4707 dey road liverpool, n.y. 13088 m.s.kennedy corp. (315) 701-6751 features: manufactured using space qualified rh1185 die total dose tested to 300 krads(si)(method 1019.7 condition a) -5v, -5.2v, -10v, -12v and -15v standard versions low dropout voltage output current to 3 amps output voltage internally set to 1% max. internal short circuit current limit internal thermal overload protection lead form options: straight, up, down and gull wing alternate output voltages available available with top tab or tabless package contact msk for mil-prf-38534 qualification and appendix g (radiation) status high efficiency linear regulators constant voltage/current regulators system power supplies switching power supply post regulators typical applications pin-out information 1 2 3 gnd vin vout 5940rh series rad hard negative, 3 amp, low dropout voltage regulator description: the msk 5940rh is a fixed, radiation hardened, negative voltage regulator which offers low dropout and output voltage accuracy to 1% maximum. the low jc combined with low dropout allows increased output current and excellent device efficiency. the msk 5940rh offers both internal current limit and thermal overload protection. the case of the device is electrically isolated for heat sinking purposes. the device is packaged in a space efficient 3 pin power package with various lead form options. the msk 5940rh series is also available in a power package with a top tab to accomodate direct mounting to a heat sink. equivalent schematic mil-prf-38534 certified 1 rev. d 11/08
dropout voltage short circuit current ripple rejection thermal resistance % % % v % % % % ma ma a db c/w part number max. 1.0 2.5 2.0 1.0 1.0 2.0 0.5 0.75 10 10 - - 4.6 storage temperature range lead temperature range (10 seconds) case operating temperature msk 5940k/h/e rh msk 5940rh -35v -30v internally limited -3a +150c -2v -65c to +150c 300c -55c to +125c -40c to +85c absolute maximum ratings t st t ld t c input voltage input voltage (wrt v out ) power dissipation output current junction temperature output reverse voltage -v in -v in p d i out t j i out output is decoupled to ground using 33f minimum, low esr capacitors unless otherwise specified. guaranteed by design but not tested. typical parameters are representative of actual device performance but are for reference only. all output parameters are tested using a low duty cycle pulse to maintain t j = t c . industrial grade and "e" suffix devices shall be tested to subgroup 1 unless otherwise specified. military grade devices ("h" and "k" suffix) shall be 100% tested to subgroups 1,2 and 3. subgroup 1 t a =t c =+25c 2 t a =t c =+125c 3 t a =t c =-55c please consult the factory if alternate output voltages are required. input voltage (v in = v out + a specified voltage) is implied to be more negative than v out . continuous operation at or above absolute maximum ratings may adversely effect the device performance and/or life cycle. pre and post irradiation limits, at 25c, up to 100krad tid, are identical unless otherwise specified. min. - - - - - - - - - - 3.0 60 - group a subgroup 1 2,3 1 1 1 2,3 1 2,3 1 2,3 - - - min. - - - - - - - - - - 3.0 60 - typ. 0.1 0.1 1.0 0.7 0.2 0.3 0.1 0.2 4.5 4.5 3.5 75 4.2 typ. 0.1 - 1.0 0.8 0.2 - 0.1 - 4.5 - 3.5 75 4.2 max. 2.0 - 2.0 1.2 2.0 - 0.6 - 12 - - - 4.6 parameter electrical specifications test conditions units msk 5940rh msk 5940k/h/e rh 3 2 2 0a i out 3a; ? v out =1% 10ma i out 3a v in =v out +3v i out =10ma (v out +3v) v in (v out +15v) v in =v out +5v i out =3a; c out =25f; f=120hz junction to case @ 125c -5.0v -5.2v -10.0v -12.0v -15.0v msk5940-5.0rh msk5940-5.2rh msk5940-10rh msk5940-12rh msk5940-15rh output voltage 7 2 1 2 3 4 5 6 7 8 9 10 2 notes: i out =10ma; v in =v out +3v 2 rev. d 11/08 10 9 post radiation quiescent current v in =v out+ 3v;i out =10ma load regulation line regulation output voltage tolerance
application notes heat sinking to determine if a heat sink is required for your application and if so, what type, refer to the thermal model and governing equa- tion below. governing equation: tj = pd x (r jc + r cs + r sa) + ta where tj = junction temperature pd = total power dissipation r jc = junction to case thermal resistance r cs = case to heat sink thermal resistance r sa = heat sink to ambient thermal resistance tc = case temperature ta = ambient temperature ts = heat sink temperature example: this example demonstrates an analysis where the regulator is at one-half of its maximum rated power dissipation, which occurs when the output current is at 1.5 amps. conditions for msk 5940-5rh: vin = -7.0v; iout = -1.5a 1.) assume 45 heat spreading model. 