microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 1 copyright ? 2000 rev. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction description description description description the lx8221 family of dual output linear regulators provide for the selection of either fixed or adjustable output voltages, and combine low dropout operation, fast transient performance, tight output voltage accuracy, and ultra-low ground current within a very small package footprint. the pmos output transistor allows for an ultra-low dropout characteristic (e.g., typically less than 175mv at 100ma). the individual regulators can be powered from either separate supply voltages or the same supply voltage between 2.8v to 6v allowing for maximum system flexibility. an optional ceramic or tantalum type capacitor may be connected to each bypass pin separately to improve performance in critical low-noise applications. overall regulator efficiency has been improved with a minimized operating ground current (typ < 140 a per regulator). further, this ground current is virtually eliminated in shutdown mode (typ < 1 a). other safety features include channel independent thermal and short circuit current protection. separate enable pins allow each regulator to be switched on and off independently by applying a ttl logic level control signal to the enable pin further enhancing system level power management. these features combined with a small footprint (i.e., 10-pin msop package) make the lx8221 especially useful for battery-operated equipment such as cellular telephones, laptop computers and pda equipment. important: for the most current data, consult micro semi? s website: http://www.microsemi.com key features key features key features key features compact regulators with two 150 ma outputs dropout voltage typically 175mv @ 100ma ultra low shutdown current typically less than 1 a output trimmed to 0.5% small msop-10 package over current & temperature protection stable with ceramic or tantalum capacitors applications applications applications applications battery operated systems laptop, notebook and pda?s cellular telephones/pagers instrumentation linear post regulators for smps product highlight product highlight product highlight product highlight r2 r1 5.0v 3.3v en1 en2 vout1 vout2 gnd adj cb1 vin1 vin2 n/c } to control logic off on fixed / adjustable application r2 r1 5.0v 3.3v en1 en2 vout1 vout2 gnd adj2 adj1 vin1 vin2 n/c } to control logic off on r1 r2 adjustable / adjustable application pac pac pac package order info kage order info kage order info kage order info t j ( c) vout1 vout2 du plastic msop 10-pin package marking -40 to 125 adjustable adjustable lx8221-aidu 8221 aidu lx -40 to 125 2.5v adjustable lx8221-bidu 8221 bidu lx -40 to 125 2.7v adjustable LX8221-DIDU 8221 didu lx -40 to 125 3.0v adjustable lx8221-gidu 8221 gidu lx contact microsemi for additional / available options note: available in tape & reel. append the letter ?t? to the part number. (i.e. lx8221-aidut) l l x x 8 8 2 2 2 2 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction absolute maximum rat absolute maximum rat absolute maximum rat absolute maximum ratings ings ings ings input voltage (vin1, vin2) ..........................................................................-0.3v to +7v output current (i out1 , i out2 ) ................................................................................. 150ma operating temperature range..................................................................... -40 to +125 c maximum junction temperature (t j ).......................................................................150 c storage temperature (t j ) ............................................................................ -65 to +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 4 3 7 8 10 9 56 vin1 en1 gnd adj vout2 vout1 cb1 nc en2 vin2 du p ackage (top view) ?nc? = no internal connection thermal data thermal data thermal data thermal data du plastic msop 8-pin thermal resistance - junction to a mbient , ja 206 c/w thermal resistance - junction to c ase , jc 39 c/w junction temperature calculation: t j = t a + (p d x jc ). the ja numbers are guidelines for the thermal performance of the device/pc-board system. all of the above assume no ambient airflow. front marking front marking front marking front marking x = voltage combination i.e. a = adj/adj functional pin descr functional pin descr functional pin descr functional pin description iption iption iption p in n ame d escription vin1/vin2 unregulated input supply voltage gnd ground pin en1/en2 enable control input: logic high = enable; logic low or open = shutdown cb1 reference bypass input. adding an additional external capacitor reduces output noise. vout1/vout2 regulated output voltage. regulator stability is achieved with external capacitor of 1uf adj (1, 2) adjust pin. connect a resistor divider to this pin to establish preferred output voltage. block diagram block