bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 1 b right p ower s emiconductor co. confidential C customer use only description the bp 3319m is a high precision primary - side regulation pwm controller with single stage a ctive pfc, specially designed for universal input offline flyback or buck - boost constant current led lighting. the controller with on - chip pfc circuit achieves high power factor and low thd. operating in critical conduction mode, the power mosfet switching loss is reduced and the inductor is fully utilized. the bp 3319m adopts proprietary primary side current sensing scheme. it can precisely control the led current without secondary side sense and feedback circuit s . the system size and cost are optimized, a s well as the system reliability. the bp 3319m utilizes patented line and load voltage compensation method to achieve excellent line and load regulation . a nd the line compensation factor can also be tuned externally for flexibility. the bp 3319m offers ric h protection functions to improve the system reliability, including led open circuit protection, led short circuit protection, vcc over voltage protection, vcc under voltage protection, cs resistor open protection and cycle by cycle current limit. all the protection functions are auto - recovery. the system reliability is further improved by the thermal regulation function . the output current is reduced when the controller is over temperature. features ? single - stage active pfc for high power factor and low thd ? primary side control constant c urrent operation, no opto - coupler required ? 3% led current a ccuracy ? excellent line and load regulation ? critical conduction mode operation ? ultra - low ( 33 ua) startup current ? high r esistance f eedback r esistor for improved e f ficiency ? led o pen and short c ircuit p rotection ? cs resistor o pen c ircuit p rotection ? cycle - by - cycle current limit ? v cc over - voltage and u nder - voltage p rotection ? auto fault recovery ? thermal regulation function ? available in tiny so p - 8 package applications ? e27 / gu10 led bulb, s pot l ight ? par30, par38 led lamp ? t8/t10 led string ? other led l ighting typical application figure 1. typical application circuit for bp 3319m n p n s a c b p 3 3 1 9 m n a c s g a t e c o m p n c g n d f b n c v c c 3 5 4 7 8 1 2 6
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 2 b right p ower s emiconductor co. confidential C customer use only ordering information part number package operating temperature package method marking bp 3319m so p8 - 40 to 105 tape 2 , 5 00 piece/roll bp331 9m xxxxxy xyy pin configuration figure 2. pin configuration pin definition pin no. name description 1 comp loop compensation node. this pin connects a capacitor to gnd for stabilization of the control loop, achieving accurate led current, high power factor and low thd. 2 fb feedback voltage input pin. this pin detects the transformer demagnetization signal and the output voltage. 3 cs current sense p in. connect a resistor to gnd to sense the power mosfet current. 4 ,7 nc no connection . 5 gate gate driver pin. connect this pin to the gate of external power mosfet. 6 vcc power supply pin. connect a bypass capacitor from this pin to gnd . 8 gnd ground . xxxxxy: lot code x: year yy week c o m p f b c s n c g n d g a t e v c c n c b p 3 3 1 9 m x x x x x y x y y
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 3 b right p ower s emiconductor co. confidential C customer use only absolute maximum ratings (note1) symbol parameters range units v cc vcc pin input voltage - 0.3 ~ 25 v i cc_max vcc pin maximum sink current 5 ma comp compensation pin voltage - 0.3 ~ 6 v fb feedback pin input voltage - 0.3 ~ 6 v cs current sense pin input voltage - 0.3 ~ 6 v gate gate driver pin voltage - 0.3 ~ 25 v p dmax power dissipation (note2) 0. 45 w ja thermal resistance (junction to ambient) 145 /w t j operating junction temperature - 40 to 150 t stg storage temperature range - 55 to 150 esd (note3) 2 kv note 1: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. under recommended op erating conditions the device operation is assured, but some particular parameter may not be achieved. the electrical characteris tics table defines the operation range of the device, the electrical characteristics is assured on dc and ac voltage by test program. for the parameters witho ut minimum and maximum value in the ec table, the typical value defines the operation range, the a ccuracy is not guaranteed by spec. note 2: the maximum power dissipation decrease if temperature rise, it is decided by t jmax , ja , and environment temperature (t a ). the maximum power dissipation is the lower one between p dmax = (t jmax - t a )/ ja an d the number listed in the maximum table. note 3: human body mode, 100pf capacitor discharge on 1.5 k resistor recommended operation conditions symbol parameter range unit v cc power supply voltage 8.5 ~ 18 v
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 4 b right p ower s emiconductor co. confidential C customer use only electrical characteristics (notes 4, 5) (unless otherwise specified, v cc =15v and t a =25 ) symbol parameter conditions min typ max units supply voltage section v cc_on v cc turn on threshold v cc rising 16. 7 v v cc_uvlo v cc turn off threshold v cc falling 7. 5 v v cc_ovp v cc over voltage protection threshold 19 v v cc_clamp v cc clamp voltage 23 v i cc_uvlo v cc startup current v cc rising v cc = v cc_on - 1v 33 50 ua i cc v cc operating current f op =10khz, load=100pf 1 2 ma feedback section v fb_fall fb falling edge threshold voltage fb falling 0. 1 v v fb_hys fb hysteresis voltage fb rising 0. 08 v v fb_ovp fb over voltage protection threshold 1.6 v t on_max maximum on time 25 us t off_min minimum off time 4.5 us t off_max maximum off time 100 us current sense section v cs_limit cs peak voltage limitation 1.0 v t leb_cs leading edge blanking time for current sense 350 ns t delay switch off delay time 200 ns compensation section v ref internal reference voltage 0.19 4 0.200 0.20 6 v v comp_lo comp low clamp voltage 1.5 v
