hv9801a features ? four level switch dimming ? very accurate current regulator ? output over-current / short circuit protection ? ic over-temperature protection ? available in 8l-soic and 16l-soic packages applications ? switch dimmable led bulbs and fxtures general description the hv9801a led driver is ideally suited for switch dimmable applications using led bulbs and fxtures. through switch dimming, the lamp can be adjusted to four discrete brightness levels by rapid cycling of the light switch. the brightness levels are traversed in up and down manner. brightness resumes at the highest level when power is removed for more than a second. the device can be powered directly from rectifed ac through an internal vdd regulator rated at 450v. typical application circuit switch dimmable led driver vin ga te cs gnd vdd rt hv9801a cddr t rcs l ac vin bus supertex inc. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
2 hv9801a -g indicates package is rohs compliant (green) absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifcations is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. parameter value v vin 470v v vdd 12v v cs , v ld , v pwmd , v gate 9wr9 vdd 9 junction temperature range -40c to +150c storage temperature range -65c to +150c continuous power dissipation (t a = +25c) 8-lead soic 16-lead soic 650mw 1000mw sym description min typ max unit conditions input v vin input voltage t 15 - 450 v --- i vin input current - - 1 2 ma --- i vin,ot supply current, otp shutdown g - - 500 --- vdd regulator v uvlo undervoltage lockout threshold t v v vin rising 9 uvlo undervoltage lockout hysteresis - - 500 - mv v vin falling i uvlo 0dlpxplsxwfxuuhwolplwhge uvlo g - - ma t a = 25c - - ma t a = 125c ordering information device package options 8-lead soic 4.90x3.90mm body 1.75mm height (max) 1.27mm pitch 16-lead soic 9.90x3.90mm body 1.75mm height (max) 1.27mm pitch hv9801a hv9801alg-g HV9801ANG-G 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 8 7 6 5 1 2 3 4 vin cs gnd gate rt dnc vdd dnc vin dnc dnc cs gnd dnc dnc gate dnc dnc rt dnc vdd dnc dnc dnc pin description product marking y = last digit of year sealed ww = week sealed l = lot number = ?green? packaging yww 9801a llll y = last digit of year sealed ww = week sealed l = lot number c = country of origin* a = assembler id* = ?green? packaging *may be part of top marking t op m ar ki ng bottom marking hv9801ang yww llllllll ccccccccc aaa 8-lead soic (lg) 16-lead soic (ng) 8-lead soic (lg) 16-lead soic (ng) electrical characteristics (s pecifcations are at t a = 25c, v vin = 15v unless otherwise noted) package may or may not include the following marks: si or package may or may not include the following marks: si or notes: g not production tested; guaranteed by design or characterization. t specifcations apply over the full operating ambient temperature range of -40c < t a < +125c. caution! dnc means do not connect! supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
3 hv9801a sym description min typ max unit conditions vdd regulator (cont.) v vdd output voltage - 7.25 7.50 7.75 v c gate = 500pf; r rt = 226k? v line line regulation - - - 1 v v in = 15 to 450v; c gate = 500pf; r rt = 226k? v dd(uv) v dd voltage margin t 500 - - mv v dd(uv) = v dd - uvlo v load load regulation - - - 100 mv i vdd = 0 to 1ma; c gate = 500pf; r rt = 226k? switch dimming i vddx supply current after power loss t - - 700 a --- v uvlo undervoltage lockout during vin power loss - - 3.5 - v --- t pl1 power loss, qualifcation-time - - 7 - ms v vin falling below v uvlo t pl2 power loss, time to reset g - 1 - s f pwm pwm dimming frequency - - 1.2 - khz --- led current regulator v cst current sense threshold t 236 250 256 mv --- t leb leading edge blanking time t 110 - 260 ns --- t onx minimum on-time - - - 760 ns v cs = v cst + 30mv d max maximum duty cycle maintaining regulation - 80 - - % led current falls beyond this duty cycle short circuit protection v csh hiccup threshold - - 440 - mv --- t dly v cs high to gate low delay - - - 180 ns v cs = v cst + 30mv t sch hiccup time - - 750 - s --- t onx minimum on-time - - - 430 ns c s = v dd t off timer t off off-time - 32 40 48 s r rt = 1m? - 8.0 10 12 r rt = 226k? gate driver i src sourcing current - 165 - - ma v gate = 0v i sink sinking current - 165 - - ma v gate = v dd t rise rise time - - 30 50 ns c gate = 500pf t fall fall time - - 30 50 ns c gate = 500pf over-temperature protection t trip trip temperature g - 140 - c --- t trip hysteresis g - 20 - c --- electrical characteristics (s shffwrvuhw a = 25c, v vin = 15v unless otherwise noted) notes: g not production tested; guaranteed by design or characterization. shffwrvssorhuwhixoorshuwphwwhpshuwxuhuhri a supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
