analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 1 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems features ? 11 v to 48 0v input voltage range . ? over 95 % efficiency . ? drives from 1 to hundreds of leds in serial and parallel combinations . ? constant led drive current . ? linear or pwm luminance dimming control . ? light sense and motion detection inputs to control the led s . ? resistor programmable oscillator frequency . ? qfn - 16 rohs compliant package . applications ? general illumination displays ? industrial and decorative led lighting . ? automotive applications. ? dc/dc or ac/dc led driver applications. ? constant current s ource. ? smps switching controller. ? led back lighting. ? security, street and parking garage lighting . general description the PA5711 is a high - efficiency led driver with multiple dimming options that include pulse w idth m odulation (pwm), linear dimming (ld ), motion detection (md) and light sense (ls) inputs. PA5711 features a direct gate driver control through an active high enable pin. it has an internal oscillator whose frequency can be set externally through a resistor . the PA5711 in fly - back mode can b e used as a current controlled led driver (isolated), driving an led load at fixed current from a few ma to over 1.4a. the PA5711 allows the users to introduce the lead ing edge blanking upon their desired delay requirements, also this can be used to contr ol the duty cycle of the driver. the ld pin allows the users to set the threshold beneath the pre - set 2 8 0mv, for smaller duty cycle and reduced dissipation across the cs resistors. the PA5711 has a pwm dimming option that through an externally programmed control signal, with duty ratio 0 - 100% and a frequency of a few kilo - hertz, can control the led brightness. PA5711 block diagram ordering information temperature range package part number - 40 to 85 c qfn - 16 PA5711 - t7 v in v dd r ext cs ld voltage regulator + + - - 280mv pwm md ls en pwm controller oscillator r osc gate gnd gate driver figure 1. block diagram www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 2 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 1. specifications 1.1 absolute maximum rating 1. 2 pin description p i n # na m e function 1 nc no connect 2 n c no co n ne c t 3 nc no connect 4 v in supply voltage 11v - 48 0v 5 r ext pin for c urrent limit ing resistor between v in and r ext. 6 r osc re sis t or t o g r ound se t s the oscil l a t or frequency. 7 md motion detection signal input; connect to v dd when unused. 8 ls light sense signal input; connect to gnd when unused. 9 en gate driver enable. connect to v dd to enable the gate driver output. 10 pwm pwm input to control the gate output. connect to v dd when unused 11 v dd 5v regulated supply voltage output . requ i res a storage capacitor to gro u nd. external voltage source can be connected to power the chip 12 ld linear dim m ing. used to reduce the thresh old voltage lower t h an the intern a l 28 0 m v . connect to vdd when unused 13 cs led c u r r e n t s en s e in p u t . 14 gnd chip ground 15 gate gate driver output 16 v dd 5v regulated supply voltage output parameter symbol max unit input voltage v in - 0.5 to 500 v input and output voltage to gnd cs, ld, pwm, md, en, gate - 0.3 to v dd +0.3 v v dd , externally applied vdd - ext 8 v power dissipa tion p d 3.45 w maximum junction temperature t jmax 168 c operating temperature ta - 40 to +85 c junction temperature (operating) t j - 40 to+150 c thermal resistance junction to ambient ? ja 12 c /w storage temper ature t stg - 55 to +150 c v in 1. 3 pin configuration gnd pwm nc nc nc en v dd ld r ext r osc 1 2 3 4 ls 5 6 7 8 md 9 10 11 12 13 14 15 16 PA5711 cs v dd gate note: continuous operation at or beyond these condition s may permanent ly damage the device. top view of the PA5711 www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 3 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 1.4 electrical specifications p arameter symbol min typ ical* max units conditions in pu t d c v oltage range v i ndc 1 1 48 0 v dc i np u t v o l tage into the v in pin shu t - d o wn mode supply cur r e n t i i nsd 1. 