datel, inc., mans eld, ma 02048 ( usa) ? tel: (508)339-3000, (800)233-2765 fax: (508)339-6356 ? email: sales@datel.com ? internet: www.datel.com single output unr d3 series features figure 1. simpli ed schematic innovation and ex c ell e n c e ? ? if your dsp and cpld core logic are demanding more 2.5v or 1.8v current from your 3.3v system, don t pay to derive more isolated power from your intermediate dc bus. datel s new, 3.3v-input, unr "d3" models derive 10a of 2.5v or 1.8v current right from your 3.3v supply. these non-isolated power converters exploit full synchronous recti cation, planar magnetics, and 100% automated assembly to deliver high ef ciencies (to 89%), low noise (typically 80mvp-p), and low costs. housed in 1" x 2" shielded metal cases, unr d3 s offer standard through-hole ("t" models) or smt ("sm" models) packaging. the new "gull-wing" smt packages (with metal shells and non-conductive plastic baseplates) weigh less than 40 grams and can withstand peak temperatures up to +235 c. they are compatible with most contemporary pick-and-place and solder-re ow processes. these versatile dc/dc s are fully line (0.1% max.) and load (0.5% max.) regulated. they feature quick transient response (25sec), user-optional on/off control (for power sequencing), and output overcurrent detection and shutdown ("hiccup" technique with auto-recovery). their impressive guaranteed ef ciencies enable them to deliver fully rated output power from 40 to +50/55 c (ambient) without supplemental cooling. if your high current requirements have made the use of inef cient linear regula- tors impractical, take a look at one of datel s new switching buck regulators. their high ef ciency, ease-of-use, long-term reliability, and overall cost effectiveness will impress you. safety agency approvals and emc characterizations are currently in progress. +v in +v out input return logic ground on/off control pwm controller voltage boost reference & error amp overcurrent detection output return v out trim +v cc non-isolated, 3.3v-to-2.5v or 1.8v 10a dc/dc s in standard or smt packaging 3.0-3.6v input range non-isolated, 2.5v or 1.8v output @ 10a 2" x 1" through-hole or smt package gull-wing leads/standard re ow for smt full synchronous-recti er topology 300khz switching; planar magnetics high ef ciency, to 89% low noise, 80mvp-p quick transient response, 25sec v out user-trimmable from 1.28v to 3v 40 to +50/55 c ambient operation with no derating remote on/off control; output overcurrent detection iec950/en60950/ul1950 pending emc compliant preliminary
unr series non-isolated, 18-25w, 3.3v-input dc/dc converters 0.10 (2.54) metal case 2.00 (50.80) 0.20 min (5.08) 0.39 (9.91) insulated base pins 1-2, 4: 0.040 ?.002 (1.016 ?.051) pins 3, 5-7: 0.062 ?.002 (1.575 ?.051) 1 2 3 4 6 7 5 1.800 (45.72) 0.10 (2.54) 0.300 (7.62) bottom view 1.00 (25.40) 0.800 (20.32) 4 eq. sp. @ 0.200 (5.08) case c16a2 pinout p23 mechanical specifications 2.00 (50.80) metal case 4 3 2 1 8 7 6 5 9 0.10 (2.54) 0.110 (2.79) 0.100 (2.54) 0.300 (7.62) 0.500 (12.70) top view 1.00 (25.40) 0.800 (20.32) 4 eq. sp. @ 0.200 (5.08) 0.055 (1.40) 0.020 (0.51) 0.110 (2.79) 0.015 (0.38) 0.41 (10.41) insulated base case c18 pinout p25 temperature derating performance speci cations and ordering guide ? output input part number structure non-isolated output con guration: u = unipolar nominal output voltage: 1.8 or 2.5 volts maximum rated output current in amps input voltage range: d3 = 3.0 to 3.6 volts (3.3v nominal) u nr 1 0 - / d3 sm - 1.8 packaging: t = through-hole package sm = surface-mount package 2 output power (watts) ambient temperature ( ? c) unr-2.5/10-d3 unr-1.8/10-d3 28 24 20 16 12 8 4 0 ? 400 404550556065707580859095100 package v out i out r/n (mvp-p) ? regulation (max.) v in nom. range i in ? ef ciency (case, model (volts) (amps) typ. max. line load ? (volts) (volts) (ma/a) min. typ. pinout) unr-1.8/10-d3t 1.8 10 80 125 0.1% 0.5% 3.3 3.0-3.6 275/6.38 82.5% 85.5% c16a2, p23 unr-1.8/10-d3sm 1.8 10 80 125 0.1% 0.5% 3. 3 3.0-3.6 275/6.38 83% 85.5% c18, p25 unr-2.5/10-d3t 2.5 10 80 125 0.1% 0.5% 3.3 3.0-3.6 370/8.51 85% 89% c16a2, p23 unr-2.5/10-d3sm 2.5 10 80 125 0.1% 0.5% 3. 