? semiconductor components industries, llc, 2001 january, 2001 rev. 6 1 publication order number: cs8281/d cs8281 5.0 v/250 ma, 5.0 v/100 ma micropower low dropout regulator with enable the cs8281 is a precision, dual 5.0 v micropower linear voltage regulator. the switched primary o utput (v out1 ) supplies up to 250 ma while the secondary (v out2 ) is capable of supplying 100 ma. both outputs have a maximum dropout voltage of 600 mv and low reverse current. quiescent current drain is typically 150 m a when supplying 100 m a from each output. the enable input provides logic level control of the primary output. with the primary output disabled, quiescent current drain is typically 100 m a when supplying 100 m a from the secondary output. the cs8281 is extremely robust with protection provided for reverse battery, short circuit, overvoltage, and overtemperature on both outputs. the cs8281 is available in a 5lead d 2 pak. features ? 5.0 v/250 ma primary output ? 5.0 v/100 ma secondary output ? 3.0% tolerance, both outputs ? on/off control for primary output ? low quiescent current drain (100 m a v out2 ) ? low reverse current ? protection features reverse battery (15 v) 74 v load dump short circuit overtemperature overvoltage (34 v) http://onsemi.com pin connections and marking diagram device package shipping ordering information* 50 units/rail cs8281ydp5 d 2 pak, 5pin 750 tape & reel cs8281ydpr5 d2pak, 5pin a = assembly location wl, l = wafer lot yy, y = year ww, w = work week *consult your local sales representative for so8, so16, dip8, dip16, to220 five lead, and d 2 pak 7pin packaging options. d 2 pak 5pin dp suffix case 936f 1 5 cs8281 awlyww 1 tab = gnd pin 1. v in 2. v out1 3. gnd 4. v out2 5. enable
cs8281 http://onsemi.com 2 figure 1. block diagram + + primary output current limit + secondary output current limit overvoltage shutdown bandgap reference thermal shutdown gnd pwr gnd enable v in v out1 v out1 sense v out2 v out2 sense absolute maximum ratings* rating value unit input voltage 15 to 74 v power dissipation internally limited operating temperature range 40 to +125 c maximum junction temperature 40 to +150 c storage temperature range 55 to +150 c electrostatic discharge (human body model) 4.0 kv lead temperature soldering reflow (smd styles only) (note 1.) 230 peak c 1. 16 second maximum above 183 c *the maximum package power dissipation must be observed.
cs8281 http://onsemi.com 3 electrical characteristics: (6.0 v v in 26 v, i out1 = i out2 = 100 m a, 40 c t c 125 c; unless otherwise specified.) characteristic test conditions min typ max unit primary output stage (v out1 ) output voltage, v out1 100 m a i out1 250 ma 4.85 5.00 5.15 v dropout voltage i out1 = 250 ma i out1 = 100 m a 400 100 600 150 mv mv line regulation 6.0 v v in 26 v 5.0 50 mv load regulation 1.0 ma i out1 250 ma, v in = 14 v 5.0 50 mv quiescent current enable = high, v in = 16v, i out1 = 250 ma 22 50 ma ripple rejection f = 120 hz, i out1 = 125 ma, 7.0 v v in 17 v 60 70 db current limit 260 400 ma short circuit current limit v out1 = 0 v, v in = 16 v 25 ma reverse current v out1 = 5.0 v, v in = 0 v 100 1500 m a secondary output (v out2 ) output voltage, (v out2 ) 100 m a i out1 100 ma 4.85 5.00 5.15 v dropout voltage i out2 = 100 ma i out2 = 100 m a 400 100 600 150 mv mv line regulation 6.0 v v in 26 v 5.0 50 mv load regulation 100 m a i out2 100 ma, v in = 14 v 5.0 50 mv quiescent current enable = low, v in = 12.8 v enable = high, v in = 16 v 100 8.0 150 25 m a ma ripple rejection f = 120 hz; i out2 = 50 ma, 7.0 v v in 17 v 60 70 db current limit 105 200 ma short circuit current limit v out2 = 0 v, v in = 16 v, i out1 = 0 a 25 ma reverse current v out2 = 5.0 v, v in = 0 v 100 250 m a enable function (enable) input threshold enable = low, 7.0 v v in 26 v enable = high, 7.0 v v in 26 v 2.0 1.2 1.2 0.8 v v input bias current 0 v v enable 5.0 v 2.0 0 2.0 m a protection circuits overtemperature threshold 150 180 c overvoltage shutdown 30 34 38 v package pin description package lead # d 2 pak, 5pin lead symbol function 1 v in supply voltage to ic, usually direct from battery. 2 v out1 5.0 v regulated output which is activated by enable input. 3 gnd ground connection. 4 v out2 standby output 5.0 v, 100 ma capability; always on. 5 enable cmos compatible input lead; switches v out1 . when enable is high, v out1 is active.
