_______________________________________________________________ maxim integrated products 1 for pricing, delivery, and ordering information, pl ease contact maxim direct at 1-888-629-4642, or visit maxim?s website at www.maxim-ic.com. max15046b evaluation kit evaluates: max15046b 19-4920; rev 0; 8/09 general description the max15046b evaluation kit (ev kit) is a fully assem- bled and tested circuit board that contains all the com- ponents necessary to evaluate the performance of the max15046b 10a synchronous step-down controller. the max15046 ic is available in a small 16-pin qsop pack- age with an exposed pad. the max15046b ev kit requires a 5v to 40v input- voltage range power supply that provides up to 7a for normal operation. the max15046b ev kit output is con- figured to 3.3v and delivers up to 10a output current. the controller?s switching frequency is programmed to 350khz. the max15046b ev kit includes pcb pads to enable the circuit and to monitor the power-good output. features s 5v to 40v (24v typ) input range s optional 4.5v to 5.5v input range s 3.3v at 10a output s 350khz switching frequency s enable input s power-good output s fully assembled and tested ordering information + denotes lead(pb)-free and rohs compliant. component list part type MAX15046BEVKIT+ ev kit designation qty description c1 1 100 f f q 20%, 50v electrolytic capaci- tor ( 8mm x 10.2mm) panasonic eevfk1h101p c2, c19 2 0.1 f f q 10%, 50v x7r ceramic capaci- tors (0603) murata grm188r71h104k c3 1 1 f f q 10%, 50v x5r ceramic capacitor (0805) murata grm21br71h105k c4 1 4.7 f f q 10%, 6.3v x5r ceramic capacitor (0603) murata grm188r60j475k c5 1 2.2 f f q 10%, 6.3v x5r ceramic capacitor (0603) murata grm188r60j225k c6, c7 2 10 f f q 20%, 50v x5r ceramic capaci- tors (1210) taiyo yuden umk325bj106mm c8 1 0.47 f f q 10%, 16v x7r ceramic capacitor (0603) murata grm188r71c474k c9 1 1000pf q 5%, 50v c0g ceramic capacitor (0805) murata grm2165c1h102j designation qty description c10, c11 2 100 f f q 20%, 6.3v x5r ceramic capacitors (1210) murata grm32er60j107m c12 1 47 f f q 10%, 6.3v x5r ceramic capaci- tor (1206) murata grm31cr60j476k c13 1 68pf q 5%, 50v c0g ceramic capacitor (0603) murata grm1885c1h680j c14 1 15pf q 5%, 50v c0g ceramic capacitor (0603) murata grm1885c1h150j c15 1 1500pf q 10%, 50v c0g ceramic capacitor (0603) murata grm1885c1h152k c16 1 220pf q 5%, 50v c0g ceramic capaci- tor (0603) murata grm1885c1h221j c17, c20 0 not installed, ceramic capacitors (0603) c18 0 not installed, ceramic capacitor (0805) downloaded from: http:///
max15046b evaluation kit evaluates: max15046b 2 ______________________________________________________________________________________ component list (continued) * ep = exposed pad. note: indicate that you are using the max15046b when contacting these component suppliers. component suppliers supplier phone website diodes, inc. 805-446-4800 www.diodes.com murata electronics north america, inc. 770-436-1300 www.murata-northamerica.com panasonic corp. 800-344-2112 www.panasonic.com taiyo yuden 800-348-2496 www.t-yuden.com vishay 402-563-6866 www.vishay.com designation qty description d1 1 0.5a, 60v schottky diode (sot23) diodes, inc. zhcs506 (top mark: s56) ju1 1 2-pin header ju2 1 3-pin header l1 1 1.5 f h, 27.5a inductor vishay ihlp-4040dz er1r5m n1 1 60v, 6.2a n-channel mosfet (powerpack 8 so) vishay (siliconix) si7850dp-t1-e3 n2 1 60v, 11a n-channel mosfet (powerpack 8 so) vishay (siliconix) si7460dp-t1-e3 pgnd (x2), vin, vout 4 uninsulated banana jacks tp1, tp2 2 pc mini red test points r1 1 0 i q 5% resistor (1210) r3 1 10 i q 5% resistor (0603) r4 1 51k i q 5% resistor (0603) r5 1 2.2 i q 5% resistor (0603) designation qty description r7 1 10 i q 1% resistor (1210) vishay (dale) crcw121010r00fnea r8 0 not installed, resistor (0603) r9 1 32.4k i q 1% resistor (0603) r10 1 22.6k i q 1% resistor (0603) r11 1 3.65k i q 1% resistor (0603) r12 1 105k i q 1% resistor (0603) r13 1 23.2k i q 1% resistor (0603) r14 1 43.2k i q 1% resistor (0603) r15 1 49.9 i q 1% resistor (0805) r16, r17 2 0 i q 5% resistors (0603) u1 1 10a synchronous step-down controller (16 qsop-ep*) maxim max15046baee+ ? 2 shunts (ju1, ju2) ? 1 pcb: max15046b evaluation kit+ downloaded from: http:///
