x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r july 2011 rev. 1.0.0 exar corporation www.exar.com 48720 kato road, fremont ca 94538, usa tel. +1 510 668-7000 ? fax. +1 510 668-7001 general description the XRP2997 is a double data rate (ddr) termination voltage regulator supporting all power requirements of ddr i, ii and iii memories and is capable of sinking or sourcing 2a continuously. tightly regulating its output voltage within 20mv, the XRP2997 converts input voltages as low as 1.1v while the output voltage is adjustable through an external resistor divider or by forcing the v ref pin voltage. it maintains a fast line and load transient response and only requires an output capacitance of 22f to operate. an enable func tion via an external mosfet and a soft start feature allow for a controlled implementation of power-up sequencing. built-in source/sink overcurrent, over- temperature and under-voltage lockout protections insure safe operation under abnormal operating conditions. the XRP2997 meets jedec sstl-2, sstl-18, hstl, scsi-1 and scsi-3 specifications for ddr sdram memories. the XRP2997 is offered in a rohs compliant, ?green?/halogen free 8-pin exposed pad soic package. applications ? ddr i/ii/iii memory termination ? active termination buses ? audio-video equipments ? video-graphics cards features ? ddr1, ddr2 and ddr3 support ? 0.75v tt generation ? 20mv output voltage offset ? 2 amps continuous current sourcing & sinking ? 1.1v to 5.5v wide input voltage range ? adjustable output voltage ? suspend to ram(str), enable & soft start functions ? stable with 22f ceramic capacitor ? uvlo, over temperature and over current protections ? minimal external components ? pin/function compatible with sp2996b ? rohs compliant ?green?/halogen free 8-pin soic package typical application diagram fig. 1: XRP2997 ddriii v tt application diagram
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 2/8 rev. 1.0.0 absolute maximum ratings these are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. v in , v ref , v cntl .......................................... -0.3v to 6.0v junction temperature range .................. -40c to +150c storage temp erature ............................ -65c to +150c lead temperature (sol dering, 10 se c) ................... 260c operating ratings operating temperature ra nge ................. -40c to +85c thermal resistance ja ...................................... 60c/w thermal resistance jc ...................................... 16c/w electrical specifications specifications are for an operating ambient temperature of t a = 25c only; limits applying over the full operating junction temperature range are denoted by a ???. minimum and maximum limits are guaranteed through test, design, or statistical correlation. typical values represent th e most likely parametric norm at t a = 25c, and are provided for reference purposes only. unless otherwise indicated, v in = 1.8v/1.5v, v cntl = 3.3v, v ref = 0.5xv in , c out = 22f (ceramic), t a = 25c. parameter min. typ. max. units conditions v in , input voltage range 1.1 1.8/1.5 5.5 v keep v cntl v in during power on and power off sequences (note 4) v cntl , input voltage range 2.375 3.3 5.5 v keep v cntl v in during power on and power off sequences (note 4) v out , output voltage v ref v i out = 0ma v os , output voltage offset -20 +20 mv i out = 0ma (note 1) ? v lor , load regulation -20 +20 mv i out = 0.1ma to +2a -20 +20 mv i out = 0.1ma to -2a i q , quiescent current 2 90 a v ref < 0.2v, v out = off i cntl , operating current of v cntl 1 2.5 ma i out = 0ma i ref , bias current of v ref 0 1 a v ref = 1.25v i il , current limit 2.4 3 a source: v out =0.33xv ref sink: v out =0.95xv in (note 3) r dschg , output discharge resistance 18 25 ? v ref =0v, v out =0.3v thermal protection t sd , thermal shutdown temperature 160 c 3.3v v cntl 5v, guaranteed by design (note 4) thermal shutdown hysteresis 30 c guaranteed by design shutdown specifications v trigger , shutdown threshold 0.8 v output on v ref = 0v ? 1.25v 0.2 output off v ref = 1.25v ? 0v note 1: v os offset is the voltage measurement defined as v out subtracted from v ref . note 2: load regulation is measured at constant junction temperature, using pulse testing with a short on time. note 3: current limit is measured by applying a short duration current pulse. note 4: in order to safely operate your system, v cntl must be > v in .