3 3.0-3.6 370/8.51 85% 89% c18, p25 i/o connections pin function p23 function p25 1 logic ground logic ground 2 on/off control on/off control 3 +output n.c. 4 trim n.c. 5 output return +output 6 input return trim 7 +input output return 8 no pin input return 9 no pin +input ? typical at t a = +25c under nominal line voltage and full-load conditions, unless otherwise noted. all models are tested and speci? ed with an external 470f input capacitor with a 20m ? esr and a 6arms ripple-current rating, as well as a 22f output capacitor with a 200m ? esr. see i/o filtering and noise reduction for more details. ? ripple/noise (r/n) is tested/speci ? ed over a 20mhz bandwidth. output noise may be further reduced by installing additional external output caps. see i/o filtering and noise reduction. ? these devices have no minimum-load requirements and will regulate under no-load conditions. ? nominal line voltage, no-load/full-load conditions. footnote see temperature derating section in technical notes for more details .
d3 models non-isolated, 18-25w, 3.3v-input dc/dc converters input input voltage range 3.0 to 3.6 volts (3.3v nominal) input current: normal operating conditions see ordering guide standby/off mode 3.6ma typical, 8ma maximum output short circuited ? ? 500ma typical, 700ma maximum input ripple current: unr-1.8/10-d3 150map-p unr-2.5/10-d3 50map-p input filter type capacitive overvoltage protection none reverse-polarity protection none on/off control: ? functionality ttl high (or open) = on, low = off logic threshold +0.8-2.0 volts (1.5v typical) output v out accuracy (50% load): unr-1.8/10-d3 1% (18mv) maximum unr-2.5/10-d3 1% (25mv) maximum v out trim range ? trim pin tied to +output: unr-1.8/10-d3 v out = 1.28 volts or less unr-2.5/10-d3 v out = 1.52 volts or less trim pin tied to output return v out = 3.0 volts or greater temperature coef cient 0.02% per c ripple/noise (20mhz bw) ? see ordering guide line/load regulation see ordering guide ef ciency see ordering guide overcurrent protection: ? technique "hiccup" with auto-recovery overcurrent detection point 140% of rated current average output current 1 amp typical, 3 amps maximum dynamic characteristics transient response (50% load step) 25sec to 2% of ? nal value start-up time: ? v in to v out 25/30msec (1.8/2.5v out models) on/off to v out 25/30msec (1.8/2.5v out models) switching frequency 300khz (30khz) environmental operating temperature (ambient): ? without derating ? 40 to +50/55 c with derating to +100 c (see derating curves) storage temperature ? 40 to +105 c physical dimensions: through-hole models 2" x 1" x 0.39" (51 x 25 x 9.9mm) surface-mount models 2" x 1" x 0.43" (51 x 25 x 10.9mm) shielding 5 sided case connection input/output return case material corrosion-resistant steel with non-conductive, epoxy-based, black enamel ? nish and plastic baseplate pin material copper, tin plated weight 1.4 ounces (39.7 grams) performance/functional speci cations typical @ t a = +25 c under nominal line voltage and full-load conditions unless noted. ? ? all models are tested and speci ? ed with an external 470f input capacitor with a 20m ? esr and a 6arms ripple-current rating, as well as a 22f output capacitor with a 200m ? esr. see i/o filtering and noise reduction for more details. these devices have no minimum-load requirements and will regulate under no-load conditions. listed speci ? cations apply for both "t" and "sm" models as appropriate. ? see output overcurrent detection for details. ? see on/off control for details. ? see output voltage trimming for details. ? for all models, output noise can be further reduced with the installation of additional external output capacitors. see i/o filtering and noise reduction for details. ? output overcurrent detection initiates at approximately 40% above rated load (14 amps). under overload or short-circuit conditions, output current "hiccups" at approximately 1 amp average and remains at that level until the overload is removed. see output overcurrent detection. ? see start-up time for details. ? see temperature derating for details. input voltage: continuous 7 volts transient (100msec) 15 volts input reverse-polarity protection none input/output overvoltage protection none output current current limited. devices can withstand a sustained output short circuit without damage. storage temperature ? 