MP6903 fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 1 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. the future of analog ic technology description the MP6903 is a low-drop diode emulator that, combined with an external switch, replaces schottky diodes in high-efficiency llc converters. the chip regulates the forward drop of an external switch to about 70mv and switches it off as soon as the voltage goes negative. MP6903 has a light-load sleep mode that reduces the quiescent current to < 300a. features ? works with standard and logic-level fets ? compatible with energy star, 1w standby requirements ? v dd range from 8v to 24v ? fast turn-off: total delay of 20ns ? max 400khz switching frequency ? <300a quiescent current in light load mode ? supports dcm, ccm and crcm operation ? supports high-side and low-side rectification ? power savings of up to 1.5w for a typical notebook adapter applications ? industrial power systems ? distributed power systems ? battery powered systems ? llc converters all mps parts are lead-free and adhere to the rohs directive. for mps green status, please visit mps website unde r products, quality assurance page. ?mps? and ?the future of analog ic technology? are registered trademarks o f monolithic power systems, inc. typical application r1 q2 output 8 MP6903 pgnd en ll v d v g nc v dd v ss 7 6 5 4 3 2 1 gnd vg1 vg1 out put u1 vg2 en vg2 8 MP6903 pgnd en ll v d v g nc v dd v ss 7 6 5 4 3 2 1 u2 en c1 c2 r2 r3 c3 c4 r4 or left open 2.2uf 100k 1nf 100k 1nf 120k 10k r5 r6 1k 1k q1 qa q b l s c s l m c in
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 2 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. ordering information part number* package top marking MP6903ds soic8 MP6903 * for tape & reel, add suffix ?z (e.g. MP6903ds?z); for rohs compliant packaging, add suffix ?lf (e.g. MP6903ds?lf?z) package reference pgnd en ll v d v g nc v dd v ss 1 2 3 4 8 7 6 5 top view absolute maxi mum ratings (1) v dd to v ss ......................................-0.3v to +27v pgnd to v ss ................................-0.3v to +0.3v v g to v ss ......................................... -0.3v to v dd v d to v ss .....................................-0.7v to +180v ll, en to v ss ...............................-0.3v to +6.5v maximum operating frequency............. 400khz continuous power dissipation (t a =25c) (2) ............................................................. 1.4w junction temperature ...............................150c lead temperature (solder).......................260c storage temperature .............. -55c to +150c recommended operation conditions (3) v dd to v ss ............................................8v to 24v operating junction temp. (t j ).... -40c to +125c thermal resistance (4) ja jc soic8 .....................................90 ...... 45 ... 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 pcb.
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 3 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. electrical characteristics v dd = 12v, -40c t j 125c, unless otherwise noted. parameter symbol conditions min typ max units v dd voltage range 8 24 v v dd uvlo rising 4.8 6.0 7.0 v v dd uvlo hysteresis 0.8 1 1.2 v operating current i cc c load =5nf, f sw =100khz 8 10 ma quiescent current i q v ss -v d =0.5v 2 3 ma v dd =4v 190 260 shutdown current v dd =20v, en=0v 350 420 a light-load mode current 290 400 a thermal shutdown (5) 170 180 190 c thermal shutdown hysteresis (5) 30 40 50 c enable uvlo rising 1.1 1.5 1.9 v enable uvlo hysteresis 0.2 0.4 v internal pull-up current on en pin 10 15 a control circuitry section v ss ?v d forward voltage v fwd 55 70 85 mv -20c t j 125c 250 380 t don c load = 5nf -40c t j <-20c 650 ns -20c t j 125c 400 680 turn-on delay t don c load = 10nf -40c t j <-20c 1200 ns input bias current on v d pin v d = 180v 0.5 3 a minimum on-time t min c load = 5nf 0.4 0.8 1.2 s light-load-enter delay t ll-delay r ll =100k ? 80 120 150 s light-load-enter pulse width t ll r ll =100k ? 1.3 1.75 2.2 s light-load-enter pulse width hysteresis t ll-h r ll =100k ? 0.2 s light-load resistor value r ll 30 300 k ? light-load mode exit pulse width threshold (v ds ) v ll-ds -400 -250 -150 mv light-load mode enter pulse width threshold (v gs ) (5) v ll-gs 1.0 v gate driver section v g (low) i load =1ma 0.05 0.1 v v dd >17v 13 14.5 16 v v g (high) v dd <17v v dd -2.2 turn off threshold (v ss -v d ) (5) 0 30 60 mv turn off threshold during blanking time (v ss -v d ) (5) 100 mv turn-off propagation delay v d =v ss 15 ns t doff v d =v ss , c load =5nf, r gate =0 ? 60 120 ns turn-off, total delay t doff v d =v ss , c load =10nf, r gate =0 ? 60 120 ns pull down impedance 1 2 ? pull down current (5) 3v MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 4 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. pin functions pin # name description 1 pgnd power ground. return for driver switch. 2 en enable. active high. 3 ll light load time set. connect a resistor to set the light load timing. 4 vd mosfet drain voltage sense. 5 vss ground. also used as reference for vd. 6 vdd supply voltage. 7 nc no connection. 8 vg gate drive output.
