current sense hiccup gate drive voltage sense ov, uv, ot shutdown switching controller +v in Cv in remote on/off +v out Cv out (1) (3) (2) (8) (4) the present trend in distributed power architec- tures (dpa) requires both high ef? ciency and some regulation of the output voltage to reduce the risk of under voltage dropout. earlier unregulated bus converters were simply ratiometric dc transform- ers. the fully isolated (2250vdc) rbc series accept a wide range 36 to 75 volt dc input (48v nominal) and convert it to an output of 12vdc. this output then drives point-of-load (pol) converters such as our okami, lsn, len, lsm or lqn series which feature precise load regulation. applications include 48v-powered datacom and telecom installations, base stations, cellular telephone repeaters and embedded systems. low overall height of 0.42" (10.7 mm) ? ts tight card cages. the rbcs synchronous-recti? er topology and ? xed frequency operation means excellent ef? ciencies. no fan or zero air? ow applications may use the optional base plate for cold surface mounting or natural-convection heatsinks. a wealth of electronic protection features include input undervoltage (uv) lockout, output current limit, short circuit hiccup, overtemperature shutdown and output overvoltage. available options include posi- tive or negative logic remote on/off control and the baseplate. assembled using iso-certi? ed automated surface-mount techniques, the rbc series includes all ul and iec emissions, safety and ? ammability certi? cations. optimized for distributed power regulated intermediate bus archi- tectures (riba), the rbc dc/dc bus converter series offer regulated outputs (1.5%) in an industry-standard quarter brick open frame package. product overview features ? up to 210 watts total output power ? up to 93% ultra-high ef? ciency @ full load ? 48v input ( up to 36-75v range) ? 12v/17a output for regulated intermediate bus architectures (riba) with pol converters ? synchronous-recti? er topology ? 225khz ? xed switching frequency ? fully isolated, 2250vdc (basic) ? 2.3" x 1.45" x 0.42" quarter brick ? stable no-load condition ? thermal shutdown ? fully i/o protected ? certi? ed to ul/iec/en 60950-1 and csa c22.2 no.60950-1-07, 2nd edition typical unit typical topology is shown. figure 1. simpli? ed block diagram rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 1 of 10 www.murata-ps.com www.murata-ps.com/support for full details go to www.murata-ps.com/rohs $ output (v) current (a) nominal input (v) 12 17 48
part number structure performance specifications summary and ordering guide root model ? v out i out (max.) r/n (mv pk-pk) regulation (max.) v in (nom.) range iin, no load iin, full load ef? ciency package v a typ. max. line load v v ma a min. typ. case pinout rbc-12/17-d48n-c 12 17 50 75 0.65% 1.5% 48 36-75 165 4.59 90.5% 92.5% c49 p65 ? please refer to the part number structure for complete model numbers bus converter regulated nominal output voltage: 12 volts input voltage range: d48 = 36 to 75 volts (48v nominal) r bc 17 - / d48 - 12 b maximum rated output: current in amps n optional baseplate, special order optional: on/off control n = negative logic , standard p = positive logic, optional rohs-6 hazardous substance compliant ( does not claim eu rohs exemption 7bClead in solder ) c - caution C this converter is not internally fused. to avoid danger to persons or equipment and to retain safety certi? cation, the user must connect an external fast-blow input fuse as listed in the speci? cations. be sure that the pc board pad area and etch size are adequate to provide enough current so that the fuse will blow with an overload. start-up considerations when power is ? rst applied to the dc/dc converter, there is some risk of start up dif? culties if you do not have both low ac and dc impedance and adequate regulation of the input source. make sure that your source supply does not allow the instantaneous input voltage to go below the minimum voltage at all times. even if this voltage depression is very brief, this may interfere with the on-board controller and possibly cause a failed start. use a moderate size capacitor very close to the input terminals. you may need two parallel capacitors. a larger electrolytic or tantalum cap supplies the surge current and a smaller parallel low-esr ceramic cap gives low ac impedance. remember that the input current is carried both by the wiring and the ground plane return. make sure the ground plane uses adequate thickness copper. run additional bus wire if necessary. note: some model number combinations may not be available. contact murata power solutions for ordering assistance. rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 2 of 10 www.murata-ps.com/support