3 1.87 ma en t o gn d v dd = 5 r osc = 1m ? intern a l dc v o l t a g e regu l a t or v dd 5 v v i n =15~ 45 0 v , i d d ( e x t ) = 0 , g a t e ou t pu t o p en maxim u m v ol t a g e t o v d d pin v dd m ax 7 v e x tern a l v o l t age appl i e d t o v dd pin v d d current available f or e x tern a l circu i t ry i d d ( e x t ) 1.0 ma limit e d by packa g e p o wer dissip a t i on p w m pull - d o wn resis t ance r en 55 70 72 k ? v pwm = 5v cur r e n t s e ns e th r e sh o l d v ol t a g e v c s ( h i gh) 272 2 80 304 m v t=25 ? c g a te high o u tp u t v ol t a g e v g a t e ( h i g h ) v dd - 0 . 2 v dd v i ou t =10ma vin =20v g a te low ou tp u t v ol t a g e v g a t e ( l ow) 0 0.2 v i ou t = - 10ma vin =20v oscil l a t or fr e q u e ncy f osc 196 200 204 khz r osc = 150 k ? 3 2 34 35 khz r osc = 1 m ? o scill a t or p w m d u t y cy c l e d 0 100 % external voltage provided to pwm linear dimming v ol t age range v ld 0 250 mv external voltage provided to the ld pin. delay f r o m cs trip to gate l ow t del a y 22.9 24.8 ns gate ou tput rise time t r i se 2 5 ns gate ou tput fall time t f a ll 20 ns quiescent current i q 1.4 1.5 1.6 ma no load, v dd = 5 pin ls input low v ls(lo) 63 5 mv v dd = 5 pin ls input high v ls(hi) 63 0 mv v dd = 5 pin en input low v en(lo) 2.28 mv v dd = 5 pin en input high v en(hi) 2.85 mv v dd = 5 pin md input low v md(lo) 2.38 mv v dd = 5 pin md input high v md ( hi ) 2.55 mv v dd = 5 pin pwm input low v pwm (lo) 2.24 mv v dd = 5 pin pwm input high v pwm (hi) 2.66 mv v dd = 5 *typical values should not be used for specification limits. ta=25 c unless otherwise specified www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 4 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 2. functional description 2.1 overview the PA5711 is a high efficiency, low cost, off - line led driver with multiple inputs for controlling the led under various environm ental conditions. the PA5711 driver utilizes a high voltage process for a broad input voltage range. this flexibilit y allows for wide range of operation from 11v to 480v dc . this enables the PA5711 to drive the applications such as decorative lighting, sig nage and rgb back lighting. the PA5711 in the buck topology (as shown above in fig.2 ) is a common choice to use the controller in non isolated led lighting. the PA5711 can drive multiple leds in a string or in parallel. this set up provides a good effici ency and constant current drive with minimal external components. the leds can be dimmed using voltage 0 - 2 5 0mv on the ld pin or by a low frequency on the pwm. to save energy by turning the leds off, t he leds can also be controlled via external signals to md, ls, and en pins . the sense resistor at cs controls the peak current thru the led string. 11 to 48 0 v 500450v fig ure 2. a t ypical application circuit r cs v in v dd r ext cs ld voltage regulator + + - - 280mv pwm md ls en pwm controller oscillator r osc gate gnd gate driver www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 5 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 2.2 led driver - theory of operation the gates of pwm, en, md, and ld are enabled when they are connected to the vdd pin. the ls must be connected to gnd. i n such a configuration the led current is solely controlled by the cs resistor. each positive edge of the oscillator turns the gate driver output high , turning on the external mosfet . this ramps the inductor current and increases the voltage drop across th e cs resistor. when this drop exceeds v cs , the gate driver output is low. this turns off the mosfet decay ing the inductor current until the next positive edge of the clock cycle. the current threshold limit is set b y comparing the voltage developed across r cs to v cs , which is 2 8 0mv for the PA5711.this default threshold level can be reduced applying a voltage lower than v cs at the ld pin. the lower of these two thresholds limits the peak current in the induc tor . 