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 5 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. typical performanc e characteristics v dd = 12v, unless otherwise noted. operation current vs. temperature c load =5nf, f sw =100khz en uvlo rising vs. temperature turn on delay vs. temperature c load =5nf light load mode current vs. temperature en uvlo rising (v) v fwd vs. temperature -50 0 50 100 150 v fwd (mv) turn off threshold vs. temperature -40 -35 -30 -25 -20 -50 0 50 100 150 turn off threshold (v) quiescent current vs. temperature 1 1.2 1.4 1.6 1.8 2 2.2 2.4 -50 0 50 100 150 quiescent current (ma) 60 65 70 75 80 shutdown current vs. temperature 50 100 150 200 -50 0 50 100 150 5 5.5 6 6.5 7 -50 0 50 100 150 v dd uvlo rising (v) v dd uvlo rising vs. temperature 6.6 6.8 7 7.2 7.4 7.6 7.8 -50 0 50 100 150 operation current (ma) 250 270 290 310 330 350 -50 0 50 100 150 1.2 1.3 1.4 1.5 1.6 1.7 -50 0 50 100 150 0 100 200 300 400 500 600 700 -50 0 50 100 150 turn on delay (ns)
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 6 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. typical performanc e characteristics (continued) v dd = 12v, unless otherwise noted. turn off delay (ns) turn off delay vs. temperature c load =5nf turn off delay vs. temperature c load =10nf turn-off threshold (5) vs. temperature minimum on time vs. temperature turn on delay (ns) turn on delay vs. temperature c load =10nf 0 200 400 600 800 1,000 1,200 1,400 -50 0 50 100 150 0 10 20 30 40 50 60 70 80 90 -50 0 50 100 150 0 10 20 30 40 50 60 70 80 90 -50 0 50 100 150 turn off delay (ns) 0.5 0.6 0.7 0.8 0.9 1.0 -50 0 50 100 150 1.5 1.6 1.7 1.8 1.9 2 -50 0 50 100 150 0 10 20 30 40 50 60 -50 0 50 100 150 turn-off threshold (5) (ns) v ds 20v/div v g 5v/div i sr 10a/div operation in llc resonant converter v in =250v, v out =12v, i out =15a dcm operation in llc resonant converter v in =263v, v out =12v, i out =15a crcm v ds 20v/div v g 5v/div i sr 10a/div operation in llc resonant converter v in =280v, v out =12v, i out =15a ccm v ds 20v/div v g 5v/div i sr 10a/div
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 7 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. functional block diagram figure 1: functional block diagram operation the MP6903 supports operation in discontinuous current mode (dcm), continuous current mode (ccm), and critical conduction mode (crcm) condition. operating in either a dcm or crcm condition, the control circuitry controls the gate in forward mode and will turn the gate off when the mosfet current goes low. in ccm operation, the control circuitry turns off the gate when very fast transients occur. blanking the control circuitry contains a blanking function. when the mosfet turns on or off, the blanking function ensures that the previous state extends for some minimum time period. the turn-on blanking time is ~0.8s. during the turn-on blanking period, the turn-off threshold is not totally blanked, but changes the threshold voltage to approximately 100mv (instead of 0mv). this assures that the part can always turn off even during the turn-on blanking period. (the synchronous period is recommended to be greater than 0.8 s in ccm in the llc converter to avoid shoot-through.) vd clamp a high-voltage jfet is used at the input because v d can go as high as 180v. to avoid excessive currents when v g goes below -0.7v, add a small resistor between v d and the drain of the external mosfet. under-voltage lockout (uvlo) when v dd drops below the uvlo threshold, the part goes into sleep mode and a 10k ? resistor pulls the v g pin low. enable pin en is internal pulled up by the regulator from v dd with a ~15ua current source. leave this pin open if unused. when use external signal to control en, it is highly recommended the pull down current be larger than 15ua to make sure the en pin can be pulled to low.