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 5 b right p ower s emiconductor co. confidential C customer use only symbol parameter conditions min typ max units v comp comp linear operating voltage range 1.5 3.5 v v comp_ovp comp protection threshold 3.6 v driver section i source_max gate pin maximum sourcing current 200 ma i sink_max gate pin maximum sinking current 6 00 ma thermal regulation section t reg thermal regulation temperature 150 note 4: production testing of the chip is performed at 25c. note 5: the maximum and minimum parameters specified are guaranteed by test, the typical value are guaranteed by design, characteriza tion and statistical analysis
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 6 b right p ower s emiconductor co. confidential C customer use only internal block diagram figure 3. bp 3319m internal block diagram application information the bp 3319m is a high precision primary - side regulation single stage active pfc controller for constant current led lighting, operating in critical conduction mode, the controller achieves high power factor, low thd and high efficiency. 1 start up after system power ed up, the vcc pin capacitor is charged up by the start up resistor. when the vcc pin voltage reaches the turn on threshold, the internal circuits start working . t he comp pin voltage is pulled up to 1.5v quickly, then the bp 3319m starts the mosfet driver. the system works at 10khz frequency at the beginning, the comp voltage rises up gradually, and the transformer primary peak current also rises up. the led current hence achieves a soft start without overshoot. after the output voltage is built up, the vcc power is supplied by the auxiliary winding. 2 constant current control the bp 3319m adopts proprietary primary side current sensing scheme. it can precisely control the led current without secondary side sense and feedback circuit. the current in led can be calculated by the equation: where, v ref : internal reference voltage n p : primary winding turns of transformer n s : secondary winding turns of transformer rcs: the current sensing resistor value + - d e m a g g m v r e f u v l o & v r e f c u r r e n t s e n s e c u r r e n t c o n t r o l p f c c o n t r o l f b c s g a t e v c c c o m p g n d 8 1 6 5 3 2 d r i v e r t h e r m a l r e g u l a t i o n l o g i c & p r o t e c t i o n s p out n n rcs v i ? ? ? 2 ref
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 7 b right p ower s emiconductor co. confidential C customer use only 3 feedback network the bp 3319m senses the output current zero crossing information through the feedback network, the fb falling threshold voltage is set to 0. 1 v with 0. 08 v hysteresis. the fb pin is also used to detect output ovp, the threshold voltage is 1.6v. the ratio of fb upper res istor to lower resistor can be set as: where, r fbl : the lower resistor of the feedback network r fbh : the upper resistor of the feedback network v ovp_fb : output over voltage setting point n s : secondary winding turns of transformer n a : auxiliary winding turns of transformer the fb upper resistor can be set to around 300k to improve the system efficiency. it is also used for fine tuning the led current line compensation. 4 thermal regulation the bp 3319m integrates thermal regulation function. when the system is over temperature, the output current is gradually reduced; the output power and thermal dissipation are also reduced. the system temperature is regulated and the system reliability is improved. th e thermal regulation temperature is set to 150 internally. 5 protection functions the bp 3319m offers rich protection functions to improve the system reliability. when the led is open circuit, the output voltage will gradually rise up. the v cc voltage wil l also rise up. when v cc voltage reaches the 19v ovp threshold, it will trigger fault logic and the system stops switching. at some catastrophic fault condition, if the v cc voltage continue s to rise, the internal clamping circuit will limit the v cc voltage to 23v, which helps improv ing the system reliability. when the led is shorted circuit, the system will work under 10khz switching frequency. meanwhile, the output voltage is low and the auxiliary winding can n ot charge the vcc pin . s o the vcc pin v oltage will gradually decrease and finally reaches the uvlo threshold. after the system enters into fault condition, the vcc voltage will decrease until it reaches uvlo threshold , t hen the system will re - start again. if the fault condition is removed, the system will resume normal operation. when the output is short circuit or the transformer is saturated, the cs peak voltage will be relatively high. when cs voltage reaches the internal limitation (1v), the power mosfet will be turned off instantaneously. this cycle by cycle current limitation can help prote cting the power mosfet, the transformer and the output rectifying diode. 6 pcb layouts the following guidelines should be followed in bp 3319m pcb layout: bypass capacitor the bypass capacitor on vcc pi n should be as close as possible to the vcc and gnd pins. ground path the power ground path for current sense resistor should be short and wide, and it should be as close as possible to the ic ground (pin 8 ) , otherwise the led output current accuracy maybe affected . the ic signal ground for comp and fb components should be connected to the ic gnd pin with short traces and should be away from the power ground path. the area of power loop the area of main current loop should be as small as possible to reduce emi radiation, such as the primary current loop, the snubber circuit and the secondary rectifying loop. fb pin a s fb ovp fbh fbl fbl n n v v r r r ? ? ? _ 6 . 1
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 8 b right p ower s emiconductor co. confidential C customer use only the feedback resistor divider should be as close as possible to the fb pin , and the trace must keep s away from dynamic node of the transfo rmer and mosfet drain trace , otherwise the fb pin ovp function might have risk to be mis - triggered by the system noise.
bp 3319m psr single - stage apfc offline led controller bp 3319m _en _ds_ rev 1. 1 www.bpsemi.com 9 b right p ower s emiconductor co. confidential C customer use only physical dimensions
|
