Evaluates: MAX15020 MAX15020 Evaluation Kit General Description Quick Start The MAX15020 evaluation kit (EV kit) is a fully assembled Recommended Equipment and tested PCB that evaluates the MAX15020 PWM step- Before beginning, the following equipment is needed: down regulator IC with an integrated high-side switch. 7.5V to 40V adjustable, 3A power supply The MAX15020 is equipped with a reference input for the feedback error amplifier, allowing dynamic output-voltage 15 resistive load rated for 75W or greater programming. The MAX15020 EV kit operates over a wide Two digital voltmeters input-voltage range of 7.5V to 40V and provides up to 2A. Procedure The MAX15020 internal switching frequency can be The MAX15020 EV kit is fully assembled and tested. set to either 300kHz or 500kHz. The MAX15020 EV kit Follow the steps below to verify board operation. Caution: features a SYNC input to provide external frequency Do not turn on the power supply until all connections synchronization for sensitive applications. The EV kit uses are completed. a MAX15020 step-down regulator in a 20-pin thin QFN package. The MAX15020 IC operates over the automotive 1) Verify that a shunt is not installed at jumper JU1 temperature range of -40C to +125C and is suitable for (default 32V turn-on voltage). printers and industrial applications. 2) Verify that shunts are installed on pins 1-2 of jumpers JU2 (REFIN = REFOUT) and JU3 (300kHz switching Features frequency). Wide 7.5V to 40V Input Range 3) Connect the resistive load between the OUT PCB pad Dynamic Output-Voltage Control from 0.8V to 36V and the PGND PCB pad. with 2A Load 4) Connect digital voltmeters across the IN and PGND Selectable 300kHz/500kHz Switching Frequency pads, and the OUT and PGND pads on the EV kit board. Turn-On/Off Control 5) Connect the power supplys positive terminal to the IN Demonstrates MAX15020 IC Low Shutdown Current PCB pad on the EV kit, and connect the power-supply High Efficiency Up to 96% (V = 36V, V = 30V, IN OUT ground terminal to the PGND PCB pad. I = 2A) LOAD 6) Turn on the power supply. Demonstrates MAX15020 IC Overcurrent and Thermal Protection 7) Set the power-supply voltage to 36V. Space-Saving 5mm x 5mm, 20-pin TQFN Package 8) Verify that the voltmeter at OUT measures 30V. Fully Assembled and Tested Ordering Information PART TYPE MAX15020EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. 19-0804 Rev 3 5/15Evaluates: MAX15020 MAX15020 Evaluation Kit Table 2. Jumper JU2 Reference-Voltage Detailed Description of Hardware The MAX15020 EV kit circuit uses a MAX15020 step- Input down regulator IC (U1) to implement a step-down DC-DC SHUNT REFIN PIN V OUT regulator circuit. The EV kit operates over a 7.5V to LOCATION 40V input range. The circuit provides a dynamically Connects directly to 1-2* 30V programmable output range of 0.8V to 36V and can REFOUT deliver up to 2A of current with excellent line and load Externally controlled by Dependent on voltage 2-3 regulation. The MAX15020 step-down regulator features an REFIN EXT voltage at REFIN EXT internal high-side-low R MOSFET to achieve higher DS(ON) *Default position. efficiency and lower overall system cost. The MAX15020 also features configurable soft-start, shutdown control, Frequency Selection cycle-by-cycle current limit, hiccup-mode output short- Jumper JU3 selects the MAX15020 operating switching circuit protection, and thermal shutdown. The undervoltage frequency between 300kHz or 500kHz. See Table 3 for lockout (UVLO) threshold is configurable by choosing the switching frequency selection. appropriate R1 and R2 resistors. Configuring the Output Voltage (OUT) The MAX15020 EV kit features a selectable 300kHz or 500kHz switching-frequency operation, in addition The MAX15020 EV kit step-down regulator output to a SYNC input that can be used to synchronize the voltage is configured to 30V by resistors R7 and R8, MAX15020 to frequencies operating in the 300kHz to and with REFIN = REFOUT. The EV kits output voltage 500kHz range. An external reference input (REFIN EXT) (OUT) can be reconfigured in the range of 0.8V to 36V by is available to dynamically change the output voltage. replacing resistors R7 and R8. To select a new value for resistor R8, refer to the Compensation Design section in Jumper Selection the MAX15020 IC data sheet. Use the following equation ON/OFF Mode to reconfigure the output voltage to the desired value: The MAX15020 EV kit features a ON/OFF mode that reduces the MAX15020 supply current to 6A (typ). R7 R8 = The 3-pin jumper JU1 selects the ON/OFF mode for V OUT 1 the MAX15020 EV kit. See Table 1 for jumper JU1 V REFIN configurations where V is the desired output voltage in volts, V OUT REFIN REFIN EXT Input is the voltage supplied by REFOUT or REFIN EXT, and R7 The MAX15020 features a reference input for the internal is typically 10k. error amplifier. The voltage applied to REFIN EXT PCB The MAX15020 output voltage can also be adjusted pad is used to dynamically change the circuits output volt- dynamically by driving REFIN EXT between 0 and 3.6V. age. Jumper JU2 connects REFIN to REFOUT to use the To use the REFIN EXT input, place a shunt across pins MAX15020s 1V internal reference voltage. See Table 2 for 2-3 of jumper JU2. jumper JU2 configurations. To change the MAX15020 EV kit output voltage using REFIN EXT, refer to the Setting the Output Voltage section in the MAX15020 IC data sheet. Table 3. Jumper JU3 Frequency Selection Table 1. Jumper JU1 ON/OFF Mode SHUNT SHUNT MAX15020 SWITCHING MAX15020 OUTPUT ON/OFF PIN FSEL PIN LOCATION LOCATION FREQUENCY 1-2 Connects to V directly MAX15020 enabled 1-2* Connects to VREG 300kHz IN 2-3 Connects to GND MAX15020 disabled 2-3 Connects to GND 500kHz Connects to V through MAX15020 enabled at *Default position. When operating the MAX15020 with an exter- IN None* R1 and R2 resistors V 32V nal clock signal at SYNC, place the shunt on pins 1-2. Refer to IN the Oscillator/Sychronization Input section of the MAX15020 IC *Default position. data sheet for more information. Maxim Integrated 2 www.maximintegrated.com