40 to +105 c lead temperature (soldering, 10 sec.) +300 c 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 3 technical notes return current paths these are non-isolated dc/dc converters. the input return, output return and logic ground pins are all connected to each other internally. to the extent possible, all input and load currents should be returned through the input return and output return, respectively (via low-impedance runs). any control signals applied to the on/off control pin should be referenced to logic ground. the internal trace leading to logic ground is not designed to carry high current. consequently, devices should never be installed in a manner that results in high current ? ow through logic ground (i.e., the input/output return pins should never be left open or connected via high- impedance paths). i/o filtering and noise reduction all models in the unr 18-25w d3 series are tested and speci ? ed with external 470f input capacitors (20m ? esr, 6arms ripple-current rating) and external 22f output capacitors (200m ? esr). in critical applications, input/output ripple/noise may be further reduced by installing additional i/o caps. external input capacitors serve primarily as energy-storage elements. they should be selected for bulk capacitance (at appropriate frequencies), low esr, and high rms-ripple-current ratings. the switching nature of modern dc/dc converters requires that dc input voltage sources have low ac imped- ance, and highly inductive source impedances can affect system stability. your speci ? c system con ? guration may necessitate additional considerations.
unr series non-isolated, 18-25w, 3.3v-input dc/dc converters output ripple/noise (also referred to as periodic and random deviations or pard) can be reduced below speci ? ed limits using ? ltering techniques, the simplest of which is the installation of additional external output capacitors. output capacitors function as true ? lter elements and should be selected for bulk capacitance, low esr, and appropriate frequency response. any scope measurements of pard should be made directly at the dc/dc output pins with scope probe ground less than 0.5" in length. all external capacitors should have appropriate voltage ratings and be located as close to the converters as possible. temperature variations for all relevant parameters should obviously be taken into consideration. the most effective combination of external i/o capacitors will be a function of your line voltage and source impedance, as well as your particular load and layout conditions. our applications engineers can recommend potential solutions and discuss the possibility of our modifying a given device ? s internal ? ltering to meet your speci ? c requirements. contact our applications engi- neering group for additional details. input fusing unr 18-25w d3 series dc/dc converters are not internally fused. certain applications and or safety agencies may require the installation of fuses at the inputs of power conversion components. fuses should also be used if the possibility of sustained, non-current-limited, input-voltage polarity reversals exists. for datel unr d3 series dc/dc converters, you should use either slow-blow or normal-blow fuses with values no greater than the following. output voltage fuse value 2.5v models 18 amps 1.8v models 12 amps start-up time the v in to v out start-up time is the interval between the time at which a ramping input voltage crosses the lower limit of the speci ? ed input voltage range (3.0 volts) and the fully loaded output voltage enters and remains within it speci ? ed accuracy band. actual measured times will vary with input source impedance, 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 remote 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 accuracy band. see typical performance curves for details figure 2. driving the on/off control pin 4 input overvoltage and reverse-polarity protection unr d3 series dc/dc converters do not incorporate either input overvoltage or input reverse-polarity protection. input voltages in excess of the listed absolute