? semiconductor components industries, llc, 2012 june, 2012 ? rev. 0 1 publication order number: nsic2050b/d NSIC2050BT3G constant current regulator & led driver for a/c off-line applications 120 v, 50 ma 15%, 3 w package the linear constant current regulator (ccr) is a simple, economical and robust device designed to provide a cost ? effective solution for regulating current in leds (similar to constant current diode, ccd). the ccr is based on self ? biased transistor (sbt) technology and regulates current over a wide voltage range. it is designed with a negative temperature coefficient to protect leds from thermal runaway at extreme voltages and currents. the ccr turns on immediately and is at 20% of regulation with only 0.5 v vak. it requires no external components allowing it to be designed as a high or low ? side regulator. the 120 v anode ? cathode voltage rating is designed to withstand the high peak voltage incurred in a/c offline applications. the high anode ? cathode voltage also protects surges common in industrial and commercial signage applications. the ccr comes in thermally robust packages and is ul94 ? v0 certified. features ? robust power package: 2.3 w ? wide operating voltage range ? immediate turn-on ? voltage surge suppressing ? protecting leds ? ul94 ? v0 certified ? sbt (self ? biased transistor) technology ? negative temperature coefficient ? also available in 30 ma (nsic2030bt1g) and 20 ma (nsic2020bt1g) ? these devices are pb ? free, halogen free/bfr free and are rohs compliant typical applications ? ac lighting panels, display signage, decorative lighting, channel lettering ? application note and8433/d ? a/c application ? application note and8493/d ? a/c capacitive drop design ? design note dn05013 ? a/c design ? design note dn06065 ? a/c design with pfc ? application notes and8391/d, and9008/d ? power dissipation considerations ? automotive applications ? consult factory http://onsemi.com smb case 403a marking diagram device package shipping ? ordering information NSIC2050BT3G smb (pb ? free) 2500 / tape & reel ?for information on tape and reel specifications, including part orientation and tape sizes, please refer to our t ape and reel packaging specifications brochure, brd8011/d. (note: microdot may be in either location) i reg(ss) = 50 ma @ vak = 7.5 v 2050 = specific device code a = assembly location y = year ww = work week = pb ? free package ayww 2050 anode 2 cathode 1 1 2 12
NSIC2050BT3G http://onsemi.com 2 maximum ratings (t a = 25 c unless otherwise noted) rating symbol value unit anode ? cathode voltage vak max 120 v reverse voltage v r 500 mv operating junction and storage temperature range t j , t stg ? 55 to +175 c esd rating: human body model machine model esd class 3a (4000 v) class c (400 v) stresses exceeding maximum ratings may damage the device. maximum ratings are stress ratings only. functional operation above t he recommended operating conditions is not implied. extended exposure to stresses above the recommended operating conditions may af fect device reliability. electrical characteristics (t a = 25 c unless otherwise noted) characteristic symbol min typ max unit steady state current @ vak = 7.5 v (note 1) i reg(ss) 42.5 50 57.5 ma voltage overhead (note 2) v overhead 1.8 v pulse current @ vak = 7.5 v (note 3) i reg(p) 48.1 57.4 66.7 ma 1. i reg(ss) steady state is the voltage (vak) applied for a time duration 80 sec, using 100 mm 2 , 1 oz. cu (or equivalent), in still air. 2. v overhead = v in ? v leds . v overhead is typical value for 80% i reg(ss) . 3. i reg(p) non ? repetitive pulse test. pulse width t 360 sec.