2.) find regulator power dissipation: pd = (vin - vout)(iout) pd = (-7-(-5))(-1.5) = 3.0w 3.) for conservative design, set tj = +125c max. 4.) for this example, worst case ta = +90c. 5.) r jc = 4.6c/w from the electrical specification table. 6.) r cs= 0.15c/w for most thermal greases. 7.) rearrange governing equation to solve for r sa: r sa = ((tj - ta)/pd) - (r jc) - (r cs) = ((125c - 90c)/3.0w) - 4.6c/w - 0.15c/w = 6.9c/w in this case the result is 6.9c/w. therefore, a heat sink with a thermal resistance of no more than 6.9c/w must be used in this application to maintain the regulator junction temperature under 125c. overload shutdown the msk 5940rh features both power and thermal overload protection. when the maximum power dissipation is not ex- ceeded, the regulator will current limit slightly above its 3 amp rating. as the vin-vout voltage increases, however, shutdown occurs in relation to the maximum power dissipation curve. if the device heats enough to exceed its rated die junction tem- perature due to excessive ambient temperature, improper heat sinking etc., the regulator will shutdown until an appropriate junction temperature is maintained. it should also be noted that in the case of an extreme overload, such as a sustained direct short, the device may not be able to recover. in these instances, the device must be shut off and power reapplied to eliminate the shutdown condition. load regulation for best results the ground pin should be connected directly to the load as shown below, this effectively reduces the ground loop effect and eliminates excessive voltage drop in the sense leg. it is also important to keep the output connection between the regulator and the load as short as possible since this directly affects the load regulation. for example, if 20 gauge wire were used which has a resistance of about .008 ohms per foot, this would result in a drop of 8mv/ft at 1amp of load current. it is also important to follow the capacitor selection guidelines to achieve best performance. refer to figure 1 for connection dia- gram. bypass capacitors for most applications a 33uf minimum, low esr (0.5-2 ohm) tantalum capacitor should be attached as close to the regulator's output as possible. this will effectively lower the regulator's output impedance, increase transient response and eliminate any oscillations that are normally associated with low dropout regu- lators. additional bypass capacitors can be used at the remote load locations to further improve regulation. these can be either of the tantalum or the electrolytic variety. unless the regulator is located very close to the power supply filter capacitor(s), a 4.7uf minimum low esr (0.5-2 ohm) tantalum capacitor should also be added to the regulator's input. an electrolytic may also be substituted if desired. when substituting electrolytic in place of tantalum capacitors, a good rule of thumb to follow is to increase the size of the electrolytic by a factor of 10 over the tantalum value. low dropout negative power supply msk 5940rh typical application: figure 1 3 rev. d 11/08 radiation performance curves for tid testing have been generated for all radiation testing performed by ms kennedy. these curves show performance trends throughout the tid test process and are located in the msk 5940rh radiation test report. the complete radiation test report is available in the rad hard products section on the msk website. total dose radiation test performance http://www.mskennedy.com/store.asp?pid=9951&catid=19680
typical performance curves 4 rev. d 11/08
the information contained herein is believed to be accurate at the time of printing. msk reserves the right to make changes to its products or specifications without notice, however, and assumes no liability for the use of its products. please visit our website for the most recent revision of this datasheet. contact msk for mil-prf-38534 class h, class k and appendix g (radiation) status. 5 mechanical specifications ordering information msk5940-5.0 h rh d lead configurations s= straight; u= bent up; d= bent down rad hard screening blank= industrial; e=extended reliability h= mil-prf-38534 class h; k=mil-prf-38534 class k output voltage 5.0=-5.0v; 5.2=-5.2v; 10=-10.0v; 12=-12.0v; 15=-15.0v general part number rev. d 11/08 the above example is a -5.0v, class h military regulator with bent down leads. m.s. kennedy corp. 4707 dey road, liverpool, new york 13088 phone (315) 701-6751 fax (315) 701-6752 www.mskennedy.com esd triangle indicates pin 1 weight=3.2 grams typical
|
