WS9252ProductDescription High Precision PSR Constant Current LED Driver Features Description Constant current control without secondary sense and The WS9252 is a high precision primary-side feedback circuit. feedback and regulation controller for LED lighting, it ±3% LED current accuracy operates in constant current control mode and is designed Ultra low operating current to improve efficiency to work in inductor current discontinuous conduction mode High resistance feedback resistor to improve efficiency and extremely suitable for buckboost/flyback convertor Universal input voltage under universal input. LED short and open circuit protection VCC under-voltage protection technology, the secondary sense and feedback circuit is Feedback loop short circuit protection eliminated. The loop compensation components are also Current sense resistor open circuit protection removed while maintaining stability overall operating Over temperature protection conditions. The low component counts and low BOM cost No external loop compensation component required are realized. Available in SOT23-5 package Since adopting primary sense and feedback control Since using the proprietary high accurate current sense method, theWS9252 realizes ±3% accuracy of LED current along with excellent line regulation and load Applications regulation. GU10/E27 LED bulb, spot light Other LED lighting The WS9252 offers rich protection functions including LED short circuit protection, LED open circuit protection, die over-temperature protection, VCC over voltage protection, VCC under voltage protection and FB short circuit protection. All the protection features are auto-recovery. Typical Application WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS Copyright@WinsemiMicroelectronics Co.,Ltd.,All rightreserved. WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 1208 WS9252ProductDescription Pin Configuration and Marking Information WS9252 is offered in SOT23-5 package, as bellows: 9252：Product Code X：Product Code YM：Production Date XX：Internal Code For QC Pin Definition Pin No. Pin Name Function Description 1 VCC Power supply 2 GND Ground 3 GATE Gate Driver Pin. Connect it to the gate of external power MOSFET. 4 CS 5 FB Current sense. This pin connects a current sense resistor to GND to detect the primary current of transformer. Feedback Pin. This pin detects the output information from auxiliary winding. Internal Block Diagram WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 2/8 WS9252ProductDescription Ordering Information Package Marking Part Number 5-Pin SOT23-5, Pb-free WS9252YP WS9252YP Recommended Operation Conditions Symbol Parameter Value Unit TA Operation temperature -20~85 ℃ Fmax Maximumworking frequency 100 khz VCC Power supply voltage 10~17.5 V POUT1 Output power(Input voltage230V±15%) <50 W POUT2 Output power(Input voltage85V～265V) <36 W Absolute Maximum Ratings (Note1) symbol paramete limites unit VCC VCC pin input voltage -0.3~20 V FB Feedback pin input voltage -0.3~6 V Gate Gate driver of external power MOSFET -0.3~20 V CS Current sense pin input voltage -0.3~6 V PDMAX Power dissipation (note2) 0.3 W Tjo Operating junction temperature -40~150 ℃ θJA Thermal resistance (Junction to Ambient) 300 ℃/W TSTG Storage temperature range -55~150 ℃ Note 1: Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. Under “recommended operating conditions” the device operation is assured, but some particular parameter may not be achieved. The electrical characteristics table defines the operation range of the device, the electrical characteristics is assured on DC and AC voltage by test program. For the parameters without minimum and maximum value in the EC table, the typical value defines the operation range, the accuracy is not guaranteed by spec. Note 2: The maximum power dissipation decrease if temperature rise, it is decided by TJMAX, θ JA, and environment temperature (TA). The maximum power dissipation is the lower one between PDMAX = (TJMAX - TA)/ θJA and the number listed in the maximum table. WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 3/8 WS9252ProductDescription Electrical Characteristics (Unless otherwise specified, VCC=8V and TA =25 ℃) Symbol Parameter Test condition Min Typ Max Units VDD Clamping Voltage 4mA 17.4 18.3 19.4 V 16.1 17.1 18.1 V 8.5 9 9 .5 V 17.9 18.9 19.9 V Supply Voltage Section VDD_CLAMP UVLO_on VDD Power Supply VDD Under Voltage UVLO_off Lockout VCCover voltage VCC_OVP protection level Ist Start up current 35 uA Iop Operating current 152 uA Current Sense Section Ipp Primary Peak Current TLEB TDELAY D_max 484 508 531 mV Lead Edge Blanking 500 ns Shutdown Delay 200 ns Maximum Duty Cycle 42 % 420 us 4 us MaxmiumON time 100 us FB voltage sense level 1 V 100 mA 20 Ω 147 ℃ FeedbackInputSection MaximumDemagnetization Toff_max time MinimumDemagnetizationt Toff_min ime Ton_max Vfb Power MOSFET Isource Rds_off GATE Pin Sourcing Current Resistor Of Gate Driver(OFF) Over