rev. 1.00 1 june 26, 2015 rev. 1.00 pb june 26, 2015 HT7L4813 non-isolation buck led lighting driver with active pfc features ? non-isolation buck topology ? integrated 500v mosfet ? wide ac input range C from 85vac to 265vac ? high power factor of >0.9 without additional circuitry ? accurate constant current (< 3%) ? low start-up current reduces power dissipation ? full protection functions for enhanced safety: ? gate driver output voltage clamp ? vcc over voltage protection C vcc ovp ? vcc under-voltage lockout with hysteresis C vcc uvlo ? output led string over current protection ? output led string short protection ? output led string open protection ? on-chip over temperature protection C otp ? package: 8-pin sop applications ? general illumination ? e26/27, t5/t8 led lamps ? other led lighting applications general description the HT7L4813 is a non-isolation buck pwm controller fo r l ed l ighting a pplications. t he de vice has a fully integrated pfc circuit which operates in a boundary conduction mode (bcm) to achieve high power factor values. a high voltage power mosfet s is integrated in the device. w ith full control provided over the internal mosfet s, the device can easily meet the exacting led current and high power factor requirements. the device provides several protection functions, which include vcc under v oltage lockout (uvlo), over current prot ection (ocp), out put l ed string open protection, output led string short protection, vcc over v oltage protection (ovp) and leading-edge bl anking (l eb) for c urrent se nsing. additionally and to ensure system reliability , the device i ncludes a fu lly i ntegrated t hermal p rotection function. the high level of functional integra tion minimises the external component count giving major advantages in terms of cost and circuit board area. the device is supplied in a 8-pin sop package. block diagram cs 7,8 drain 5,6 ea driver logic control 0.2v 2 pwm generator leb ocp zcd ovp otp uvlo vcc reference & bias min off time vcc ovp zcd comparator ocp otp starter otp ocp 4 3 1 zcd comp vss
rev. 1.00 2 june 26, 2015 HT7L4813 pin assignment HT7L4813 8 sop-a cs cs drain drain vss comp vcc zcd 1 2 3 4 8 7 6 5 pin description pin no. symbol description 1 vss ground pin. 2 comp loop compensation pin. a capacitor is placed between comp and gnd. 3 vcc power supply pin. 4 zcd zero-current detect pin. 5, 6 drain internal high voltage power mosfet drain terminals. 7, 8 cs current sense pin. a resistor is connected to sense the mosfet current. absolute maximum ratings parameter range internal mosfet drain source voltage -0.3v to 500v vcc supply voltage -0.3v to 33v cs pin input voltage -0.3v to 6v comp pin output voltage -0.3v to 6v zcd pin maximum current 3ma (source), 3ma (sink) maximum operating junction temperature 150c storage temperature range -55c to 150c recommended operating ranges parameter range vcc supply voltage 17v~25v operating junction temperature -40c~125c output power 12.5w@150ma, 90~264vac 17.6w@150ma,180~264vac
rev. 1.00 3 june 26, 2015 HT7L4813 electrical characteristics v cc =18v, ta=25c symbol parameter test condition min typ max unit power supply (vcc pin) vcc on uvlo on 18 v vcc off uvlo off 10 v vcc hys uvlo hysteresis 7 v v ovp vcc ovp trip point 26 29 32 v i start start-up current before turn-on, @ vcc=uvlo on - 1v 10 20 a i q quiescent current no switching 0.6 1.0 ma error amplifer v fb feedback reference voltage t a=25c 194 200 206 mv current sense comparator t leb leading edge blanking time 400 ns v cl current limit threshold 1.1 v v ocp over current trip point 0.9 v over current release point 0.2 v zero current detector v zcdh upper clamp voltage i zcd =300a 3 v v zcdl lower clamp voltage i zcd =-2.5ma -0.2 v v zcda positive-going edge 1.5 v v zcdt negative-going edge 1 v i ovp ovp current on zcd pin 270 300 330 a t b_ovp blanking time for ovp detection 1 s starter t start start timer period 40 s t off minimum off time 4 s over t emperature protection otp over temperature trip point 150 c power mosfet r ds power mosfet switch on resistance @ v gs =10v , i ds =0.5a 6 bv dss power mosfet drain-source voltage @ v gs =0v , i ds <250a 500 v
rev. 1.00 4 june 26, 2015 HT7L4813 4 6 8 10 12 14 16 -40 -20 0 20 40 60 80 100 120 temperature ( ) start up current (ua) figure 1. start-up current vs. temperature 1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2 -40 -20 0 20 40 60 80 100 120 temperature ( ) operating current (ma) figure 2. operation current vs. temperature 17 17.4 17.8 18.2 18.6 19 -40 -20 0 20 40 60 80 100 120 temperature ( ) uvlo_on(v) figure 3. uvlo_on vs. temperature 9 9.4 9.8 10.2 10.6 11 -40 -20 0 20 40 60 80 100 120 temperature ( ) uvlo_off(v) figure 4. uvlo_off vs. temperature 198 198.5 199 199.5 200 200.5 201 -40 -20 0 20 40 60 80 100 120 temperature ( ) vfb (mv) figure 5. vfb vs. temperature figure 6. temperature vs. wide ac voltage typical performance characteristics
rev. 1.00 5 june 26, 2015 HT7L4813 figure 7. effciency vs. wide ac voltage figure 8. temperature vs. high ac voltage figure 9. effciency vs. high ac voltage typical application circuit cs 5 2 3 6 HT7L4813 4 1 7 8 cs zcd vss comp vcc drain drain 90vac~265vac led+ led-
