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| 1/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. hi-performance regulator ic series for pcs termination regulator for ddr-sdrams BD35390FJ description BD35390FJ is a termination regulator compatible with jede c ddr1/2/3-sdram, which functions as a linear power supply incorporating an n-channel mosfet and provides a sink/source current capability up to 1a respectively. a built-in high-speed op-amp specially designed offers an excellent transient response. requires 3.3 volts or 5.0 volts as a bias power supply to drive the n-channel mosfet. has an independent reference voltage input pin (vddq) and an independent feedback pin (vtts) to maintain the accuracy in voltage required by jedec, and offers an excellent output voltage accuracy and load regulation. features 1) incorporates a push-pull power supply for termination (vtt) 2) incorporates an enabler 3) incorporates an under voltage lockout (uvlo) 4) employs sop-j8 package : 3.9 4.9 1.375(mm) 5) incorporates a thermal shutdown protector (tsd) 6) operates with input vo ltage from 2.7 to 5.5 volts 7) compatible with dual channel (ddr1, ddr2, ddr3) 8) incorporates pgood function use power supply for ddr1/2/3 sdram absolute maximum ratings parameter symbol limit unit input voltage vcc 7 *1*2 v enable input voltage ven 7 *1*2 v termination input voltage vtt_in 7 *1*2 v vddq reference voltage vddq 7 *1*2 v output current (when pulse is active *3 ) itt 1 *1 a power dissipation1 pd1 563 *4 mw power dissipation2 pd2 675 *5 mw operating temperature range topr -30 +100 storage temperature range tstg -55 +150 maximum junction temperature tjmax +150 *1 should not exceed pd. *2 instantaneous surge voltage, back electromotive force and voltage under less than 10% duty cycle. *3 voltage under less than 10u sec. *4 reduced by 4.50 /w for each increase in ta of 1 over 25 (when don?t mounted on a heat radiation board) *5 reduced by 5.40 /w for each increase in ta of 1 over 25 (when mounted on a 70mm 70mm 1.6mm glass epoxy board) operating conditions(ta=25 ) parameter symbol limit unit min max input voltage vcc 2.7 5.5 v termination input voltage vtt_in 1.0 5.5 v vddq reference voltage vddq 1.0 2.75 v enable input volta ge ven -0.3 5.5 v no.09030eat25
BD35390FJ technical note 2/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. electrical characteristics(un less otherwise noted, ta=25 , vcc=3.3v, ven=3v, vddq =1.8v, vtt_in=1.8v) parameter symbol limit unit condition min typ max standby current ist - 0.5 1.0 ma ven=0v bias current icc - 2 4 ma ven=3v [enable] high level enable input voltage venhigh 2.3 - 5.5 v low level enable input voltage venlow -0.3 - 0.8 v enable pin input current ien - 7 10 a ven=3v [termination] termination output voltage (ddr2) vtt2 1/2 vddq -30m 1/2 vddq 1/2 vddq +30m v itt=-1.0a to 1.0a ta = 0 to 100 termination output voltage (ddr1) vtt1 1/2 vddq -30m 1/2 vddq 1/2 vddq +30m v vcc = 5.3v, vddq = 2.5v vtt_in = 2.5v itt=-1.0a to 1.0a ta = 0 to 100 termination output voltage (ddr3) vtt3 1/2 vddq -15m 1/2 vddq 1/2 vddq +15m v vcc = 3.3v, vddq =1.5v vtt_in =1.5v itt=-1.0a to 1.0a ta = 0 to 100 source current itt+ 1.0 - - a sink current itt- - - -1.0 a load regulation S vtt - - 50 mv itt=-1.0a to 1.0a upper side on resistance hron - 0.35 0.65 lower side on resistance lron - 0.35 0.65 [vref] input impedance zvddq 140 200 260 k [pgood] vtt pgood low threshold voltage pgdlow - 1/2 vddq -30m - v vtt pgood high threshold voltage pgdhigh - 1/2 vddq +30m - v pgood output on resistor pgdron - 10 20 pgood output leakage current pgdleak - - 1 a pgood=6v pgood delay time pgddelay 1 2 4 ms [uvlo] threshold voltage vuvlo 2.35 2.50 2.65 v vcc : sweep up hysteresis voltage S vuvlo 120 180 240 mv vcc : sweep down BD35390FJ technical note 3/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. reference data fig.1 ddr3 (1a -1a) (10sec/div.) fig.2 ddr2 (1a -1a) (10sec/div.) fig.3 ddr1(1a -1a) fig.4 ddr3 (-1a 1a) vcc en vddq vtt_in vtt fig.5 ddr2 (-1a 1a) fig.6 ddr1 (-1a 1a) fig.7 input sequence1 fig.8 input sequence2 (2sec/div.) (200sec/div.) fig.9 input sequence3 fig.13 en soft start (ddr2) fig.14 pgood delay (start up-shut down) fig.15 pgood delay (tsd off-tsd on) (2sec/div.) (2sec/div.) (10sec/div.) (10sec/div.) (10sec/div.) (10sec/div.) (10sec/div.) (1msec/div.) (100sec/div.) vtt(20mv/div) itt(1a/div) sin k source vtt(20mv/div) itt(1a/div) sin k source vtt(20mv/div) itt(1a/div) sink source vtt(20mv/div) itt(1a/div) sink source vtt(20mv/div) itt(1a/div) sink source vcc en vddq vtt_in vtt vcc en vddq vtt_in vtt fig.10 itt-vtt(ddr2) fig.11 itt- vtt(ddr1) fig.12 itt-vtt(ddr3) 1050 1000 