1 typical operating circuit 19-6023; rev 1; 5/12 ordering information appears at end of data sheet. for related parts and recommended products to use with this part, refer to www.maxim-ic.com/max15103.related . general description the max15103 is a small, low-dropout linear regulator optimized for networking, datacom, and server applica - tions. the regulator delivers up to 3a from a 1.7v to 5.5v input supply with output accuracy of q 1.6%. the output is adjustable down to 0.6v with a guaranteed dropout voltage of less than 200mv at full load. the internal p-channel switch is protected with a foldback current limit and thermal shutdown. the max15103 features an external bypass input to reduce noise. this bypass input also serves as a soft- start control. an enable input and power-good output are included for power sequence control. the max15103 is available in a 1.6mm x 2.7mm wlp package and is fully specified from the -40 n c to +85 n c operating temperature range. applications networking telecom/datacom servers base stations pll power features s 1.7v to 5.5v operating range s 200mv dropout guaranteed at 3a s 1.6% output accuracy over line, load, and temperature s adjustable output from 0.6v to 5.2v s foldback current protection s thermal shutdown protection s low noise 15v rms (typ) s small 1.6mm x 2.7mm wlp package r1 0 to 4.6ki r2 600i out fb pg en in c out 22f c in 2.2f inpu t (1.7v to 5.5v) power-good output c ss 100nf ss_byp gnd output (0.6v to v in - 200mv) max15103 max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com. evaluation kit available
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 2 in, en, pg, ss_byp, fb to gnd ........................... -0.3v to +6v out to gnd ............................................... -0.3v to (v in + 0.3v) out short circuit ...................................................... continuous continuous power dissipation (t a = +70 n c) wlp (derate 19.2mw/ n c above +70 n c) .................... 1538mw operating temperature range ........................ -40 n c to +85 n c storage temperature range ......................... -65 n c to +150 n c junction temperature .................................................... +150 n c soldering temperature (reflow) (note 1) ........................ +260 n c wlp junction-to-ambient thermal resistance ( q ja ) .......... 30 c/w absolute maximum ratings note 2: package thermal resistances were obtained using the method described in jedec specification jesd51-7, using a four- layer board. for detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial . stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional opera - tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. package thermal characteristics (note 2) electrical characteristics (v in = 3.3v, v out = 1.5v, v en = v in , i out = 100ma, c in = 2.2f, c out = 22f, t a = t j = -40 n c to +85 n c, typical values are at t a = +25 n c, unless otherwise noted.) (note 3) note 1: the wlp package is constructed using a unique set of package techniques that impose a limit on the thermal profile. the device can be exposed during board-level solder attach and rework. this limit permits only the use of the solder profiles recommended in the industry-standard specification jedec 020a, paragraph 7.6, table 3 for ir/vpr and convection reflow. preheating is required. hand or wave soldering is not allowed. parameter symbol conditions min typ max units in input voltage range v in 1.7 5.5 v input undervoltage lockout v in_uv v in rising 1.624 1.69 v input undervoltage lockout hysteresis v in_uv_hys 40 mv out output voltage range v out 0.6 5.2 v load regulation i out = 30ma to 3a 0.1 %/a line regulation v in = 1.7v to 5.5v, v out = 0.6v, i out = 190ma -0.15 +0.15 %/v dropout voltage i out = 3a, v fb = 580mv (note 4) 65 200 mv in-regulation current limit v in = 5.5v, v fb = 500mv 3.7 a short-circuit foldback current limit v in = 5.5v, v out = 0v, v fb < 100mv 1.8 a output shutdown leakage v in = 5.5v, v out = 0v, v en = 0v, t a = -40 n c to +85 n c 4 f a line transient d v in = 0.5v, t rise = t fall = 5 f s 2 %