NSIC2050BT3G http://onsemi.com 3 thermal characteristics characteristic symbol max unit total device dissipation (note 1) t a = 25 c derate above 25 c p d 1210 8.0 mw mw/ c thermal resistance, junction ? to ? ambient (note 1) r ja 124 c/w thermal reference, junction ? to ? tab (note 1) r jl 17.5 c/w total device dissipation (note 2) t a = 25 c derate above 25 c p d 1282 8.5 mw mw/ c thermal resistance, junction ? to ? ambient (note 2) r ja 117 c/w thermal reference, junction ? to ? tab (note 2) r jl 18.2 c/w total device dissipation (note 3) t a = 25 c derate above 25 c p d 1667 11.1 mw mw/ c thermal resistance, junction ? to ? ambient (note 3) r ja 90 c/w thermal reference, junction ? to ? tab (note 3) r jl 16.4 c/w total device dissipation (note 4) t a = 25 c derate above 25 c p d 1765 11.8 mw mw/ c thermal resistance, junction ? to ? ambient (note 4) r ja 85 c/w thermal reference, junction ? to ? tab (note 4) r jl 16.7 c/w total device dissipation (note 5) t a = 25 c derate above 25 c p d 1948 13 mw mw/ c thermal resistance, junction ? to ? ambient (note 5) r ja 77 c/w thermal reference, junction ? to ? tab (note 5) r jl 15.5 c/w total device dissipation (note 6) t a = 25 c derate above 25 c p d 2055 12.7 mw mw/ c thermal resistance, junction ? to ? ambient (note 6) r ja 73 c/w thermal reference, junction ? to ? tab (note 6) r jl 15.6 c/w total device dissipation (note 7) t a = 25 c derate above 25 c p d 2149 14.3 mw mw/ c thermal resistance, junction ? to ? ambient (note 7) r ja 69.8 c/w thermal reference, junction ? to ? tab (note 7) r jl 14.8 c/w total device dissipation (note 8) t a = 25 c derate above 25 c p d 2269 15.1 mw mw/ c thermal resistance, junction ? to ? ambient (note 8) r ja 66.1 c/w thermal reference, junction ? to ? tab (note 8) r jl 14.8 c/w total device dissipation (note 9) t a = 25 c derate above 25 c p d 2609 17.4 mw mw/ c thermal resistance, junction ? to ? ambient (note 9) r ja 57.5 c/w thermal reference, junction ? to ? tab (note 9) r jl 13.9 c/w total device dissipation (note 10) t a = 25 c derate above 25 c p d 2500 16.7 mw mw/ c thermal resistance, junction ? to ? ambient (note 10) r ja 60 c/w thermal reference, junction ? to ? tab (note 10) r jl 16 c/w total device dissipation (note 11) t a = 25 c derate above 25 c p d 3000 20 mw mw/ c thermal resistance, junction ? to ? ambient (note 11) r ja 50 c/w thermal reference, junction ? to ? tab (note 11) r jl 16 c/w note: lead measurements are made by non ? contact methods such as ir with treated surface to increase emissivity to 0.9. lead temperature measurement by attaching a t/c may yield values as high as 30% higher c/w values based upon empirical measurements and method of attachment. 1. 100 mm 2 , 1 oz. cu, still air. 2. 100 mm 2 , 2 oz. cu, still air. 3. 300 mm 2 , 1 oz. cu, still air. 4. 300 mm 2 , 2 oz. cu, still air. 5. 500 mm 2 , 1 oz. cu, still air. 6. 500 mm 2 , 2 oz. cu, still air. 7. 700 mm 2 , 1 oz. cu, still air. 8. 700 mm 2 , 2 oz. cu, still air. 9. 1000 mm 2 , 3 oz. cu, still air. 10. 400 mm 2 , pcb is denka k1, 1.5 mm al, 2kv thermally conductive dielectric, 2 oz. cu, or equivalent, still air. 11. 900 mm 2 , pcb is denka k1, 1.5 mm al, 2kv thermally conductive dielectric, 2 oz. cu, or equivalent, still air.