2. 2 . 1 voltage regulator the PA5711 has an internal voltage regulator that can regulate 11v to 480v input voltage , with an appropriate current limiting resistor at r ext , down to 5v . the v dd pin needs to have a holding cap of 22f to provide filtering against bounces and a 0.1f to by pass any high frequency switching noise. the PA5711 v dd pin c an supply 1ma for external circuitry. the internal voltage regulator can be bypassed by providing a voltage higher than internal v dd . this feature reduces the power dissipation and can be implemented in an ap plication where an auxiliary supply can power to the PA5711 . the total input current from the v in supply is a sum of the quiescent current of the PA5711 , which is about 1.87ma and the gate driver current. the gate driver current is dependent on the gate c harge of the external mosfet and switching frequency . this input current approximation can be done by using the following equation: i in 1.87ma + (q gate * f s ) where q gate is the total gate charge of the external mosfet. 2.2.2 current sense resistor the peak led current is set by the external sense resistor connected from the cs pin to ground. the value of this resistor is determined by the average led current, the inductor ripple current and the internal threshold voltage. the inductor is selected to keep the inductor ripp le current less than 30% of the average led current.the dissipation across this resistor is given by the formula : p = r cs * i led 2 it is a safe practice to select the resistor with atleast twice the power rating that is calculated. 2.2.3 current sense blanking the PA5711 has no internal current sense blanking circuit. this allows the user to choose and introduce the right time delay that fits the application. the user can add a rc delay network on the cs path i.e. between the r cs and the cs pin. a time delay approximation can be made using : 2.2.4 enable / disable the enable pin (en) of the PA5711 is active high. if this pin is grounded then the driver is disabled and chip will consume minimal current. the gate driver is disabled and th e leds cannot be driven during this period. for normal operation the enable pin must be connected high. r ext in k ? v in range in volts 10 11 - 50 20 30 - 100 100 75 - 200 330 175 - 300 560 290 - 400 750 400 - 480 ? = 5*r*c where r and c are the delay elements volt age across r cs gate driver output figure 3. PA5711 waveforms an indicative table to choose the approximate val ue of r ext depending on v in www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 6 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 2.2. 5 linear dimming the PA5711 comes with a linear dimming function which is one of the four different ways the led can be controlled. while v cs is the maximum threshold against which the current sense resistor voltage drop is compared against, the ld pin can be used to reduce this threshold. an external resistive divider setup will allow the user to adjust the led light intensity. the r cs vo ltage drop is compared against the lower of these two voltages. hence decreasing the voltage provided at ld below 250mv would reduce the intensity of the led light. this allows the user to choose from available resistors rather than calculating the resisto r value in accordance with the internal threshold. since a voltage lowe r than the internal threshold can enable linear dimming it is advisable to connect ld to v dd wh en linear dimming is not required. a soft start f unction can be implemented on the pa571 1 by using rc network to slowly ramp the voltage applied to the ld pin from gnd potential to over 300mv, at which the v cs overrides the linear dimming function. the ld pin can also be used as a feed back to the c hip , especially in an isolated driver application , a feedback from the isolated portion can be applied to the ld pin to achieve greater control over the calculate current drive. 2.2. 