mp8904 500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 1 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. the future of analog ic technology description the mp8904 is a low-current, low-dropout linear regulator operating over a single input supply between 2.5v to 6.5v. the output voltage of the mp8904 is adjustable via an external resistor divider. the mp8904 can supply up to 500ma of load current. the enable pin (en) allows the part to be put into a low current shutdown mode (en=0). the mp8904 features thermal overload and current limit protection. it is available in an 8-pin qfn (2mm x 3mm) package features ? power good open collector output ? operates from 2.5v ? 6.5v input ? low 300mv dropout at 500ma output ? stable with very small ceramic capacitors ? 2% feedback reference ? adjustable output voltage option from 0.5v to 5v using an external resistor divider ? better than 0.001%/ma load regulation ? stable with low-esr output capacitor ? low 100 a ground current ? internal thermal protection ? current limit protection ? 6a typical quiescent current at shutdown applications ? low current regulators ? battery powered systems ? cellular phones ?mps? and ?the future of analog ic technology? are registered trademarks of monolithic power systems, inc. typical application mp8904 out fb gnd 8 5 3 1 4 6 in en pg v out r1 r2 v in power good 5v
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 2 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. ordering information part number* package top marking free air temperature (t a ) MP8904DD qfn8 (2mm x 3mm) t3 ?40 c to +85 c * for tape & reel, add suffix ?z (e.g. MP8904DD?z) for rohs compliant packaging, add suffix ?lf (e.g. MP8904DD?lf?z) package reference top view out nc pg fb 1 2 3 4 in nc gnd en 8 7 6 5 exposed pad on backside connect to gnd absolute maxi mum ratings (1) in, fb to gnd................................?0.3v to +7v en to gnd ............................ ?0.3v to v in +0.3v out ..................................... ?0.3v to v in + 0.3v continuous power dissipation (t a = +25c) (2) ??????????????????.2.5w junction temperature ...............................150 c lead temperature ....................................260 c storage temperature ............. ?65c to +150 c recommended operating conditions (3) input voltage v in .............................2.5v to 6.5v output voltage ...................................0.5v to 5v load current ...........................500ma maximum operating junct. temp (t j )..... ?40 c to +125 c thermal resistance (4) ja jc qfn8 (2mm x 3mm) ...............55 ...... 12 ... c/w notes: 1) exceeding these ratings may damage the device. 2) the maximum allowable power dissipation is a function of the maximum junction temperature t j (max), the junction-to- ambient thermal resistance ja , and the ambient temperature t a . the maximum allowable continuous power dissipation at any ambient temperature is calculated by p d (max)=(t j (max)- t a )/ ja . exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. internal thermal shutdown circuitry protects the device from permanent damage. 3) the device is not guaranteed to function outside of its operating conditions. 4) measured on jesd51-7 4-layer board.
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 3 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. electrical characteristics v in = 3.3v, v out = 1.2v, c out = 4.7f, c in = 2.2f, t a = +25 c, unless otherwise noted. parameter symbol condition min typ (5) max units operating voltage i out = 1ma 2.5 6.5 v i out = 1ma (7) 100 a ground pin current i out = 500ma 5 ma shutdown current v en = 1.45v, v in = 5v 7 a 0.484 0.496 0.508 fb regulation voltage ?40 c t a +85 c 0.481 0.496 0.510 v dropout voltage (8) i out = 500ma 300 mv line regulation i out = 1ma, v in = (v out + 0.5v) to 6.5v (8) 0.005 %/v load regulation i out = 1ma to 500ma, v in = v out + 0.5v 0.001 %/ma power good output voltage low (9) v ol i sink = 5ma 0.5 v en input high voltage 1.5 v en input low voltage 0.4 v en input bias current v en = 1.5v, 5v 0.01 1 a thermal protection 155 c current limit 550 730 ma notes: 5) parameter is guaranteed by design, not production tested. 6) resistors for v out measurement are 10k ? , 14k ? , 1% 7) the ground current does not include current through feedback current 8) dropout voltage is defined as the input to output different ial when the output voltage drops 1% below its nominal value 9) v feedback is 90% of the regulated value with 10k ? pull-up to 5v