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 3 note 3: all devices 100% production tested at t a = +25c. limits over the temperature range are guaranteed by design. note 4: dropout is defined as v in - v out when v out falls 3% below its nominal voltage value. electrical characteristics (continued) (v in = 3.3v, v out = 1.5v, v en = v in , i out = 100ma, c in = 2.2f, c out = 22f, t a = t j = -40 n c to +85 n c, typical values are at t a = +25 n c, unless otherwise noted.) (note 3) parameter symbol conditions min typ max units load transient i out = 100ma to 1a to 100ma, t rise = t fall = 1 f s 1.3 % power-supply rejection frequency = 100khz, i out = 500ma 40 db output voltage noise frequency = 500hz to 100khz, i out = 100ma 15 f v rms fb fb threshold accuracy i out = 190ma, v out = 1.5v to 5v, v in = (v out + 0.3v) to 5.5v 593 600 606 mv i out = 3ma to 3a, v out = 1.5v to 5v, v in = (v out + 0.3v) to 5.5v 590 610 fb input current v fb = 0.6v, v in = 5.5v 1 f a gnd ground supply current i out = 3a 1.8 3.5 ma ground shutdown current v in = 1.7v to 5.5v 1 f a power-good output power-good (pg) threshold v fb moving out of regulation, v hys = 15mv fb = high 638 650 662 mv fb = low 538 550 562 power-good (pg) output- voltage low i pg = 2ma (sink) 25 80 mv power-good (pg) delay 100 f s power-good (pg) leakage v pg = 5.5v 1 f a enable enable input high threshold v en_high 1.2 v enable input low threshold v en_low 0.4 v enable input bias current v en = 0 to 5.5v -1 +1 f a soft-start soft-start charging current v ss_byp = 100mv 8 9.2 12 f a soft-start pulldown resistance v en = 0v, i ss_byp = 2ma 45 100 i thermal shutdown thermal shutdown threshold +160 n c thermal shutdown hysteresis threshold falling 15 n c
4 typical operating characteristics (v in = 1.8v, v out = 1.5v, t a = +25 n c, unless otherwise noted.) dropout voltage vs. output current max15103 toc01 output current (a) dropout (mv) 2.5 2.0 0.5 1.0 1.5 10 20 30 40 50 60 70 80 0 0 3.0 v out = 2.5v v out = 1.8v v out = 5v v out = 3.3v defined v in - v out when v out nominal falls 2% output voltage error vs. output current max15103 toc02 output current (a) output voltage error (%) 2.5 2.0 1.5 1.0 0.5 -0.05 0 0.05 0.10 -0.10 0 3.0 v out = 3v v out = 2.5v v out = 1.5v output voltage vs. input voltage max15103 toc03 input voltage (v) output voltage (v) 4.8 4.3 3.8 3.3 2.8 2.3 1.490 1.495 1.500 1.505 1.510 1.515 i out = 0.5a 1.485 1.8 5.3 output voltage vs. temperature max15103 toc04 temperature (c) output voltage (v) 60 35 10 -15 1.482 1.484 1.486 1.488 1.490 3a load 2a load 1a load 1.492 1.494 1.496 1.498 1.500 1.480 -40 85 no load startup waveforms max15103 toc05 c ss =100nf v en 1v/div i in 2a /div v out 1v/div v pg 1v/div 1ms/div soft-start time vs. capacitor value max15103 toc06 capacitor value (nf) soft-start time (ms) 85 65 45 25 1 2 3 4 5 6 7 8 9 10 0 5 100 fb voltage vs. temperature (v out = 1.5v) max15103 toc07 temperature (c) fb voltage (v) 60 35 10 -15 0.592 0.593 0.594 0.595 0.596 0.597 0.598 0.599 0.600 0.591 -40 85 3a load 2a load no load 1a load 1a load-transient response max15103 toc08 i out 500ma/div v out ac-coupled 50mv/div 100ma 1a 40s/div max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package
5 typical operating characteristics (continued) (v in = 1.8v, v out = 1.5v, t a = +25 n c, unless otherwise noted.) ground current vs. input voltage max15103 toc13 input voltage (v) ground current (ma) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.5 1.0 1.5 2.0 i load = 1a i load = 0a 2.5 3.0 0 05 .5 short-circuit waveforms max15103 toc14 i out 5a/div v pg 2v/div v out 1v/div v in 2v/div 3.3v 200s/div 2a load-transient response max15103 toc09 i out 1a/div v out ac-coupled 50mv/div 100ma 2a 40s/div 3a load-transient response max15103 toc10 i out 1a/div v out ac-coupled 50mv/div 100ma 3a 40s/div line-transient response max15103 toc11 v out ac-coupled 20mv/div v in 200mv/div 1.8v 2.3v i load = 1a 100s/div foldback current-limit waveforms max15103 toc12 i out 2a/div v out 500mv/div 100s/div psrr vs. frequency (i load = 0.5a) max15103 toc15 90 80 70 60 50 40 30 20 10 10hz 1mhz 100khz frequency psrr (db) noise density (i load = 100ma) max15103 toc16 frequency (hz) noise density (v rms ) 10k 1k 6 9 12 15 18 3 100 100k no c ss c ss = 4.7nf c ss = 100nf max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 6 bump description bump configuration bump name function a1 en active-high enable input. drive en logic-high to enable the ldo. connect to in for always-on operation. a2 pg power-good output. open-drain output asserts high when the voltage is within regulation. a3 gnd ground a4 ss_byp ss_byp bypass/soft-start input. connect a ceramic capacitor from ss_byp to gnd to reduce the output noise and set the soft-start ramp time. a5 fb feedback input. connect a resistive divider from out to gnd to set the output voltage. b1, b2, b3, b4, b5 in supply voltage input. connect to supply voltage from 1.7v to 5.5v. bypass in to gnd with a 2.2 f f or greater ceramic capacitor. c1, c2, c3, c4, c5 out regulated output. connect a 22 f f capacitor from out to gnd. for better load transient performance a larger capacitor can be used. wlp top view out out in in ss_byp en max15103 + 12 34 5 a out out in in pg gnd b c out in fb
