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product s p eci f ication DF1084 5a low dropout voltage regulator no: tdspec2009e date: 2002.08
tide microelectronics 5a low dropout voltage regulator 2 of 13 general description the DF1084 series of adjustable and fixed vo ltage regulators are designed to provide 5a output current and to operate down to 1v input-t o-output differential. the dropout voltage of the device is guaranteed maximum 1.5v at maxi mum output current, decreasing at lower load currents. on-chip trimming adjusts the reference voltage to 1% . current limit is also trimmed, minimizing the stress under overload conditions on both t he regulator and power source circuitry. the DF1084 devices are pin compatible with older three-terminal regulators and are offered in 3 lead to-220 package and 3 and 2 lead to-263 (plastic dd). features ? three terminal adjustable or fixed ?? 5v, 2.5v, 2.85v, 3.0v, 3.3v, 3.5v and 5.0v ? output current of 5a ?? ? operates down to 1v dropout ?? ? line regulation: 0.015% ?? ? load regulation: 0.1% ?? ? to ?? -220 and to-263 packages available applications ? high efficiency linear regulators ?? post regulators for switching supplies ? microprocessor supply ?? ? battery chargers ?? ? constant current regulators ?? ? notebook/personal computer supplies ?? ? portable instrumentation ?? ordering information: package type 3 lead to-220 2&3 lead to-252/to-263 operating junction DF1084-adj DF1084-adj 0 to 125 ? c ?? DF1084-1.5 DF1084-1.5 0 to 125 ? c ?? DF1084-2.5 DF1084-2.5 0 to 125 ? c ?? DF1084-2.85 DF1084-2.85 0 to 125 ? c ??
tide microelectronics 5a low dropout voltage regulator 3 of 13 DF1084-3.0 DF1084-3.0 0 to 125 ? c ?? DF1084-3.3 DF1084-3.3 0 to 125 ? c ?? DF1084-3.5 DF1084-3.5 0 to 125 ? c ?? DF1084-5.0 DF1084-5.0 0 to 125 ? c ?? pin connections fixed version ad justable version 1- ground 1 - adjust 2- v out 2- v out 3- v in 3- v in absolute maximum ratings (note 1) power dissipation internally limited soldering information input voltage 15v lead temperature (10 sec) 300 c ?? operating junction temperature thermal resistance control section 0 c to 125 c ???? to-220 package ? ?? ja = 50 c/w ?? power transistor 0 c to 150 c ???? to-263 package ? ?? ja = 30 c/w * ?? storage temperature - 65 c to +150 c ???? * with package soldering to 0.5in 2 copper area over backside ground plane or internal power plane ? ?? ja ca n vary from 20 c/w to >40 c/w ???? depending on mounting technique. electrical characteristics electrical characteristics at i out = 0 ma, and t j = +25c unless otherwise specified. parameter min device conditions min typ max units reference voltage (note 2) DF1084 i out = 10 ma 10ma ? i ?? out ?? ? 5a, 1.5v ? (v ?? in - v out ) ? ? 12v ?? 1.238 1.225 1.250 1.250 1.262 1.270 v v output voltage (note 2) DF1084-1.5 0 ? i ?? out ? 5a , 3v ? v ???? in ? 12v ?? 1.485 1.470 1.500 1.500 1.515 1.530 v v DF1084-2.5 0 ? i ?? out ? 5a , 4v ? v ???? in ? 12v ?? 2.475 2.525 v
tide microelectronics 5a low dropout voltage regulator 4 of 13 2.450 2.500 2.500 2.550 v DF1084-2.85 0 ? i ?? out ? 5a , 4.35v ? v ???? in ? 12v ?? 2.82 2.79 2.850 2.850 2.88 2.91 v v DF1084-3.0 0 ? i ?? out ? 5a , 4.5v ? v ???? in ? 12v ?? 2.970 2.940 3.000 3.000 3.300 3.360 v v DF1084-3.3 0 ? i ?? out ? 5a , 4.75v ? v ???? in ? 12v ?? 3.267 3.235 3.300 3.300 3.333 3.365 v v DF1084-3.5 0 ? i ?? out ? 5a, 5v ? v ???? in ? 12v ?? 3.465 3.430 3.500 3.500 3.535 3.570 v v DF1084-5.0 0 ? i ?? out ? 5a , 6.5v ? v ???? in ? 12v ?? 4.950 4.900 5.000 5.000 5.050 5.100 v v line regulation DF1084/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 i load = 10 ma , 1.5v ? (v ?? in - v out ) ? 12v ?? 0.3 0.6 6 10 mv mv load regulation (notes 2, 3) DF1084 (v in - v out ) =3v, 10ma ? i ?? out ? 5a ?? 0.1 0.2 0.3 0.4 % % DF1084-1.5 v in = 5v, 0 ? i ?? out ? 5a ?? 3 6 12 20 mv mv DF1084-2.5 v in = 5v, 0 ? i ?? out ? 5a ?? 