microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 1 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity description description description description the lx8211 fixed/adjustable voltage linear regulators combines low dropout, high accuracy, ultra-low ground current and fast response in a very small footprint. using the enable pin the regulators is switched on with ttl logic levels, which is especially useful for battery- operated equipment. other features include independent thermal and short circuit current protection. the regulator is stable with a low value ceramic output capacitors. for ultra low noise operation a bypass pin is brought out to connect an optional capacitor. significant performance improvements over bipolar technology are achieved designing in cmos: increased regulator efficiency by minimizing operating ground current (typ<100ua) and it is nearly eliminated (typ<1ua) in shutdown. the pmos output transistor allows for ultra low dropout typically less than 300mv at 100ma. important: for the most current data, consult micro sem i?s website: http://www.microsemi.com key features key features key features key features dropout voltage typically 300mv @ 100ma ultra low shutdown current typically less than 1ua high output accuracy trimmed to 0.25% standard pinout in sot-23a-5 noise bypass feature available current and over temperature protection stable with low cost ceramic output capacitor application application application applications s s s battery operated systems laptop, notebook and pda?s cellular telephones/pagers hand-held instruments linear post regulators for smps product highlight product highlight product highlight product highlight c in 1f 470pf optional c out 1f on off v in enable c by/adjust v out gnd + package order info t j ( c) o utput v oltage se plastic sot-23 5-pin p ackage m arking -40 to 125 adjustable lx8211-00ise 82a1 -40 to 125 2.5v LX8211-25ISE 82b1 -40 to 125 2.7v lx8211-27ise 82d1 -40 to 125 3.0v lx8211-30ise 82g1 other voltages available. contact microsemi for detail note: available in tape & reel. append the letter ?t? to the part number. (i.e. LX8211-25ISEt) l l x x 8 8 2 2 1 1 1 1
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 2 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity absolute maximum rat absolute maximum rat absolute maximum rat absolute maximum ratings ings ings ings input voltage (v in ) ........................................................................................-0.3v to +7v enable input ........................................................................................... -0.3v to v in +.3v output current (i out )............................................................................................. 150ma operating temperature range .................................................................... -40 to +125 c maximum junction temperature (t j ) ...................................................................... 150 c note: exceeding these ratings could cause damage to the device. all voltages are with respect to ground. currents are positive into, negative out of specified terminal. package pin out package pin out package pin out package pin out 1 2 3 5 4 se p ackage (top view) thermal data thermal data thermal data thermal data se 5-p in sot-23 p ackage thermal resistance ? junction to ambient, ja two ? layer board 220c/w four ? layer board 220c/w junction temperature calculation: t j = t a + (p d x ja ). the ja numbers are guidelines for the thermal performance of the device/pc-board system. all of the above assume no ambient airflow. functional pin descr functional pin descr functional pin descr functional pin description iption iption iption p in n ame p in n umber d escription vin 1 unregulated input supply voltage gnd 2 ground pin enable 3 enable control input, enable high cby/adjust 4 reference bypass input. adding an additional external capacitor reduces output noise . or adjust control input for lx8211-00. vout 5 regulated output voltage. regulator stability is achieved with external capacitor of 1uf application application application application c in r1 r2 c out v in v out c by/adjust enable gnd on off 1 5 4 2 3 + ? ? ? ? ? ? + = 2 r 1 r 1 v out adj v figure 1 ? output voltage set externally p p a a c c k k a a g g e e d d a a t t a a
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 3 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity recommended operatin recommended operatin recommended operatin recommended operating conditions g conditions g conditions g conditions lx8211-xx parameter symbol min typ max units input operating voltage range (note 1) v in 2.5 6 v enable input voltage range enable 0 v in + .3v continuous output current range i out .1 150 ma input capacitor (v in to gnd) c in 1.0 1.0* f output capacitor (v out to gnd) c out 1.0 2.2* f note 1: the minimum v in has to meet two conditions v in > 2.5v and v in > v out +v dropout . * size your output capacitor to meet the transient loading requirement. if you have a very dynamic load, a lower esr and large r value capacitor will improve the response to these load steps. electrical character electrical character electrical character electrical characteristics istics istics