features: ? manufactured using space qualifed rh 137 die ? radiation hardened to 100 krads(si) (method 1019.7 condition a) ? output current limit ? internal thermal overload protection ? output current to 1.5 amps ? adjustable output using two external resistors ? available in 3 lead form options: straight, up and down (to-257) ? available to dscc smd 5962r09214 ? equivalent non rad hard device msk5173 description: the MSK5973RH is a radiation hardened 3-terminal negative adjustable regulator capable of supplying up to 1.5a of current. the output is adjustable using external resistors for a range of vref to -27v. excellent line and load regulation characteristics ensure accurate performance. the MSK5973RH has full protection with current and thermal limiting. the MSK5973RH is packaged in two space saving packages, the 3 pin power surface mount ceramic smd-1 or the to-257 package with 3 lead form options: straight, up and down. to-257 smd-1 3 pad ceramic case=isolated 1 8548-84 rev. j 9/17 rad hard 1.5a, negative adjustable linear regulator mil-prf-38534 and 38535 certified facility 5973rh equivalent schematic typical applications pin-out information ? satellite system power supplies ? switching power supply post regulators ? constant voltage/current regulators ? high efciency linear regulators ? to-257 1 adj 2 vin 3 vout smd-1 1 adj 2 vout 3 vin
2 8548-84 rev. j 9/17 absolute maximum ratings electrical specifications v in input voltage (v in -v out )........................................ 30vdc t st storage temperature range.................... -65c to +150c p d power dissipation................................... internally limited t ld lead temperature range i out output current........................................................... 1.5a (10 seconds)............................................................. 300c t j junction temperature............................................ +150c t c case operating temperature MSK5973RH............................................... -40c to +85c msk5973(k/h)rh..................................... -55c to +125c parameter test conditions 9 group a subgroup msk5973k/hrh MSK5973RH units min. typ. max. min. typ. max. reference voltage 3v (vin - vout) 30v 1 -1.30 -1.25 -1.20 -1.35 -1.25 -1.15 v iout = 10ma 2, 3 -1.30 - -1.20 - - - v line regulation 3v (vin - vout) 30v 1 -0.02 0.002 +0.02 -0.02 0.002 +0.02 %/v iout = 10ma 2, 3 -0.05 - +0.05 - - - %/v adjust pin current 3v (vin - vout) 30v 1 - 65 100 - 65 100 a iout = 10ma 2, 3 - - 100 - - - a adjust pin current change 3v (vin - vout) 30v 1 -5.0 0.2 +5.0 -5.0 0.2 +5.0 a iout = 10ma 2, 3 -6.0 - +6.0 - - - a load regulation vin = -8v, vout = -5v 1 -25 - +25 -25 - +25 mv 10ma iout 1.5a 2, 3 -50 - +50 - - - mv current limit 7 vin = -10v 1 1.5 2.3 - 1.5 2.3 - a vout = -5v 2, 3 1.5 - - - - - a ripple rejction 2 vout = -10v, f = 120hz, cadj = 10f 4 66 - - 66 - - db minimum load current 2 (vin - vout) = 30v 1 - - 5 - - 5 ma thermal resistance 2 junction to case @ 125c to-257 package - - 4.4 4.8 - 4.4 4.8 c/w thermal resistance 2 junction to case @ 125c smd-1 package - - 3.7 4.1 - 3.7 4.1 c/w notes: 1 output is decoupled to ground using 10f low esr tantalum capacitors and 0.1f ceramic. 2 guaranteed by design but not tested. typical parameters are representative of actual device performance but are for reference only. not applicable to post irradiation performance. 3 all output parameters are tested using a low duty cycle pulse to maintain tj = tc. 4 industrial grade and devices shall be tested to subgroup 1 unless otherwise specifed. 5 military grade devices ("h" and "k" sufx) shall be 100% tested to subgroups 1,2 and 3. 6 subgroup 1 ta = tc = +25c subgroup 2 ta = tc = +125c subgroup 3 ta = tc = -55c 7 the output current limit function provides protection from transient overloads but it may exceed the maximum continuous rating. continuous operation in current limit may damage the device. 8 continuous operation at or above absolute maximum ratings may adversely efect the device performance and/or life cycle. 9 pre and post irradiation limits at 25c, up to 100 krad tid, are identical unless otherwise specifed. post irradiation performance is guaranteed by design with a 2x radiation design margin. 10 reference dscc smd 5962r09214 for electrical specifcation for devices purchased as such. 11 internal solder refow temperature is 180c, do not exceed. 8 11
load regulation the MSK5973RH is capable of providing extremely good load regulation but a few precautions are needed to obtain maximum performance. the current set resistor connected between the adjustment terminal and the output terminal should be tied directly to the output pin as close to the case of the regulator as possible rather than near the load. this eliminates package pin and trace drops from appearing efectively in series with the reference and degrading regulation. for example, if the regulator is set to -5v with 0.05 ? resistance between the regulator and the current set resistor, the output will droop 225mv at 1a due to package pin and trace resistance. the amount of droop can be calculated as follows: (vout at 5ma) - (1.250-(0.05 ? *il))*(1+r2/r1). the ground of r2 can be returned near the ground of the load to provide remote ground sensing and improve load regulation. figure 2a shows the efect of resistance between the regulator and 240 ? set resistor. figure 2a (degraded regulation) figure 2b (best case regulation) output voltage the MSK5973RH