3 6 12 20 mv mv DF1084-2.85 v in = 5v, 0 ? i ?? out ? 5a ?? 3 6 12 20 mv mv DF1084-3.0 v in = 5v, 0 ? i ?? out ? 5a ?? 3 6 12 20 mv mv DF1084-3.3 v in = 5v, 0 ? i ?? out ? 5a ?? 3 7 15 25 mv mv DF1084-3.5 v in = 5.25v, 0 ? i ?? out ? 5a ?? 3 6 15 25 mv mv DF1084-5.0 v in = 8v, 0 ? i ?? out ? 5a ?? 5 10 20 35 mv mv` dropout voltage (v in - v out ) DF1084/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 v ?? out , v ?? ref = 1%, i out = 5 a (note 4) 1.3 1.5 v current limit DF1084/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 (v in - v out ) = 5v 5.00 6.00 7.00 a minimum load current DF1084 (v in - v out ) = 12v (note 5) 10 12 15 ma quiescent DF1084/-1.5/-2.5/-2.85/ v in ? 12v ?? 5 10 ma
tide microelectronics 5a low dropout voltage regulator 5 of 13 current -3.0/-3.3/-3.5/-5.0 ripple rejection DF1084 f =120hz , c out = 25 f ?? tantalum, i out = 5a, (v in -v out ) = 3v, c adj =25 f ?? 60 75 db DF1084-1.5 f =120hz , c out = 25 f ?? tantalum, i out = 5a, v in = 4.5v 60 72 db DF1084-2.5 f =120hz , c out = 25 f ?? tantalum, i out = 5a, v in = 5.5v 60 72 db DF1084-2.85 f =120hz , c out = 25 f ?? tantalum, i out = 5a, v in = 6v 60 72 db DF1084-3.0 f =120hz , c out = 25 f ?? tantalum, i out = 5a v in = 6v 60 72 db DF1084-3.3 f =120hz , c out = 25 f ?? tantalum, i out = 5a v in = 6.3v 60 72 db DF1084-3.5 f =120hz , c out = 25 f ?? tantalum, i out = 5a v in = 6.5v 60 72 db DF1084-5.0 f =120hz , c out = 25 f ?? tantalum, i out = 5a v in = 8v 60 68 db thermal regulation DF1084 t a = 25c, 30ms pulse 0.008 0.04 %w adjust pin current DF1084 10ma ? i ?? out ? 5a , 1.5v ? (v ???? in - v out ) ? 12v ?? 55 120 a ?? a ?? adjust pin current change DF1084 10ma ? i ?? out ? 5a , 1.5v ? (v ???? in - v out ) ? 12v ?? 0.2 5 a ?? temperature stability 0.5 % long term stability t a =125c, 1000hrs 0.3 1 % rms output t a = 25c , 10hz ? f ? 10khz ???? 0.003 %
tide microelectronics 5a low dropout voltage regulator 6 of 13 noise (% of v out ) thermal resistance junction-to-case m package: control circuitry/ power transistor t package: control circuitry/ power transistor 1.5/4.0 1.5/4.0 c/w c/w parameters identified with boldface type apply over the full operating temperature range. note 1: absolute maximum ratings indicate limits beyond which damage to the device may occur. for guaranteed specifications and test conditions, see the electrical characteristics . the guaranteed specifications apply only for the test conditions listed. note 2: line and load regulation are guaranteed up to the maximum power dissipation of 15w. power dissipation is determined by the input/output differential and the output current. guaranteed maximum power dissipation will not be available over the full input/output range. note 3: see thermal regulation specificat ions for changes in output voltage due to heating effects. line and load regulation are measured at a constant junction temperature by low duty cy cle pulse testing. load regulation is measured at the output lead ~1/8? from the package. note 4: dropout voltage is specified over the fu ll output current range of the device. note 5: minimum load current is defined as the minimum output current required to maintain regulation. when (v in - v out ) = 12v the device is guaranteed to regulate if the output current is greater than 10ma. application hints the DF1084 series of adjustable and fixed regulat ors are easy to use and have all the protection features expected in high performance voltage regulators: short circuit protection and thermal shut-down. pin compatible with older three terminal adjustabl e regulators, these devices offer the advantage of a lower dropout voltage, more precise reference tolerance and improved reference stability with temperature. stability the circuit design used in the DF1084 series require s the use of an output c apacitor as part of the device frequency compensat ion. the addition of 150 f aluminum electrolytic or a 22 f solid ???? tantalum on the output will ensure stabilit y for all operating conditions. when the adjustment terminal is bypassed with a c apacitor to improve the ripple rejection, the requirement for an output capacitor incr eases. the value of 22 f tantalum or ?? 