maximum ratings and input polarity reversals of longer than "instan- taneous" duration can cause permanent damage to these devices. +input logic ground on/off control 1k ? output overvoltage protection unr d3 series dc/dc converters do not incorporate output overvoltage protection. in the extremely rare situation in which the device ? s feedback loop is broken, the output voltage may run to excessively high levels. if it is absolutely imperative that you protect your load against any and all possible overvoltage situations, voltage limiting circuitry must be provided external to the power converter. output overcurrent detection overloading the output of a power converter for an extended period of time will invariably cause internal component temperatures to exceed their maximum ratings and eventually lead to component failure. high-current- carrying components such as transformers, fet's and diodes are at the high- est risk. unr d3 series dc/dc converters incorporate an output overcurrent detection and shutdown function that serves to protect both the power converter and its load. applying an external voltage to the on/off control pin when no input power is applied to the converter can cause permanent damage to the converter. the on/off control function, however, is designed such that the converter can be disabled (control pin pulled low) while input power (system 3.3v power) is ramping up and then "released" once the input has stabilized. the time duration between the point at which the converter is released and its fully loaded output settles to within speci ? ed accuracy can be found in the performance/functional speci ? cations table. see start-up time for more details. on/off control the on/off control pin may be used for remote on/off operation. unr d3 series dc/dc converters are designed so that they are enabled when the control pin is pulled high or left open (normal mode) and disabled when the control pin is pulled low (to less than +0.8v relative to logic ground). as shown in figure 2, both 2.5v out and 1.8v out models have internal 1k ? pull-up resistors to v in (+input). dynamic control of the on/off function is best accomplished with a mechani- cal relay or open-collector/open-drain drive circuit (optically isolated if appro- priate). the drive circuit should obviously be able to sink appropriate current when activated and withstand appropriate voltage when deactivated.
d3 models non-isolated, 18-25w, 3.3v-input dc/dc converters 5 load 20k ? 5-10 tu r n s +input input return +output trim output return trim down trim up load +input input return +output trim output return figure 4. trim connections using fixed resistors temperature derating the outstanding electrical ef ? ciency of the unr d3 series' synchronous- recti ? er design and the excellent thermal conductivity of its encapsulated metal package combine to eliminate the need for heat sinking or supplemen- tal forced-air cooling in the majority of routine applications. as shown in the derating curves on page 2, 2.5v out models deliver full rated output power (25 watts) up to +55 c (ambient) and then derate linearly to +100 c. 1.8v out models deliver full rated output power (18 watts) up to +50 c (ambient) and similarly derate linearly to +100 c. note: install either a ? xed trim-up resistor or a ? xed trim-down resistor depending upon desired output voltage. output voltage trimming for 2.5v out devices, the output can be trimmed to any voltage between 1.52v and 3.0v. for 1.8v out devices, the output can be trimmed to any voltage between 1.28v and 3.0v. trimming is accomplished with either a trimpot or a single ? xed resistor. the trimpot should be connected between +output and output return with its wiper connected to the trim pin as shown in figure 3 below. a trimpot can be used to determine the value of a single ? xed resistor which should be connected, as shown in figure 4, between the trim pin and +output to trim down the output voltage, or between the trim pin and output return to trim up the output voltage. fixed resistors should be metal- ? lm types with absolute tcr ? s less than 100ppm/ c to ensure stability. the equations and look-up table below can be used as starting points