TemperatureProtection T_comp WINSEMI Thermal Regulation Temperature MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 4/8 WS9252ProductDescription Application Information recommended to about 4.0. The FB upper resistor can be The WS9252 is a high performance power switch set to 300KΩ~750KΩ to improve efficiency of convertor. specially designed for LED lighting, it uses the patent constant current control technology of WINSEMI. The Operation Switching Frequency accurate LED current can be realized without opto-coupler The WS9252 is designed to work in discontinuous and TL431 feedback circuit while minimizing the external conduction mode and no external loop compensation component count, lowering the total bill of material cost. component is required while maintaining stability. The maximum duty cycle is limited to 42%. The maximum Start Up switching frequency should be set to less than 100KHz and The VCC capacitor will be charged through the start-up the minimum switching frequency should be set to more resistor when the system is powered on, once the voltage than 20KHz. The maximum and minimum switching on VCC reaches the start-up threshold, the WS9252 will frequency is limited in WS9252 to ensure the stability of start to operate, and then the VCC is supplied by the system. auxiliary winding. The switching frequency can be set by the formula: f Constant Current Control Np 2 VLED 8 Ns 2 Lp I LED Cycle-by-Cycle current sense is offered in WS9252, the Where, LP is the primary winding inductance of CS is connected to the current sense comparator, and the voltage on CS will be compared with the internal 508mV reference voltage, the MOSFET will be switched off when the voltage on CS reaches the threshold. The output of the transformer. Protection Function The WS9252 has several protection functions. The comparator also includes a 500nS leading edge blanking internal MOSFET will be shut down immediately when the time voltage on VCC reaches the threshold of OVP and the The primary peak current is given by: I P_PK device will not recover until the protection condition is 508 ( mA) RCS removed. A 18V zener diode is designed in the WS9252 to prevent the chip damage from the abnormal situation. The current in LED can be calculated by the equation: I OUT I P_PK 4 The thermal protection circuitry in the WS9252 senses the die temperature after start up, and the thermal protection NP NS threshold is set to 147℃ The system will work in low consumption mode when Where, the output LED short circuit or open circuit is detected. NP: primary winding turns of transformer While the WS9252 continuous to detect output status until NS: secondary winding turns of transformer the LED recover to normal condition, and then the device IP_PK: peak current in MOSFET will be operate in normal mode. Feedback Network PCB Layout The WS9252 senses the output information through the feedback network and the FB threshold voltage is set to 1V. The following rules should be followed in WS9252 PCB layout: The ratio of FB upper resistor to lower resistor is WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 5/8 WS9252ProductDescription Bypass Capacitor The Area of Power Loop The bypass capacitor on VCC should be as close as The area of main current loop should be as small as possible to the VCC pin possible to reduce EMI radiation, such as the primary Ground Path current loop, the snubber circuit and the secondary The power ground path for current sense should be rectifying loop. short, and the power ground path should be separated from FB Pin small signal ground path before the negative of the bulk The feedback divider should be as close as possible to capacitor. FB Pin and the node must keep away from dynamic node of transformer. WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 6/8 WS9252ProductDescription Package Information SOT23-5 Package Outline Dimensions Winsemi Dimensions in Millimeters Symbol WINSEMI MICROELECTRONICS Min Max A - 1.45 A1 0 0.15 A2 0.90 1.30 A3 0.60 0.70 b 0.39 0.49 b1 0.35 0.45 c 0.08 0.22 c1 0.08 0.20 D 2.80 3.00 E 2.60 3.00 E1 1.50 1.70 e 0.85 1.05 e1 1.80 2.00 L 0.35 0.60 L1 0.60REF L2 0.25BSC R 0.10 - R1 0.10 0.25 θ 0° 8° θ1 7° 11° θ2 8° 12° WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 7/8 WS9252ProductDescription NOTE: 1.We strongly recommend customers check carefully on the trademark when buying our product, if there is any question, please don't be hesitate to contact us. 2.Please do not exceed the absolute maximum ratings of the device when circuit designing. 3.Winsemi Microelectronics Co., Ltd reserved the right to make changes in this specification sheet and is subject to change without prior notice. CONTACT: Winsemi Microelectronics Co., Ltd. ADD:Futian District, ShenZhen Tian An Cyber Tech Plaza two East Wing 1002 Post Code : 518040 Tel : +86-755-8250 6288 FAX : +86-755-8250 6299 Web Site : www.winsemi.com WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 8/8