cs8281 http://onsemi.com 4 definition of terms current limit peak current that can be delivered to the output. dropout voltage the inputoutput voltage differential at which the circuit ceases to regulate against further reduction in input voltage. measured when the output voltage has dropped 100 mv from the nominal value obtained at 14 v input, dropout voltage is dependent upon load current and junction temperature. input output differential the voltage difference between the unregulated input voltage and the regulated output voltage for which the regulator will operate. input voltage the dc voltage applied to the input terminals with respect to ground. line regulation the change in output voltage for a change in the input voltage. the measurement is made under conditions of low dissipation or by using pulse techniques such that the average chip temperature is not significantly affected. load regulation the change in output voltage for a change in load current at constant chip temperature. long term stability output voltage stability under accelerated lifetest conditions after 1000 hours with maximum rated voltage and junction temperature. quiescent current the part of the positive input current that does not contribute to the positive load current, i.e., the regulator ground lead current. ripple rejection the ratio of the peaktopeak input ripple voltage to the peaktopeak output ripple voltage. short circuit current limit peak current that can be delivered by the outout when forced to 0 v. temperature stability of v out the percentage change in output voltage for a thermal variation from room temperature to either temperature extreme. 14 v 0 v 0 v 2.0 v 0.8 v v in enable v out1 v out2 system condition load dump low v in line noise, etc. v out1 short circuit thermal shutdown turn off turn on v out2 short circuit 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 5.0 v 2.4 v 2.4 v 0 v 0 v 0 v 0 v 3.0 v 60 v 34 v 26 v 14 v figure 2. typical circuit waveform application notes general the cs8281 is a micropower dual 5.0 v regulator. all bias required to operate the internal circuitry is derived from the standby output, v out2 . if this output experiences an over current situation and collapses, then v out1 will also collapse (see figure 2). if there is critical circuitry that must remain active under most conditions it should be connected to v out2 . any circuitry that is likely to be subjected to a short circuit, e.g., circuitry outside the module, should be connected to v out1 . external capacitors output capacitors are required for stability with the cs8281. without them, the regulator outputs will oscillate. actual size and type may vary depending upon the application load and temperature range. capacitor effective series resistance (esr) is also a factor in the ic stability. worstcase is determined at the minimum ambient temperature and maximum load expected. output capacitors can be increased in size to any desired value above the minimum. one possible purpose of this would be to maintain the output voltages during brief conditions of negative input transients that might be characteristic of a particular system. capacitors must also be rated at all ambient temperatures expected in the system. to maintain regulator stability down to 40 c, capacitors rated at that temperature must be used. more information on capacitor selection for smart regulator ? s is available in the smart regulator application note, acompensation for linear regulators,o document number sr003an/d, available through the literature distribution center or via our website at http://www.onsemi.com.