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 8 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. thermal shutdown if the junction temperature of the chip exceeds 180c, the vg will be pulled low and the part stops switching. the part will resume normal function after the junction temperature has dropped to 150c. turn-on phase when the synchronous mosfet is on, current flows through its body diode and generates a negative v ds . this body diode voltage drop (< - 500mv) is much smaller than the turn-on threshold of the control circuitry (-70mv), which then pulls the gate driver voltage high to turn on the synchronous mosfet after about 250ns turn-on delay (shown in figure 2). when the turn-on delay ends, turn-on starts with a blanking time (minimum on-time: ~0.8s), and the turn-off threshold changes from +30mv to +100mv. this blanking time helps to avoid errors around the turn-off threshold caused by turn-on ringing of the synchronous mosfet. figure 2: turn on/off timing diagram conducting phase when the synchronous mosfet turns on, v ds rises according to the mosfet?s on resistance. when v ds rises above the turn-on threshold (- 70mv), the control circuitry stops pulling up the gate driver, so the gate voltage is pulled down by the internal pull-down resistance (10k ? ) and leakage to increase the on resistance of the synchronous mosfet, which to limit the v ds slew rate, stabilizes v ds to around -70mv even when the current through the mosfet is fairly small. this function limits the driver voltage when the synchronous mosfet is turned off (this function is still active during turn-on blanking, which means the gate driver could still be turned- off even with very small duty cycles of the synchronous mosfet). turn-off phase when v ds triggers the turn-off threshold (30mv), the gate voltage is pulled to low after a 20ns turn- off delay (shown in figure 2) by the control circuitry. figure 3 shows synchronous rectification operation at heavy load. the gate driver initially saturates due to the high current. after v ds rises above -70mv, the gate driver voltage decreases to adjust the v ds to around -70mv. figure 4 shows synchronous rectification operation at light load. the gate driver voltage never saturates due to the low current, but decreases as soon as the synchronous mosfet turns on and adjusts the v ds . figure 3: synchronous rectification operation at heavy load figure 4: synchronous rectification operation at light load
MP6903- fast turn-off intelligent controller MP6903 rev. 1.04 www.monolithicpower.com 9 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. light-load latch-off function the gate driver of MP6903 is latched to save the driver loss at light-load condition to improve efficiency. see figure5, when the synchronous mosfet?s conducting period keeps lower than light load timing (t ll ) for longer than the light- load-enter delay (t ll-delay ), MP6903 enters light- load mode and latches off the gate driver. here the synchronous mosfet?s conducting period is from turn on of the gate driver to the moment when v gs drops to below 1v (v ll_gs ). secondary side current normal mode light load mode t ll t ll t ll t ll-delay figure 5: MP6903 enters light load mode during light-load mode, MP6903 monitors the synchronous mosfet?s body diode conducting period by sensing the time duration of the v ds below -250mv(v ll_ds ). if it is longer than t ll +t ll- h (t ll-h , light-load-enter pulse width hysteresis), the light-load mode is finished and gate driver of MP6903 is unlatched to restart the synchronous rectification, see figure6. for MP6903, the light load enter timing (t ll ) is programmable by connecting a resistor (r ll ) on ll pin, by monitoring the ll pin current (the ll pin voltage keeps at ~2v internally), t ll is set as following (a 1nf capacitor is recommended to decouple the noise on this pin): ll ll 2.2us tr(k) 100k ??? ? figure 6: MP6903 exits light load mode
MP6903- fast turn-off intelligent controller 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. MP6903 rev. 1.04 www.monolithicpower.com 10 1/31/2013 mps proprietary information. patent protec ted. unauthorized photocopy and duplication prohibited. ? 2013 mps. all rights reserved. package information soic8 0.016(0.41) 0.050(1.27) 0 o -8 o detail "a" 0.010(0.25) 0.020(0.50) x 45 o see detail "a" 0.0075(0.19) 0.0098(0.25) 0.150(3.80) 0.157(4.00) pin 1 id 0.050(1.27) bsc 0.013(0.33) 0.020(0.51) seating plane 0.004(0.10) 0.010(0.25) 0.189(4.80) 0.197(5.00) 0.053(1.35) 0.069(1.75) top view front view 0.228(5.80) 0.244(6.20) side view 14 85 recommended land pattern 0.213(5.40) 0.063(1.60) 0.050(1.27) 0.024(0.61) note: 1) control dimension is in inches. dimension in bracket is in millimeters. 2) package length does not include mold flash, protrusions or gate burrs. 3) package width does not include interlead flash or protrusions. 4) lead coplanarity (bottom of leads after forming) shall be 0.004" inches max. 5) drawing conforms to jedec ms-012, variation aa. 6) drawing is not to scale. 0.010(0.25) bsc gauge plane
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