max15046b evaluation kit evaluates: max15046b _______________________________________________________________________________________ 3 quick start required equipment ? adjustable 5v to 40v, 7a dc power supply ? electronic load capable of sinking up to 10a (e.g., hp6060b) ? two voltmeters procedure the max15046b ev kit is fully assembled and test- ed. follow the steps below to verify board operation. caution: do not turn on the power supply until all connections are completed. 1) verify that a shunt is not installed on jumper ju1 (vin input source for u1). 2) install a shunt on pins 1-2 of jumper ju2 (vout enabled). 3) connect a voltmeter to the vout and pgnd pcb pads. 4) connect a voltmeter to the pgood and gnd pcb pads. 5) connect a 10a electronic load to the vout and pgnd banana jack connectors. 6) connect a dc power supply to the vin and pgnd banana jack connectors and set the voltage to 24v. 7) enable the power supply. 8) enable the electronic load and set it to 5a. 9) verify that the voltmeters at vout and pgood are 3.3v and approximately 5.2v, respectively. detailed description of hardware the max15046b ev kit is a fully assembled and tested circuit board that contains all the components neces- sary to evaluate the performance of the max15046b 10a synchronous step-down controller. the circuit uses a max15046b step-down controller ic to implement a step-down synchronous dc-dc converter circuit. the max15046b ev kit is designed to operate from a single dc power supply that provides 5v to 40v and 7a of cur- rent. for improved efficiency, the max15046b controller can also be operated using a 4.5v to 5.5v power source applied at the vin and pgnd pcb pads and shorting together (ju1) the max15046b ic in and vcc inputs. when operating the max15046b ev kit using separate power-supply sources at the vin connector and vcc pcb pads, apply power at the vin and pgnd connec- tors and then the vcc and gnd pcb pads. the max15046b ev kit converter is configured to 3.3v and provides up to 10a output current. the switching frequency is set to 350khz using resistor r14. the ev kit features pcb pads to evaluate the enable input signal (en) and to monitor the power-good (pgood) output signal. converter input source banana jack connectors vin and pgnd connect the power source for the converter. the max15046b ev kit converter output performance is optimized over the 5v to 40v vin input voltage, while providing up to 10a output current. the max15046b ev kit can operate at higher output currents; however, performance may be degraded due to the limitation of the components used on the circuit, which might require reevaluation. max15046b ic bias input (ju1) the max15046b ev kit features an option to select the bias input for the max15046b ic controller when config- uring the ev kit to operate with an input source less than 6v. jumper ju1 selects the input-voltage source for the max15046b ic controller vcc pin. remove the shunt on jumper ju1 to power the max15046b ic using the power source applied at the vin and pgnd banana jack con- nectors. the input-voltage range at vin in this configu- ration is 5.5v to 40v. when operating the max15046b ev kit using separate power-supply sources at the vin connector and vcc pcb pads, apply power at the vin and pgnd connectors first and then the vcc and gnd pcb pads. to operate with a source less than 6v, install a shunt across jumper ju1. then power the max15046b ev kit vin input using a power source applied at the vin and pgnd pcb pads. note that the power source applied to the vin pcb pad in this configuration has a 4.5v to 5.5v input-voltage range. table 1. max15046b bias input configuration (ju1) shunt position max15046b in pin max15046b ev kit input range (v) installed connected to vcc 4.5 to 5.5 not installed connected to vin 5.5 to 40 downloaded from: http:///