NSIC2050BT3G http://onsemi.com 4 typical performance curves (minimum fr ? 4 @ 100 mm 2 , 1 oz. copper trace, still air) ? 0.130 ma/ c figure 1. general performance curve for ccr figure 2. steady state current (i reg(ss) ) vs. anode ? cathode voltage (vak) figure 3. pulse current (i reg(p) ) vs. anode ? cathode voltage (vak) figure 4. steady state current vs. pulse current testing vak, anode ? cathode voltage (v) i reg(p) , pulse current (ma) figure 5. current regulation vs. time time (s) 60 50 40 20 10 0 54 56 58 i reg , current regulation (ma) 30 80 49 52 figure 6. power dissipation vs. ambient temperature @ t j = 175 c: small footprint t a , ambient temperature ( c) p d , power dissipation (mw) 53 55 57 51 vak, anode ? cathode voltage (v) 80 60 40 140 20 0 ? 20 ? 20 0 10 30 50 70 i reg , current regulation (ma) ? 10 20 40 100 vak, anode ? cathode voltage (v) 60 9 6 5 4 3 10 30 40 50 i reg(ss) , steady state current (ma) 710 dc test steady state, still air 8 20 2 1 0 60 70 0 11 12 13 14 15 10 9 8 7 6 5 4 25 35 40 64 60 42 44 46 i reg(p) , pulse current (ma) i reg(ss) , steady state current (ma) 30 48 50 3 45 50 52 54 48 56 56 58 55 65 2 1 t a = 25 c non ? repetitive pulse test 11 12 13 14 15 52 66 62 50 58 54 vak @ 7.5 v t a = 25 c vak @ 7.5 v t a = 25 c 60 68 50 t a = 25 c t a = ? 55 c t a = 25 c t a = 85 c ? 0.224 ma/ c t a = 125 c 80 60 20 0 ? 20 ? 40 500 1000 2000 2500 40 500 mm 2 /2 oz 300 mm 2 /1 oz 100 mm 2 /2 oz 1500 3000 0 100 mm 2 /1 oz 500 mm 2 /1 oz 300 mm 2 /2 oz 120 100 120 t j(max) , maximum die temperature limit 175 c (100 mm 2 , 1 oz cu) ? 0.130 ma/ c 70 fr ? 4 board
NSIC2050BT3G http://onsemi.com 5 typical performance curves (minimum fr ? 4 @ 100 mm 2 , 1 oz. copper trace, still air) figure 7. power dissipation vs. ambient temperature @ t j = 175 c: large footprint t a , ambient temperature ( c) 80 60 20 0 ? 20 ? 40 500 1000 2000 2500 power dissipation (mw) 40 denka k1, 900 mm 2 /2 oz fr ? 4, 700 mm 2 /2 oz 1500 3000 0 fr ? 4, 1000 mm 2 /3 oz 3500 4000 4500 120 100 denka k1, 400 mm 2 /2 oz fr ? 4, 700 mm 2 /1 oz
NSIC2050BT3G http://onsemi.com 6 applications information the ccr is a self biased transistor designed to regulate the current through itself and any devices in series with it. the device has a slight negative temperature coefficient, as shown in figure 2 ? tri temp. (i.e. if the temperature increases the current will decrease). this negative temperature coefficient will protect the leds by reducing the current as temperature rises. the ccr turns on immediately and is typically at 20% of regulation with only 0.5 v across it. the device is capable of handling voltage for short durations of up to 120 v so long as the die temperature does not exceed 175 c. the determination will depend on the thermal pad it is mounted on, the ambient temperature, the pulse duration, pulse shape and repetition. ac applications the ccr is a dc device; however, it can be used with full wave rectified ac as shown in application notes and8433/d and and8492/d and design notes dn05013/d and dn06065/d. figure 8 shows the basic circuit configuration. figure 8. basic ac application single led string the ccr can be placed in series with leds as a high side or a low side driver. the number of the leds can vary from one to an unlimited number. the designer needs to calculate the maximum voltage across the ccr by taking the maximum input voltage less the voltage across the led string (figures 9 and 10). figure 9. figure 10.
NSIC2050BT3G http://onsemi.com 7 higher current led strings two or more fixed current ccrs can be connected in parallel. the current through them is additive (figure 11). figure 11. other currents the adjustable ccr can be placed in parallel with any other ccr to obtain a desired current. the adjustable ccr provides the ability to adjust the current as led efficiency increases to obtain the same light output (figure 12). figure 12. dimming using pwm the dimming of an led string can be easily achieved by placing a bjt in series with the ccr (figure 13). figure 13. the method of pulsing the current through the leds is known as pulse width modulation (pwm) and has become the preferred method of changing the light level. leds being a silicon device, turn on and off rapidly in response to the current through them being turned on and off. the switching time is in the order of 100 nanoseconds, this equates to a maximum frequency of 10 mhz, and applications will typically operate from a 100 hz to 100 khz. below 100 hz the human eye will detect a flicker from the light emitted from the leds. between 500 hz and 20 khz the circuit may generate audible sound. dimming is achieved by turning the leds on and off for a portion of a single cycle. this on/off cycle is called the duty cycle (d) and is expressed by the amount of time the leds are on (ton) divided by the total time of an on/off cycle (ts) (figure 14). figure 14.