performance/functional speci? cations input voltage: continuous 75 volts transient (100msec max.) 100 volts input reverse-polarity protection none, see notes. install external fuse. output current current limited. devices can withstand an inde? nite output short circuit without damage. storage temperature C55 to +125c lead temperature (soldering, 10 sec.) +280c these are stress ratings. exposure of devices to any of these conditions may adversely affect long-term reliability. proper operation under conditions other than those listed in the performance/functional speci? cations table is not implied. absolute maximum ratings typical at t a = +25c under nominal input voltage and full-load conditions unless noted. refer to required air? ow and derating curves for thermal speci? cations. [1] input input voltage range 36-75 volts recommended external fuse 20 amp fast blow start-up threshold 35v undervoltage shutdown 33.5v overvoltage shutdown none [note 12] input current, nominal see ording guide input current, v in = v min 6.00a input current, shut-down mode 6.5ma max. inrush transient 0.05a 2 -seconds re? ected ripple current [2] 15map-p internal filter type l-c reverse polarity protection none (see note 11), install external fuse remote on/off control [5] positive logic on = open or +3.5 to +13.5 v. off = gnd. pin or 0 to +1v. negative logic on = gnd. pin or 0 to +1v. off = pin open or +3.5v to +13.5v. current 2ma max. output total output power [3] 210w max. [15] setpoint accuracy (50% load) 3% of v nominal extreme accuracy [14] 11.4v min. to 12.6v max. output current [7] see ordering guide minimum load no minimum load ripple and noise (20mhz bandwidth) see ordering guide line and load regulation [10] see ordering guide ef? ciency see ordering guide isolation voltage (input/output) 2250vdc min. (input to baseplate) 1500vdc min. (baseplate to output) 1500vdc min. isolation resistance 100m : isolation capacitance 1500pf isolation safety rating basic current limit inception (98% of v out ) 27a, after warm up short circuit current [6] 5 amps (hiccup autorestart C remove short for recovery) short circuit duration (+v out grounded) continuous, no damage overvoltage protection 15vdc max. via magnetic feedback max. capacitive loading (resistive load) 10,000f, low esr 0.02 ohms temperature coef? cient 0.02% per c dynamic characteristics dynamic load response 75sec, 50-75-50% load step (to within 3% of v out ) 100sec, 25-75-25% load step start up time (v in to v out regulated) 60msec (remote on to vout regulated) 60msec fixed switching frequency 225 25khz environmental calculated mtbf [4] 1,247,727 hours operating case temperature [13] +110c max. electronic thermal shutdown +125c min. operating temperature range -40oc to +85oc, see derating curves (with derating) storage temperature range C55 to +125c flammability ul94v-0 relative humidity to 85% / +85c safety compliance ul60950-1, csa-c22.2 no.60950-1, iec/en60950-1 electromagnetic interference en55022/cispr22 conducted or radiated (may require external ? lters) physical pin material copper alloy with gold plate over nickel underplate weight 1 ounce (28.4 grams) (1) all models are tested and speci? ed with external 1 || 10uf ceramic/tantalum output capacitors and external 22uf input capacitor. all capacitors are low esr types. these capacitors are necessary to accommodate our test equipment and may not be required to achieve speci? ed performance in your applications. all models are stable and regulate within spec under no-load conditions. general conditions for speci? cations are +25c, vin = nominal, vout = nominal, full load. (2) input ripple current is tested and speci? ed over a 5 hz to 20 mhz bandwidth. input ? ltering is cin = 33f/100v tantalum, cbus = 220f/100v electrolytic, lbus = 12h. (3) note that maximum power derating curves indicate an average current at nominal input voltage. at higher temperatures and/or lower air? ow, the dc/dc converter will tolerate brief full current outputs if the total rms current over time does not exceed the derating curve. all derating curves are presented at sea level altitude. be aware of reduced power dissipation with increasing density altitude. (4) mean time before failure is calculated using the telcordia (belcore) sr-332 method 1, case 3, ground ? xed conditions, tpcboard = +25c, full output load, natural air convection. (5) the on/off control may be driven with external logic or by applying appropriate external voltages which are referenced to input common. the on/off control input should use either an open collector/open drain transistor or logic gate which does not exceed +13.5v. (6) short circuit shutdown begins when the output voltage degrades approximately 2% from the selected setting. (7) the outputs are not intended to sink appreciable reverse