6 pwm dimming pulse width modulation dimming or pwm dimming can be implemented on the PA5711 by using a low frequency square wave signal to drive the pwm pin. the square wave frequency can be in the range of a few hundred hertz. in this setup the pwm wave will be directly driving the output of the gate driver. pwm signals can be generated using a microcon troller or pulse generators. the duty cycle of the input pwm is directly proportional to the intensity of led light. if the pwm input is driven low the leds are turned off. 2.2. 7 light sense the PA5711 has a light sense input to accept signal from an ex ternal light sensor. the leds are turned on/off dependent on the signal from the light sensors. this pin must be connected to ground if not used. 2.2.8 motion detection the PA5711 has a motion detection input. an external motion detector can drive this pin to turn the leds on/off. this pin needs to be connected to vdd when not used. 2.2. 9 gate driver the PA5711 can dr ive external mo sfets with a gate capacitance of up to 600pf. 2.2. 10 oscillator the PA5711 operates at a constant frequency. the extern al resistor r osc determines the oscillator frequency. the inductor size, total chip power dissipation and filter capacitors are the basis on which the switching frequency is decided. the internal oscillator has a 20 % frequency accuracy. in a non - isolated mode the driver switching frequency is between 30 khz and 200khz. this large operating range gives the designer a reasonable compromise between switching frequency and inductor size. v dd ld r 1 r 2 c figure 4 . soft - start rc arrangement figure 5 . frequency variation across r osc www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 7 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems 2.2. 11 inductor design the led ripple current along with fact ors such as maximum t on , minimum input voltage and total forward voltage drop across the leds (v f ) at the desired average led current decide the value of the inductor. the minimum voltage is dependent on the specific application and the maximum t on is de termined by the duty cycle and the switching frequency. the maximum duty cycle - d max is given by : the maximum duty cycle must be maintained below 50% to maintain open loop stability and sub harmonic oscillations . the maximum on - time can be calculated as follows: the size of the inductor can be calculated using the equation : the peak inductor current is given by : 2 i lmax = i led * [1+ ] v ledstring v in d max = where v ledstring is the desired forward voltage drop across led string at the designed led current v in is the minimum input voltage d max f s t onmax = where f s is the switching frequency t onmax * (v in C v ledstring ) i led * l min = where is the inductor ripple www.datasheet.co.kr datasheet pdf - http://www..net/
analog products division 2929 south fair lane, tempe tel: ( 602 ) 431 - 8101 . fax: ( 602 ) 431 - 2288 8 www.protek devices .com PA5711 high voltage led driver rev. 0 . 03/12 not for use in life support systems qfn - 16 pad layout min typical max mm in mm in mm in a 4.30 0.169 4.35 0.171 4.40 0.173 b 2.85 0.112 2.90 0.114 2.95 0.116 c 2.10 0.083 2.15 0.085 2.20 0.0866 d 0.67 0.026 0.72 0.028 0.77 0. 030 e 0.25 0.010 0.30 0.012 0.35 0.014 f 0.65 0.026 tape and reel specifications reel dia a0 b0 k0 d e f w p0 p2 p t - max 178 (7) 4.1 0.05 4.1 0.05 0.800.05 1.500.10 1.750.10 3.500.05 12.000.30 4.000.10 2.000.05 4.000.10 0.25 q f n - 1 6 d im en s i ons m i n t y p i c a l m a x mm in m m in mm in a 0 . 7 0 0 . 028 0 . 75 0 . 030 0 . 8 0 . 031 b 3 . 925 0 . 155 4 . 00 0 . 157 4 . 075 0 . 160 c 3 . 925 0 . 155 4 . 00 0 . 157 4 . 075 0 . 160 d 2 . 2 5 0 . 089 2 . 30 0 . 091 2 . 35 0 . 093 e 2 . 2 5 0 . 089 2 . 30 0 . 091 2 . 35 0 . 093 f 0 . 6 5 0 . 026 0 . 000 g 0 . 3 5 0 . 014 0 . 55 0 . 022 0 . 75 0 . 030 h 0 . 2 0 0 . 008 0 . 000 j 0 . 2 5 0 . 010 0 . 30 0 . 012 0 . 35 0 . 014 p0 p2 d a0 b0 p e f w pin 1 indicated by dot k0 top cover tape t 10 pitches cumulative tolerance on tape 0.2 711 711 711 a c h j b d e f g a b c d e f 3. qfn - 16 package dimensions and layout www.datasheet.co.kr datasheet pdf - http://www..net/
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