WS3412 ProductDescription Non-isolated Buck APFC Offline LED Driver Features Description Internal 550V Power MOSFET The WS3412 is a high precision non-isolated buck driver Active PFC for High Power Factor and Low THD with active PFC, specially designed for universal input offline Critical Conduction Mode Operation constant current LED lighting. The driver with on-chip PFC System Efficiency up to 95% circuit achieves high power factor and low THD. Operating in Without auxiliary winding critical conduction mode, the power MOSFET switching loss Excellent Line and Load Regulation is reduced and the inductor is fully utilized. ±3% LED Output Current Accuracy Thermal Regulation Function few external components, the LED output current can be LED Short/Open Protection precisely controlled. Current Sensing Resistor Open Protection Auto Fault Recovery the system reliability, including LED open circuit protection, Available in SOP8 Package LED short circuit protection, CS resistor open circuit The WS3412 integrates a 550V power MOSFET. With The WS3412 offers rich protection functions to improve protection and cycle by cycle current limit. All the protection functions are auto-recovery. The system reliability is further Applications improved by the thermal regulation function. The output E27 LED Bulb, Spot Light PAR30, PAR38 Lamp T8/T10 LED String Other LED Lighting current is reduced when the driver is over temperature. The WS3412 has ultra low start up current and ultra low operating current. The WS3412is available in SOP8 Package Typical Application WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS Copyright@WinsemiMicroelectronics Co.,Ltd.,All rightreserved WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 1030 WS3412 ProductDescription Pin Configuration and Marking Information The WS3412 is available in SOP8 Package，the top marking is shown as below: WS3412S8P A：Product Code X：Internal Code BCY：Internal Code For QC YMX：D/C Pin Definition Name Pin No. Description COMP 1 GND 2 Ground. VCC 3 Power Supply Pin. Connect a bypass capacitor from this pin to GND. FB 4 D 5/6 Internal HV Power MOSFET Drain. CS 7/8 Current Sense Pin. Connect a resistor to GND to sense the inductor current. 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. Feedback Voltage Input Pin. This pin detects the inductor demagnetization signal and the output voltage. 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 WS3412 ProductDescription Ordering Information Package 8-Pin SOP-8, Pb-free Marking Part Number WS3412S8P WS3412S8P Recommended Operation Conditions Part Number Package WS3412S8P SOP8 Input voltage Maximum output power 175VAC-264VAC 120V/170mA 90VAC-264VAC 80V/170mA Absolute Maximum Ratings symbol paramete Range unit VCC Vcc pin voltage -0.3~8 V VD Internal HV MOSFET Drain to Source voltage -0.3~550 V VCS Current sense pin input voltage -0.3~7 V VFB Feedback pin input voltage -0.3~7 V VCOMP Compensation pin voltage -0.3~7 V PDMAX Power dissipation 0.5 W TJ Operating junction temperature 165 ℃ TSTG Storage temperature range -55~165 ℃ Note : Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. 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 WS3412 ProductDescription Electrical Characteristics (Unless otherwise specified, VCC=8V and TA =25 ℃) Symbol Parameter Conditions Min Typ Max 7.5 8.0 8.5 Units Supply Voltage Section Vcc_clamp VCC Clamp Voltage Icc_clamp VCC Clamp Current VCC_ST VCC Turn On Threshold VCC Rising Vuvlo_HYS VCC Turn Off hysteresis VCC Falling 1.32 Ist VCC Startup Current VCC<VCC_ST-0.5V 70 Iop VCC Operating Current 5 7.07 V mA 7.57 8.07 V V 100 uA 400 uA 1 V 350 ns 200 ns Current Sense Section Over current Vocp TLEB Protectionthreshold Leading Edge Blanking Time for Current Sense Td Switch off Delay Time Compensation Section VREF Internal Reference Voltage 194 200 206 mV VCL COMP Low Clamp Voltage 1.5 V VCH COMP High Clamp Voltage 4 V Internal driver TOFF_MIN Minimum Off Time 3 us TON_MAX Maximum On Time 20 us 1.6 V 0.2 V Feedback Section VFB FB Over Voltage Protection Threshold FB Falling Edge VZCD Threshold Voltage Power MOSFET RDSON VDS Static Drain-source 5.5 On-resistance Drain-Source Breakdown 6.9 550 Voltage Ω V Thermal Regulation Section TREG WINSEMI Thermal Regulation Temperature MICROELECTRONICS WINSEMI MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 ℃ 150 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 4/8 WS3412 ProductDescription Application Information RFBL 1.6V RFBL RFBH VOVP The WS3412 is a high precision Active PFC driver integrating 550V power MOSFET, specially designed for non-isolated buck offline constant current LED lighting. Where, Operating in critical conduction mode, the driver achieves RFBL: The lower resistor of the feedback network high power factor, low THD and high efficiency. RFBH: The upper resistor of the feedback network VOVP: Output over voltage setting point Start Up The minimum VOVP should be set about 1.3Vo.It is After system powered up, the VCC pin capacitor