150 f ?? aluminum covers all cases of bypassing the adjustment terminal. wi thout bypassing the adjustment terminal smaller capacitors can be used with equally good results. to ensure good transient response with heavy load current changes capacitor values on the order of 100 f are used in the ?? output of many regulators. to further improve stability and transient response of these devices larger values of output capacit or can be used. protection diodes
tide microelectronics 5a low dropout voltage regulator 7 of 13 unlike older regulators, the DF1084 family does not need any protec tion diodes between the adjustment pin and the output and from t he output to the input to prevent over-stressing the die. internal resistors are limiting the inter nal current paths on the DF1084 adjus tment pin, therefore even with capacitors on the adjustment pi n no protection diode is needed to ensure device safety under short-circuit conditions. diodes between the input and output are not usuall y needed. microsecond surge currents of 50a to 100a can be handled by the internal diode between the input and output pins of the device. in normal operations it is difficult to get those values of surge currents even with the use of large output capacitances. if high value out put capacitors are used, such as 1000 f to 5000 f a ???? nd the input pin is instantaneously shorted to ground, damage can occur. a diode from out put to input is recommended, when a crowbar circuit at the i nput of the DF1084 is used. normal power supply cycling or even plugging and unplugging in the system will not generate current large enough to do any damage. the adjustment pin c an be driven on a transient basis 25v, with ?? respect to the output without any devic e degradation. as with any ic regulat or, none the protection circuitry will be functional and the internal transistors will break down if the maximum input to out put voltage differential is exceeded. overload recovery when the power is first turned on, as the input vo ltage rises, the output follows the input, permitting the regulator to start up into heavy loads. during t he start-up, as the input voltage is rising, the input-to-output voltage differential remains small, allowi ng the regulator to supply large output currents. a problem can occur with a heavy output load when the input voltage is high and t he output voltage is low, when the removal of an output short will not permit the output voltage to recover. the load line for such a load may intersect two points on the output current cu rve. in this case, there are two stable output operating points for the regulator. with this double intersection, the power supply may need to be cycled down to zero and brought up again to make the output recover. ripple rejection the ripple rejection values are measured with the adjustment pin bypass ed. the impedance of the
tide microelectronics 5a low dropout voltage regulator 8 of 13 adjust pin capacitor at the ri pple frequency should be less than the value of r1 (normally 100 ? to120 ) ???? for a proper bypassing and ripple rejection approaching the values shown. the size of the required adjust pin capacitor is a function of the input ripple frequency. if r1=100 ? at 120hz the ?? adjust pin capacitor should be 25 f. at 10kh ?? z only 0.22 f is ?? needed. the ripple rejection will be a function of output vo ltage, in circuits without an adjust pin bypass capacitor. the output ripple will increas e directly as a ratio of the out put voltage to the reference voltage (v out / v ref ). output voltage the DF1084 series develops a 1.25v reference vo ltage between the output and the adjust terminal. placing a resistor between these two terminals causes a constant current to flow through r1 and down through r2 to set the overall output voltage. this current is normally the specified minimum load current of 10ma. because i adj is very small and constant it represents a small error and it can usually be ignored. v out = v ref ? 