evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit general description the maxm17504 evaluation kit (ev kit) is a demonstration circuit of the maxm17504 high-voltage, high-eficien - cy, current-mode scheme, synchronous step-down dc-dc switching power module. the maxm17504 ev kit is designed for 5v output and delivers up to 3.5a load current from a wide input voltage range of 11v to 60v. the ev kit switches at an optimal 500khz switching frequency to allow the use of small component sizes that help minimize solution size while maintaining high performance. the ev kit provides a precision- enable input, an open-drain reset output signal, and external frequency synchronization to provide a simple and reliable startup sequence and eliminate beat frequency between regulators. the ev kit also includes option - al component footprints to program different output voltages, an adjustable input undervoltage-lockout, and a soft-start time to control inrush current during startup. the maxm17504 data sheet provides a complete description of the part that should be read in conjunction with this evaluation kit data sheet prior to modifying the demo circuit. features highly integrated solution with integrated shield inductor wide 11v to 60v input range preset 5v output with a fixed resistor-divider on feedback pin (fb) programmable output voltage feature (0.9v to 12v) up to 3.5a output current high 92.5% efficiency (v in = 12v, v out = 5v at 1.0a) 500khz switching frequency enable/uvlo input, resistor-programmable uvlo threshold adjustable soft-start time selectable pwm, pfm, or dcm mode open-drain reset output external frequency synchronization overcurrent and overtemperature protection low-profile, surface-mount components lead(pb)-free and rohs compliant fully assembled and tested 19-7590; rev 0; 4/15 ordering information appears at end of data sheet. downloaded from: http:///
maxim integrated 2 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit quick start recommended equipment maxm17504 evaluation kit 11v to 60v dc power supply (v in ) dummy load capable of sinking 3.5a digital voltmeter (dvm) 100mhz dual-trace oscilloscope procedure the maxm17504 ev kit is fully assembled and tested. please follow the steps below to verify board operation. caution: do not turn on the power supply until all connections are completed. 1) set the power supply at a voltage between 11v and 60v. disable the power supply. 2) connect the positive and negative terminals of the power supply to in and pgnd pcb pads, respectively. 3) connect the positive and negative terminals of the 3.5a load to out and pgnd2 pcb pads, respectively, and set the load to 0a. 4) connect the dvm across the out pcb pad and the pgnd2 pcb pad. 5) verify that no shunts are installed across pins 1-2 on jumper ju1 to enable uvlo (see table 1 for details). 6) verify that a shunt is installed across ju3 to disable the external synchronization (see table 3 for details). 7) verify that a shunt is installed across ju2 to enable pwm mode (see table 2 for details). 8) enable the input power supply. 9) verify the dvm display 5v. 10) increase the load up to 3.5a to verify the dvm continue displaying 5v. detailed description of hardware the maxm17504 ev kit is a proven circuit to demonstrate the high-voltage, high-efficiency, and compact solution size of the synchronous step-down dc-dc power mod - ule. the output voltage is preset to 5v to operate from 11v to 60v and provides up to 3.5a load current. the optimal frequency is set at 500khz to maximize efficiency and minimize component size. the ev kit includes jumper ju1 to enable/disable uvlo of the device, ju2 to configure in pwm, pfm, or dcm mode in advance of light-load efficiency, and ju3 to enable/disable external clock synchronize (sync). the reset pcb pad is also available for monitoring output-voltage regulation to enable/disable the application circuit of the load. soft-start input (ss) the device utilizes an adjustable soft-start function to limit inrush current during startup. the soft-start time is programmed by the value of c1, the external capacitor from ss to gnd. the selected output capacitance (c sel ) and the output voltage (v out ) determine the minimum value of c1, as shown by the