diagram block diagram block diagram vout1 cb1 gnd + - control logic thermal sensor current limit vref vin1 en1 + - control logic thermal sensor current limit vref vin2 en2 adj vout2 8221 xidu lx 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction recommended operatin recommended operatin recommended operatin recommended operating conditions g conditions g conditions g conditions lx8221 parameter symbol min typ max units input operating voltage range (note 1) vin1, vin2 2.5 6 v enable input voltage range en1/2 v in + 0.3v v continuous output current range i out 1, i out 1 150 ma input capacitor (v in to gnd) c in 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 = 1 f; c out = 1 f; t j = t a using low duty cycle pulse testing methods. lx8221 parameter symbol test conditions min typ max units t j = 25c -1 1 output voltage (2.5, 2.7, 3.0, adj) vout1/2 0ma i out1/2 150ma, (v out1/2 + 0.5v) v in 6v -2.5 2.5 % t j = 25c 1.163 1.187 adjust reference voltage v adj 0ma i out1/2 150ma, 2.85v v in 6v 1.152 1.175 1.200 v line regulation ? ? ? ? ? ? ? ? in o v v v rv (v out1/2 + 0.5v) v in 6v, i out1/2 = 0.1ma 0.04 0.15 %/v load regulation ? ? ? ? ? ? ? ? o o i v v ri 0.5ma i out1/2 100ma 1.5 %v nom i load1/2 = 1ma, ? vo = -1% 0.050 i load1/2 = 50ma, ? vo = -1% 0.175 i load1/2 = 100ma, ? vo = -1% 0.175 0.3 dropout voltage () o in v v ? (note 2) v do i load1/2 = 150ma, ? vo = -1% 0.25 0.4 v i gnd en1 = high, en2 = high 280 440 ground pin current i stby en1 = low, en2 = low 1 a adjust input bias current i adj v adj = 1.25v 100 na enable pin current i en v en1/2 = v in 100 na v en(ih) 2.0 enable threshold v en(il) 0.4 v short circuit current limit i out(sc) vout1 = 0v, vout2 = 0v 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. dropout voltage specification applies only to output voltages greater than 2.8 v. for output voltages below 2.8 v, the dropout voltage is nothing but the inp ut to output differential, since the minimum input voltage is 2.8 v. 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction applications applications applications applications description the lx8221 family of ldo linear regulators is available in a 10-pin msop package and provides a cost effective power management solution for battery driven applications. the regulator family includes both fixed/adjustable and adjustable/adjustable output voltage versions. the internal pmos power device provides low dropout regulation with a fast line and load transient response. it also includes internal current limiting and thermal shutdown circuitry. in this section you will find information about capacitor, thermal, and layout design considerations. 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 this capacitor to ensure that the capacitor?s value will be around 1 f over the entire operating temperature range. for the lx8221, a 1 f ceramic type capacitor may be connected between both vin1/2 and ground. output capacitor the lx8221 uses an internal feedback loop to maintain a constant output voltage. this feedback loop induces a natural phase shift and the amount of phase shift determines the loop?s stability. therefore, like any low- dropout regulator, an output capacitor with low esr (equivalent series resistance) is required between vout and gnd to stabilize the internal control loop. a ceramic, tantalum or electrolytic capacitor with a minimum recommended capacitance value of 1.0 f and esr between 5m ? and 1 ? will satisfy the stability for the entire operating range. optional bypass capacitor the fixed/adjustable voltage version of the lx8221 includes a separate bypass pin (cb1) for the fixed regulator that allows for further reduction of output noise. if the regulator?s output noise performance meets system design specifications without the capacitor, omit it. the bypass capacitor impacts the start up time, which is inversely proportional to the size of bypass capacitor. further, the bypass capacitor reduces the regulator phase margin. hence, implementing the bypass capacitor will require the use of a larger output capacitor to maintain the ldo?s stability. the lx8221-x adjustable regulator?s output voltage can be externally set by connecting the adj p in/s to an external resistor divider (see figure 1 and 2). the output voltage can be calculated using the formula: ? ? ? ? ? ? ? ? + = 2 1 adj out r r 1 v v enable the enable pin allows the lx8221 to be independently turned on and off. the enable pins are compatible with standard ttl-cmos levels. a logic zero (0.4v) on the en 1 / en 2 pins shuts the lx8221 off and reduces the supply current to less than 1 a (typ). pulling the enable inputs 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 although line regulation is improved with a minimum load of 100 a, the lx8221 does not have a minimum load current in order to maintain stability. this is an especially important feature in certain applications. temperature protection the thermal protection shuts the lx8221 down when the junction temperature exceeds approximately 150 0 c; there is no appreciable thermal hysteresis. short circuit current protection the lx8221 includes over-current protection, when the output load current exceeds about 400ma. when this occurs, the protection circuit forces the regulator to decrease its output current. thermal consideration thermal shutdown protects the integrated circuit from thermal overload caused from a rise in junction temperature during power dissipation. this type 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 each regulator can 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 5 copyright ? 