develops a nominal -1.25v reference voltage between the output and adjustment terminal. with a constant reference voltage drop across program resistor r1, a constant current fows through the output set resistor r2. since the current from the adjustment terminal represents an error in the programmed output voltage, the MSK5973RH was designed to minimize i adj and make it very constant with line and load changes. to do this, all quiescent operating current is returned to the output establishing a minimum load current requirement. if there is insufcient load on the output, the output will rise. figure 1 shows the output voltage calculations. figure 1 input voltage the minimum required input voltage for proper operation is vout+ dropout voltage. see typical performance curves for dropout performance. external capacitors input bypassing with a 1uf tantalum in parallel with a 0.1uf ceramic on the input is suitable in most applications. to maximize transient response and minimize input supply transients more input capacitance can be added. the adjustment terminal can be bypassed to ground on the MSK5973RH to improve ripple rejection. this bypass capacitor prevents ripple from being amplifed at higher output voltages. the impedance of the adjust pin capacitor at the ripple frequency should be less than the value of r1. for most application a 10f bypass capacitor will provide sufcient ripple rejection at any output level. increases over 10f do not appreciably improve the ripple rejection at frequencies above 120hz. output bypassing with 10f low esr tantalum in parallel with a 0.1f ceramic attached as close to the regulator's output as possible is best. this will efectively lower the regulator output impedance, increase transient response and eliminate any oscillations. any increase of the load capacitance larger than 10f will merely improve the loop stability and output impedance. see figure 3 for typical application schematic. 3 8548-84 rev. j 9/17 application notes
protection diodes when external capacitors are used with any ic regulator it is sometimes necessary to add protection diodes to prevent the capacitors from discharging through low current points into the regulator. most 10f capacitors have low enough internal series resistance to deliver 20a spikes when shorted. although the surge is short, there is enough energy to stress MSK5973RH. when an output capacitor is connected to a regulator and the input is shorted or crowbarred, the output capacitor will discharge into the output of the regulator. the discharge current depends on the value of the capacitor, the output voltage of the regulator, and the rate of decrease of vin. figure 3 shows an MSK5973RH with protection diodes included. d2 is only required if the adjust pin has external capacitance tied to it . figure 3 total dose radiation test performance 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 is located in the MSK5973RH radiation test report. the complete radiation test report is available in the rad hard products section on the msk website. http://www.mskennedy.com/store.asp?pid=9951&catid=19680 4 8548-84 rev. j 9/17 application notes cont'd 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 equation 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 with the output set to -10v, where the output current is at 0.5 amp and the input is -15v. conditions for MSK5973RH: vin = -15v; iout = 0.5a 1.) assume 45 heat spreading model. 2.) find regulator power dissipation: pd = (vin - vout)(iout) pd = (15v-10v)(0.5a) pd = 2.5w 3.) for conservative design, set tj = +125c max. 4.) for this example, worst case ta= +90c. 5.) r jc = 4.8c/w from the electrical specifcation 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)/2.5w - 4.8c/w - 0.15c/ = 9.0c/w in this case the result is 9.0c/w. therefore, a heat sink with a thermal resistance of no more than 9.0c/w must be used in this application to maintain regulator circuit junction temperature under 125c.
5 8548-84 rev. j 9/17 typical performance curves
ordering information lead configurations s= straight; u= bent up; d= bent down radiation hardened screening blank= industrial; h=mil-prf-38534 class h; k=mil-prf-38534 class k general part number msk5973 k rh u the above example is an adjustable class k regulator with leads bent up. note: see dscc smd 5962r09214 for dscc part number options. esd triangle indicates pin 1 weight=3.2 grams typical all dimensions are specified in inches 6 8548-84 rev. j 9/17 mechanical specifications
ordering information 3 pad ceramic smd-1 package radiation hardened screening blank= industrial; h=mil-prf-38534 class h; k=mil-prf-38534 class k general part number msk5973 k rh l the above example is an adjustable class k regulator. weight = 2.2 grams typical note: see dscc smd 5962r09214 for dscc part number options. all dimensions are specified in inches 7 8548-84 rev. j 9/17 mechanical specifications
8 8548-84 rev. j 9/17 revision history rev status date description h released 10/14 format update, add internal note and clarify mechanical outline j released 09/17 update parameters to better correlate to manufacturer's pre and post rad specs. the information contained herein is believed to be accurate at the time of printing. anaren, msk products reserves the right to make changes to its products or specifcations 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. anaren, msk products www.anaren.com/msk
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