general description the max1541 evaluation kit (ev kit) demonstrates the max1541? standard 4a application circuit. this dc-dc converter steps down high-voltage batteries and/or ac adapters, generating precision low-voltage gpu, dpr, and chipset power supplies for notebook computers. the max1541 ev kit provides a dynamically adjustable 1.0v/1.5v output voltage (out1), a fixed 2.5v output voltage (out2), and a fixed 5v, 100ma linear regulator (ldoout) from the 7v to 24v battery input range. it delivers up to 4a output current for each output voltage with greater than 90% efficiency. the ev kit operates at 355khz/485khz switching frequency (out2/out1, respectively) and has superior line- and load-transient response. this ev kit is a fully assembled and tested circuit board. it also allows the evaluation of other dynamically adjustable output voltages in the 0.7v to 5.5v range by changing resistors r9, r10, and r11 (out1) and other fixed output voltages in the 0.7v to 5.5v range by changing resistors r18 and r19 (out2). features 7v to 24v input voltage range dynamically selectable output voltages 1.0v/1.5v (out1, adjustable from 0.7v to 5.5v) fixed 2.5v/1.8v output voltage (out2, adjustable from 0.7v to 5.5v) fixed 5v or adjustable 100ma linear regulator 4a output current for each output 355khz/485khz switching frequency (out2/out1, respectively) selectable inductor saturation protection separate power-good outputs selectable overvoltage/undervoltage protection low-profile components fully assembled and tested evaluates: max1541 max1541 evaluation kit ________________________________________________________________ maxim integrated products 1 designation qty description c1, c2 2 10f, 25v ceramic capacitors (1812) taiyo yuden tmk432bj106km or tdk c4532x5r1e106m c3 1 470f, 4v, 10m ? low-esr capacitor sanyo 4tpd470m c4 1 220f, 4v, 15m ? low-esr capacitor sanyo 4tpe220mf c5, c6 2 1f 20%, 10v x5r ceramic capacitors (0805) taiyo yuden lmk212bj105kg or tdk c2012x5r1a105m c7, c8, c14 3 0.1f 10%, 25v x7r ceramic capacitors (0603) murata grm188r71e104k or tdk c1608x7r1e104k c9 1 47pf 5%, 50v c0g ceramic capacitor (0603) murata grm1885c1h470j designation qty description c10 1 0.22f, 25v x5r ceramic capacitor (0805) murata grm219r71e224kc01d or taiyo yuden emk212bj224kg c11 1 1000pf 10%, 50v c0g ceramic capacitor (0603) tdk1608x7r1h102k or murata grm188r71h102k c12, c13 2 470pf 10%, 50v x7r ceramic capacitors (0603) murata grm188r71h471k c15 1 10f, 10v tantal um cap aci tor ( case b) av x tajb10m 010r c16 1 3.3f, 35v tantal um cap aci tor ( case b) avx tajb335m035r c17 c22 0 not installed (0603) d1, d2 2 100ma, 30v schottky diodes central semiconductor cmpsh-3 ordering information 19-2861; rev 0; 7/03 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part temp range ic package MAX1541EVKIT 0 c to +70 c 40 thin qfn 6mm x 6mm component list