950 900 850 800 750 1400 1350 1300 1250 1200 1150 1100 900 850 800 750 700 650 600 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 vtt[mv] vtt[mv] vtt[mv] vtt(20mv/div) itt(1a/div) sink source vtt (0.3v/div) en (1v/div) en (1v/div) vtts (0.3v/div) pgood (1v/div) pgood (1v/div.) BD35390FJ technical note 4/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. block diagram pin configration pin function pin no. pin name pin function 1 pgood pgood output pin 2 gnd gnd 3 vtts detector pin for termination voltage 4 en enable input pin 5 vddq reference voltage input pin 6 vcc vcc pin 7 vtt_in termination power supply pin 8 vtt termination output pin vtt_in pgood gnd vtts en vtt vcc vddq 1 2 3 4 5 6 7 8 vcc vcc vddq vddq vtt_in vcc vcc soft uvlo tsd reference block thermal protection enable en gnd pgood vtts vtt vtt vtt_in tsd en uvlo tsd en uvlo vcc tsd en uvlo en 2 4 1 3 8 7 5 6 c3 c5 c7 r1 delay logic BD35390FJ technical note 5/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. description of operations ? vcc in BD35390FJ, an independent power input pin is provided for an internal circuit operation of the ic. this is used to drive the amplifier circuit of the ic, and its maximum current rating is 4ma. the power supply voltage is 2.7 to 5.5 volts. it is recommended to connect a bypass capacitor of 1 f or so to vcc. ? vddq reference input pin for the output voltage that may be used to satisfy the jedec requirement for ddr1/2/3-sdram (vtt = 1/2vddq) by dividing the voltage inside the ic with two 100k ? voltage-divider resistors. for BD35390FJ, care must be taken to an input noise to vddq pi n because this ic also cuts such noise input into half and provides it with the voltage output divided in half. such noise may be reduced with an rc filter consisting of such resistance and capacitance (220 ? and 2.2 f, for instance) that may not give significant effect to voltage dividing inside the ic. ? vtt_in vtt_in is a power supply input pin for vtt output. voltage in the range between 1.0 and 5.5 volts may be supplied to this vtt_in terminal, but care must be taken to the current limitation due to on-resistance of the ic and the change in allowable loss due to input/output voltage difference. generally, the following voltages are supplied: ? ddr1 vtt_in=2.5v ? ddr2 vtt_in=1.8v ? ddr3 vtt_in=1.5v higher impedance of the voltage input at v tt_in may result in oscillation or degradat ion in ripple rejection, which must be noted. to vtt_in terminal, it is recommended to use a 10 f capacitor characterized with less change in capacitance. but it may depend on the characteristics of the power supply input and the impedance of the pc board wiring, which must be carefully checked before use. ? pgood pgood pin is power good output pin. this is the open drain pin, so pull up resistor is connec ted via other power supply if vtt voltage becomes over 1/2 vddq+30mv,or under 1/2 vddq+30mv, it outputs high voltage. ? vtts an isolated pin provided to improve load regulation of vtt output. in case that longer wiring is needed to the load at vtt output, connecting vtts from the load side may improve the load regulation. ? vtt a ddr memory termination output pin. BD35390FJ has a sink /source current capability of 1.0a respectively. the output voltage tracks the voltage divided in half at vddq pin. vtt output is tu rned to off when vcc uvlo or thermal shutdown protector is activated with en pin level turned to ?low?. do not fail to connect a capacitor to vtt output pin for a loop gain phase compensation and a reduction in output vo ltage variation in the event of sudden change in load. insufficient capacitance may cause an oscillation. high esr (equivalent series resistance) of the capacitor may result in increase in output voltage variation in the event of sudden change in load. it is recommended to use a 10 f or so ceramic capacitor, though it depends on am bient temperature and other conditions. ? en with an input of 2.3 volts or higher, the level at en pin turns to ?high? to provide vtt output. if the input is lowered to 0. 