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 7 functional diagram detailed description the max15103 is a small, low-dropout linear regulator optimized for server, network, and telecom applications. the regulator delivers up to 3a from a 1.7v to 5.5v input supply with output accuracy of q 1.6%. the output is adjustable down to 0.6v with a guaranteed dropout volt - age of less than 200mv at full load. the internal p-chan - nel switch is protected with a foldback current limit and thermal shutdown. the max15103 features an external bypass input to reduce noise. this bypass input also serves as a soft- start control. an enable input and power-good output are included for power sequence control. internal p-channel pass transistor the max15103 features a 3a p-channel mosfet pass transistor. unlike similar designs with pnp pass transistors, the gate-drive current to the p-channel power transistor is extremely low. pnp-based regulators also waste consider - able current in dropout when the pass transistor saturates and uses high base-drive currents under large loads. the max15103 does not suffer from these deficiencies and consumes only 1.8ma of quiescent current even in dropout. output voltage selection the max15103 features an adjustable output. the out - put voltage can be set between +0.6v to v in - 200mv using an external resistive voltage-divider to fb (see the typical operating circuit ). the output voltage is set using the following equation: v out = v fb (1 + r1/r2) where v fb = +600mv. to simplify resistor selection: r1 = r2 (v out /v fb - 1) set r2 to 600 i . thermal- overload protection shutdown logic pg circuitry undervoltage lockout error amplifier i lim out fb pg ref en in 0.60v ss_byp 0.55v 0.65v g m p n gnd max15103
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 8 enable a logic-low on en disables the max15103. in shutdown, the pass transistor, control circuitry, reference, and all biases are turned off, reducing supply current to typically 1 f a. connect en to in for normal operation. in shutdown, the soft-start capacitor is discharged using an internal pulldown resistance. soft-start as shown in the typical operating circuit , the max15103 uses a g m stage and integrating capacitor c ss to control the regulators feedback set point. when en is driven low, the soft-start capacitor is discharged. when en is driven high or power is applied to the device, a constant 9.2 f a current charges the soft-start capacitor. at startup, the feedback set point increases linearly, which reduces the inrush supply current. t ss = 6.315 x 10 -5 x c ss where c ss is in nf. use capacitor values between 30nf to 100nf with voltage ratings greater than 5v. because this ramp is applied to the current-limit com - parator, the actual time for the output voltage to ramp up depends on the load current and output capacitor. leave ss_byp unconnected to disable soft-start. foldback current limiting the max15103 features a 3.7a current limit when the output voltage is in regulation. when the voltage at the output drops to 17% of its nominal value, the current limit exponentially folds back to 1.8a. the output can be shorted to ground for an indefinite period of time without damaging the device. avoid continuous output current of greater than 3a to prevent damage to the regulator. thermal-overload protection a thermal-overload circuit limits total power dissipation in the max15103. when the junction temperature exceeds t j = +160 n c, the thermal sensor turns off the pass tran - sistor, allowing the ic to cool. the thermal sensor turns the pass transistor on once the ics junction temperature drops approximately 15 n c. continuous short-circuit condi - tions will consequently result in a foldback limited output. thermal-overload protection is designed to safeguard the max15103 in the event of fault conditions. for contin - uous operation, do not exceed the junction temperature rating of t j = +125 n c. operating region and power dissipation the power dissipation across the device is p = i out (v in - v out ). the resulting maximum power dissipation is: p max = [(t j(max) - t a )/( b ja )] where (t j(max) - t a ) is the temperature difference between the maximum allowed die junction (+150 n c) and the surrounding air. figure 1 shows the allowable power dissipation for typical pcbs at +25 n c, +50 n c, and +70 n c ambient temperatures (refer to the max15103 ev kit). applications information capacitor selection and regulator stability capacitors are required at the max15103s input and output. connect at least a 2.2 f f capacitor between in and gnd (c in ) and a 22 f f capacitor between out and gnd (c out ). 