us72/73 single coil fan driver 3901090261 page 1 of 9 data sheet rev. 002 may/04 features and benefits full bridge driver high sensitivity hall sensor locked rotor shutdown and auto-restart power-efficient cmos and power mosfets integrated tachometer (us72) or alarm (US73) signa l outputs applications for 12v/24v fans ordering information part no. temperature suffix package code us72 e (-40c to 85c) dc (8-pin narrow soic) US73 e (-40c to 85c) dc (8-pin narrow soic) functional diagram locked-rotor protection n1 p2 n2 hall amp. gate drive p1 gate drive 6 3 regulator 4 switching logic clamp 1 out1 out2 8 5 2 7 fg/rd vdd gnd description the us72 and US73 provide a monolithic solution for driving single-coil fans. the bridge drivers provide bi-directional current through the single phase motor winding. us72: the tachometer/frequency generator (fg) version produces a logic signal, which is aligned with the hall plate signal. US73: the rotation detector (rd) / alarm signal version has a low output in the normal condition. when a locked rotor condition occurs the rd changes to a high state.
us72/73 single coil fan driver 3901090261 page 1-2 of 9 data sheet rev. 002 may/04 table of contents features and benefits .............................. ................................................... ............................... 1 applications ....................................... ................................................... .......................................... 1 ordering information ............................... ................................................... ............................... 1 functional diagram................................. ................................................... ............................... 1-1 1. glossary of terms.................................. ................................................... ........................ 3 2. absolute maximum ratings........................... ................................................... ............... 3 3. us72/73 electrical specifications .................. ................................................... .......... 3 4. us72/73 magnetic specifications.................... ................................................... ............ 4 5. general description ................................ ................................................... ...................... 4 6. unique features .................................... ................................................... ........................... 4 7. performance graphs................................. ................................................... .................... 5 8. applications information ........................... ................................................... ................. 6 9. application comments............................... ................................................... .................... 6 10. reliability information............................ ................................................... ..................... 7 11. esd precautions.................................... ................................................... ........................... 7 12. dc package information (soic-8) .................... ................................................... ........... 8 13. disclaimer ......................................... ................................................... .................................. 9
us72/73 single coil fan driver 3901090261 page 3 of 9 data sheet rev. 002 may/04 1. glossary of terms full bridge: two output drivers that can both sour ce or sink current. when a load is placed between the drivers, current can flow through the load in both directions. fg: the frequency generator or tachometer signal; p rovides one pulse for every magnetic pole rd: the rotation detection or lock alarm signal is high when the rotor is blocked or spinning very sl owly. millitesla (mt), gauss: units of magnetic flux dens ity; 1 millitesla = 10 gauss single coil fan: a fan with only one coil winding, usually requiring a bipolar or full-bridge driver locked rotor: the condition of a fan that has stop ped spinning due to mechanical blockage 2. absolute maximum ratings supply voltage, v dd (overvoltage) 28v output voltage, fg or rd 28v output current, i out 500ma operating temperature range, t a -40 to 85 c junction temperature, t j 125 c storage temperature, t s -55 to 150 c esd sensitivity (aec q100 002) 2kv magnetic flux density no limit exceeding the absolute maximum ratings may cause pe rmanent damage. exposure to absolute- maximum-rated conditions for extended periods may a ffect device reliability. 3. us72/73 electrical specifications dc operating parameters t a = 25 o c, v dd = 12v (unless otherwise specified) parameter symbol test conditions min typ max units supply voltage v dd operating 4.5 28 volts supply current i dd v dd = 24v, no load 4 6 ma on resistance r dson full bridge, r nmos + r pmos 3 5.3 ohms bridge current i load peak 500 ma bridge current i load continuous 350 ma thermal resistance r th one-sided pcb, zero lfpm 150 o c/watt locked-rotor period t on 0.25 s locked-rotor period t off 1.25 s freewheel switching delay t fw 200 us fg/rd output leakage i off v out = 24v 10 ua fg/rd on voltage v dson iout = 5ma 0.5 volts
us72/73 single coil fan driver 3901090261 page 4 of 9 data sheet rev. 002 may/04 4. us72/73 magnetic specifications dc operating parameters t a = 25, t a = 25 o c, v dd = 12v (unless otherwise specified) parameter symbol test conditions min typ max units operate point bop 3.0 6.0 mt release point brp -6.0 -3.0 mt hysteresis hys 6.0 mt note: 1 mt = 10 gauss 5. general description the us72 / US73 provide a one-chip solution for 2-w ire or 3-wire fans with a single coil winding. the chip contains the hall-effect sensor, dynamic offset cor rection, and power drivers in a single package. th e output drivers and supply pins are fully protected against switching transients. the fg or rd open-dr ain signal outputs are compatible with any ttl or cmos logic input. 6. unique features the switching of the load current is controlled to limit current slew-rate, and eliminate shoot-throug h currents. the 200us (typical) recirculation allows the current to decay, reducing the switching noise . the built-in locked-rotor protection will automati cally shut off the coil current when the rotor is mechanically blocked, or the rotational speed drops below 60 rpm. the fan will try to restart every 1 .5 seconds until the obstruction is clear. the on / o ff cycling reduces the average stall current to 1/6 normal; this is enough to prevent overheating or da mage to most fans. a common two-coil fan with unipolar drivers only us es half of the coil windings at any time. the one- coil design with full-bridge drivers uses all the windin gs all the time to generate torque. this generally allows for a smaller, more efficient stator design.
