information appears at end of data sheet. 19-7561 Rev 0 3/15Evaluates: MAX15462A MAX15462A Evaluation Kit undervoltage-lockout (UVLO) threshold. Jumpers JU1 Detailed Description and JU2 configure the EV kits output for turn-on/turn-off The MAX15462A EV kit is a fully assembled and control. Install a shunt across pins 1-2 on jumper JU2 to tested circuit board that demonstrates the performance of disable VOUT. See Table 1 for proper jumper settings. the MAX15462A 42V, 300mA ultra-small, high-efficiency, Additionally, resistors R1 and R2 are included to set the synchronous step-down converter. The EV kit operates over a wide 4.5V to 42V input voltage range, UVLO to a desired turn-on voltage. Refer to the Enable Input (EN/UVLO), Soft-Start section in the MAX15462A/ and provides up to 300mA at the preset 3.3V output. The device features undervoltage lockout, overcurrent MAX15462B IC data sheet for additional information on setting the UVLO threshold voltage. protection, and thermal shutdown. The EV kit switches at a fixed frequency of 500kHz, and delivers a peak Active-Low Open-Drain Reset Output (RESET) efficiency of 90% with the supplied components. The EV kit provides a PCB pad to monitor the status The EV kit includes an EN/UVLO PCB pad and jumpers of the RESET output. RESET goes high when V OUT JU1 and JU2 to enable control of the converter output. rises above 95% (typ) of its nominal regulated output The MODE PCB pad and jumper JU3 are provided for voltage. When V falls below 92% (typ) of its nominal OUT selecting the mode of operation of the converter. The regulated voltage, RESET is pulled low. VCC PCB pad helps measure the internal LDO voltage. An additional RESET PCB pad is available for monitoring PFM or Forced-PWM Mode (MODE) the open-drain logic output. The EV kit includes a jumper (JU3) to program the mode of operation of the converter. Install a shunt across JU3 Enable Control (JU1, JU2) before powering up the EV kit to enable the forced-PWM The EN/UVLO pin of the device serves as an on/off operation. Keep JU3 open to enable the light-load PFM control while also allowing the user to program the input operation. See Table 2 for proper JU3 configuration. Table 1. Enable Control (EN/UVLO) SHUNT POSITION EN/UVLO PIN VOUT OUTPUT JU1 JU2 1-2 Open Connected to VIN Enabled Open 1-2 Connected to GND Disabled Connected to midpoint of the 1-2* 1-2* Enabled at VIN 4.5V R1, R2 resistor-divider *Default position. Table 2. Mode Control (JU3) SHUNT POSITION MODE PIN MODE OF OPERATION 1-2 Connected to GND Forced PWM Open* Unconnected PFM *Default position. Maxim Integrated 2 www.maximintegrated.com