istics unless otherwise specified, the following specifications apply over the operating ambient temperature -40 c t a 125 c except where otherwise noted. test conditions: v in = v out + 0.5v; i out =10ma; c in = 1uf; c out = 1uf; t j =t a using low duty cycle pulse testing methods. lx8211-xx parameter symbol test conditions min typ max units t j = 25c -1 1 % output voltage v o i out = 0ma to 100ma, v in = v out + .5v to 6v -2.5 2.5 % t j = 25c 1.237 1.263 adjust reference voltage v adj i out = 0ma to 100ma, v in = 2.85v to 6v 1.219 1.250 1.281 v line regulation ? ? ? ? ? ? ? ? in o v v v rv v in : v out + 0.5 to 6 v olts , i out =0.1ma 0.1 0.3 %/v t j = 25c, i out : 0.5 to 100ma 15 mv load regulation ? ? ? ? ? ? ? ? o o i v v ri i out : 0.5 to 100ma 30 mv i load = 1ma, ? vo = -1% 0.050 v i load = 50ma, ? vo = -1% 0.175 v i load = 100ma, ? vo = -1% 0.175 0.3 v dropout voltage () o in v v ? (note2) v do i load = 150ma, ? vo = -1% 0.25 0.4 v i gnd enable = hi 140 180 a ground pin current i stby enable = low 1 a adjust input bias current i adj v adj = 1.25v 100 na enable pin current i en v en = v in 100 na v ih 2.0 v enable threshold v il 0.4 v short circuit current limit i out sc v out = 0v 180 400 ma power supply rejection ratio psrr t j = 25c, f = 120hz 50 db output noise e n t j = 25c, c out = 10uf,c bypass = 470 pf 50 v thermal shutdown temperature t sd 170 c note 2: dropout voltage is defined as the input to output differential at which the output voltage drops 1% below the nominal v alue. e e l l e e c c t t r r i i c c a a l l s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 4 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity block diagram block diagram block diagram block diagram enable gnd v in c by/adjust v out r a r b + - current limit thermal shutdown control logic vref figure 2 ? simplified fixed version block diagram (lx8211-25 / 27 / 30ise) enable gnd v in c by/adjust v out + - current limit thermal shutdown control logic vref figure 3 ? simplified adjustable version block diagram (lx8211-00ise) b b l l o o c c k k d d i i a a g g r r a a m m
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 5 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity applicatio applicatio applicatio application information n information n information n information description the lx8211 is a family of ldo (low drop-out) linear regulators in a small sot-23 package, which provides a compact and cost effective solution. the family includes several fixed output voltages, along with an adjustable version. the internal pmos power device provides low dropout regulation with fast line and load transient response. it also includes internal current limit and thermal shutdown circuitry. in this section you will find information about selection of external capacitors, thermal and layout consideration. input capacitor to improve load transient response and noise rejection a bypass capacitor is recommended, but it is not required for stability. there are no requirements for the esr (equivalent series resistor) on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitor will be around 1uf over the entire operating temperature range. for lx8211 connect ceramic type capacitor (1uf) between v in and ground. output capacitor to maintain a constant output voltage a feedback loop is n ecessary. the feedback loop causes a well known a phase shift, the amount of phase shift determines the loop stability. therefore, lx8211 like any low-dropout regulator, requires an output capacitor with low esr (equivalent series resistor) connected between vout and gnd to stabilize the internal control loop. for the lx8211 a ceramic, tantalum or electrolytic capacitor with the minimum recommended capacitance value at 1.0 uf with esr between 5m ? and 1 ? will satisfy the stability for whole operating range. bypass capacitor (optional) / adjustable output voltage the lx8211 includes the extra bypass pin to help further reduce the already low output noise in the regulator. if the output noise requirement meets the specification, omit the bypass capacitor, that?s because the capacitor impacts the start up time which is inversely proportional to the size of bypass capacitor. the bypass capacitor reduces the regulator phase margin, therefore it requires a larger output capacitor to maintain stability. the lx8211-00 adjustable regulator?s output voltage can be externally set by connecting the adj pin to an external resistor divider (see figure 1). the output voltage can be calculated using: ? ? ? ? ? ? + = 2 r 1 r 1 v out adj v enable the enable pin allows the lx8211 to be turned on and off. the enable pin is compatible with standard ttl-cmos levels. a logic zero (0.4v) on the enable pin shuts the lx8211 off and reduces the supply current to less than 1ua. pulling the enable input high (2.0v) causes normal operation to resume. if the enable feature is not used, this pin can be connected to v in . minimum load requirement the lx8211 is stable even at zero load; no minimum load is required for operation, which is especially important in keep-alive applications. however line regulation is improved with a minimum load of 100ua. temperature protection the thermal protection shuts the lx8211 down when