is charged up by the start up resistor. When the VCC pin recommended that the FB lower resistor is set to 3.3KΩ—5.1KΩparalleled with a 22pF ceramic capacitor. voltage reaches the turn on threshold, the internal circuits start working. The COMP pin voltage is pulled up to 1.5V Protection Functions quickly, then the WS3412starts switching. The system works at 10k Hz frequency at the beginning, the COMP voltage The WS3412 offers rich protection functions to improve the system reliability. rises up gradually, and the inductor peak current also rises When the LED is open circuit, the output voltage will up. The LED current hence achieves a soft start without gradually rise up. The output voltage is sensed by the FB pin overshoot. After the output voltage is built up, the VCC when power MOSFET is turned off. When FB voltage power is supplied by the output voltage through a diode. reaches the OVP threshold, it will trigger fault logic and the The maximum value of the startup current is 100uA. For system stops switching. the application of 85VAC—264VAC, the startup resistor can be calculated by the equation: Rst Vin _ min I st _ max When the LED is shorted circuit, the system will work under 10k Hz switching frequency. Meanwhile, the output voltage is low and the VCC pin cannot be charged up by the 85V 850 KΩ 100uA output voltage, so the VCC pin voltage 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. Then Constant Current Control The WS3412 utilizes floating ground structure. The inductor current is sensed during the whole switching cycle, 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 inductor is thus it achieves high precision output current control and saturated, the CS peak voltage will be relatively high. When also excellent line and load regulation. The current in LED can be calculated by the equation: CS voltage reaches the internal limitation (1V), the power MOSFET will be turned off instantaneously. This cycle by V 200mV I O CS RCS Rcs cycle current limitation can help protecting the power MOSFET, the inductor and the output diode. Rcs is the current sensing resistor. Thermal Regulation The WS3412 integrates thermal regulation function. Feedback Network When the system is over temperature, the output current is The WS3412 senses the output current zero crossing information through the feedback network, the FB falling threshold voltage is set to 0.2V with 0.15V hysteresis. The FB pin is also used to detect output OVP, the threshold gradually reduced; the output power and thermal dissipation are also reduced. The system temperature is regulated and the system reliability is improved. The thermal regulation temperature is set to 150℃ internally. voltage is 1.6V. The ratio of FB upper resistor to lower resistor can be set as: PCB Layouts The following guidelines should be followed in WS3412 PCB layout: 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 WS3412 ProductDescription Bypass Capacitor FB Pin The bypass capacitor on VCC pin should be as close as The feedback resistor divider should be as close as possible to the VCC and GND pins. possible to the FB pin, and the trace must keeps away from Ground Path dynamic node of the inductor (DRAIN pin trace、the positive The power ground path for current sense resistor pin and the negative pin of Vo trace), otherwise the FB pin should be short and wide, and it should be as close as OVP function might have risk to be mis-triggered by the possible to the IC ground (pin 2), otherwise the LED output system noise. current accuracy maybe affected. The IC signal ground for DRAIN Pin COMP and FB components should be connected to the IC To increase the copper area of DRAIN pin for better GND pin with short traces and should be away from the thermal dissipation. However, too large copper area may power ground path. compromise EMI performance. The Area of Power Loop The material of PCB The area of main current loop should be as small as Avoid choosing the material that is easy to absorb the possible to reduce EMI radiation. WINSEMI MICROELECTRONICS WINSEMI moisture, just like paper copper-clad laminates. MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 6/8 WS3412 ProductDescription Package Information SOP8Package Outline Dimensions B2 A1 A2 0.5* 0.125± 0. 05 球形标记 D D1 B B1 A C4 A3 R2 θ4 C C1 C2 θ2 C3 R1 θ1 θ3 Winsemi Symbol Dimensions in Millimeters Dimensions in Inches Min Max Min Max A 4.70 5.10 0.185 0.201 B 3.70 4.10 0.146 0.161 C 1.30 1.50 0.051 0.059 A1 0.35 0.48 0.014 0.019 A2 1.27TYP 0.05TYP A3 0.345TYP 0.014TYP B1 5.80 B2 6.20 0.228 5.00TYP 0.244 0.197TYP C1 0.55 0.70 0.022 0.028 C2 0.55 0.70 0.022 0.028 C3 0.05 0.225 0.002 0.009 C4 0.203TYP 0.008TYP D 1.05TYP 0.041TYP D1 WINSEMI 0.40 MICROELECTRONICS WINSEMI 0.80 MICROELECTRONICS www.winsemi.com Tel : +86-755-8250 6288 WINSEMI 0.016 MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS 0.031 WINSEMI MICROELECTRONICS 7/8 WS3412 ProductDescription 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