dcdc specification 300 watts ? wide input range ? 350 w peak power ? high efficiency ? high power density ? baseplatecooled ? remote on/off & remote sense ? 3 year warranty qsb series input input voltage range ? 24 v (9-36 v), 48 v (18-75 v), (see note 3) input current ? see table input reverse voltage ? none protection input filter ? pi network input surge ? 24 v: 50 vdc for 100 ms 48 v: 100 vdc for 100 ms undervoltage lockout ? 24 v: on 8.8 v, off 8.0 v 48 v: on 17.0 v, off 16.0 v output output voltage trim ? 10%, see application notes initial set accuracy ? 1.5% max at full load line regulation ? 0.2% max measured from high line to low line load regulation ? 0.2% max measured from 0-100% load start up time ? 120 ms typical transient response ? 5% max deviation, recovery to within 1% in 500 s, 25% step load change ripple & noise ? 3.3 & 5 v models: 100 mv pk-pk 12 & 15 v models: 150 mv pk-pk 24 & 28 v models: 280 mv pk-pk 20 mhz bandwidth (see note 1) overvoltage protection ? 115-140% short circuit protection ? continuous thermal shutdown ? case temperature >105 c temperature ? 0.03%/c coefficient current limit ? 115-140% nominal output remote on/off ? see note 2. output is off if pin 2 is low (<1.8 v) wrt -vin, pin 4. remote sense ? compensates up to 10% of vout nominal, total of output trim and remote sense xppower.com general efficiency ? see table isolation voltage ? 1500 vdc input to output 1500 vdc input to case 1500 vdc output to case isolation resistance ? 10 7 ? isolation capacitance ? 2000 pf typical switching frequency ? 220 khz typical power density ? 109 w/in 3 mtbf ? 300 khrs typical to mil-hdbk-217f at 25 c, gb environmental operating base plate ? -40 c to +100 c, see derating curve temperature storage temperature ? -55 c to +105 c operating humidity ? up to 90% non-condensing cooling ? baseplate-cooled, see derating curve shock ? 30 g pk, halfsink wave for 18 ms 3 pulses per face, all 6 faces tested vibration ? 5-500 hz st 3 g, 10 mins per axis emc & safety emissions ? en55022, level a conducted, with external components. see application note. esd immunity ? en61000-4-2, level 2, perf criteria b radiated immunity ? en61000-4-3, 3 v/m, perf criteria a eft/burst ? en61000-4-4, level 1, perf criteria a surge ? en61000-4-5, level 1, perf criteria a conducted immunity ? en61000-4-6, 3 v rms, perf criteria a
bottom view (48.3) 1.90 2.28 (57.9) 1.14 (29.0) 1.20 (30.5) 1.40 2.00 1 0.60 (35.6) (50.8) (15.2) 3 2 4 mounting hole diameter: 0.126 (3.2) clearance hole 0.18 min. 2.40 side view (13.2) 0.52 9 6 7 8 5 (61.0) (4.6) ? 0.04 (1.02) pins 2,3, 6,7 & 8 ? 0.08 (2.03) pins 1,4, 5 & 9 pin connections pin function 1 +vin 2 remote on/off 3 case 4 -vin 5 -vout 6 -sense 7 trim 8 +sense 9 +vout 1. all dimensions are in inches (mm) 2. weight: 0.57 lbs (260 g) approx 3. tolerances: x.xx = 0.02 (x.x = 0.5) x.xxx = 0.01 (x.xx = 0.25) notes 1. output ripple and noise measured with 10 f tantalum and 1 f ceramic capacitor across output. 2. add suffix n to the model number to receive the unit with negative logic remote on/off. 3. minimum of 220 f required on input. 4. measured at nominal input voltage. 5. peak current is for max duration of 3s with 10% duty cycle. average output power not to exceed 300w. 6. 48 v output models require minimum 220 f capacitor across output rails to maintain regulation. dcdc models & ratings qsb300 output voltage adjustment input voltage output voltage output current input current efficiency (4) max. capacitive load model number (2) nom. peak (5) no load full load 9-36 v 5.0 v 60.0 a 70.00 a 200 ma 14.21 a 88.0% 10000 f QSB30024S05 12.0 v 25.0 a 29.16 a 200 ma 13.89 a 90.0% 10000 f qsb30024s12 24.0 v 12.5 a 14.58 a 100 ma 14.21 a 88.0% 4700 f qsb30024s24 28.0 v 10.7 a 12.50 a 100 ma 14.11 a 88.0% 4700 f qsb30024s28 48.0 v 6.25 a 7.29 a 100 ma 14.37 a 87.0% 2200 f qsb30024s48 (6) 18-75 v 5.0 v 60.0 a 70.00 a 100 ma 6.94 a 90.0% 10000 f qsb30048s05 12.0 v 25.0 a 29.16 a 100 ma 6.94 a 90.0% 10000 f qsb30048s12 24.0 v 12.5 a 14.58 a 80 ma 6.98 a 89.0% 4700 f qsb30048s24 28.0 v 10.7 a 12.50 a 80 ma 6.94 a 90.0% 4700 f qsb30048s28 48.0 v 6.25 a 7.29 a 80 ma 7.02 a 89.0% 2200 f qsb30048s48 (6) mechanical details notes the trim input permits the user to adjust the output voltage up or down according to the trim range specification (90% to 110% of nominal output). this is accomplished by connecting an external resistor between the +vout and +sense pin for trim up and between the trim and -sense pin for trim down, see figure: load +vin + -vin +s +vout -vout -s trim c2 rv rt c1 + vin + - the trim pin should be left open if trimming is not being used. the output voltage can be determined by the following equations: rt x 33 rt + 33 1.24 x vf = rt x 33 rt + 33 7.68 + ( vnom + rv ) x vf vout = rv = vout vf - vnom recommended value of rt is 6.8k % , therefore vf = 0.525 examples: 1. to trim 12 v unit up by 10% - 12 = 13.145k rv = 13.2 0.525 2. to trim 24 v unit down by 10% - 24 = 17.14k rv = 19.2 0.525