cs8281 http://onsemi.com 5 enable the enable function controls v out1 . when enable is high, v out1 is on. when enable is low, v out1 is off. calculating power dissipation in a dual output linear regulator the maximum power dissipation for a dual output regulator (figure 3) is p d(max) v in(max) v out1(min) i out1(max) v in(max) v out2(min) i out2(max) v in(max) iq (1) where: v in(max) is the maximum input voltage, v out1(min) is the minimum output voltage from v out1 , v out2(min) is the minimum output voltage from v out2 , i out1(max) is the maximum output current, for the application, i out2(max) is the maximum output current, for the application, and i q is the quiescent current the regulator consumes at both i out1(max) and i out2(max) . once the value of p d(max) is known, the maximum permissible value of r q ja can be calculated: r ja 150 c t a p d (2) the value of r q ja can be compared with those in the package section of the data sheet. those packages with r q ja 's less than the calculated value in equation 2 will keep the die temperature below 150 c. in some cases, none of the packages will be sufficient to dissipate the heat generated by the ic, and an external heatsink will be required. figure 3. dual output regulator with key performance parameters labeled. smart regulator control features v out1 i out1 v out2 i out2 v in i in i q heat sinks a heat sink effectively increases the surface area of the package to improve the flow of heat away from the ic and into the surrounding air. each material in the heat flow path between the ic and the outside environment will have a thermal resistance. like series electrical resistances, these resistances are summed to determine the value of r q ja : r ja r jc r cs r sa (3) where: r q jc = the junctiontocase thermal resistance, r q cs = the casetoheatsink thermal resistance, and r q sa = the heatsinktoambient thermal resistance. r q jc appears in the package section of the data sheet. like r q ja , it too is a function of package type. r q cs and r q sa are functions of the package type, heatsink and the interface between them. these values appear in heat sink data sheets of heat sink manufacturers. test & application diagram figure 4. test & application circuit * c 1 required if regulator is located far from power supply filter. ** c 2 and c 3 required for stability. capacitor must operate at minimum temperature expected during system operations. enable v out2 v in v out1 cs8281 gnd load v batt v cc i/o gnd p c 3 ** c 1 * c 2 ** 0.1 m f 22 m f esr < 8 w 22 m f esr < 8 w
cs8281 http://onsemi.com 6 package dimensions d 2 pak, five pin dp suffix case 936f01 issue o t dim min max min max millimeters inches a 0.326 0.336 8.28 8.53 b 0.396 0.406 10.05 10.31 c 0.170 0.180 4.31 4.57 d 0.026 0.035 0.66 0.91 e 0.045 0.055 1.14 1.40 f 0.090 0.110 2.29 2.79 g 0.067 bsc 1.70 bsc h 0.098 0.108 2.49 2.74 j 0.018 0.025 0.46 0.64 k 0.204 0.214 5.18 5.44 m 0.055 0.066 1.40 1.68 n 0.000 0.004 0.00 0.10 notes: 1. dimensions and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: inch. 3. tab contour optional within dimensions b and m. 4. dimensions a and b do not include mold flash or gate protrusions. mold flash and gate protrusions not to exceed 0.025 (0.635) max. b n a k m e c seating plane f h j d 5 pl g t m 0.13 (0.005) m b 12345 package thermal data parameter d 2 pak, 5pin unit r q jc typical 2.4 c/w r q ja typical 1050* c/w * depending on thermal properties of substrate. r q ja = r q jc + r q ca
cs8281 http://onsemi.com 7 notes
cs8281 http://onsemi.com 8 on semiconductor and are trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to make changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. atypicalo parameters which may be provided in scill c data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body , or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a sit uation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthori zed use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. publication ordering information central/south america: spanish phone : 3033087143 (monfri 8:00am to 5:00pm mst) email : onlitspanish@hibbertco.com asia/pacific : ldc for on semiconductor asia support phone : 3036752121 (tuefri 9:00am to 1:00pm, hong kong time) toll free from hong kong & singapore: 00180044223781 email : onlitasia@hibbertco.com japan : on semiconductor, japan customer focus center 4321 nishigotanda, shinagawaku, tokyo, japan 1410031 phone : 81357402745 email : r14525@onsemi.com on semiconductor website : http://onsemi.com for additional information, please contact your local sales representative. cs8281/d smart regulator is a registered trademark of semiconductor components industries, llc (scillic). north america literature fulfillment : literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 3036752175 or 8003443860 toll free usa/canada fax : 3036752176 or 8003443867 toll free usa/canada email : onlit@hibbertco.com fax response line: 3036752167 or 8003443810 toll free usa/canada n. american technical support : 8002829855 toll free usa/canada europe: ldc for on semiconductor european support german phone : (+1) 3033087140 (monfri 2:30pm to 7:00pm cet) email : onlitgerman@hibbertco.com french phone : (+1) 3033087141 (monfri 2:00pm to 7:00pm cet) email : onlitfrench@hibbertco.com english phone : (+1) 3033087142 (monfri 12:00pm to 5:00pm gmt) email : onlit@hibbertco.com european tollfree access*: 0080044223781 *available from germany, france, italy, uk, ireland
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