2000 rev. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction applications applications applications applications be calculated using the following equation: ( ) max out min out max in d i v v p ? = (note: power dissipation resulting from quiescent current is negligible) for the msop 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: rise a j t t t + = where: () ja d rise p t = example : given the following conditions: t a = 60c v in = 4.2v v out = 2.7v i out = 100ma calculate the total power dissipation and junction temperature: total power dissipation: () w 15 . 0 a 1 . 0 v 7 . 2 v 2 . 4 p d = ? = junction temperature: () c w c w c t o o o j 93 / 220 15 . 0 60 = + = layout consideration: the layout must be implemented with low impedance paths for v in , v out and ground by creating sufficiently wide traces to avoid voltage drops and pick up noise. adding an area of pcb copper to the gnd pin (pin 8) will reduce the overall ja since it is thermally connected to the device substrate. this will lower the device junction temperature improving overall output voltage accuracy. the input/output capacitors must be placed as close as possible to each voltage regulator output pin. 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction application circuits application circuits application circuits application circuits r2 r1 5.0v 3.3v en1 en2 vout1 vout2 gnd adj cb1 vin1 vin2 3.0v 2.7v n/c resistor table r1 = 13.0k ? r2 = 10.0k ? figure 1. fixed / adjustable output application r2 r1 5.0v 3.3v en1 en2 vout1 vout2 gnd adj2 adj1 vin1 vin2 n/c 2.7v 2.5v resistor table vout1 r1 = 13.0k ? r2 = 10.0k ? vout2 r1 = 11.3k ? r2 = 10.0k ? r1 r2 figure 2 ? adjustable / adjustable output application a a p p p p l l i i c c a a t t i i o o n n s s a a p p p p l l i i c c a a t t i i o o n n 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction output voltage vs t output voltage vs t output voltage vs t output voltage vs temperature emperature emperature emperature dropout voltage vs t dropout voltage vs t dropout voltage vs t dropout voltage vs temperature emperature emperature emperature 1.155 1.16 1.165 1.17 1.175 1.18 1.185 -50 -25 0 25 50 75 100 125 temperature (c) output voltage (v) 50 75 100 125 150 175 200 225 250 275 300 325 350 -50 -25 0 25 50 75 100 125 temperature ( c) i l =150ma i l =100ma output current vs su output current vs su output current vs su output current vs supply voltage pply voltage pply voltage pply voltage short circuit curren short circuit curren short circuit curren short circuit current vs temperature t vs temperature t vs temperature t vs temperature -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) -40c 25c 85c 115c -430 -420 -410 -400 -390 -380 -370 -360 -350 -340 -40 -25 0 25 85 100 115 125 supply voltage (v) 5v 4v 3v ps ps ps psrr vs frequency rr vs frequency rr vs frequency rr vs frequency psrr vs frequency in psrr vs frequency in psrr vs frequency in psrr vs frequency in dropout dropout dropout dropout 0 50 100 0.1 1 10 100 frequency (khz) 0 50 100 0.1 1 10 100 frequency (khz) 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. p p e e r r f f o o r r m m a a n n c c e e
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 8 copyright ? 2000 rev. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction package dimensions package dimensions package dimensions package dimensions du 10-pin plastic msop c g f b a j d p h * lead coplanarity m illimeters i nches dim min max min max a 2.85 3.05 0.112 0.120 b 2.90 3.10 0.114 0.122 c - 1.10 - 0.043 d 0.16 0.31 0.006 0.0124 f 0.40 0.60 0.015 0.023 g 0.50 bsc 0.019 bsc h 0.050 0.150 0.002 0.006 j 0.10 - 0.004 - p 4.75 5.05 0.187 0.198 *lc - 0.10 - 0.004 note: 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 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. 1.0, 2002-01-02 www. microsemi . com lx8221 dual 150ma cmos low dropout regulato r p roduction notes notes notes notes production data ? information contained in this document is proprietary to microsemi and is current as of publication date. this document may not be modified in any way without the express written consent of microsemi. product processing does not necessarily include testing of all parameters. microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. n n o o t t e e s s
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