current. (8) output noise may be further reduced by adding an external ? lter. see i/o filtering and noise reduction. (9) all models are fully operational and meet published speci? cations, including cold start at C40c. (10) regulation speci? cations describe the deviation as the line input voltage or output load current is varied from a nominal midpoint value to either extreme. (11) if reverse polarity is accidentally applied to the input, a body diode will become forward biased and will accept considerable current. to ensure reverse input protection with full output load, always connect an external input fuse in series with the +vin input. use approximately twice the full input current rating with nominal input voltage. (12) input overvoltage shutdown on 48v input models is normally deleted in order to comply with certain telecom reliability requirements. these requirements attempt continued operation despite signi? cant input overvoltage. (13) note that the converter may operate up to +110c pcb temperature with the baseplate installed. however, thermal self-protection occurs near +125c and there is a temperature gradient from high power components. therefore, +100c baseplate temperature is recommended to avoid thermal shutdown. (14) extreme accuracy refers to all combinations of line and load regulation, output current, initial setpoint accuracy and temperature coef? cient. (15) vo = (11.64v to 12.36v) power = (197.88w to 210.12w) rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 3 of 10 www.murata-ps.com/support
mechanical specifications input/output connections pin function 1 +input 2 remote on/off* 3 -input 4 -output 8 +output third angle projection dimensions are in inches (mm shown for ref. only). components are shown for reference only. tolerances (unless otherwise speci?ed): .xx 0.02 (0.5) .xxx 0.010 (0.25) angles 2? * the remote on/off can be provided with either positive (p suf? x) or negative (n suf? x) logic. 0.42 without baseplate 10.7 0.14 ref 3.5 0.19 pin length above seating plane (see note 1 on sheet 2) 4.8 0.010 min from seating plane to highest component 2.000 0.600 15.24 0.300 7.62 gold (5u"min) over nickel (50u" min) dimensions are in inches [mm] tolerances: 2 place 0.02 angles: 1 3 place 0.010 components shown are for reference only material: 0.040 pins: copper alloy 0.060 pins: copper alloy finish: (all pins) 'b' option side view aluminum baseplate top view m3 x 0.5-6h thread x 0.15 dp typ (4 pls) 1.860 47.24 2.30 58.4 1.030 26.16 1.45 36.8 0.002 [1.52 3x at pins 1-3 0.05] 2x at pins 4-5 0.060 0.05] 0.040 0.002 [1.02 seating plane 0.50 with baseplate 12.7 end view 2 4 3 bottom view 8 1 1.45 ref 36.8 rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 4 of 10 www.murata-ps.com/support
recommended footprint (view through converter) third angle projection dimensions are in inches (mm shown for ref. only). components are shown for reference only. tolerances (unless otherwise speci?ed): .xx 0.02 (0.5) .xxx 0.010 (0.25) angles 2? 2.32 58.9 37.3 1.47 50.8 2.000 25.4 1.00 shoulders for pin @ 1-4, 8 min 0.100 7.6 0.300 0.300 7.6 top view 1 2 3 4 8 c l @ pins 4 & 8 finished hole sizes (per ipc-d-275, level c) 0.070-0.084 (sec) c l (pri) c l finished hole sizes @ pins 1-3 (per ipc-d-275, level c) 0.048-0.062 ref: dosa standard specification for quarter brick dc/dc converters (hatched area) it is recommended that no parts be placed beneath converter 1. alternate pin lengths available (contact murata-ps for information) 2. components shown for ref only 3. dimensions are in inches with nearest metric equivalent shown as [mm] 4. pin location dimensions apply at circuit board level rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 5 of 10 www.murata-ps.com/support
rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 6 of 10 www.murata-ps.com/support shipping trays and boxes, through-hole mount shipping tray dimensions 30 converters per carton carton accommodates two (2) trays yielding mpq=30 .25 11.00 .25 10.50 2.750.25 closed height each static dissipative polyethylene foam tray accommodates 15 converters in a 3 x 5 array 9.92 ref ref 9.92 0.88 ref rbc modules are supplied in a 15-piece (5 x 3) shipping tray. the tray is an anti-static closed-cell polyethylene foam. dimensi ons are shown below. notes: material: dow 220 antistat ethafoam 1. (density: 34-35 kg/m3) dimensions: 252 x 252 x 19.1 mm 2. 5 x 3 array (15 per tray) 3. all dimensions in millimeters [inches] 4. tolerances unless otherwise speci?ed: +1/-0 [9.92] 252.0 l 36.83 [1.450] typ typ 18.67 [0.735] 60.96 [2.400] typ 15.875 [0.625] 18.42 [0.725] typ c 6.35 [.25] chamfer typ (4-pl) 6.35 [.25] r typ -.062 +.000 [9.92] 252.0 -.062 +.000 46.36 [1.825] typ