rev. 1.00 6 june 26, 2015 HT7L4813 HT7L4813 preliminary functional description the HT7L4813 is a universal ac/dc led driver designed for led lighting applications. the device can achieve high power factor values without resorting to additional circuits and can also generate high accuracy led drive currents with very few external components. separate grounds are provided. one is a foating ground for the device while the other is the earth terminal. users should be aware that the two grounds cannot be directly connected together to avoid ic damage and system malfunction. start-up current a very low start-up current, i start , allows the users to select a larger value of start-up resistor which reduces power dissipation. vcc under voltage lockout C uvlo the device includes a uvlo feature which has 8v hysteresis. the pwm controller turns on when vcc is higher than 18v and turns off when vcc is lower than 10v. the hysteresis characteristics guarantee that the device can be powered by an input capacitor during start-up. when the output voltage increases to a certain value after start-up, vcc will be charged by an output through an auxiliary winding or a zener diode. v z =v led - v cc . boundary conduction mode C bcm the power mosfet is turned on by inductor current zero-crossing detection. the current zero-crossing can be detected by a zcd voltage. when the inductor current is at the zero crossing point, the voltage on the zcd pin will drop rapidly. the device then detects the falling edge and turns on the internal power mosfet. the boundary conduction mode provides for low turn-on switching losses and high conversion effciency. zero current detection C zcd the zcd voltage is designed to operate between 0v and 3v for normal operation. if the voltage on the zcd pin goes higher than 1.5v, the zcd comparator waits until the voltage goes below 1v. when the inductor current is at the zero crossing point, the voltage on the zcd pin will drop rapidly. the device will then detect the 1v falling edge and turn on the power mosfet. the 0.5v hysteresis avoids any false triggering actions due to noise. constant current control the HT7L4813 will sense the overall inductor current and form a closed-loop with an internal error amplifier to obtain high constant current accuracy. the cs voltage and the 0.2v reference voltage form the inputs to an internal gm amplifer whose output is integrated via an external comp capacitor. the on time of the mosfet is controlled by the comp voltage to adjust the output current. leb on cs C leading-edge blanking each time the internal power mosfet is switched on, a turn-on spike will inevitably occur at the sense resistor. to avoid faulty triggering, a 400ns leading- edge blank time is generated. as this function is provided conventional rc filtering is therefore unnecessary. during this blanking period, the current- limit comparator is disabled and can therefore not switch off the gate driver. ovp on vcc C over voltage protection in order to prevent pwm controller damage, the device includes an ovp function on vcc. should the vcc voltage be higher than the ovp threshold voltage of 29v, the pwm controller will stop operating immediately. when the vcc voltage decreases below the uvlo off level, the controller will reset. led open protection C zcd ovp the led voltage is reflected on the zcd pin through a resistor rzcd. when the current on the resistor rzcd is higher than 300a, then zcd ovp protection will take place. here the pwm controller will stop operating immediately. when the vcc voltage decreases below the uvlo off level, the controller will reset. v ovp-zcd can be set using the following equation : v ovp-zcd = v zcdh +i ovp r zcd v zcdh is the 3v upper clamp voltage on the zcd pin. i ovp represents the ovp current level on the zcd pin which is 300a. r zcd stands for the resistor con - nected between the zcd pin and the led positive terminal.
rev. 1.00 7 june 26, 2015 HT7L4813 ocp C over current protection the device includes an over current protection function on the cs pin. an internal circuit detects the current level and when the current is lar ger than the over current protection threshold level, v ocp /r cs , the gate output will remain at a low level. led short protection C scp the output voltage drops when a number of leds in a st ring a re sho rted re sulting i n a vol tage drop a t vcc. onc e t he vcc drops be low 10v , t he de vice will stop operating. under such situations, the start-up operation will rechar ge the vcc pin through the start- up resistor and the device will enter the uvlo hiccup mode. thermal protection a t hermal p rotection f eature i s i ncluded t o p rotect the device from excessive heat damage. when the junction temperature exceeds a threshold of 150c, the t hermal prot ection func tion wi ll t urn of f t he drain terminal immediately . when the vcc decreases be low t he uvl o of f l evel, t he c ontroller will reset.
rev. 1.00 8 june 26, 2015 HT7L4813 package information note that the package information provided here is for consultation purposes only. as this information may be updated at regular intervals users are reminded to consult the holtek website for the latest version of the package/ carton information . additional supplementary information with regard to packaging is listed below. click on the relevant section to be transferred to the relevant website page. ? package information (include outline dimensions, product tape and reel specifcations) ? the operation instruction of packing materials ? carton information
rev. 1.00 9 june 26, 2015 HT7L4813 8-pin sop (150mil) outline dimensions symbol dimensions in inch min. nom. max. a 0.236 bsc b 0.154 bsc c 0.012 0.020 c 0.193 bsc d 0.069 e 0.050 bsc f 0.004 0.010 g 0.016 0.050 h 0.004 0.010 0 8 symbol dimensions in mm min. nom. max. a 6.00 bsc b 3.90 bsc c 0.31 0.51 c 4.90 bsc d 1.75 e 1.27 bsc f 0.10 0.25 g 0.40 1.27 h 0.10 0.25 0 8
rev. 1.00 10 june 26, 2015 HT7L4813 copyright ? 2015 by holtek semiconductor inc. the information appearing in this data sheet is believed to be accurate at the time of publication. however, holtek assumes no responsibility arising from the use of the specifcations described. the applications mentioned herein are used solely for the purpose of illustration and holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. holtek's products are not authorized for use as critical components in life support devices or systems. holtek reserves the right to alter its products without prior notifcation. for the most up-to-date information, please visit our web site at http://www.holtek.com.tw.
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