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 4 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. typical performanc e characteristics c1=2.2 f, c2 =4.7 f, c3=1nf, t a = +25 c, unless otherwise noted. (reference figure 2) 3.33 3.32 3.31 3.30 3.29 3.28 load regulation v in =3.6v 3.83 3.32 3.3 3.30 3.29 3.28 0 3.5 3.9 4.3 4.7 5.1 5.5 line regulation 1.83 1.82 1.81 1.80 1.79 1.78 0 100 200 300 400 500 600 v in =2.5v v in =3.3v v in =5v 1.83 1.82 1.81 1.80 1.79 1.78 0 100 200 300 400 500 0 100 200 300 400 500 load regulation v in =2.5v 1.82 1.81 1.80 1.79 1.78 1.77 line regulation 1.808 1.804 1.800 1.796 1.792 1.788 v o (v) v o (v) v o (v) v o (v) v o (v) v o (v) 100 200 300 400 500 600 2.5 3.0 3.5 4.0 4.5 5.0 i load current (ma) i load current (ma) v in =5v 0.61 0.60 0.59 0.58 0.57 0.56 0 100 200 300 400 500 i load current (ma) i load current (ma) i load current (ma) load regulation v in =2.5v 0.63 0.62 0.61 0.60 0.59 0.58 2.5 3 3.5 4 4.5 5 5.5 v in voltage (v) input voltage (v) input voltage (v) line regulation 0.40 0.35 0.30 0.25 0.20 0.15 0.10 vdropout (v) 100 200 300 400 500 i load current(ma) voltage dropout vs current v o =1.8v-3.3v v in =2.5v v in =3.3v v o (v) v o (v) 85 c load regulation -40 c load regulation
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 5 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. typical performanc e characteristics c1=2.2 f, c2 =4.7 f, c3=1nf, t a = +25 c, unless otherwise noted. (reference figure 2) v o 50mv/div. v in 0.5v/div. 2 ms/div. line transient v in = 2.5v to 3.5v, v o = 1.8v, v en = v in , i load = 50ma, with resisitor load v o 100mv/div. i load 0.2a/div. 400 s/div. load transient v in = 2.5v, v o = 1.8v, v en = v in , i load = 50 to 300ma, with resistor load v o 1v/div. v en 1v/div. i load 0.1a/div. 100 s/div. v in = 3.3v, v o = 1.8v,v en = 0v - 2v, i o = 200ma, with resisitor load v in = 3.3v, v o = 1.8v,v en = 2v - 0v, i o = 200ma, with resisitor load en 2v/div. v o 0.5v/div. i load 0.2a/div. 1ms/div. 90 80 70 60 50 40 30 20 10 0 psrr vs frequency enable turn on enable turn off v fb (mv) -50 -20 10 40 70 100 0.1 1.0 10 100 1000 10000 temperature (c) v fb vs temperature v in =2.5v, v en =v in, i load =1ma 10 9 8 7 6 5 495.0 494.5 494.0 493.5 493.0 492.5 492.0 1 2 3 4 5 6 input voltage (v) input voltage (v) frequency (hz) 170 160 150 140 130 120 i s current ( ? ) i q current ( ? ) 1 2 3 4 5 6 supply current vs. input voltage shut down current vs. input voltage psrr (db) v in 2v/div. pg 5v/div. v o 1/div. i load 0.5/div. 400 s/div. thermal protection v in = v en = 5v, v o = 1.8v, i load = 0.5a v pg 0.2a/div. v pg 0.2a/div.
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 6 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. typical performanc e characteristics c1=2.2 f, c2 =4.7 f, c3=1nf, t a = +25 c, unless otherwise noted. (reference figure 2) pg 2v/div. v o 1v/div. i load 1a/div. short circuit protection v in = 4v, v o = 1.8v, v en = v in pg 2v/div. v o 1v/div. i load 1a/div. short circuit recovery v in = 4v, v o = 1.8v, v in = v en
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 7 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. pin functions operation the mp8904 is a low-current, low-voltage, low- dropout, linear regulator. it is intended for use in devices that require very low voltage, low quiescent current power, such as wireless modems, pagers, and cellular phones. the mp8904 uses a pnp pass element and features internal thermal shutdown and internal current limit circuit. v in pg gnd fb out en 5v pg 8 -- + -- + v out c2 r2 0.5v ref r1 r3 thermal protect c1 3 5 6 4 1 figure 1?block diagram of ultra low noise adjustable output regulator pin # name description 1 out regulator output. out is the output of the linear regulator. bypass out to gnd with a 4.7 f or greater capacitor. 2 nc no connect. 3 pg power good open collector output 4 fb feedback input. connect a resistive voltage di vider from out to fb to set the output voltage. out feedback threshold is 0.5v. 5 en enable input. drive en higher than 1.5v to turn on the mp8904, drive en lower than 0.4v to turn it off. 6 gnd exposed pad the exposed pad and gnd pin must be connected to the same ground plane. 7 nc no connect. 8 in power source input. in supplies the inter nal power to the mp8904 and is the source of the pass transistor. bypass in to gnd with a 2.2 f or greater capacitor.