performance data power dissipation vs. load current @ ta = +25c ef? ciency vs. line voltage and load current @ ta = +25c maximum power temperature derating at sea level vin = 48 (air ? ow from pin 1 to pin 3 on pcb, with baseplate) maximum power temperature derating at sea level vin = 48 (air ? ow from pin 1 to pin 3 on pcb, no baseplate) rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 7 of 10 www.murata-ps.com/support 83 85 87 89 91 93 95 3 5 7 9 11 13 15 17 load current (a) ef?ciency (%) vin = 75v vin = 60v vin = 48v vin = 36v 5 7.5 10 12.5 15 17.5 20 2.5 5 7.5 10 12.5 15 17.5 load current (a) power dissipation (w) vin = 75v vin = 60v vin = 48v vin = 36v 6 7 8 9 10 11 12 13 14 15 16 17 18 30 35 40 45 50 55 60 65 70 75 80 85 65 lfm 100 lfm 200 lfm 300 lfm 400 lfm ambient temperature (c) load current (a) 9 10 11 12 13 14 15 16 17 18 30 35 40 45 50 55 60 65 70 75 80 85 65 lfm 100 lfm 200 lfm 300 lfm 400 lfm ambient temperature (c) load current (a)
oscillograms stepload transient response (vin=48v, iout=25-75-25% of imax, cout=1 & 10uf, ta=+25c, scope bw=20mhz) stepload transient response (vin=48v, iout=50-75-50% of imax, cout=1 & 10uf, ta=+25c, scope bw=20mhz) output ripple and noice (vin=48v, iout=17a, cout=1 & 10uf, ta=+25c, scope bw=20mhz) rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 8 of 10 www.murata-ps.com/support
technical notes i/o filtering and noise reduction the rbc is tested and speci? ed with external output capacitors. these capacitors are necessary to accommodate our test equipment and may not be required to achieve desired performance in your application. the rbc is designed with high-quality, high-performance internal i/o caps, and will oper- ate within spec in most applications with no additional external components . in particular, the rbc input capacitors are speci? ed for low esr and are fully rated to handle the units' input ripple currents. similarly, the internal output capacitors are speci? ed for low esr and full-range frequency response. in critical applications, input/output ripple/noise may be further reduced using ? ltering techniques, the simplest being the installation of external i/o caps. external input capacitors serve primarily as energy-storage devices. they minimize high-frequency variations in input voltage (usually caused by ir drops in conductors leading to the dc/dc) as the switching converter draws pulses of current. input capacitors should be selected for bulk capacitance (at appropriate frequencies), low esr, and high rms-ripple-current ratings. the switching nature of modern dc/dc's requires that the dc input voltage source have low ac impedance at the frequencies of interest. highly inductive source impedances can greatly affect system stability. your speci? c system con? guration may necessitate additional considerations. input fusing most applications and or safety agencies require the installation of fuses at the inputs of power conversion components. the rbc series may have an optional input fuse. therefore, if input fusing is mandatory, either a normal- blow or a fast-blow fuse with a value no greater than twice the maximum input current should be installed within the ungrounded input path to the converter. input overvoltage and reverse-polarity protection the rbc does not incorporate input reverse-polarity protection. input voltages in excess of the speci? ed absolute maximum ratings and input polarity rever- sals of longer than "instantaneous" duration can cause permanent damage to these devices. start-up time the v in to v out start-up time is the interval between the time at which a rising input voltage crosses the lower limit of the speci? ed input voltage range c in v in c bus l bus c in = 33f, esr < 700m 7 @ 100khz c bus = 220f, esr < 100m 7 @ 100khz l bus = 12h +input common current probe to oscilloscope + C figure 2. measuring input ripple current and the fully loaded output voltage enters and remains within its speci? ed regulation band. actual measured times will vary with input source imped- ance, external input capacitance, and the slew rate and ? nal value of the input voltage as it appears to the converter. the on/off to v out start-up time assumes the converter is turned off via the on/off control with the nominal input voltage already applied to the converter. the speci? cation de? nes the interval between the time at which the converter is turned on and the fully loaded output voltage enters and remains within its speci? ed regulation band. thermal considerations and thermal protection the typical output-current thermal-derating curves shown below enable designers to determine how much current they can reliably derive from each model of the rbc under known ambient-temperature and air-? ow conditions. similarly, the curves indicate how much air ? ow is required to reliably deliver a speci? c