8 volts or less, the level at en pin turns to ?low? and vtt status turns to hi-z. BD35390FJ technical note 6/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. evaluation board BD35390FJ evaluation board application components designation value company part no. designation value company part no. u1 - rohm BD35390FJ c5 10f kyocera cm21b106m06a r1 10k rohm mcr031002 c6 - - - r4 220 rohm mcr032200 c7 10f kyocera cm21b106m06a j1 0 - - c8 - - - j2 0 - - c9 2.2f kyocera cm105b225k06a c3 1f kyocera cm105b105k06a c10 - - - c4 - - - c11 - - - BD35390FJ evaluation board circuit c5, c6 gnd e v c v d v tt vcc sw1 c11 j2 r4 c9 j1 c3,c4 c7 c8 c10 4 7 5 6 2 8 3 1 u1 vtt_in vcc vtt pgood vddq en vtts gnd r1 BD35390FJ technical note 7/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. heat loss thermal design must be conducted with the operation under the conditions listed below (which are the guaranteed temperature range requiring considerat ion on appropriate margins etc); 1: ambient temperature ta: 100 or lower 2:chip junction temperature tj: 150 or lower the chip junction temperature tj can be considered as follows: most of heat loss in BD35390FJ occurs at the output n-channel fet. the powe r lost is determined by multiplying the voltage between vin and vo by the output current. as this ic employs the power pkg, the thermal derating characteristics significantly depends on the pc board conditions. when designing, care must be taken to the si ze of a pc board to be used. power consumption (w) = input voltage (v tt_in )-output voltage (v tt P 1/2vddq) io(ave) example) where v tt_in =1.8v, vddq=1.8v, io(ave)= 0.5a = 0.45(w) heat dissipation characteristics power consumption(w) = 1.8(v)-0.9(v) 0.5(a) (1) mounted on 70mm 70mm 1.6mm glass-epoxy board j-c=185.2 /w (2) with no heat sink j-a=222.2 /w 600 0 25 75 100 125 150 50 200 100 0 [ ] 400 500 300 [mw] (2) 563mw 100 (1) 675mw power dissipation [pd] 700 ambient temperature [ta] BD35390FJ technical note 8/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. note for use 1.absolute maximum ratings for the present product, thoroughgoing qua lity control is carried out, but in t he event that applied voltage, working temperature range, and other absolute maximum rating are exceeded, the pr esent product may be destroyed. because it is unable to identify the short mode, open mode, etc., if any special mode is assumed, which exceeds the absolute maximum rating, physical safety measures are requested to be taken, such as fuses, etc. 2.gnd potential bring the gnd terminal potential to the mini mum potential in any op erating condition. 3.thermal design consider allowable loss (pd) under actual working condition and carry out thermal design with sufficient margin provided. 4.terminal-to-terminal short-circuit and erroneous mounting when the present ic is mounted to a printed circuit board, take utmost care to direction of ic and displacement. in the event that the ic is mounted erroneously, ic may be destroyed. in the event of short-circuit caused by foreign matter that enters in a clearance between outputs or out put and power-gnd, the ic may be destroyed. 5.operation in strong electromagnetic field the use of the present ic in the strong electromagnetic field may result in malo peration, to which care must be taken. 6.built-in thermal shutdown protection circuit the present ic incorporates a thermal shutdown protection circuit (tsd circuit). the working temperature is 175c (standard value) and has a -15c (standard value) hysteresis width. when the ic chip temperature rises and the tsd circuit operates, the output terminal is br ought to the off state. the built-in t hermal shutdown protection circuit (tsd circuit) is first and foremost intended fo r interrupt ic from thermal runaway, and is not intended to protect and warrant the ic. consequently, never attempt to continuously use the ic afte r this circuit is activated or to use the circuit with the activation of the circuit premised. 7.capacitor across output and gnd in the event a large capacitor is connected across output and gnd, when vcc and vin are short-circuited with 0v or gnd for some kind of reasons, current charged in the capacitor fl ows into the output and may destroy the ic. use a capacitor smaller than 1000 f between output and gnd. 8.inspection by set substrate in the event a capacitor is connected to a pin with low impedanc e at the time of inspection with a set substrate, there is a fear of applying stress to the ic. therefore, be sure to discharge electricity for every process. as electrostatic measures, provide grounding in the assembly process, and take utmost care in transportati on and storage. furthermore, when the set substrate is connected to a jig in the inspection process, be sure to turn off power supply to connect the jig and be sure to turn off power supply to remove the jig. 9. inputs to ic terminals this device is a monolithic ic with p + isolation between p-substrate and each el ement as illustrated below. this p-layer and the n-layer of each element form a pn junction which works as: ? a diode if the electric potentials at the terminals satisfy the following relationship; gnd>terminal a>terminal b, or ? a parasitic transistor if the