max15046b evaluation kit evaluates: max15046b 4 ______________________________________________________________________________________ configuring the output voltage the max15046b ev kit?s vout voltage can be recon- figured between 0.6v to 0.85 x vin. to configure the max15046b ev kit?s output voltage, refer to the setting the output voltage section in the max15046 ic data sheet for instructions on selecting new resistor values. capacitors c13?c16 and resistors r10 and r11 provide a compensation network for vout on the max15046b ev kit circuit. refer to the inductor selection , input capacitor , and compensation design sections in the max15046 ic data sheet to verify whether other components need replace- ment for proper operation after reconfiguring the output voltage. current-limit thresholds the max15046b ic employs a current-sensing algorithm using the low-side mosfet on-resistance as a current- sensing element to limit the inductor current. the induc- tor current is sensed in the converter by sensing the volt- age drop across the on-resistance (r dson ) of low-side mosfet n2. the max15046b ev kit?s valley and sink current limits are set to 13.5a and 6.75a, respectively. resistor r9 sets vout valley current-limit voltage thresh- old (v ith ) to 162mv. the sink current-limit voltage threshold is approximately one-half the valley current- limit voltage threshold. use the following equation to reconfigure the valley current-limit voltage threshold: ith lim 6 v 10 r ( ) 50 10 ? ? = where v ith is the valley current-limit voltage threshold in volts and r lim is r9 in ohms. refer to the current-limit circuit (lim) and setting the valley current limit sections in the max15046 ic data sheet for further instructions on computing the max15046b ev kit valley and sink current limits. surface-mount pcb pads for resistor r8 are provided to implement foldback current-limit capabilities if required. switching frequency the max15046b controller switching frequency is set to 350khz by resistor r14. replace resistor r14 with a new resistor value to program the switching frequency between 100khz and 1mhz. use the following equa- tion to calculate r14 when reconfiguring the switching frequency: 9 7 2 sw sw 17.3 10 r14 f (1x10 )x(f ) ? = + where f sw is in hertz and r14 is in ohms. when reconfiguring the ev kit controller switching fre- quency, it may be necessary to change compensa- tion network component to new values. refer to the compensation design section in the max15046 ic data sheet for computing new compensation component values. power-good output (pgood) the max15046b ev kit provides a pgood pcb pad to monitor the status of the u1 power-good output signal. pgood is high when vout rises 94.5% (typ) above its programmed output voltage. when vout falls below 92% (typ) of its nominal regulated voltage, pgood is pulled low. the pgood signal is pulled up to vcc by resistor r4. enable control (ju2) jumper ju2 configures the max15046b ev kit?s output enable for turn on/off control. install a shunt on pins 1-2 of jumper ju2 to enable vout. conversely, vout is disabled when the shunt is placed across pins 2-3 of jumper ju2. alternatively, the max15046b ic enable pin (en) can be controlled by an external controller. surface- mount pcb pads for optional capacitor c17 are included to filter noise that may be introduced on the en pin. table 2. enable control (ju2) shunt position en pin vout output 1-2 connected to vcc through r3 enabled 2-3 pulled down to gnd disabled not installed external controller external controller enables/disables downloaded from: http:///
max15046b evaluation kit evaluates: max15046b _______________________________________________________________________________________ 5 figure 1. max15046b ev kit schematic downloaded from: http:///
max15046b evaluation kit evaluates: max15046b 6 ______________________________________________________________________________________ figure 2. max15046b ev kit component placement guide? component side figure 4. max15046b ev kit pcb layout?gnd and vin l ayer 2 figure 3. max15046b ev kit pcb layout?component side 1.0? 1.0? 1.0? downloaded from: http:///
maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 7 ? 2009 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. max15046b evaluation kit evaluates: max15046b figure 5. max15046b ev kit pcb layout?pgnd layer 3 figure 6. max15046b ev kit pcb layout?solder side 1.0? 1.0? downloaded from: http:///
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