WS9822B Product Description Non-isolated Buck High Precision Three-stage Dimming LED Driver Features Description Three-stage switcher dimming: 100%-40%-15% The WS9822B is a three-stage dimming constant current Compatible PCB with WS3442 LED driver with high precision and is applied to non-isolated Internal 500V Power MOSFET buck LED power system. The WS9822B integrates a switch Critical Conduction Mode Operation dimming circuit and can change the output current through ±3% LED Current Accuracy switch shifting. without Auxiliary Winding for power supplying Efficiency up to 93% suitable for universal input offline LED lighting to dim with LED Open and Short Circuit Protection three-stage by switcher. Thermal Regulation Function to avoid lights flicking The device operates in critical conduction mode and is under high temperature. The WS9822B utilizes proprietary current control method. It can achieve precise LED output current and excellent line regulation. The operating current of the IC is as low as 120uA. So it doesn’t need the auxiliary winding for supplying the chip, which brings more simplified designs and lower cost. The WS9822B adopts intelligent temperature control and thoroughly solves the problem of LED flickering under high Typical Applictions temperature. T5/T8 LED Strings Ceiling Lamps Bulbs protection, LED short circuit protection, and VCC under Other LED Lightings voltage protection. The WS9822B offers multiple protection functions to improve the system reliability, including LED open circuit Typical Application Circuit WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS Copyright@Winsemi Microelectronics Co., Ltd., All right reserved. WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 0121 WS9822B Product Description Pin Definition and Device Marking WS9822B is available in DIP-7 and SOP-7 packages: WS9822BD7P：Product Code A：Product Code X：Internal Code BCY：Internal QC Code YMX：D/C WS9822BS7P：Product Code A：Product Code X：Internal Code BCY：Internal QC Code YMX：D/C Package Pin Definition Pin name Pin No. 1 GND 2 ROVP 3 NC 4 VCC Power Supply Pin 5/6 Drain Internal HV Power MOSFET Drain. 7 CS WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI Desciption Ground Over Voltage Protection Setting Pin. Connect a resistor to GND. No connection, must be floated. Current Sense Pin. Connect a sensing resistor between this pin and GND pin. MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 2/11 WS9822B Product Description Internal Block Diagram Ordering Information Package Marking Part Number 7-Pin DIP-7, Pb-free WS9822BD7P WS9822BD7P 7-Pin SOP-7, Pb-free WS9822BS7P WS9822BS7P Recommended Operation Conditions Part Number Maximum output Package Input voltage DIP7 175VAC-264VAC 28W SOP7 175VAC-264VAC 24W power WS9822B WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 3/11 WS9822B Product Description Absolute Maximum Ratings Symbol Parameter Limit Unit VD Internal HV MOSFET drain voltage -0.3~500 V ICC_MAX Maximum sink current 20 mA -0.3~7 V LED open circuit protection voltage VROVP regulation VCS Current sense pin input voltage -0.3~7 V PDMAX Power dissipation (note 2) 0.9 W TJ Maximum operating junction temperature 165 ℃ TSTG Minimum/Maximum Storage temperature -55~165 ℃ Note 1：Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. Note 2： The value of power dissipation is closely related to the heat emission conditions. The values in the table above are measured on the test board without heat sink and case, and Ta<40℃. WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 4/11 WS9822B Product Description Electrical Characteristics Conditions： TA=25℃，VCC=14V（Unless otherwise specified） Symbol Parameter Test condition Min Typ Max Unit Power Supply Section VCC_CLAMP VCC Clamp Voltage ICC_CLAMP VCC Clamp Current UVLO_OFF Chip Startup Voltage Under voltage UVLO_ON _HYS Protection Hysteresis IST Startup Current IOP Operating Current IVCC=1mA 16 5 V 20 mA VCC Rising 15.8 V VCC Falling 3.5 V VCC=UVLO_off-0.5V 65 130 195 uA 120 uA 400 mV 114 mV 350 ns 200 ns Current Detection Section VCS_TH Threshold Voltage for Peak Current Limitation Threshold Value for VCS_DIM Dimming Test Leading Edge Blanking Time TLEB for Current Sense TDELAY Switch Off Delay Time Switching Frequency Section TOFF_MIN Minimum OFF Time 3 us TOFF_MAX Maximum OFF Time 240 us TON_MAX Maximum On Time 40 us VROVP ROVP PIN Voltage 0.5 V Shutdown Reset Time 5 S DIM Dimming Section TRESET MOSFET Section Power MOSFET Drain IDSS Leakage Current BVDSS RDS_ON VGS=0V,VDS=500V Drain-Source Breakdown 10 500 Voltage Static Drain-source V 4.8 On-state resistance uA 6 Ω Thermal section Thermal Regulation TREG WINSEMI 150 Temperature MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS ℃ WINSEMI MICROELECTRONICS 5/11 WS9822B Product Description Function Description winding is not needed to supply the IC. VCC Capacitor Selection The WS9822B is a three-stage dimming constant current LED driver with high precision and is applied to The Vcc capacitor is used to bypass noise to IC, so that non-isolated buck LED power system. The WS9822B to assure its stable operation, and should be as close as integrates a switcher dimming circuit and can change the possible to the chip. output current through