1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com lr645 features accepts inputs from 15 to 450v output currents up to 3.0ma continuous, 30ma peak supply current typically 50a line regulation typically 0.1mv/v output can be trimmed from 8.0 to 12v output current can be increased to 150ma with external fet applications off-line smps startup circuits (pulse loads) low power off-line regulators regulators for noisy inputs ? ? ? ? ? ? ? ? ? general description the supertex lr645 is a high input voltage, low output current linear regulator. it has a 3-terminal ?xed output voltage version available in to-92, to-220 and sot-89 packages, as well as an adjustable voltage version available in an 8- lead soic package. the 3-terminal version functions like any other low voltage 3-terminal regulator except it allows the use of much higher input voltages. when used in a smps start- up circuit, it eliminates the need for large power resistors. in this application, current is drawn from the high voltage line only during start-up. only leakage current ?ows after start-up, thereby reducing the continuous power dissipation to a few milliwatts. the adjustable voltage version allows trimming of the output voltage from 8.0 to 12v. this version can also be connected to an external depletion mode mosfet for increased output current. when used in conjunction with supertex depletion mode mosfet dn2540n5, an output current of up to 150ma is achieved. high input voltage smps start-up / linear regulator caution! the lr645 does not provide galvanic isolation . when operated from an ac line, potentially lethal voltages can be present on the ic. adequate means of protecting the end user from such voltages must be provided by the circuit developer. ordering information device package options 8-lead soic to-92 to-220 to-243aa (sot-89) lr645 lr645lg-g lr645n3-g lr645n5-g lr645n8-g -g indicates package is rohs compliant (green) absolute maximum ratings parameter value input voltage 450v output voltage 15.5v operating and storage temperature -55c to +150 o c soldering temperature* 300 o c absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditions is not implied. continuous operation of the device at the absolute rating level may affect device reliability. all voltages are referenced to device ground. * distance of 1.6mm from case for 10 seconds. pin con?gurations +vin vout nc gnd nc trim ga te nc gnd vi n vout +vin vout gnd gnd vin vout gnd gnd to-92 (n3) to-220 (n5) 8-lead soic (lg) to-243aa (sot-89) (n8)
2 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com thermal characteristics package power dissipation @t a = 25 o c (w) jc ( o c/w) ja ( o c/w) 8-lead soic 0.31 156 400* to-92 0.74 125 170 to-220 1.8 8.3 70 to-243aa (sot-89) 1.6 15 78* * mounted on fr5 board; 25mm x 25mm x 1.57mm signi?cant p d increase possible on ceramic substrate sym parameter min typ max units conditions v out output voltage 9.3 10 10.7 v no load output voltage over temperature 1 9.0 10 11.5 v t j = - 40 to +125c, no load v out line regulation - 40 200 mv v in = 15 to 400v, no load load regulation - 150 400 mv v in = 50v, i out = 0 to 3.0ma v in operating input voltage range 15 - 450 v --- i inq input quiescent current - 50 150 a no load i off v in off-state leakage current - 0.1 10 a v aux v out +1v applied to v out pin i aux input current to v out - - 200 a v aux v out +1v applied to v out pin v out /v in ripple rejection ratio 1 50 60 - db 120hz, no load e n noise voltage 1 - 25 - v 0.01 to 100khz i peak output peak current 2 - 30 - ma c out = 10f, v in = 400v v aux external voltage applied to v out - - 13.2 v --- 8-lead, adjustable output voltage version only: test conditions unless otherwise speci?ed: t a = 25c; v in = 15 to 450v, c out = 0.01f v out output regulation trim range 1 8 - 12 v no load v out load regulation at 8v trim 1 - 200 400 mv v in = 15v, i out = 0 to 1.0ma load regulation at 12v trim 1 - 100 400 mv v in = 50v, i out = 0 to 3.0ma notes: guaranteed by design, not tested in production. pulse test duration <1.0msec, duty cycle <2% 1. 2. electrical characteristics (test conditions unless otherwise speci?ed: t a = 25c; v in = 15 to 450v, c out = 0.01f) package markings yy = year sealed ww = week sealed l = lot number = green packaging yyww lr645 l l l l 8-lead soic (lg) to-243aa (sot-89) (n8) l = lot number yy = year sealed ww = week sealed = green packaging top marking lr645n5 lllllllll yyw w to-220 (n5) l r 6 4 5 y w l l y = last digit of year sealed w = code for week sealed l = lot number = green packaging to-92 (n3) lr6 w w = code for week sealed = green packaging