input fusing and safety considerations qsb300 suggested circuits for conducted emi class a emc considerations the qsb300 series converters have no internal fuse. in order to achieve maximum safety and system protection, always use an input line fuse. we recommended a 60 a time delay fuse for 24 vin models and 30a for 48vin models. it is recommended that the circuit have a transient voltage suppressor diode ((tvs), type smcj78a 1500 w or above) across the input terminal to protect the unit against surge or spike voltage and input reverse voltage (as shown). -vout +vout -vin +vin tvs vin + - load c1 c2 l1 +vout -vout dc/dc converter + + vin + - load +vin -vin c1 c2 l1 220uf/100v 220uf/100v 1.5mh, core: sm cm20 x 12 x 10 remote on/off control recommended value for r is 15k (0.25w) for 24 vin and 30k (0.5w) for 48vin +vin -vin 1k +on/off -on/off i(on/off) sw r vin + - the converters output on/off function can be controlled via pin 2, remote on/off output voltage turns off when current flows through on/off pins by opening or closing the switch. the maximum current through the on/off pin is 10ma, and is determined by current limit resistor r. dcdc
thermal resistance information air flow rate typical r ca natural convection 20 ft. / min (0.1 ms) 7.12 c/w 100 ft./min (0.5 ms) 6.21 c/w 200 ft./min (1.0 ms) 5.17 c/w 300 ft./min (1.5 ms) 4.29 c/w 400 ft./min (2.0 ms) 3.64 c/w 500 ft./min (2.5 ms) 2.96 c/w 600 ft./min (3.0 ms) 2.53 c/w 700 ft./min (3.5 ms) 2.37 c/w 800 ft./min (4.0 ms) 2.19 c/w r ca = thermal resistance from case to ambient derating curve 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 power dissipated ,pd (w) natural convection 20 ft./min. (0.1 m/s) 100 ft./min. (0.5 m/s) 200 ft./min. (1.0 m/s) 300 ft./min. (1.5 m/s) 400 ft./min. (2.0 m/s) 500 ft./min. (2.5 m/s) 600 ft./min. (3.0 m/s) 7 00 ft./min. (3.5 m/s) 8 00 ft./min. (4.0 m/s) ambient temperature ,t ( c) maximum power dissipation vs ambient temperature and air flow without heatsink a 27-feb-14 dcdc application notes qsb300 example 1.calculate power dissipated = [power in C power out] = [(5v*45a)/90% efficiency C 5v*45a] = 25 w 2.use de-rating curve to establish airflow using 25 w dissipated power and 35 c ambient, airflow is 600 ft/min (3.0 m/s) 3.use table to establish typical thermal resistance rca airflow of 600ft/min gives typical rca of 2.53 c/w 4.check that airflow is adequate to limit case temperature to 100 c maximum case temperature = temperature rise + ambient temperature temperature rise = power dissipated * typical thermal resistance rca = 25 w* 2.53 c/w = 63.25 c case temperature = 63.25 c + 35 c = 98.25 c i.e. <100 c air flow rate typical r ca natural convection 20 ft. / min (0.1 ms) 3.00 c/w 100 ft./min (0.5 ms) 1.44 c/w 200 ft./min (1.0 ms) 1.17 c/w 300 ft./min (1.5 ms) 1.04 c/w 400 ft./min (2.0 ms) 0.95 c/w power dissi pa te d vs ambi ent temperature a nd air flow with xp part ich heatsink 0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 60 70 80 90 100 ambi ent tem pe rature, t a (c) power d isspated, p d (watts) natural c on vecti on 20 ft./min. (0.1 m/s) 100 ft./min. (0.5 m/s) 200 ft./min. (1.0 m/s) 300 ft./min. (1.5 m/s) 400 ft./min. (2.0 m/s) a example 1.calculate power dissipated = [power in C power out] = [(12v*20a)/90% efficiency C 12v*20a] = 26.27 w 2.use de-rating curve to establish airflow using 26.27 w dissipated power and 65 c ambient, airflow is 200 ft/min (1.0 m/s) 3.use table to establish typical thermal resistance rca airflow if 200 ft/min gives typical rca of 1.17 c/w 4.check that airflow is adequate to limit case temperature to 100 c maximum case temperature = temperature rise + ambient temperature temperature rise = power dissipated * typical thermal resistance rca = 26.67 w* 1.17 c/w = 31.2 c case temperature = 31.2 c + 65 c = 96.2 c i.e. <100 c airflow required for qsb30048s05 at 45a output current and 35c ambient airflow required for qsb30048s12 at 20a output current and 65 c ambient
|