shifting external switcher ON/OFF to A 4.7uF/25V electrolytic capacitor can be used to Vcc Pin. perform the dimming function. If selecting MLCC, the material of X7R will be used to satisfy The WS9822B is compatible the PCB board with the stability of the capacity under high temperature. Due to mainstream non-dimming products in the markets, such as external damage resulted from small volume and brittle texture WS3442, thus it can achieve the seamless upgrades from of MLCC, it is easy to cause Vcc currents leakage, which will non-dimming to ON/OFF dimming. make the WS9822B unable to start. Strict control measures are taken in the layout and productive process. Switcher Dimming Control In order to avoid the return flickering and the disorder time, The switcher is opened first and closed again when the the Vcc capacitor should be in parallel with discharge resistor, dimming is required, and the output current changes in which value should be chosen from 150KΩ to 240KΩ. accordance with the presetted current. The switching time Constant Current Control should be more than 500mS. The dimming current cyclically varies in the sequence of 100% to 40% to15%. The reset Utilizing proprietary current control method, the time is 5S. So it is a normal dimming if the time interval of the WS9822B can achieve precise LED output current with a few switch from turn-off to turn-on is less than 5s; otherwise it will external components. Cycle by Cycle current sense is adopted be considered as a reset signal. The output current reaches in WS9822B, the CS pin is connected to the current sense up to 100% after the switch is on again whatever the output comparator, and the voltage on CS pin is compared with the stage of the preceding current is. internal 400mV reference voltage. The MOSFET will be switched off when the voltage on CS pin reaches the threshold. Start Up The CS comparator includes a 350ns leading edge blanking The VCC capacitor will be charged through the start-up time. The peak inductor current is calculated by the equation resistor when the system is powered on. When the VCC pin （2）: voltage reaches the turn on threshold, the internal circuits I PK start operating. The WS9822B integrates the 16V ZENER for clamping the VCC. The typical value of the start-up current is 130uA (the The current in LED can be calculated by the equation（3） : 264VAC, the start-up resistor can be calculated by the equation（1）: Rst I st _ max （2） Where, RCS is the current sense resistor value. maximum value is 195 uA). For the application of 176VAC— Vin _ min 1.414 0.4 (mA) Rcs 176V 1.414 1.27M （1） 195uA I LED I PK (mA) 2 （3） Where, IPK is the peak current of the inductor. The start-up resistor can be chosen from 720K Ω to 1.2MΩ. Two resistors in 1206 size SMD or 1/4W metal film resistors can be used in series. The diode will bear the reverse voltage equal to the Due to the ultra-low operating current, the auxiliary WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI Freewheeling Diode MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI input voltage when the MOSFET is on. A 600V diode was MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 6/11 WS9822B Product Description suggested to use. Besides, the operating frequency of t off freewheeling diode is from 20K to 120 KHz, such ultra fast recovery diodes as ES and ER whose Trr is less than 50ns L Input voltage should be considered in to the capacitor （5） The inductance can be calculated by the equation（6）: are good choice. Input Buck Electrolytic Capacitor L I PK V LED V LED (V IN V LED ) f I PK V IN （6） Where, f is the maximum system switching frequency, which is proportional to the input voltage. So the minimum pressure, and the common value is 400V. In general, the capacitor design can be calculated by the switching frequency is set at lowest input voltage, and the maximum switching frequency is set at highest input voltage. following empirical equations: 90Vac~264Vac: 1W output uses1uF intput electrolytic The minimum and maximum off time of WS9822B is set at 3us and 240us respectively. Referring to the equation of Toff capacitor; 176Vac~264Vac: 1W output uses 0.5uF intput calculation, if the inductance is too small, the Toff may be smaller than the minimum off time, the system will operate in electrolytic capacitor. discontinuous conduction mode and the output current will be Output Capacitor smaller than the designed value. If the inductance is too large, Electrolytic capacitor is recommended to be used. Its the Toff may be larger than the maximum off time, the system stable capacitance can improve the efficiency of power will operate in continuous conduction mode and the output supply, the LED ripple current and luminous efficiency. current will be higher than the designed value. So it is Vovp voltage should be considered in output capacitor important to choose a proper inductance. In addition, the OVP voltage changes with the Inductance pressure. value. Due to open magnetic flux of DR core, the Inductance Inductor Selection value changes easily under the influence of temperature and The WS9822B works under inductor current critical external environment. Therefore, please don’t use them along conduction mode. When the power MOFET is