3 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com lr645: smps start-up circuit one of the main applications for the lr645 is a start-up circuit for off-line switch-mode power supplies (smps), as shown in figure1. a minimum output capacitance of 0.01f is recommended for stability. the wide operating input volt - age range of the lr645 allows the smps to operate and start-up from recti?ed ac or a dc voltage of 15 to 450v with - out adjustment. during start-up, the lr645 powers the vcc line of the pwm ic with a nominal output voltage of 10v. the auxiliary voltage connected through a diode to the vout pin of the lr645 will start to increase. when the auxiliary voltage becomes larger than the output voltage the lr645 turns off its internal high voltage input line and output voltage, allowing the auxiliary voltage to power the vcc line of the pwm ic. the input current drawn by the lr645 from the high voltage line after start-up will therefore only be leakage current of the internal mosfet switch, which is typically 0.1a. the 3-terminal version shown in figure 1 has load regula - tion guaranteed from 0 to 3.0ma at a ?xed nominal output voltage of 10v. applications requiring higher output current and/or a different output voltage can use the 8 pin adjustable version. figure 1: smps start-up circuit + 15 v to 450v C + 5.0v C v au x = 12 v c out c in v cc pwm ic lr6 gnd v in lr645 block diagram v ou t gn d gate v in trim + C lr645
4 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com figure 2: high current smps start-up circuit r2 r1 + 15v to 400v C + 5.0v C dn2540 c out c in v cc v au x = 12v note: when used with the dn25, +v in is not connected on the lr6. pwm ic lr645 v out gnd gate trim lr645: high current smps start-up circuit the 8 lead version of the lr645 has connections for an ex - ternal depletion-mode mosfet for higher output current and external resistors for adjustable output voltage. as shown in figure 2, the output current is increased to 150ma by using the supertex 400v depletion-mode mosfet dn2540. the maximum operating input voltage will be limited by the drain- to-source breakdown voltage of the external mosfet, but cannot exceed the 450v rating of the lr645. the output voltage can be adjusted from 8 to 12v with 2 ex - ternal resistors, r1 and r2. the ratio of r2/r1 determines the output voltage. r2 is connected between the v out and trim pins. r1 is connected between trim and gnd pins. figure 5 is a curve showing output voltage versus resistor ratio r2/r1. the optimum range for r1 + r2 is 200k? to 300k?. this minimizes loading and optimizes accuracy of the output voltage. figure 5 uses an r1 + r2 of 250k?. lr645: off line linear regulator circuits requiring low voltages to operate logic and analog circuits bene?t from the lr645. the conventional use of step down transformers can be eliminated, thereby saving space and cost. some examples of these applications are: proximity controlled light switches, street lamp controls, and low voltage power supplies for appliances such as washing machines, dishwashers, and refrigerators. the wide operating input voltage range of 15 to 450v as well as the ripple rejection ratio of 50db minimum allows the use of a small, high voltage input capacitor. the input ac line can be either full-wave or half-wave recti?ed. a minimum output capacitance of 0.01f is recommended for output stability. figure 3 shows the lr645 as a pre-regulator to a precision - regulator for high precision regulation. higher output cur - rent is also possible by using an external depletion-mode mosfet dn2540n5 as shown in figure 4. power dissipation considerations the lr645 is a true linear regulator. its power dissipation is - therefore a function of input voltage and output load current. forexample, if the lr645 is providing a continuous load cur - rent of 3maat 10v while its input voltage is 400v, total dis - sipation in the lr645 will be: p diss = (v in - v out ) x (i out + i max quiescent ) = (400v - 10v) x (3.0ma + 150a) = 1.23 watts the 1.23 watts is for continuous operation. this is within the dissipation capabilities of the to-220 and sot-89 packag - es. see the thermal characteristics chart on page 2 for derat - ings. for smps start-up applications, the output current is usually required only during start-up. this duration depends upon the auxiliary supply output capacitor and c out , but is typically a few hundred milliseconds. all package types of the lr645 have been characterized for use with a c out of at least 10f, and an ac line of 277v. 5.000v 0.002v @ 0 to 3m a a c line 24v to 277v c out 0.1f c in 1.0f lr6 max 875 acsa figure 3: cascading for precision
5 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com a c line 24v to 277v 5.0v 0 to 150ma 5.0v reg + C c ou t c in v out gate dn2540n5 gn d lr645lg figure 4: high current regulation figure 5: typical output voltage vs resistor ratio 12 10 8 2.5 3 .0 4. 0 3. 5 resistor ratio (r2/r1 ) e (v ) g a t l o v t u p t u o r1 + r2 = 250k ?