10f can be used for lower current opera - tion (1a for example). use only surface-mount ceramic capacitors that have low equivalent series resistance (esr). make the input and output traces at least 2.5mm wide, and connect c in and c out within 6mm of the ic to minimize the impact of pcb trace inductance. the output capacitors esr can affect stability and output noise. use capacitors with 50m i or less esr to ensure stability and optimum transient response. this is par - ticularly true in applications with very low output voltage (< 2v) and high output current (> 0.5a). since some capacitor dielectrics can vary over bias volt - age and temperature, consult the capacitor manufacturer specifications to ensure that the capacitors meet these requirements over all combinations of operating voltage and temperature. figure 1. maximum output current curves input-output differential voltage (v) maximum output current (a) 4 3 2 1 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0 0 5 t a = +25nc t a = +50nc t a = +70nc t j = +125nc (based on max15103 ev kit)
max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package 9 input-output (dropout) voltage a regulators minimum input-to-output voltage differential (dropout voltage) determines the lowest usable supply voltage. the dropout voltage is simply the product of regulators r ds(on) for the pass device and rated load current. the max15103s r ds(on) is 20m i , at 3a this yields a dropout voltage of 60mv (see the electrical characteristics and the dropout voltage vs. output current graph in the typical operating characteristics ). noise, psrr, and transient response the max15103 is designed to achieve low dropout voltage while still maintaining good noise, transient response, and ac rejection. when operating from very noisy sources, supply noise rejection and transient response can be improved by increasing the values of the input and output capacitors. the max15103 output noise is typically 15 f v rms (see the noise density graph in the typical operating characteristics ). thermal considerations in pcb layout the rated package dissipation strongly depends on the copper area connected to the regulator. the maximum power dissipation allowed in the package is 1538mw (measured from the max15103 ev kit). more power dissipation can be handled by the package if great attention is given during pcb layout. for example, using the top and bottom copper as a heatsink and connecting the thermal vias to one of the middle layers (gnd) transfers the heat from the package into the board more efficiently, resulting in lower junction temperature at high power dissipation in some max15103 applications. furthermore, the solder mask around the ic area on both top and bottom layers can be removed to radiate the heat directly into the air. the maximum allowable power dis - sipation in the ic is as follows: p max = [(t j(max) - t a )/( b ja )] where (t j(max) - t a ) is the temperature difference between the maximum-allowed die junction (+150 n c) and the surrounding air. a sample layout is available on the max15103 ev kit. + denotes a lead(pb)-free/rohs-compliant package. ordering information part temp range pin-package max15103ewl+ -40 n c to +85 n c 15 wlp chip information process: bicmos package information for the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. package type package code outline no. land pattern no. 15 wlp w151b2+1 21-0205 refer to application note 1891
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. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated products, inc. 160 rio robles, san jose, ca 95134 usa 1-408-601-1000 10 ? 2012 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 0 9/11 initial release 1 5/12 updated the electrical characteristics . 2 max15103 small 3a, low-dropout linear regulator in a 2.7mm x 1.6mm package
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