switched on, with the product in order to prevent from false triggering of the current in the inductor rises up from zero. The on time of OVP. the MOSFET can be calculated by the equation (4): t on Over Voltage Protection L I PK V IN V LED （4） The over voltage protection of the WS9822B can be programmed by the ROVP pin resistor. The voltage of ROVP Where, pin is 0.5V. L is the inductance value, When the LED is open circuit, the period of the output IPK is the peak current of the inductor, VIN is the DC bus voltage after the rectifier bridge, voltage increases gradually, the demagnetization time gets shorter. The demagnetization time at OVP---- Tovp can be VLED is the voltage on the LED. After the power MOSFET is switched off and the current in the inductor decreases. When the inductor current reaches zero, the power MOSFET is turned on again by IC internal calculated by the open circuit protection voltage by the equation （7）: TOVP logic. The off time of the MOSFET is given by the equation L VCS RCS VOVP （7） Where， （5）: Vcs is the CS pin turn off threshold (400mV); WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 7/11 WS9822B Product Description Vovp is the open circuit protection voltage. At some abnormal fault condition, such as CS resistor And then the Rovp resistor value can be calculated by the equation （8）: shorted or inductor saturation, the internal fast fault detection circuit ROVP 5 TOVP 10 6 ( K ) will be triggered, the system stops switching immediately. （8） After the system enters into faulty condition, the VCC In normal application, the value of Tovp cannot be lower than 4us, or in other words, the value of Rovp cannot be lower than 20K, with its recommended range from 20K to voltage will decrease until it reaches the UVLO threshold, then the system will restart again. If the fault condition is removed, the system will recover to normal operation. 50K. The resistance of Rovp with 1% accuracy should be used to assure the accuracy of OVP. PCB Layout Line Voltage Compensation The following rules should be followed in WS9822B PCB The WS9822B integrates line voltage compensation function, which makes LED current remain unchanged in the range of full voltage, thus has good line regulation and current accuracy. layout: VCC Capacitor: The VCC capacitor should be as close as possible to the VCC Pin and GND pin. Ground Path: The power ground path for current sense resistor should be as short as possible, and the power ground Thermal Regulation The WS9822B integrates thermal regulation function. When the system is under higher 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. The thermal path should be separated from small signal ground path before connecting to the negative node of the bulk capacitor. The Area of Power Loop: The area of main current loop should be as small as possible to reduce EMI radiation, and it should be away from diodes and other heating components. DRAIN PIN: The copper area of DRAIN pin can be regulation temperature is set at 150℃ internally. increased for better thermal dissipation. And it should be away Protection Function from CS / VCC and ROVP Pin. The WS9822B offers full protection functions to improve the system reliability, including LED open/short protection, ROVP PIN: The ROVP resistor should be as close as possible to the ROVP Pin to prevent from the interference. CS resistor short protection, VCC under voltage protection, The material of PCB: Avoid choosing the material that is thermal regulation. When the LED is open circuit, the system easy to absorb the moisture, just like paper copper-clad will trigger the over voltage protection and stop switching. laminates. When the LED short circuit is detected, the system works at lowest frequency. So the system power consumption is very low. WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 8/11 WS9822B Product Description DIP7 Package Dimension Winsemi Dimensions in Millimeters Symbol Min Max Min Max A 9.00 9.50 0.354 0.374 B 6.10 6.60 0.240 0.260 C 3.0 3.4 0.118 0.134 A1 1.474 1.574 0.058 0.062 A2 0.41 0.53 0.016 0.021 A3 2.44 2.64 0.096 0.104 A4 0.51TYP 0.02TYP A5 0.99TYP 0.04TYP C1 6.6 C2 7.30 0.260 0.50TYP 0.287 0.02TYP C3 3.00 3.40 0.118 0.134 C4 1.47 1.65 0.058 0.065 D 7.62 9.3 0.300 0.366 D1 0.24 0.32 0.009 0.013 D2 WINSEMI Dimensions in Inches 7.62TYP MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI 0.3TYP MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 9/11 WS9822B Product Description SOP7 Package Dimension Winsemi Dimensions in Millimeters Symbol 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 www.winsemi.com WINSEMI 0.80 MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI 0.016 MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS 0.031 WINSEMI MICROELECTRONICS 10/11 WS9822B Product Description 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：Room 1002, East, Phase 2, HighTech Plaza,Tian-An Cyber Park,Chegongmiao, FuTian, Shenzhen, P.R. China Post Code : 518040 Tel : +86-755-8250 6288 FAX : +86-755-8250 6299 Web Site : www.winsemi.com WINSEMI MICROELECTRONICS www.winsemi.com WINSEMI MICROELECTRONICS Tel : +86-755-8250 6288 WINSEMI MICROELECTRONICS Fax : +86-755-8250 6299 WINSEMI MICROELECTRONICS WINSEMI MICROELECTRONICS 11/11