following equation: 3 sel out c1 28 10 c v ? ? where c1 is in nf and c sel is in f. the soft-start time (t ss ) is calculated by the equation below: ss t c1/ 5.55 = where t ss is in ms and c1 is in nf. programmable undervoltage-lockout (uvlo) the ev kit offers an adjustable input undervoltage-lockout level by resistor-dividers connecting between the in, en/ uvlo, and gnd pins. for normal operation, a shunt should not be installed across pins 1-2 on ju1 to enable the output through an internal pullup 3.3m? resistor from en/uvlo pin to in pin. to disable the output, install the shunt across pins 1-2 on ju1 to pull the en/uvlo pin to gnd. see table 1 for ju1 setting details. the ev kit also provides an optional r3 pcb footprint to program a uvlo threshold voltage at which an input voltage level device turns on. the r3 resistor can be calculated by the following equation: inu 4009.5 r3 (v 1.215) = ? where v inu is the input voltage at which the device is required to turn on, and r3 unit is in k?. table 1. uvlo enable/disable configuration (ju1) * default position. shunt position en pin maxm17504_ output installed connected to gnd disable not installed* connected to vin enable downloaded from: http:///
maxim integrated 3 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit mode selection (mode) the devices mode pin can be used to select among pwm, pfm, or dcm modes of operation in advance of constant frequency or high-efficiency at light-load. the logic state of the mode pin is latched when the v cc and en/uvlo voltage exceed the respective uvlo rising thresholds and all internal voltages are ready to allow lx switching. the changes on the mode pin are ignored during normal operation. refer to the maxm17504 data sheet for more information on the pwm, pfm, and dcm modes of operation. table 2 shows ev kit jumper settings that can be used to configure the desired mode of operation. external clock synchronization (sync)the internal oscillator of the device can be synchronized to an external clock signal to eliminate beat frequency between regulators through the sync pin. the external synchronization clock frequency must be between 1.1f sw to 1.4f sw , where f sw is the frequency of operation set by r5. the minimum external clock high-pulse width and amplitude should be greater than 50ns and 2.1v, respec - tively. the minimum external clock low-pulse width should be greater than 160ns, and the maximum external clock low-pulse amplitude should be less than 0.8v. table 3 describes the connection of the sync pin.setting v out with a resistive voltage divider at fb the maxm17504 ev kit is preset for 5v and offers an adjustable output voltage range from as low as 0.9v up to 12v at 3.5a maximum load. the adjustable output voltage can be programmed by the set of resistor dividers r1 and r2. refer to table 1 (selection component values) in the maxm17504 data sheet to select optimal component values for each specific input voltage range from 4.5v up to 60v and an output voltage from 0.9v up to 12v. to obtain an output voltage other than the default setting outputs in table 1, only seven component (r1, r2, c1, c2, c3, c4, and c8) values are needed to modify the equation described in the setting the output voltage section of the maxm17504 data sheet. table 2. mode description (ju2) table 3. sync description (ju3) * default position. * default position. shunt position mode pin maxm17504 mode not installed unconnected pfm mode of operation 1-2 connected to v cc dcm mode of operation 2-3* connected to gnd pwm mode of operation shunt position sync pin maxm17504_sync 1-2* connected to sgnd sync feature unused not installed connected to test loop on pcb frequency can be synchronized with an external clock downloaded from: http:///