evaluates: max1541 max1541 evaluation kit 2 _______________________________________________________________________________________ designation qty description d3, d4 2 1a, 30v schottky diodes nihon ep10qy03 or toshiba crs02 ju1, ju2, ju8, ju9 4 3-pin headers, 0.1 centers ju3, ju6, ju7 3 4-pin headers, 0.1 centers l1 1 1.8h, 5.4a power inductor sumida cdep105(l)-1r8 l2 1 4.3h, 6.8a power inductor sumida cdep105(l)-4r3 n1a, n1b, n2a, n2b 2 dual n-channel mosfets fairchild fds6982a r1 1 20 ? 5% resistor (0805) r2, r3 2 0.015 ? 1%, 1/2w resistors (2010) irc lr2010-01-r015-f or dale wsl-2010-r015f r4, r6, r7, r8, r19, r23, r27, r28, r34 90 ? resistors (0603) designation qty description r5, r16, r17, r18, r22, r24, r25, r31, r32, r33, r35 r38 0 not installed (0603) r9, r10 2 75k ? 1% resistors (0603) r11 1 150k ? 1% resistor (0603) r12, r14 2 100k ? 1% resistors (0603) r13, r15 2 49.9k ? 1% resistors (0603) r20, r21 2 100k ? 5% resistors (0603) r26 1 10 ? 5% resistor (0805) r29, r30 0 not installed (short pc trace) (0603) u1 1 max1541e tl (40-pi n qfn 6mm x 6mm ) none 4 rubber bumpers n one 7 shunts, 0.1 centers none 1 max1541 pc board component list (continued) component suppliers supplier phone fax website avx 843-946-0238 843-626-3123 www.avxcorp.com central semiconductor 516-435-1110 516-435-1824 www.centralsemi.com dale-vishay 402-564-3131 402-63-6296 www.vishay.com fairchild 408-721-2181 408-721-1635 www.fairchildsemi.com irc 361-992-7900 361-992-3377 www.irctt.com murata 770-436-1300 770-436-3636 www.murata.com nihon 847-843-7500 847-843-2798 www.niec.co.jp sanyo 619-661-6835 619-661-1055 www.sanyovideo.com sumida 708-956-0666 708-956-0702 www.sumida.com taiyo yuden 800-348-2496 847-925-0899 www.t-yuden.com tdk 847-390-4373 847-390-4428 www.component.tdk.com note: please indicate that you are using the max1541 when contacting these component suppliers.
evaluates: max1541 max1541 evaluation kit _______________________________________________________________________________________ 3 quick start equipment needed 7v to 24v power supply, battery, or notebook ac adapter dummy loads capable of sinking 4a digital multimeters (dmms) 100mhz dual-trace oscilloscope 1) ensure that the circuit is connected correctly to the supplies and dummy load prior to applying any power. 2) verify that the shunts are across: a) ju1 pins 1 and 2 (on1 high), ju2 pins 1 and 2 (on2 high). b) ju3 pins 1 and 2 (skip/high, forced pwm), ju6 pins 1 and 2 (ovp/uvp enabled). c) ju7 pins 1 and 3 (ton = ref, 450khz switching frequency), ju8 pins 1 and 2 (gate low, v out1 = 1.5v). d) ju9 pins 1 and 2 (linear regulator enabled) 3) turn on vin, input/battery power supply. 4) verify that the output voltages are v out1 = 1.5v, v out2 = 2.5v, and v ldoout = 5v. detailed description jumper settings table 1. jumper ju1 functions (output voltage out1 control) table 2. jumper ju2 functions (output voltage out2 control) table 3. jumper ju3 functions (low- noise mode) ju2 on2 pin out2 1 & 2 (default) connected to v cc . out2 enabled, v out2 = 2.5v . 2 & 3 connected to gnd. out2 shutdown mode. not installed on2 must be driven by an external signal connected to on1 pad. out2 operation depends on the external on2 signal levels. ju3 skip pin operational mode 1 & 2 (default) connected to v cc . low- noise mod e, ou t1 and ou t2 ar e i n for ced - pwm mod e. 1 & 3 connected to ref. out1 is in pulse- skipping mode; out2 is in forced- pwm mode. 1 & 4 connected to gnd. out1 and out2 are in pulse-skipping mode. not installed open. out1 is in forced- pwm mode; out2 is in pulse-skipping mode. ju1 on1 pin out1 1 & 2 (default) connected to v cc . out1 enabled, v out1 = 1.5v . 2 & 3 connected to gnd. out1 shutdown mode. not installed on1 must be driven by an external signal connected to on1 pad. out1 operation depends on the external on1 signal levels.