1+ r2/r1)+i adj r2 figure 1. basic adjustable regulator load regulation true remote load sensing it is not possible to provide, because the DF1084 is a three terminal device. the resistance of the wire connecting the regulator to the load will limit the load regulation. the data sheet specification for load regulation is measured at the bo ttom of the package. negative side sensing is a true kelvin connection, with the bottom of the output divider retu rned to the negative side of the load. the best load regulation is obtained when the top of the resistor divider r1 is connected directly to the case not to the load. if r1 were connected to the load, the effective resistance between the regulator and the load would be: r p x ?? ( r2+r1 )/ r1 ?1 , r p = parasitic line resistance
tide microelectronics 5a low dropout voltage regulator 9 of 13 connected as shown, r p is not multiplied by the divider ratio. using 16-gauge wire the parasitic line resistance is about 0.004 ? per foot, translating to 4mv/ft at 1a load current. it is ?? important to keep the positive lead between regulator and l oad as short as possible and use large wire or pc board traces. thermal considerations the DF1084 series have internal power and thermal limiting circuitry designed to protect the device under overload conditions. however maximum junc tion temperature ratings should not be exceeded under continuous normal load conditions. careful consider ation must be given to all sources of thermal resistance from junction to ambient, including junction- to-case, case-to-heat sink interface and heat sink resistance itself. to ensure safe operating temper atures and reflect more accurately the device temperature, new thermal resistance specifications have been developed. unlike older regulators with a single junction-to-case thermal resistance specification, the data section for these new regulators prov ides a separate thermal resistance and maximum junction temperature for bot h the control section and the power transistor. calculations for both temperatures under certain c onditions of ambient temperatur e and heat sink resistance and to ensure that both the rmal limits are met. junction-to-case thermal resistance is specified from the ic junction to the bottom of the case directly below the die. this is the lowest resistance path for the heat flow. in order to ensure the best possible thermal flow from this area of the package to t he heat sink proper mounti ng is required. thermal compound at the case-to-heat sink interface is recommended. a the rmally conductive spacer can be used, if the case of the device must be electrically isolated, but its added contribution to thermal resistance has to be considered.
tide microelectronics 5a low dropout voltage regulator 10 of 13 typical performance characteristics
tide microelectronics 5a low dropout voltage regulator 11 of 13 package dimensions inches (millimeters) unless otherwise noted. 3 lead to-220 plastic package 3 lead to-263 plastic
tide microelectronics 5a low dropout voltage regulator 12 of 13 2 lead to-263 plastic to-252 plastic note: tide corporation assumes no responsibility fo r any errors which may appear in this document. reserves the right to change devices or specific ations detailed herein at any time without notice.
tide microelectronics 5a low dropout voltage regulator 13 of 13 attach: revision history date rev description page 2002-08 1.0

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