us72/73 single coil fan driver 3901090261 page 5 of 9 data sheet rev. 002 may/04 7. performance graphs rdson (nmos + pmos) vs. vdd, temperature 0 2 4 6 8 10 -40 0 40 80 120 junction tem perature (c) rdson (ohms) 4 v 5 v 12 v 30 v us72 / 73 rdson (nmos + pmos) vs. vdd, temperature 0 2 4 6 8 10 4 8 12 16 20 24 28 vdd voltage (v) rdson (ohms) 25 125 us72 / 73 bop, brp vs. temperature -5 -3 -1 1 3 5 -40 0 40 80 120 junction temperature (c) bop, brp (mt) us72 / 73 bop brp bop, brp vs. vdd voltage -5 -3 -1 1 3 5 0 10 20 30 vdd (volts) bop, brp (mt) us72 / 73 bop brp
us72/73 single coil fan driver 3901090261 page 6 of 9 data sheet rev. 002 may/04 8. applications information the optional diode protects against reverse voltage 0.1uf minimum bypass capacitor fg / rd open drain 5v - 24v vdd out2 vss vss 1 vss out1 fg/rd vdd 1 2 4 3 7 8 6 5 0 0 2.438 center of package 0.270 0.130 hall plate die 1.950 center of package measurements in mm. tolerance +/- 0.15 mm. hall sensor location 9. application comments it is advisable to use a vdd C ground bypass capaci tor of at least 0.1uf, located close to the device. ceramic / monolithic types are preferrable. this c apacitor is necessary to maintain a stable power su pply during the switching transients C especially if the re is a series diode in the circuit.
us72/73 single coil fan driver 3901090261 page 7 of 9 data sheet rev. 002 may/04 10. reliability information this melexis device is classified and qualified reg arding soldering technology, solderability and mois ture sensitivity level, as defined in this specification , according to following test methods: ipc/jedec j-std-020 moisture/reflow sensitivity classification for nonh ermetic solid state surface mount devices (classification reflow profiles according to table 5-2) eia/jedec jesd22-a113 preconditioning of nonhermetic surface mount device s prior to reliability testing (reflow profiles according to table 2) cecc00802 standard method for the specification of surface mo unting components (smds) of assessed quality eia/jedec jesd22-b106 resistance to soldering temperature for through-hol e mounted devices en60749-15 resistance to soldering temperature for through-hol e mounted devices mil 883 method 2003 / eia/jedec jesd22-b102 solderability for all soldering technologies deviating from above mentioned standard conditions (regarding peak temperature, temperature gradient, temperature prof ile etc) additional classification and qualificatio n tests have to be agreed upon with melexis. the application of wave soldering for smds is allo wed only after consulting melexis regarding assuran ce of adhesive strength between device and board. based on melexis commitment to environmental respon sibility, european legislation (directive on the restriction of the use of certain hazardous substan ces, rohs) and customer requests, melexis has installed a roadmap to qualify their package famili es for lead free processes also. various lead free generic qualifications are runnin g, current results on request. for more information on manufacturability/solderabi lity see quality page at our website: http://www.melexis.com/html/pdf/mlxleadfree-stateme nt.pdf 11. esd precautions electronic semiconductor products are sensitive to electro static discharge (esd). always observe electro static discharge control pro cedures whenever handling semiconductor products.
us72/73 single coil fan driver 3901090261 page 8 of 9 data sheet rev. 002 may/04 12. dc package information (soic-8) notes: 1. measurements in millimeters. 2. body dimensions do not include mold flash, protrusion s, or burrs - not to exceed 0.15mm . 3. lead frame material: copper 194. 4. tolerances: +/- 0.25 mm unless otherwise indicated. 4.80 4.95 0.33 0.51 1.27 3.81 3.99 0.38 1.27 0 o to 8 o 5.79 6.20 1.47 1.73 0.010 min. 1 2 4 3 7 8 6 5 .
us72/73 single coil fan driver 3901090261 page 9 of 9 data sheet rev. 002 may/04 13. disclaimer devices sold by melexis are covered by the warranty and patent indemnification provisions appearing in its term of sale. melexis makes no warranty, expres s, statutory, implied, or by description regarding the information set forth herein or regarding the freed om of the described devices from patent infringemen t. melexis reserves the right to change specifications and prices at any time and without notice. therefo re, prior to designing this product into a system, it i s necessary to check with melexis for current infor mation. this product is intended for use in normal commerci al applications. applications requiring extended temperature range, unusual environmental requiremen ts, or high reliability applications, such as milit ary, medical life-support or life-sustaining equipment a re specifically not recommended without additional processing by melexis for each application. the information furnished by melexis is believed to be correct and accurate. however, melexis shall no t be liable to recipient or any third party for any d amages, including but not limited to personal injur y, property damage, loss of profits, loss of use, inte rrupt of business or indirect, special incidental o r consequential damages, of any kind, in connection w ith or arising out of the furnishing, performance o r use of the technical data herein. no obligation or liability to recipient or any third party shall ari se or flow out of melexis rendering of technical or other ser vices. ? 2002 melexis nv. all rights reserved. for the latest version of this document, go to our website at: www.melexis.com or for additional information contact melexis direc t: europe and japan: all other locations: phone: +32 13 67 04 95 phone: +1 603 223 2362 e-mail: sales_europe@melexis.com e-mail: sales_usa@ melexis.com iso/ts16949 and iso14001 certified
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