6 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com 8-lead soic (narrow body) package outline (lg/tg) 4.90x3.90mm body, 1.75mm height (max), 1.27mm pitch 1 8 seating plane gauge plane l l1 l2 e e1 d e b a a2 a1 seating plane a a to p v iew side v iew vi ew b vi ew b 1 note 1 (index area d/2 x e1/2) vi ew a-a h h note 1 symbol a a1 a2 b d e e1 e h l l1 l2 1 dimension (mm) min 1.35* 0.10 1.25 0.31 4.80* 5.80* 3.80* 1.27 bsc 0.25 0.40 1.04 ref 0.25 bsc 0 o 5 o nom - - - - 4.90 6.00 3.90 - - - - max 1.75 0.25 1.65* 0.51 5.00* 6.20* 4.00* 0.50 1.27 8 o 15 o jedec registration ms-012, variation aa, issue e, sept. 2005. * this dimension is not speci?ed in the original jedec drawing. the value listed is for reference only. drawings are not to scale. supertex doc. #: dspd-8solgtg, version h101708. note: this chamfer feature is optional. a pin 1 identi?er must be located in the index area indicated. the pin 1 identi?er can be: a molded mark/identi?er; an embedded metal marker; or a printed indicator. 1.
7 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com 3-lead to-92 package outline (n3) symbol a b c d e e1 e e1 l dimensions (inches) min .170 .014 ? .014 ? .175 .125 .080 .095 .045 .500 nom - - - - - - - - - max .210 .022 ? .022 ? .205 .165 .105 .105 .055 .610* jedec registration to-92. * this dimension is not speci?ed in the original jedec drawing. the value listed is for reference only. ? this dimension is a non-jedec dimension. drawings not to scale. supertex doc.#: dspd-3to92n3, version d080408. seating plane 1 2 3 front v iew side v iew bottom v iew e1 e d e1 l e c 1 2 3 b a
8 lr645 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com 3-lead to-220 package outline (n5) symbol a a1 a2 b b2 c d d1 d2 e e1 e2 e h1 l l1 q p dimen - sion (inches) min .140 .020 .080 .015 .045 .012 ? .560 .326 ? .474 ? .380 .270 0.20* .100 bsc .230 .500 .200* .100 .139 nom - - - .027 .057 - - - - - - - - - - - - max .190 .055 .120 ? .040 .070 .024 .650 .361 ? .507 .420 .350 .030 .270 .580 .250 .135 .161 jedec registration to-220, variation ab, issue k, april 2002. * this dimension is not speci?ed in the original jedec drawing. the value listed is for reference only. ? this dimension is a non-jedec dimension. drawings not to scale. supertex doc. #: dspd-3to220n5, version b090308. l a2 a e view b 1 2 3 d d1 q 4 e2 e p seating plan e a1 a a chamfer optional h1 e d2 thermal pad front v iew side v iew vi ew a - a l1 b b2 1 2 3 e1 view b c
supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such appl ications unless it receives an adequate product liability indemnification insurance agreement. supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. no responsibility is assumed for possible omissions and inaccuracies. circuitry and specifications are subject to change without notice. for the latest product specifications refer to the supertex inc. website: http//www .supertex.com . ?2008 all rights reserved. unauthorized use or reproduction is prohibited . 1235 bordeaux drive, sunnyvale, ca 9408 9 te l: 408-222-8888 www .supertex.com 9 lr645 (the package drawings in this data sheet may not re?ect the most current speci?cations. for the latest package outline information go to http://www.supertex.com/packaging.htm l .) doc.# dsfp-lr645 a103008 3-lead to-243aa (sot-89) package outline (n8) symbol a b b1 c d d1 e e1 e e1 h l dimensions (mm) min 1.40 0.44 0.36 0.35 4.40 1.62 2.29 2.13 1.50 bsc 3.00 bsc 3.94 0.89 nom - - - - - - - - - - max 1.60 0.56 0.48 0.44 4.60 1.83 2.60 2.29 4.25 1.20 jedec registration to-243, variation aa, issue c, july 1986. drawings not to scale . supertex doc. #: dspd-3to243aan8, version d070908. b b1
|
