ver: 1.5 nov 22, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 1 G2998/g2999 global mixed-mode technology ddr termination regulator features ? support and ddr i (1.25vtt), ddr ii (0.9 vtt) , ddr iii (0.75 vtt) , and ddr iiil (0.675vtt) requirements ? input voltage range: 3v to 5.5v ? vtt_in voltage range: 1.2v to 3.6v ? requires only 20 f ceramic output capacitance ? vtt pulled low by 2k resistor in stand-by mode (G2998 version) ? vtt tri-state in stand-by mode (g2999 version) ? integrated divider tracks 1/2 vddq for both vtt and vref ? remote sensing (vtts) ? 20mv accuracy for vtt ? 30mv accuracy for vref ? built-in soft-start ? over current protection ? thermal shutdown protection ? msop-8 and sop-8(thermal pad) package applications ? ddr i/ii/iii/iiil memory termination ? sstl ? 2, sstl ? 18 ? hstl termination general description the G2998/g2999 is a 3a sink/source tracking termi- nation regulator. it is specifically designed for low-cost/ low-external component count systems. the G2998/ g2999 maintains a high speed operational amplifier that provides fast load transient response and only requires 20 f (2 10 f) of ceramic output capacitance. the G2998/g2999 supports remote sensing functions and all features required to power the ddr i / ddr ii / ddr iii / ddr iiil vtt bus termination according to the jedec specification. in addition, the G2998/ g2999 also has an enable (en) pin that provides suspend to ram (str) functionality. when en is pulled low, vref will remain active, but vtt output will be turned off and discharged to the ground through internal mosfets in G2998 version and vtt output will be in tri-state in g2999 version. a power saving advantage can be ob- tained in this mode through lowering the quiescent cur- rent to150 a @ vcc=3.3v. the G2998/g2999 is available in the msop-8 and sop-8 package with the thermal pad. ordering information order number marking temp. range package (green) G2998p81u G2998 -40 c~85 c msop-8 G2998f11u G2998 -40 c~85 c sop-8 (fd) g2999f11u g2999 -40 c~85 c sop-8 (fd) note: p8: msop-8 f1: sop-8 (fd) 1: bonding code u: tape & reel pin configuration note: recommend c onnec ting the thermal p ad to t h e gnd fo r e xce lle n t po we r d is sipa tio n. sop- 8 (fd) top view G2998/g2999 vtts 8 6 5 1 2 3 4 en gnd vtt vtt_in vcc vddq 7 vref thermal pad ddr ii vtt_ in vre f vddq vcc vtts en vtt gnd 1.8v v cc =3.3v c2 0.1 f c1 2 x 1 0 f en vtt_ in vre f vddq vcc vtts en vtt gnd 1.5v v cc =3.3v c2 0.1 f c1 2 x 1 0 f en ddr iii* * recommended v cc =3.3v vtt_in vref vddq vcc vtts en vtt gnd 2.5v v cc =3.3v c2 0.1 f c1 2 x 10 f en ddr i typical application circuit msop- 8 G2998 vtts 8 6 5 1 2 3 4 en gnd vtt vtt_in vcc vddq 7 vref note: recommend c onnec ting the thermal p ad to t h e gnd fo r e xce lle n t po we r d is sipa tio n. sop- 8 (fd) top view G2998/g2999 vtts 8 6 5 1 2 3 4 en gnd vtt vtt_in vcc vddq 7 vref thermal pad ddr ii vtt_ in vre f vddq vcc vtts en vtt gnd 1.8v v cc =3.3v c2 0.1 f c1 2 x 1 0 f en vtt_ in vre f vddq vcc vtts en vtt gnd 1.5v v cc =3.3v c2 0.1 f c1 2 x 1 0 f en ddr iii* * recommended v cc =3.3v vtt_in vref vddq vcc vtts en vtt gnd 2.5v v cc =3.3v c2 0.1 f c1 2 x 10 f en ddr i typical application circuit msop- 8 G2998 vtts 8 6 5 1 2 3 4 en gnd vtt vtt_in vcc vddq 7 vref
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