4 hv9801a functional block diagram vin vdd cs rt gate hv9801a 250m v 440mv vdd regulator current mirror from vdd rail leading edge blanking s q r q or average current regulator off time generator ot p and uv lo gnd hiccup application information current control continuous conduction mode the hv9801a is designed for control of a buck converter operating in continuous conduction mode. ccm operation is characterized by converter operation with non-zero inductor current throughout the switching cycle. such operation can be achieved by selection of the induc - tance. led current the hv9801a regulates the led current with an accuracy far superior to that of competing peak current mode control- lers. average led current is set by the current sense resistor rcs and the current regulator reference voltage : 9 ,5 p9 , / 5 rcs ) for example, a 2 resistor correponds to a 125ma (aver - age) led current. current control performance the control method of the hv9801a virtually eliminates the regulation errors associated with peak current mode control - lers, such as errors caused by: inductor tolerance; propa - gation delay of the current sense comparator; tolerance in the oscillator frequency or off-timer; and changes in line and load voltage. fig. 1 compares the load regulation of the hv9801a and that of a device with peak current control. the difference in load regulation between the hv9801a and the hv9910b, a peak current regulator, is clearly visible. fig.1. typical output characteristic of the hv9801a led driver. 0.60 0.55 0.50 0.45 0.40 0.35 0.30 0.25 0 10 20 30 40 50 60 hv9910b hv9801a v in = 170vdc output v oltage, v led current, a output characteristics supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
5 hv9801a duty cycle, off-time, on-time, inductor duty cycle the duty cycle (d) is related to the load voltage (v led ) and input voltage (v bus ) by the simple relation: v out in ) v /( bus ) off-time the hv9801a employs constant off-time control. operation with constant off-time suppresses subharmonic oscillation. switching period and switching frequency are related to on- time and off-time as follows: t sw = (t on + t off ) f sw = 1 / t sw on-time is related to off-time and duty cycle as follows: 7 on ) / (t on + t off ) with a given t off , the hv9801a dynamically adjusts t on to regulate the led current. specifcally, t on adapts to the duty cycle associated with given v bus and v led . off-time programming off -time is programmed by the r t resistor: t off 5 rt ) + b where a = 40ps / and b = 300ns for instance, a 200k resistor corresponds to 8.3s off-time. an acceptable range for rt is 30k to 1m, corresponding to an off-time range between 1.5s and 40.3s. inductor the converter should operate in continuous conduction mode. as such, the inductor current should not fall to zero within a switching cycle, and inductor current ripple should be sized accordingly. a common choice for peak-to-peak inductor current ripple (ppr) is 30 to 40% of nominal led current. inductance can be calculated from the current drop during off-time: /, 97 /5, / ) = (v /( off ) for instance, 30% ppr on 350ma average current equates to 105ma ripple, which together with 5s off-time, and 30v led string voltage corresponds to 1.43mh inductance. a design with 30v led voltage and with 150v bus voltage corresponds to 20% duty cycle; respectively, with a 120v bus voltage to 25% duty cycle. 20% duty cycle corresponds to 1.25s on-time, 25% duty cycle corresponds to 1.67s. hence, the switching frequency is 167khz at 150v bus volt - age and 150khz at 120v bus voltage. maximum duty cycle duty cycle should be limited to the specifed maximum (80%). accordingly, the led string voltage and the bus volt - age are limited to the same ratio. operation at a larger duty cycle results in an led current lower than programmed. minimum duty cycle duty cycle is limited on the low side by the minimum on-time specifcation (760ns). operation at a smaller on-time causes the led current to exceed the programmed value. led string voltage can not be made arbitrarily low. minimum led voltage can be determined from the following: min = (t onx ) / (t off + t onx ) v /( min bus ) for instance, with 5s off-time, the duty cycle should be kept above 13%. such a duty cycle corresponds to an led string voltage of 19.5v at 150v bus voltage. a design requiring a lower led string voltage requires change to a longer off-time. short circuit protection a rise of the led current sense signal above 440mv (176% of nominal) trips the short circuit comparator thereby caus - ing the converter to switch to hiccup mode. in hiccup mode, off-time is lengthened to about 750s to allow the inductor current to drop to a safe level. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