evaluates: max1541 table 5. jumper ju7 functions (switching-frequency selection) note: do not change the operating frequency without first recalculating component values because the frequency has a significant effect on preferred inductor value, peak current-limit level, mosfet heating, pfm/pwm switchover point, output noise, efficiency, and other critical parameters. table 6. jumper ju8 functions (gate) table 7. jumper ju9 functions (linear regulator ldoout control) evaluating other dynamic output voltages (out1) the ev kit output is preset to 1.0v/1.5v (out1), 2.5v (out2), and 5v (ldoout). however, out1 can also be adjusted between 0.7v and 2v (fb1 = out1) by selecting r9, r10, and r11 values. the max1541 regu- lates fb1 to the voltage set at refin1. by changing the voltage at refin1, the max1541 can be used in appli- cations that require dynamic output-voltage changes between two set points. using the gate signal and open-drain output (od), a resistor can be switched in and out of the refin1 resistor-divider, changing the voltage at refin1. a logic high on gate turns on the internal n-channel mosfet, forcing od to a low- impedance state. a logic low on gate disables the n- channel mosfet, so od is high impedance. the two output voltages (fb1 = out1) are determined by the following equations: v out1(low) = v ref (r10 / (r9 + r10)) v out1(high) = v ref (r10 + r11) / (r9 + r10 + r11) where v ref = 2.0v. refer to the max1540/max1541 data sheet for selec- tion of output capacitor and inductor values for output voltages greater than 2v. max1541 evaluation kit 4 _______________________________________________________________________________________ table 4. jumper ju6 functions (overvoltage/undervoltage protection selection) note: the max1541 detects and latches the discharge-mode state set by ovp/uvp on startup. ju6 ovp/uvp pin uvp ovp/discharge mode 1 & 2 (default) connected to v cc . uvp is enabled; uvp threshold is 70% of nominal. ovp and discharge mode are enabled; ovp threshold is 116% of nominal. 1 & 3 connected to ref. uvp is enabled. ovp and discharge mode are disabled. 1 & 4 connected to gnd. uvp is disabled. ovp and discharge mode are disabled. not installed floating. uvp is disabled. ovp and discharge mode are enabled. ju7 ton pin frequency (out1/out2) (khz) 1 & 2 connected to v cc . 235/170 1 & 3 (default) connected to ref. 485/355 (as shipped) 1 & 4 connected to gnd. 620/460 not installed floating. 345/255 ju8 gate pin out1 1 & 2 (default) connected to gnd. a l og i c l ow on gate tur ns off the i nter nal m os fe t so that od ap p ear s as hi g h i m p ed ance, v o u t 1 = 1 .5 v . 2 & 3 connected to v cc . a l og i c hi g h on g ate tur ns on the i nter nal m os fe t, p ul l i ng o d to g r ound , v ou t 1 = 1.0v . not installed gate m ust b e d r i ven b y an exter nal si g nal connected to gate p ad . out1 voltage depends on the external gate signal levels. ju9 ldoon pin ldoout 1 & 2 (default) connected to ldoin through ju5. ldoout enabled, v ldoout = 5v . 2 & 3 connected to gnd. shutdown mode. not installed ldoon connected to voltage-divider r24/r25. r24 and r25 set the ldoin undervoltage lockout threshold.