electric potentials at the terminals satisfy the following relationship; terminal b>gnd terminal a. the structure of the ic inevitably forms parasitic elements, the activation of which may cause interference among circuits, and/or malfunctions contributing to breakdown . it is therefore requested to take care not to use the device in such manner that the voltage lowe r than gnd (at p-substrate) may be applied to the input terminal, which may result in activation of parasitic elements. resistor transistor (npn) n n n p + p + p p substrate gnd parasitic element pin a n n p + p + p p substrate gnd parasitic element pin b c b e n gnd pin a p aras iti c element pin b other adjacent elements e b c gnd p aras iti c element BD35390FJ technical note 9/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. 10. gnd wiring pattern when both a small-signal gnd and high current gnd are presen t, single-point grounding (at the set standard point) is recommended, in order to separate the small-signal and high current patterns, and to be sure the voltage change stemming from the wiring resistance and high current does not cause any voltage change in the small-signal gnd. in the same way, care must be taken to avoid wiring pattern fluctuations in any connected external component gnd. 11. output capacitor (c7) do not fail to connect a capacitor to vtt output pin for stabi lization of output voltage. this output capacitor works as a loop gain phase compensator and an output voltage variation reduc er in the event of sudden change in load. insufficient capacitance may cause an oscillation. and if the equivalent seri es resistance (esr) of this capacitor is high, the variation in output voltage increases in the event of sudden change in load. it is recommended to use a 10 f or so ceramic capacitor, though it depends on ambient te mperature and load conditions. it is therefore requested to carefully check under the actual temperature and load conditions to be applied. 12. input capacitors setting (c3 and c5) these input capacitors are used to reduce the output impedance of power supply to be connected to the input terminals (vcc and vtt_in). increase in the power supply output impedance may result in oscillation or degradation in ripple rejecting characteristics. it is recommended to use a low temperature coefficient 1 f (for vcc) and 10 f (for vtt_in) capacitor, but it depends on the characteristics of the power supply input, and the capacitance and impedance of the pc board wiring pattern. it is therefore requested to carefully check under the actual temperature and load conditions to be applied. 13. input terminals (vcc, vddq, vtt_in and en) vcc, vddq, vtt_in and en terminals of this ic are m ade up independent one another. to vcc terminal, the uvlo function is provided for malfunction prot ection. irrespective of the input orde r of the inputs terminals, vtt output is activated to provide the output voltage when uxlo and en vo ltages reach the threshold voltage while vref output is activated when uxlo voltage reaches the threshold. if v ddq and vtt_in terminals have equal potential and common impedance, any change in current at vtt_in terminal may resu lt in variation of vtt_in voltage, which affects vddq terminal and may cause variation in the output voltage. it is t herefore required to perform wiring in such manner that vddq and vtt_in terminals may not have common impedance. if impossible, take appropriate corrective measures including suitable cr filter to be inserted between vddq and vtt_in terminals. 14. vtts terminal a terminal used to improve load regulation of vtt output. connection with vtt terminal must be done not to have common impedance with high current line, which may offer better load regulation of vtt output. 15. operating range within the operating range, the operation and function of the circuits are generally guaranteed at an ambient temperature within the range specified. the values specified for elec trical characteristics may not be guaranteed, but drastic change may not occur to such characteristics within the operating range. 16. allowable loss pd for the allowable loss, the thermal derating characteristics ar e shown in the exhibit, which should be used as a guide. any uses that exceed the allowable loss may result in degr adation in the functions inherent to ic including a decrease in current capability due to chip temperature increase. use within the allowable loss. 17. thermal shut down circuits this ic incorporates a built-in-thermal shutdown circuit, to prevent the ic from thermal breaking down. in thermal shut down circuit operation, vtt output turns to be off. the thermal shut down circuit is originally designed to protect he incorporated ic, so that thermal design needs to be designed below the temperature, which enables to run the thermal shut down circuits. 