unisonic technologies co., ltd L5107 preliminary linear integrated circuit www.unisonic.com.tw 1 of 9 copyright ? 2013 unisonic technologies co., ltd qw-r125-026.a constant cuttent boost controller for driving high power leds ? description the utc L5107 is a high powered pwm boost converter optimized for constant current app lications such as driving one or more strings of high power leds. the powerful drive circuitry can deliver up to 70w to the led system. the output current can be set by an external resistor connected the iadj pin and gnd. this average current can be reduced by applying a pwm signal to the pwmd pin. the utc L5107 offers a dither feature to reduce emi. the utc L5107 has a large input voltage range from 6v to 45v and the switching frequency can be set by an external resistor between 100khz and 1mhz for diffident led systems. to protect the device over volt age protection circuit and under voltage lock-out circuit have been incorporated as well as thermal shutdown circuit. the utc L5107 is available in the htssop 16-pin tssop package. ? features * input voltage range: 6v~45v * feedback voltage: 0.25v3% * maximum out power of 70w * programmable switching frequency and led drive current * ultra low emi via dithering on the utc L5107 * single pin for pwm dimming * protection circuit: over voltage protection circuit over temperature protection circuit under-voltage lock-out circuit * accurate over the -40~125c temperature range ? ordering information ordering number package packing lead free halogen free L5107l-p16-t L5107g-p16-t tssop-16 tube L5107l-p16-r L5107g-p16-r tssop-16 tape reel note: xx: output voltage, refer to marki ng information.
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 2 of 9 www.unisonic.com.tw qw-r125-026.a ? pin configuration ? pin description pin no. pin name description 1 nc no connection. 2 v in power input pin. the external voltage suppl y is connected to this pin. a 4.7f/50v capacitor must be connected across this pin and gnd. 3 en enable control pin. pull high to turn on. a 100k ? resistor can be connected across this pin and vin. 4 pwmd dimming pwm control pin. logic high terminates the output power. logic low starts up the output power. 5 comp error amp output pin. a 10nf capacitor must be connected across this pin and gnd for external compensation. 6 iadj output feedback pin. the reference is 0.25v. 7 fs timing resistance connection pin. connected to a resistor to determine the operating frequency. 8 agnd analog ground. 9 nc no connection. 10 sync frequency synchronize pin. the utc L5107 can be connected together by this pin to synchronize multiple converters. 11 is current sense pin. connected to external current sense resistor which in turn is connected to the source of the external fet as well as an external slope compensation resistor. 12 ovp ovp divider connect pin. connect the top of the divider string to the output. if the load is disconnected, the output voltage will rise until ovp reaches 1.25v and then will regulate around this point. 13 pgnd power ground. 14 drv drive output. connect to the gate of external fet. 15 v dd vdd filter connect pin. connect a 10 f/10v capacitor to gnd. it is also the positive supply for the driver. do not connect an external load to this pin. 16 nc no connect. epad connect to agnd.
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 3 of 9 www.unisonic.com.tw qw-r125-026.a ? block diagram ldo v in 0.25v v in en pwnd comp c comp iadj fs r fs err enable pwmcontrol q1 d1 led0 led1 led2 1.2v ovp v dd drv pgnd drv ovp r cs is r scl sync c out osc/ramp osc ramp l1 r adj c in
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 4 of 9 www.unisonic.com.tw qw-r125-026.a ? absolute maximum rating(note 1) parameter symbol ratings unit supply voltage v in +48 v enable pin voltage v en -0.3~+6 v iadj voltage v adj +6 v storage temperature t s -65~+150 c note: absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? thermal data(note 3) parameter package symbol ratings unit junction thermal resistance ja 36.5 /w ? operating ratings(note 3) parameter symbol ratings unit supply voltage v in +6~+45 v junction temperature t j -40~+125 c
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 5 of 9 www.unisonic.com.tw qw-r125-026.a ? electrical characteristics(note 4) (v in =12v, v en =3.6v, l=47h, c=4.7f, t j =25c, bold values indicate -40c t j +125c, unless noted) parameter symbol test conditions min typ max unit supply voltage range v in 6 45 v under voltage lockout uvlo 3.5 4.9 5.5 v quiescent current i vin v fb >275mv (to ensure device is not switching) 3.2 10 ma shutdown current i sd v en =0v 30 a feedback voltage (at iadj) v iadj room temperature (3%) 242.5 250 257.5 mv -40c t j +125c (5%) 237.5 250 262.5 mv feedback input current i adj v fb =250mv 1.2 3 a line regulation s v v in =12v~24v 2 % load regulation s i v out to 2v out 2 % maximum duty cycle d max 88 % enable threshold v en turn on 1.15 1.5 v turn off 0.4 1.1 enable pin current i en v en =3.3v, ren=100k ? 17 30 a pwmd threshold v pwm turn on 0.75 1.5 v turn off 0.4 0.7 pwmd frequency range f pwmd l=47 h, c=4.7 f (note 5) 0 500 hz programmable oscillator frequency f sw r ereq =82.5k ? 109 khz r ereq =21k ? 360 400 440 r ereq =8.25k ? 950 low emi f dither frequency dither shift from nominal 12 % current limit threshold voltage v sens r sense =390 ? 0.315 0.45 0.585 v i sense peak current out i sense r sense =390 ? 250 a over voltage protection v ovp 1.203 1.24 1.277 v driver impedance r on sink 2.4 3.5 ? source 2 driver voltage high v drh v in =12v 7 9 11 v over-temperature threshold shutdown t j 150 c thermal shutdown t h hysteresis 5 c notes: 1. exceeding the absolute ma ximum rating may damage the device. 2. devices are esd sensitive. handling prec autions recommended. human body model, 1.5k ? in series with 100pf. 3. the device is not guaranteed to function outside its operating rating. 4. specification for packaged product only. 5. guaranteed by design