maxim integrated 4 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit (v in = 11v - 60v, v out = 5v, i out = 0 C 3.5a, t a = +25c, unless otherwise noted.) 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 0 1000 2000 3000 v out (v) output current (ma) load and line regulation v out = 5v, pfm mode toc04 mode = open v in = 24v, f sw = 500khz v in = 12v, f sw = 500khz v in = 48v, f sw = 500khz v in = 36v, f sw = 500khz 40 50 60 70 80 90 100 0 1000 2000 3000 efficiency (%) output current (ma) efficiency vs. output current v out = 5v, pfm mode toc01 mode = open v in = 12v, f sw = 500khz v in = 24v, f sw = 500khz v in = 36v, f sw = 500khz v in = 48v, f sw = 500khz 40 50 60 70 80 90 100 0 1000 2000 3000 efficiency (%) output current (ma) efficiency vs. output current v out = 5v, pwm mode toc02 mode = sgnd v in = 12v, f sw = 500khz v in = 24v, f sw = 500khz v in = 36v, f sw = 500khz v in = 48v, f sw = 500khz 40 50 60 70 80 90 100 0 1000 2000 3000 efficiency (%) output current (ma) efficiency vs. output current v out = 5v, dcm mode toc03 mode = v cc v in =12v, f sw = 500khz v in = 24v, f sw = 500khz v in = 36v, f sw = 500khz v in = 48v, f sw = 500khz 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 0 1000 2000 3000 v out (v) output current (ma) load and regulation v out = 5v, pwm mode toc05 mode = sgnd v in = 12v, f sw = 500khz v in = 24v, f sw = 500khz v in = 36v, f sw = 500khz v in = 48v, f sw = 500khz typical operating characteristics (continued) downloaded from: http:///
maxim integrated 5 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit (v in = 11v - 60v, v out = 5v, i out = 0 C 3.5a, t a = +25c, unless otherwise noted.) 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 0 1000 2000 3000 v out (v) output current (ma) load and line regulation v out = 5v, dcm mode toc6 mode = v cc v in = 12v, f sw = 500khz v in = 24v, f sw = 500khz v in = 36v, f sw = 500khz v in = 48v, f sw = 500khz load current transient response v in = 24v, v out = 5v, i out = 0.05a - 1.75a, mode = v cc 2a/div toc09 200s/div i out v out 200mv/div (ac coupled) load current transient response v in = 24v, v out = 5v, i out = 0.05a - 1.75a, mode = open 2a/div toc07 200s/div i out v out 200mv/div (ac coupled) load cur rent t ra nsient r es ponse v in = 24v, v out = 5v, i out = 1.75a - 3.5a, mode = sgnd 2a/div toc10 200 s/div i out v out 20 0mv/div (ac coupled) load current transient response v in = 24v, v out = 5v, i out = 0.05a - 1.75a, mode = sgnd 2a/div toc08 200s/div i out v out 200mv/div (ac coupled) -150 -120 -90 -60 -30 0 30 60 90 120 150 1k 10k 100k 1meg -50 -40 -30 -20 -10 0 10 20 30 40 50 phase margin ( ) gain (db) frequency (hz) closed- loop bode plot v in = 24v, v out = 5v, i out = 3.5a, mode = sgnd gain toc11 phase crossover frequency = 43khz phase margin = 72.8 ? typical operating characteristics downloaded from: http:///
maxim integrated 6 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit note: indicate that you are using the maxm17504 when contacting these component suppliers. supplier website murata americas www.murata.com nec tokin america, inc. www.nec-tokinamerica.com panasonic corp. www.panasonic.com sanyo electric co., ltd. www.sanyodevice.com tdk corp. www.component.tdk.com toko america, inc. www.tokoam.com component supplierscomponent list and schematic refer to the following files attached to this data sheet for component information and schematic: maxm17504ev_bom.xls maxm17504_ev_schematic.pdf downloaded from: http:///
maxim integrated 7 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit figure 2. maxm17504 ev kit component placement guidesolder side figure 1. maxm17504 ev kit component placement guidecomponent side figure 3. maxm17504 ev kit pcb layoutcomponent side downloaded from: http:///
maxim integrated 8 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit figure 4. maxm17504 ev kit pcb layoutpgnd layer 2 figure 5. maxm17504 ev kit pcb layoutpgnd layer 3 figure 6. maxm17504 ev kit pcb layoutsolder side downloaded from: http:///
maxim integrated 9 www.maximintegrated.com evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit #denotes rohs compliant. part type MAXM17504EVKIT# ev kit ordering information downloaded from: http:///
maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and speciications without n otice at any time. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. ? 2015 maxim integrated products, inc. 10 evaluates: maxm17504 in 5v output-voltage application maxm17504 5v output evaluation kit revision number revision date description pages changed 0 4/15 initial release revision history for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com. downloaded from: http:///
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