18. the use in the strong elec tromagnetic field may sometimes cause malfun ction, to which care must be taken. in the event that load containing a large inductance compon ent is connected to the output terminal, and generation of back-emf at the start-up and when output is turned off is a ssumed, it is requested to insert a protection diode. 19. in the event that load containi ng a large inductance component is connected to the output terminal, an d generation of back-emf at the start-up and when output is turned o ff is assumed, it is requested to insert a protection diode. 20. we are certain that examples of appl ied circuit diagrams are recommendable, but you are requested to thoroughly confi rm the characteristics before using the ic. in addition, when the ic is used with the external circuit changed, decide the ic with sufficient margin provided while consideration is being given not only to static characteristics but also variati ons of external parts and our ic includin g transient characteristics. output pin (example) BD35390FJ technical note 10/10 www.rohm.com 2009.10 - rev. a ? 2009 rohm co., ltd. all rights reserved. ordering part number b d 3 5 3 9 0 f j - e 2 part no. part no. 35390 package fj : sop-j8 packaging and forming specification e2: embossed tape and reel ? order quantity needs to be multiple of the minimum quantity. r0039 a www.rohm.com ? 2009 rohm co., ltd. all rights reserved. notice rohm customer support system http://www.rohm.com/contact/ thank you for your accessing to rohm product informations. more detail product informations and catalogs are available, please contact us. notes no copying or reproduction of this document, in part or in whole, is permitted without the consent of rohm co.,ltd. the content specied herein is subject to change for improvement without notice. the content specied herein is for the purpose of introducing rohm's products (hereinafter "products"). if you wish to use any such product, please be sure to refer to the specications, which can be obtained from rohm upon request. examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the products. the peripheral conditions must be taken into account when designing circuits for mass production. great care was taken in ensuring the accuracy of the information specied in this document. however, should you incur any damage arising from any inaccuracy or misprint of such information, rohm shall bear no responsibility for such damage. the technical information specied herein is intended only to show the typical functions of and examples of application circuits for the products. rohm does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by rohm and other parties. rohm shall bear no responsibility whatsoever for any dispute arising from the use of such technical information. the products specied in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, ofce-automation equipment, commu- nication devices, electronic appliances and amusement devices). the products specied in this document are not designed to be radiation tolerant. while rohm always makes efforts to enhance the quality and reliability of its products, a product may fail or malfunction for a variety of reasons. please be sure to implement in your equipment using the products safety measures to guard against the possibility of physical injury, re or any other damage caused in the event of the failure of any product, such as derating, redundancy, re control and fail-safe designs. rohm shall bear no responsibility whatsoever for your use of any product outside of the prescribed scope or not in accordance with the instruction manual. the products are not designed or manufactured to be used with any equipment, device or system which requires an extremely high level of reliability the failure or malfunction of which may result in a direct threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuel-controller or other safety device). rohm shall bear no responsibility in any way for use of any of the products for the above special purposes. if a product is intended to be used for any such special purpose, please contact a rohm sales representative before purchasing. if you intend to export or ship overseas any product or technology specied herein that may be controlled under the foreign exchange and the foreign trade law, you will be required to obtain a license or permit under the law. |
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