NSIC2050BT3G http://onsemi.com 8 the current through the leds is constant during the period they are turned on resulting in the light being consistent with no shift in chromaticity (color). the brightness is in proportion to the percentage of time that the leds are turned on. figure 15 is a typical response of luminance vs duty cycle. figure 15. luminous emmitance vs. duty cycle duty cycle (%) 100 90 80 70 60 50 40 0 1000 3000 illuminance (lx) 2000 30 4000 6000 20 10 0 5000 lux linear reducing emi designers creating circuits switching medium to high currents need to be concerned about electromagnetic interference (emi). the leds and the ccr switch extremely fast, less than 100 nanoseconds. to help eliminate emi, a capacitor can be added to the circuit across r2. (figure 13) this will cause the slope on the rising and falling edge on the current through the circuit to be extended. the slope of the ccr on/off current can be controlled by the values of r1 and c1. the selected delay / slope will impact the frequency that is selected to operate the dimming circuit. the longer the delay, the lower the frequency will be. the delay time should not be less than a 10:1 ratio of the minimum on time. the frequency is also impacted by the resolution and dimming steps that are required. with a delay of 1.5 microseconds on the rise and the fall edges, the minimum on time would be 30 microseconds. if the design called for a resolution of 100 dimming steps, then a total duty cycle time (ts) of 3 milliseconds or a frequency of 333 hz will be required. thermal considerations as power in the ccr increases, it might become necessary to provide some thermal relief. the maximum power dissipation supported by the device is dependent upon board design and layout. mounting pad configuration on the pcb, the board material, and the ambient temperature affect the rate of junction temperature rise for the part. when the device has good thermal conductivity through the pcb, the junction temperature will be relatively low with high power applications. the maximum dissipation the device can handle is given by: p d(max) t j(max) t a r ja referring to the thermal table on page 2 the appropriate r ja for the circuit board can be selected.
NSIC2050BT3G http://onsemi.com 9 package dimensions smb case 403a ? 03 issue h e b d c l1 l a a1 notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: inch. 3. d dimension shall be measured within dimension p. 2.261 0.089 2.743 0.108 2.159 0.085 mm inches scale 8:1 *for additional information on our pb ? free strategy and soldering details, please download the on semiconductor soldering and mounting techniques reference manual, solderrm/d. soldering footprint* dim a min nom max min millimeters 1.90 2.20 2.28 0.075 inches a1 0.05 0.10 0.19 0.002 b 1.96 2.03 2.20 0.077 c 0.15 0.23 0.31 0.006 d 3.30 3.56 3.95 0.130 e 4.06 4.32 4.60 0.160 l 0.76 1.02 1.60 0.030 0.087 0.090 0.004 0.007 0.080 0.087 0.009 0.012 0.140 0.156 0.170 0.181 0.040 0.063 nom max 5.21 5.44 5.60 0.205 0.214 0.220 h e 0.51 ref 0.020 ref d l1 h e polarity indicator optional as needed on semiconductor and are registered trademarks of semiconductor co mponents industries, llc (scillc). scillc owns the rights to a numb er of patents, trademarks, copyrights, trade secrets, and other intellectual property. a list ing of scillc?s product/patent coverage may be accessed at ww w.onsemi.com/site/pdf/patent ? marking.pdf. scillc reserves the right to make changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and s pecifically disclaims any and all liability, including without limitation special, consequential or incidental damages. ?typical? parameters which may be provided in scillc data sheets and/ or specifications can and do vary in different applications and actual performance may vary over time. all operating parame ters, including ?typicals? must be validated for each customer application by customer?s technical experts. scillc does not convey any license under its patent rights nor the right s of others. scillc products are not designed, intended, or a uthorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in whic h the failure of the scillc product could create a situation where personal injury or death may occur. should buyer purchase or us e scillc products for any such unintended or unauthorized appli cation, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unin tended or unauthorized use, even if such claim alleges that scil lc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyrig ht laws and is not for resale in any manner. publication ordering information n. american technical support : 800 ? 282 ? 9855 toll free usa/canada europe, middle east and africa technical support: phone: 421 33 790 2910 japan customer focus center phone: 81 ? 3 ? 5817 ? 1050 nsic2050b/d literature fulfillment : literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 303 ? 675 ? 2175 or 800 ? 344 ? 3860 toll free usa/canada fax : 303 ? 675 ? 2176 or 800 ? 344 ? 3867 toll free usa/canada email : orderlit@onsemi.com on semiconductor website : www.onsemi.com order literature : http://www.onsemi.com/orderlit for additional information, please contact your local sales representative
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