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 6 of 9 www.unisonic.com.tw qw-r125-026.a ? functional descriptiom the utc L5107 dc-dc converter is based on a peak current m ode pwm architecture which regulates the feedback voltage at 0.25v under normal op erating conditions. the c onstant output curr ent converter is the preferred method for driving leds. figure 2 show s the typical application schematic. the utc L5107 configured as a boost controller can allow for t he design of multiple leds in series to help maintain color and brightness. the input voltage range of the utc L5107 is very wide, from 6v to 45v. in addition, the led current and the switching frequency can be programmed to a wide range of values through the external resistors for diffident led systems. the utc L5107 can also control the brightness of the leds through its pwmd pin. ? power topology constant output current controller the utc L5107 as a peak current mode boost controller has bee n designed to provide a constant output current. in the boost configuration, the output can be set from v in up to 100v. this led driver features a built-in soft- start circuitry in order to prevent st art-up surges. other protection features include: * current limit (i limit )-current sensing for over current and overload protection * over voltage protection (o vp)-output over voltage protection to prev ent operation above a safe upper limit * under voltage lockout (uvlo)-uvlo designed to prevent operation at very low input voltages setting the led current the current through the led stri ng is set by the resistor, r adj . this value can be calculated using equation 1: eq. (1) adj led r 0.25v i ? v dd v dd is an internal linear regulator power supply for the internal circuitry of the utc L5107 . a 10 f ceramic bypass capacitor is required at the v dd pin. this pin is for filtering only and shou ld not connect an external load to this pin. soft start a soft start build in the boost switching converter is used to limit the inrush current from the line supply. the soft start delay can be set using the compensation capacitor (c comp in figure 2). a 10nf ceramic capacitor will be ok at all operating conditions. oscillator and switching frequency selection in the utc L5107 , the switching frequency can be set by choosing the appropriate value for the resistor, r fs according to equation 2: eq. (2) ?? ?? 1.035 sw fs khz f 7530 k ? r ? ? ? ? ? ? ? ? ? dithering the utc L5107 has a feature which dithers the switching frequency by 10%. the purpose of this dithering is to help achieve a spread spectrum of the conducted emi noise . this can allow for an overall reduction in noise emission by approximately 10db. led dimming the utc L5107 of led drivers can dim the brightness of the led string. a pwm input signal of up to 500hz can be applied to the pwmd pin (see figure 2) to pulse t he led string on and off. it is recommended to use pwm dimming signals above 120hz to avoid any recognizable flicker by the human eye. pwm dimming is the preferred way to dim a led in order to prevent color/wavelength shifting, as occurs with analog dimming. the output current level remains constant during each pwmd pulse.
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 7 of 9 www.unisonic.com.tw qw-r125-026.a ? power topology(cont.) output over voltage protection (ovp) the utc L5107 provides an ovp circuitry with a reference value of 1.25v in order to protect the system from an over voltage fault condition. this ovp point can be progra mmed through the use of external resistors (r1 and r2 in figure 2). this ovp voltage can be calculated using equation 3: eq. (3) 2 2 1 ovp r ) r (r 1.25 v ? ? ? current limit the utc L5107 features a current limit protection feature to prevent any current runaway conditions. the current limit circuitry monitors current on a pulse by pulse basis. it limits the current through the inductor by sensing the voltage across r cs . when 0.45v is present at the is pin, the pul se is truncated. the next pulse continues as normally until the is pin reaches 0.45v and it is truncat ed once again. this will continue until the output load is decreased. select r cs using equation 4: eq. (4) ?? pk_limit min max l sw in out cs i f l d v - v 0.45 r ? ? ? ? slope compensation the utc L5107 requires slope compensation for the peak current mode controller. the utc L5107 uses an external resistor, r slc for slope compensation. the ability to set the proper slope compensation through the use of a single external component results in design flexibility. select r slc using equation 5: eq. (5) ? ? sw cs in out slc f 250 l r v v r min max ? ? ? ? ?
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 8 of 9 www.unisonic.com.tw qw-r125-026.a ? typical application circuit
L5107 preliminary linear integrated circuit unisonic technologies co., ltd 9 of 9 www.unisonic.com.tw qw-r125-026.a utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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