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 8 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. application information setting the output voltage the mp8904 has an adjustable output voltage, set via an external resistor divider (r1 and r2 in figure 2). ? ? ? ? ? ? ? ? ? = fb fb out v v v 2 r 1 r where v fb = 0.5v, is the out feedback threshold voltage. example: for 2.5v output and r2=10k ? k 40 5 . 0 5 . 0 5 . 2 k 10 1 r = ? ? ? ? ? ? ? = a standard 40k ? ( 1%) resistor can be selected for r1. table 1 lists the selected r1 values for some typical output voltages (assuming r2 = 10k ? ). pg the power good pin is an open collector output a pull up resistor (10k ? recommended). the pull up resistor can be tied to a supply within the voltage range of then pin (0 to 5.5v). for example, the pull up resistor can be tied to the input voltage when it is being monitored by an ic powered from this input voltage. it is mornitor the output voltage, if the output voltage is 10% below its regulation point, the pg pin becomes low. table 1?adjustable output volt age r1 values (r2=10k ? ) v out (v) r1 ( ? ) 1.25 15k 1.5 20k 1.8 26k 2 30k 2.5 40k 2.8 46k 3 50k 3.3 56k 4 70k 5 90k bypass capacitors for lower noise, the reference voltage can be bypassed by an external capacitor. a low esr capacitor, such as the ceramic type, will provide the best performance. typical application circuit mp8904 out fb gnd 8 5 3 1 4 6 in en pg 1.8v c3 1nf v in pg figure 2?typical application circuit
mp8904 ?500ma linear regulator mp8904 rev. 0.91 www.monolithicpower.com 9 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. pcb layout guide pcb layout is very important to achieve good regulation, ripple rejection, transient response and thermal performance. it is highly recommended to duplicate evb layout for optimum performance. if change is necessary, please follow these guidelines and take figure 3 for reference. 1) input and output bypass ceramic capacitors are suggested to be put close to the in pin and out pin respectively. 2) ensure all feedback connections are short and direct. place the feedback resistors and compensation components as close to the chip as possible. 3) connect in, out and especially gnd respectively to a large copper area to cool the chip to improve thermal performance and long-term reliability. mp8904 4 6 8 5 out fb gnd en pg in v in v out r1 r3 r2 c1 c2 in c3 c1 out gnd r3 pg nc en fb gnd nc in out 6 7 8 1 2 3 4 5 c2 r1 r2 top layer figure 3?pcb layout
mp8904 ?500ma linear regulator notice: the information in this document is subject to change wi thout notice. users should warra nt and guarantee that third party intellectual property rights are not infringed upon w hen integrating mps products into any application. mps will not assume any legal responsibility for any said applications. mp8904 rev. 0.91 www.monolithicpower.com 10 4/7/2010 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2010 mps. all rights reserved. package information qfn8 (2mm x 3mm) side view top view bottom view 2.90 3.10 1.90 2.10 0.00 0.05 pin 1 id marking 1.70 0.50 0.25 recommended land pattern 2.90 note: 1) all dimensions are in millimeters. 2) exposed paddle size does not include mold flash. 3) lead coplanarity shall be 0.10 millimeter max. 4) drawing conforms to jedec mo-229, variation vced-2. 5) drawing is not to scale. 1.60 0.70 pin 1 id option b r0.20 typ. detail a pin 1 id index area 1 8 5 4 1.65 1.85 1.50 1.70 0.50 bsc 0.18 0.30 pin 1 id see detail a 0.30 0.50 0.80 1.00 0.20 ref pin 1 id option a 0.30x45? typ.
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