evaluating other fixed-output voltages (out2) the max1541 provides a fixed 2.5v output (out2) when fb2 is connected to gnd (r18 = open, r19 = 0, r38 = open) or fixed 1.8v output when fb2 is connect- ed to v cc (r18 = open, r19 = open, r38 = 0). out2 can also be adjusted from 0.7v to 5.5v by using a resistive voltage-divider formed by r18 and r19 (r38 = open). the max1541 regulates fb2 to a fixed refer- ence voltage (0.7v). the adjusted output voltage is: v out2 = v fb2 (1 + r18 / r19) where v fb2 = 0.7v. refer to the max1540/max1541 data sheet for selec- tion of output capacitor and inductor values for different output voltages. evaluating other linear-regulator output voltages (ldoout) the max1541 provides a fixed 5v linear-regulator out- put (ldoout) when ldoon is connected to vin. however, the linear output voltage can be adjusted between 1.25v and 24v by selecting r22 and r23 val- ues. the adjusted linear output voltage is: v ldoout = v fbldo (1 + r22 / r23) where v fbldo = 1.25v. note: when ldoout is set to a voltage other than +5v, cut the trace short across ju4 and connect a sep- arate 5v source to vbias. note: make sure ldoout capacitors c14 and c15 have the correct voltage rating to match the ldoout voltage. evaluates: max1541 max1541 evaluation kit _______________________________________________________________________________________ 5
evaluates: max1541 max1541 evaluation kit 6 _______________________________________________________________________________________ n n max1541 u1 vbias vdd v dd v cc lsat bst2 dh2 lx2 dl2 gnd csp2 csn2 ldoin ldoon out2 ldoout fbldo pgood1 pgood2 on2 on1 fb2 ovp/uvp bst1 dh1 lx1 dl1 csp1 csn1 out1 cc1 fb1 skip refin1 ref od fblank ilim1 ilim2 gate ton v+ vdd vcc ju3 vcc ju4 ju5 ju1 ju2 ju6 ju9 n2-b 1 1 2 2 3 1 2 3 1 2 3 1 2 3 4 3 4 5 6 78 n2-a vout2 vout2 2.5v 4a vout2 ref ldoout vin ref ref ref ref ref ref ref 450khz 600khz 200khz vcc vcc vcc vcc vcc gate vin vcc vcc vcc vcc vcc vcc on2 on1 ldoin ldoon ldoout ldoout pgood1 pgood2 d4 n1-b 1 1 2 2 3 3 4 4 ju7 ju8 float = 300khz 1 3 2 2 3 1 4 5 6 7 8 n1-a d3 gnd gnd vin 24v max vin vout1 vout1 vout1 1.5v/1v 4a d2 cmpsh-3 d1 cmpsh-3 l2 4.3 h l1 1.8 h c8 0.1 f c7 0.1 f c10 0.22 f c6 1 f 10v c14 0.1 f gnd r3 0.015 ? 1% r26 10 ? r34 0 ? r23 0 ? r20 100k ? r21 100k ? r38 open r18 open r19 0 ? r22 open r24 open r25 open r33 open r1 20 ? r7 0 ? r8 0 ? r6 0 ? r4 0 ? r9 75k ? 1% r10 75k ? 1% r11 150k ? 1% r12 100k ? 1% r13 49.9k ? 1% r15 49.9k ? 1% r14 100k ? 1% r5 open r16 open r36 open r37 open r35 open r27 0 ? r28 0 ? r2 0.015 ? 1% r31 open r32 open r30 r29 short (pc trace) short (pc trace) c4 220 f 4v c2 10 f 25v c5 1 f 10v c18 open c17 open c20 open r17 open c21 open c9 47pf c11 1000pf c13 470pf c12 470pf c19 open c16 3.3 f 35v c3 470 f 4v c1 10 f 25v c15 10 f 10v skip vin 5 3 30 32 31 28 37 36 34 7 35 2 11 10 12 38 8 9 6 4 25 23 20 18 19 22 21 13 14 24 29 16 26 27 33 17 39 40 15 1 vout2 c22 open figure 1. max1541 ev kit schematic
evaluates: max1541 max1541 evaluation kit _______________________________________________________________________________________ 7 figure 4. max1541 ev kit pc board layout?omponent side figure 5. max1541 ev kit pc board layout?round layer 2 figure 2. max1541ev kit component placement guide?op silkscreen figure 3. max1541 ev kit component placement guide bottom silkscreen
evaluates: max1541 max1541 evaluation kit maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2003 maxim integrated products printed usa is a registered trademark of maxim integrated products. figure 6. max1541 ev kit pc board layout?round layer 3 figure 7. max1541 ev kit pc board layout?older side
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