for selecting speci ? c trim-resistor values. recall that untrimmed devices are guaranteed to be 1% accurate. when the output current of a thermally stabilized converter exceeds the maxi- mum rating (10a) by 40% (typical) to 80% (maximum), the internal overcur- rent detection circuit automatically shuts down the converter by discharging the soft-start circuit of the pulse width modulator (pwm). in this off state, which is similar to that achieved by pulling the on/off control low, the output voltage quickly drops as the output capacitors discharge into the load. since there is no longer any output current, the overcurrent detection circuit is released, allowing the soft-start circuit to recharge and the converter to turn on again. if the faulty load condition persists, the overcurrent detection circuit will again discharge the soft-start circuit and shut down the converter. this continuous on/off cycling of the converter is referred to as ? hiccup mode. ? once the overload condition is removed, the converter remains on, and the output voltage is quickly restored to its regulated value. the components used to sense the output current have large temperature coef ? cients. consequently, in a ? cold-start ? situation, the overcurrent detec- tion point may temporarily move to 80% to 120% above the rated current speci ? cation. the device quickly heats up, particularly if an overload situation exists, and restores the normal (40%) overcurrent detection point. the device easily survives starting up into an output-short-circuit condition. the overcurrent detection circuitry helps keep internal current levels and operating temperatures within safe operating limits. nevertheless, sustained operation at current levels above the rated output current (10 amps) but below the overcurrent detection point (typically 14 amps) may result in permanent damage to the converter (unless active cooling keeps internal temperatures below safe limits). trim-resistor equations for 2.5v out devices trim-resistor equations for 1.8v out devices trim-resistor look-up table for common output voltages desired output voltage (volts) trim resistor ( ? ) connect to trim resistor ( ? ) connect to 1.28 0 +output n.a. n.a. 1.52 2.07k +output 0 +output 1.8 open open 4.03k +output 2 16.9k ? output 9.35k +output 2.5 4.83k ? output open open 2.8 3.38k ? output 29.7k ? output 3 2.82k ? output 17.15k ? output 2.5v out models 1.8v out models figure 3. trim connections using a trimpot v out = v out desired r trim (ohms) = 7500 (v out ? 1.267) 2.5 ? v out ? 1740 r trim (ohms) = trim down trim up v out ? 2.5 ? 1740 9465 v out = v out desired r trim (ohms) = 2670 (v out ? 1.267) 1.8 ? v out r trim (ohms) = v out ? 1.8 3380 trim down trim up
unr series non-isolated, 18-25w, 3.3v-input dc/dc converters 6 recommended pc board layout if necessary, a single pc board layout can accommodate both through-hole and smt models of the unr d3 series. note that on page 2 of this data sheet, the through-hole package is drawn with a bottom view of its pin locations, and the surface-mount package is drawn with of top view of its pin locations. as shown below, the through-hole pin locations, when viewed from above, fall just inside (on 1.8 inch centers) the smt pin locations (which essentially begin on 2.1 inch centers). the table below shows how the pin functions align. 260 240 220 200 180 160 140 120 100 80 60 40 20 0 0 30 60 90 120 150 180 210 240 270 300 pre-heat and temperature soak solder reflow peak temp. 235 c time (seconds) temperature ( c) solder re ow for the surface-mount models ("sm" suf ? x) of the unr d3 series, the packages' gull-wing leads are made of tin-plated (150 microinches) copper. the gull-wing con ? guration, as opposed to "j" leads, was selected to keep the solder joints out from under the package to minimize both heat conduction away from the leads (into the encapsulated package) and ir shadowing effects. through a series of experiments, using 8 mil-thick, 63/37/2 (lead/tin/silver) solder paste and single-layer test boards, we have determined an optimal solder-re ? ow temperature pro ? le as shown in figure 6. obviously, your optimal pro ? le will be a function of many factors including paste