6 hv9801a without the extended off-time the inductor current increases with every switching cycle, thereby causing over-current damage to the converter. the extension of the off-time can be observed in fig.2: fig.2. short-circuit inductor current. leading edge blanking the mosfet drain current, and thereby the current sense signal, exhibits a spike at the start of a switching cycle which arises from the mosfet gate charging current and the current required for discharge of the mosfet drain node. these two currents typically exceed the inductor by quite a margin. the current sense signal is blanked at the start of the switch - ing cycle in order to avoid a premature trigger of the current sense and the short circuit protection comparators. vdd regulator the vdd regulator generates a source of regulated voltage for operation of internal and external circuits from the power applied at the vin pin. alternatively, the vdd voltage can be supplied from a source directly connected to the vdd pin. the vdd regulator will turn off. switch dimming general lamp brightness can be adjusted to one of four discrete lev - els by rapidly cycling power with the light switch. the bright - ness levels are traversed in an up and down manner, the levels being 100%, 50%, 25% and 12.5%. brightness re - sumes at the highest level when power is removed for more than a second. reduction of led current is accomplished through pwm dimming with a pwm dimming frequency of about 1khz. the pwm frequency is generated by an internal oscillator and the duty cycle by means of digital logic. turning the light switch off and on within one second ad - justs led current to the next higher or lower level, see the illustration below. the sequence starts at 100% and adjusts to a lower level with the following step. upon reaching the highest or lowest level the direction of the sequence revers - es. when power is removed for more than one second, the dimming sequence is terminated and brightness is reset to 100% upon turn-on of the light switch. vdd capacitor the vdd voltage should be maintained for at least one sec- ond and above the 3.5v level after loss of vin power to allow certain timing circuits to function. the minimum required capacitance can be calculated from: 9 ,7 (c , ; v with 700a of i vddx the bypass capacitance should be 175f. detection of power cycling the presence of ac line power is detected at the vin pin. to this end, loss of ac power should result in a rapidly falling voltage at the output of the bridge rectifer. the v vin voltage drops due to the current draw from the v dd regulator. in order to facilitate a quick fall of the voltage, a diode should be added to isolate the bus capacitor from the vin pin as shown in the typical application circuit. fig.3. led brightness and ac line power. ~750s 440mv /r cs s on/off cycle time 1second (max.) 100% 50% 25%1 2.5% 25% 100% brightness ac line power on supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
7 hv9801a pin description pin # function description 8-lead soic 16-lead soic 1 1 vin connect to bridge rectifer output. supplies power to the vdd regulator . detects light switch power-off event through loss of bridge rectifer output voltage. do not connect excessive capacitance before or after the bridge so as to allow v in to drop rapidly after loss of power. 2 4 cs current sense input. 3 5 gnd ground. 4 8 gate gate driver output. 6 12 vdd vdd regulator output. connect a high frequency bypass and a hold-up capacitor at vdd. bypass capacitor to be 100nf minimum. see applications section for hold-up capacitance. 8 14 rt off-time programming input. connect programming resistor to gnd. 5, 7 2, 3, 6, 7, 9, 10, 11, 13, 15, 16 dnc caution! dnc means do not connect! supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
8 hv9801a 8-lead soic (narrow body) package outline (lg) 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 pp min bsc ref bsc 0 o 5 o nom - - - - - - - - max 8 o 15 o -5hjlvwudwlr069duldwlr,vvxh6hsw 7klvglphvlrlvrwvshflhglwkh-gudlj drawings are not to scale. supertex doc. #: 3279, note: 1. vfpihuihwxuhvrswroghwhupxvwhorfwhgwhghuhgfwhghghwhufhproghgpunghwhu an embedded metal marker; or a printed indicator. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
9 hv9801a (the package drawing(s) in this data sheet may not refect the most current specifcations. for the latest package outline information go to http://www.supertex.com/packaging.html .) doc.# dsfp-hv9801a a122111 16-lead soic (narrow body) package outline (ng) 9.90x3.90mm body, 1.75mm height (max), 1.27mm pitch symbol a a1 a2 b d e e1 e h l l1 l2 dimension pp min bsc ref bsc 0 o 5 o nom - - - - - - - - max 8 o 15 o jedec registration ms-012, variation ac, issue e, sept. 2005. * this dimension is not specifed in the jedec drawing. drawings are not to scale. supertex doc. #: dspd-16song, version g041309. d seating plane gauge plane l l1 l2 to p v iew side v iew vi ew a-a vi ew b vi ew b 1 e1 e a a2 a1 a a seating plane e b h h 16 1 note 1 note 1 (index area d/2 x e1/2) note: 1. this chamfer feature is optional. if it is not present, then a pin 1 identifer must be located in the index area indicated. the pin 1 identifer can be: a molded mark/identifer; an embedded metal marker; or a printed indicator . 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) ?201 1 supertex inc. a ll rights reserved. unauthorized use or reproduction is prohibited. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
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