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 3/8 rev. 1.0.0 block diagram fig. 2: XRP2997 block diagram pin assignment fig. 3: XRP2997 pin assignment pin description name pin number description v in 1 power input voltage gnd 2 ground signal exposed pad v ref 3 reference input voltage. this input can also be used as an enable signal; pulling this pin low shuts down the XRP2997. refer to typical application circuit. v out 4 output voltage nc 5, 7, 8 nc v cntl 6 voltage for the driver circuit and all analog blocks ordering information part number temperature range marking package packing quantity note 1 note 2 XRP2997idb-f/tr -40c t a +85c XRP2997i yywwf xxxxxx exposed pad soic-8 2.5k/tape & reel rohs compliant halogen free ?yy? = year ? ?ww? = work week ? ?l? = lead free indicator - ?x? = lot number; when applicable.
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 4/8 rev. 1.0.0 typical performance characteristics all data taken at v in = 1.8v/1.5v, v cntl = 3.3v, v ref = 0.5xv in , c out = 22f (ceramic), t a = 25c, unless otherwise specified - schematic and bom from application in formation section of this datasheet. fig. 4: turn on and turn off vs. temperature fig. 5: output voltage vs. temperature fig. 6: current limit (sourcing) vs. temperature fig. 7: current limit (sinking) vs. temperature fig. 8: v in =1.5v, v ref =0.75v source response fig. 9: v in =1.8v, v ref =0.9v source response
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 5/8 rev. 1.0.0 fig. 10: v in =2.5v, v ref =1.25v source response fig. 11: v in =1.5v, v ref =0.75v sink response fig. 9: v in =1.8v, v ref =0.9v sink response fig. 10: v in =2.5v, v ref =1.25v sink response fig. 14: v in =1.5v, v ref =0.75v source short circuit fig. 15: v in =1.8v, v ref =0.9v source short circuit
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 6/8 rev. 1.0.0 fig. 11: v in =2.5v, v ref =1.25v source short circuit fig. 12: v in =1.5v, v ref =0.75v sink short circuit fig. 13: v in =1.8v, v ref =0.9v sink short circuit fig. 14: v in =2.5v, v ref =1.25v sink short circuit application information l ayout c onsiderations the XRP2997 is offered in the 8-pin exposed- pad soic package in order to facilitate power dissipation (heat dissipation). power dissipation can be maximized by soldering the exposed pad to a large land area on top layer of pcb and by using vias to connect the exposed pad to an interlayer(s) or bottom layer. all capacitors should be placed as close as possible to the respective pins.
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 7/8 rev. 1.0.0 package specification 8-p in soic e xposed p ad unit: mm (inch) eject hole, oriented hole and mold mark are optional.
x x r r p p 2 2 9 9 9 9 7 7 2 2 a a d d d d r r i i / / i i i i / / i i i i i i b b u u s s t t e e r r m m i i n n a a t t i i o o n n r r e e g g u u l l a a t t o o r r ? 2011 exar corporation 8/8 rev. 1.0.0 revision history revision date description 1.0.0 07/22/2011 initial release of datasheet for further assistance email: customersupport@exar.com exar technical documentation: http://www.exar.com/techdoc/default.aspx? e xar c orporation h eadquarters and s ales o ffices 48720 kato road fremont, ca 94538 ? usa tel.: +1 (510) 668-7000 fax: +1 (510) 668-7030 www.exar.com notice exar corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. exar corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and make s no representation that the circuits are free of patent infringement. charts and schedules contai ned herein are only for illustration pu rposes and may vary depending upon a user?s specific application. while the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. exar corporation does not recommend the us e of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause fa ilure of the life support system or to significantly affect it s safety or effectiveness. products are not authorized for use in such applications unless exar corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of exar corporation is adequately protected under the circumstances. reproduction, in part or whole, without the prior written consent of exar corporation is prohibited.
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