thick- ness, board thickness, number of conductive layers, copper weight, the density of surrounding components, etc. the pro ? le in figure 6 should be used as a starting point for your own experi- ments. if you'd like, datel can provide you with complimentary "dummy" units to be used in such tests. under no circumstances should the peak temperature exceed +235 c for an extended period of time. as shown in figure 7, our tests have determined the optimal landing-pad size to be 160 mils by 130 mils. figure 6. optimal solder re ow pro le figure 7. pc board land pattern 0.130* (3.30) 0.015 (0.38) 0.100** (2.54) * pad dimension ** lead dimension 0.160* (4.06) 0.110** (2.79) 4 3 2 1 8 7 6 5 9 0.10 (2.54) 0.110 (2.79) 0.100 (2.54) 0.300 (7.62) 0.500 (12.70) top view 1.00 (25.40) 0.800 (20.32) 4 eq. sp. @ 0.200 (5.08) 0.10 (2.54) 1 2 3 4 6 7 5 1.800 (45.72) 0.10 (2.54) 0.300 (7.62) top view 1.00 (25.40) 0.800 (20.32) 4 eq. sp. @ 0.200 (5.08) pins 1-2, 4: 0.040 ?.002 (1.016 ?.051) pins 3, 5-7: 0.062 ?.002 (1.575 ?.051) case c16a2 case c18 +input +output on/off control trim power ground 4 no pin n.c. 3 no pin n.c. 2 2 on/off control 1 1 logic ground 9 7 +input 8 6 input return 7 5 output return 6 4 trim 5 3 +output smt through-hole pin number pin number pin function figure 5. recommended board layout
d3 models non-isolated, 18-25w, 3.3v-input dc/dc converters typical performance curves 7 v in to v out start-up time on/off control to v out start-up time unr-1.8/10-d3 models (v in = 3.3v, i out = 10a, 22? output capacitor.) v out 1v/div v in 1v/div 4msec/div unr-2.5/10-d3 models (v in = 3.3v, i out = 10a, 22? output capacitor.) v out 1v/div v in 1v/div 4msec/div unr-1.8/10-d3 models (v in = 3.3v, i out = 10a, 22? output capacitor.) v out 1v/div v control 1v/div 4msec/div unr-2.5/10-d3 models (v in = 3.3v, i out = 10a, 22? output capacitor.) v out 1v/div v control 1v/div 4msec/div
unr series non-isolated, 18-25w, 3.3v-input dc/dc converters datel makes no representation that the use of its products in the circuits described herein, or the use of other technical info rmation contained herein, will not infringe upon existing or future patent rights. the descriptions contained herein do not imp ly the granting of licenses to make, use, or sell equipment constructed in accordance therewith. speci cations are subject to change without notice. the date l logo is a registered datel, inc. trademark. datel (uk) ltd. tadley, england tel: (01256)-880444 datel s.a.r.l. montigny le bretonneux, france tel: 01-34-60-01-01 datel gmbh m ? nchen, germany tel: 89-544334-0 datel kk tokyo, japan tel: 3-3779-1031, osaka tel: 6-354-2025 datel, inc. 11 cabot boulevard, mans eld, ma 02048-1151 tel: (508) 339-3000 (800) 233-2765 fax: (508) 339-6356 internet: www.datel.com email: sales@datel.com ds-0482a 9/00 innovation and excellence iso 9001 registered datel ? s world-class design, development and manufacturing team stands ready to work with you to deliver the exact power converter you need for your demanding, large volume, oem applications. and . . . we ? ll do it on time and within budget! our experienced applications and design staffs; quick-turn prototype capa- bility; highly automated, smt assembly facilities; and in-line spc quality- control techniques combine to give us the unique ability to design and deliver any quantity of power converters to the highest standards of quality and reliability. we have compiled a large library of dc/dc designs that are currently used in a variety of datacom/telecom, medical, computer, railway, aerospace and industrial applications. we may already have the converter you need. contact us. our goal is to provide you the highest-quality, most cost- effective power converters available. custom capabilities 90 85 80 75 70 65 60 12345678910 load current (amps) efficiency ( % ) v in = 3.0v v in = 3.6v v in = 3.3v unr-2.5/10-d3 models (guaranteed efficiency = 85% at v in = 3.3v and i out = 10a) 90 85 80 75 70 65 60 123 4 5 67 8 910 load current (amps) efficiency ( % ) unr-1.8/10-d3 models (guaranteed efficiency = 82.5% at v in = 3.3v and i out = 10a) v in = 3.6v v in = 3.3v v in = 3.0v ef ciency vs. output current and input voltage typical performance curves 8
|