output current at known temperatures. the highest temperatures in rbc's occur at their output inductor, whose heat is generated primarily by i 2 r losses. the derating curves were developed using thermocouples to monitor the inductor temperature and varying the load to keep that temperature below +110c under the assorted conditions of air ? ow and air temperature. once the temperature exceeds +125c (approx.), the thermal protection will disable the converter using the hiccup shutdown mode. undervoltage shutdown when the input voltage falls below the undervoltage threshold, the converter will terminate its output. however, this is not a latching shutdown mode. as soon as the input voltage rises above the start-up threshold, the converter will restore normal operation. this small amount of hysteresis prevents most uncommanded power cycling. since some input sources with higher output impedance will increase their output voltage greater than this hysteresis as soon as the load is removed, it is possible for this undervoltage shutdown to cycle inde? nitely. to prevent this, be sure that the input supply always has adequate voltage at full load. thermal shutdown extended operation at excessive temperature will initiate overtemperature shutdown triggered by a temperature sensor inside the pwm controller. this operates similarly to overcurrent and short circuit mode. the inception point of the overtemperature condition depends on the average power delivered, the ambient temperature and the extent of forced cooling air? ow. remote on/off control the rbc may be turned off or on using the external remote on/off control. this terminal consists of a digital input to the internal pwm controller through a protective resistor and diode. the on/off input circuit should be cmos logic referred to the Cinput power terminal however ttl or ttl-ls logic will also work or a switch to ground. if preferred, you can even run this using a bipolar transistor in open collector con? guration or an open drain fet transistor. you may also leave this input unconnected and the converter will run whenever input power is applied. rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 9 of 10 www.murata-ps.com/support
figure 3. vertical wind tunnel ir video camera ir transparent optical window variable speed fan heating element ambient temperature sensor air?ow collimator precision low-rate anemometer 3 below uut unit under test (uut) vertical wind tunnel murata power solutions employs a computer controlled custom-designed closed loop vertical wind tunnel, infrared video camera system, and test instru- mentation for accurate air? ow and heat dissipation analysis of power products. the system includes a precision low ? ow-rate anemometer, variable speed fan, power supply input and load controls, temperature gauges, and adjustable heating element. the ir camera monitors the thermal performance of the unit under test (uut) under static steady-state conditions. a special optical port is used which is transparent to infrared wavelengths. both through-hole and surface mount converters are soldered down to a host carrier board for realistic heat absorption and spreading. both longitudinal and transverse air? ow studies are possible by rotation of this carrier board since there are often signi? cant differences in the heat dissipation in the two air? ow directions. the combination of adjustable air? ow, adjustable ambient heat, and adjustable input/output currents and voltages mean that a very wide range of measurement conditions can be studied. the collimator reduces the amount of turbulence adjacent to the uut by minimizing air? ow turbulence. such turbulence in? uences the effective heat transfer characteristics and gives false readings. excess turbulence removes more heat from some surfaces and less heat from others, possibly causing uneven overheating. both sides of the uut are studied since there are different thermal gradients on each side. the adjustable heating element and fan, built-in temperature gauges, and no-contact ir camera mean that power supplies are tested in real-world conditions. rbc-12/17-d48 series quarter brick, regulated bus converters mdc_rbc-12/17-d48.b02 page 10 of 10 www.murata-ps.com/support murata power solutions, inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. the descriptions contained her ein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. speci? cations are subject to cha nge without notice. ? 2012 murata power solutions, inc. murata power solutions, inc. 11 cabot boulevard, mans? eld, ma 02048-1151 u.s.a. iso 9001 and 14001 registered this product is subject to the following operating requirements and the life and safety critical application sales policy : refer to: http://www.murata-ps.com/requirements/
|