the junction temperature exceeds approximately 150 0 c, there is no appreciable thermal hysteresis. short circuit current protection the lx8211 includes over current protection, when the output load current exceeds typically 400ma the circuit forces the regulator decrease in output. thermal consideration thermal shutdown protects the integrated circuit from thermal overload caused from a rise in junction temperature during power dissipation. this means of protection is intended for fault protection only and not as a means of current or power limiting during normal application usage. proper thermal evaluation should be done to ensure that the junction temperature dose not exceed it?s maximum rating. operating at the maximum t j of 150c can impact reliability . due to variation in individual device electrical characteristics and thermal resistance , the built in thermal overload protection may be activated at power levels slightly above or below the rated dissipation. power dissipation for regulator can be calculated using the following equation: p d = (v in(max) -v out(min) ) * i out(max) (note: power dissipation resulting from quiescent current is negligible) for the sot23 package, thermal resistance, ja is 220 0 c/w when mounted on a fr4 copper clad pcb. junction temperature of the integrated circuit can be calculated using: t j = t a + t rise , substituting: t a + (p d * ja ) . an example: given conditions: t a = 60c, v in = 4.2v, v out = 2.7v, i out = 100ma. calculated values: total power dissipation p d(total) = (4.2-2.7) v * 0.1a =0.15w junction temperature t j = 60c +(0.15w *220c/w) = 93c layout consideration: the layout must be done with low impedance paths for v in , v out and ground by applying sufficient wide tr aces to avoid voltage drops and pick up noise. adding an area of pcb copper to the gnd pin (pin2) will reduce the overall ja since it is thermally connected to the device substrate. this will lower the device junction temperature improving the overall output accuracy. the i nput/output capacitors must be placed as close as possible to the voltage regulator output pin. to allow the same voltage reference for all circuits, use a star configuration from the output capacitor to the different loads. a a p p p p l l i i c c a a t t i i o o n n
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 6 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity typical characterist typical characterist typical characterist typical characteristics ics ics ics typical performance characteristics, unless otherwise specified are: c in = c out = 1f, c by = 470pf, v in = v out = 2.5v, t a = 25c, enable is tied to v in. outp ut voltage vs tem p erature 2.43 2.44 2.45 2.46 2.47 2.48 2.49 -50 -25 0 25 50 75 100 125 tem p era tu re ( c ) dropout voltage vs temperature 50 75 100 125 150 175 200 225 250 275 300 325 350 -50 -25 0 25 50 75 100 125 temperature (c) dropout (mv) i l =150ma i l =100ma ground current vs supply voltage -250 -200 -150 -100 -50 0 2.8 3.3 3.8 4.3 4.8 5.3 5.8 6.3 supply voltage (v) current -40 25 85 115 short circuit current vs tem perature vs sup p ly voltage -430 -420 -410 -400 -390 -380 -370 -360 -350 -340 -50 -25 0 25 50 75 100 125 tem p era tu re ( c ) v in =5v v in =4v v in =3v c c h h a a r r t t s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 7 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity typical characterist typical characterist typical characterist typical characteristics ics ics ics (continued) (continued) (continued) (continued) enable response v in = 3.3v c in = 1f, c out = 22f, c bvp = 470pf, i out = 100ma load transient response v in = 3.3v, c in = 1f, c out = 2.2f, step load = 50ma line regulation step response c in = 1f, c out = 22f, c bvp = 470pf, i out = 100ma load transient response v in = 3.3v, c in = 1f, c out = 2.2f, step load = 100ma c c h h a a r r t t s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 8 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity package dimension package dimension package dimension package dimension se 5 pin plastic sot-23 h g f e a1 j i c k a b d note: 1. dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006?) on any side. lead dimension shall not include solder coverage. m illimeters i nches dim min max min max a 0.90 1.30 0.035 0.051 a1 0.90 1.45 0.035 0.057 b 0.25 0.50 0.010 0.020 c 0.09 0.20 0.004 0.008 d 2.80 3.10 0.110 0.122 e 1.50 1.75 0.059 0.069 f 0.95 bsc 0.038 bsc g 1.90 bsc 0.075 bsc h 2.60 3.00 0.102 0.118 i 0.35 0.55 0.014 0.022 j 0.00 0.15 0.000 0.006 k 10 max 10 max m m e e c c h h a a n n i i c c a a l l s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 9 copyright ? 2000 rev. 0.3d, 2001-05-25 www. microsemi . com lx8211 150ma cmos low dropout regulator p reliminary d ata s heet a microsemi company l infinity n n n notes otes otes otes preliminary data ? information contained in this document is pre-production data and is proprietary to linfinity. it may not be modified in any way without the express written consent of linfinity. product referred to herein is offered in sample form only and linfinity reserves the right to change or discontinue this proposed product at any time. n n o o t t e e s s
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