WS3254 Product Description High Precision Primary-Side Off-line PWM Power Switch Features � 5uA ultra-low startup current � 2mA Low operating current � ±5% Constant Voltage Regulation at Universal AC input � Primary-side Sensing and Regulation Without TL431 � � � � � � � WS3254 operates in primary-side sensing and regulation. Consequently, optocoupler and TL431 could be eliminated, thus reduce the cost. It can achieve ±5% constant voltage precision in full input voltage range. CC/CV Control as shown in fig.1. In CC and Opto-coupler Control, the current and output power setting can be adjusted Programmable CV and CC Regulation externally by the sense resistor Rs at CS pin. In CV control, Built-in Primary winding inductance compensation multi-mode Programmable cable drop compensation performance and high efficiency. In addition, good load Built-in soft start regulation is achieved by the built-in cable drop compensation. Built-in Leading-edge blanking Device operates in PFM in CC mode as well at large load Cycle by cycle over current protection (OCP) condition and it operates in PWM with frequency reduction at VCC over voltage clamp & under voltage are utilized to achieve high light/medium load. Vo lockout( UVLO) � � � operations Maximum Gate output voltage clamped at 12V 5% Frequency jittering Ultra low standby power (<100mW) Applications Io Low power AC/DC offline SMPS for � Cell Phones/Cordless phones Charger � Digital Cameras Charger � Small Power Adapter WS3254 offers power on soft start control and protection � Auxiliary Power for PC, TV etc. coverage with auto-recovery features � Linear Regulator/RCC Replacement including Cycle-by-Cycle current limiting, VCC Ic c Fig.1 Typical CC/CV Curve OVP, VCC clamp and UVLO. The gate-driven output is clamped to maximum 12V to protect the internal MOSFET. Excellent EMI performance is achieved by using the General Description WS3254 is a high-integrated offline PWM power switch, optimized for high performance low power AC/DC charger soft-switching and frequency jittering at the totem-pole-gate-drive output. The WS3254 is the ideal substitute of the linear power supply or the RCC-mode power, and adapter application. for a better performance of the whole switch power system and a lower cost. WS3254 is available in DIP8 package. W/T-D012-Rev.A/1 Jul.2013 WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS Copyright@Winsemi Microelectronics Co., Ltd., All right reserved. WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS 0612 WS3254 Product Description Typical Application Circuit VO CO NS NP AC NA U X VCC GND COMP GND IN V CS RS G ra in G ra in W S3 2 5 4 n Definition and Device Marking Pi Pin WS3254 is available in DIP8 package: VCC COMP IN V 1 8 2 7 3 D IP 8 D: DIP8 GND A:wafer information; GND WS3254D8P A1a 2C 6 D R A IN 4 5 CS P: no Pb 1:Ver.; a: Package Code 2C:Y+M(2=2012 C=12 Month D R A IN (1,2…A=10,B=11,C=12) Pin Function Description Pin Name Pin Number VCC 1 Power Power supply COMP 2 Loop Compensation Loop Compensation for CV Stability INV 3 Feedback Input CS 4 DRAIN 5/6 Current Monitoring Power transistor drain GND 7/8 Pin Type GND Function Description The voltage feedback from auxiliary winding. Connected to resistor divider from auxiliary winding reflecting output voltage. PWM duty cycle is determined by EA output and current sense signal at pin4. Current sense input. This pin connects directly to the primary lead of the transformer. Ground W/T-D012-Rev.A/1 Jul.2013 WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS Copyright@Winsemi Microelectronics Co., Ltd., All right reserved. WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS WINSEM I M ICROELECTRONICS 0612 WS3254 Product Description Block Diagram vcc 1 UVLO 5V POR D R A IN Insernal S u p p ly 5 /6 G a te Driver Po we r M O SF ET CC Controller Soft start PW M Generator D ro p Com p OCP 2V CLK Genterator EA IN V Sampler 3 CS 4 LEB Sa mp lin g Co n tro lle r Frequency Shuffling GND 7 /8 COMP 2 Output Power Table 230VAC±15% 85-264VAC Adapter1 Adapter1 12W 8W Product WS3254 Note Note: Maximum practical continuous power in an Adapter design with sufficient drain pattern as a heat sink, at 50℃ ambient. Ordering Information Package IC Marking Information Purchasing Device Name 8-Pin DIP-8, Pb-free WS3254D8P WS3254D8P Recommended Operating Condition Symbol Parameter Value Unit VCC VCC supply voltage 10~30 V TA Operating temperature -20~85 ℃ WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 3/10 WS3254 Product Description Absolute Maximum Ratings Symbol Drain voltage(off-state) VCC VINV VCS VCOMP TJ TSTG ICC Parameter Value Unit Drain Voltage (off state) DC supply voltage INV input voltage CS input voltage COMP input voltage Max. Operating junction temperature Min./Max. Storage temperature VCC Clamp Continuous Current -0.3~600 30 -0.3~7 -0.3~7 -0.3~7 150 -55~150 10 V V V V V ℃ ℃ mA Note Note: Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions section are not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability. WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 4/10 WS3254 Product Description Electrical Characteristics (TA=25℃，VCC=16V, if not otherwise noted) Supply Voltage (VCC) symbol parameter Test condition I_VCC_ST Start up current I_VCC_OP Typ Max Unit VCC=13V 5 20 uA Operation Current VCC=18V,INV=2V,CS=0V 2 3 mA UVLO_ON Turn on threshold Voltage VCC falling 8.2 9.0 10.5 V UVLO_OFF Turn-off threshold Voltage VCC rising 13.5 14.8 16.0 V VCC_Clamp VCC Zener Clamp Voltage IVCC=10mA 28 29 31 V OVP Over voltage Threshold Ramp VCC until gate shut down 27 28.3 30 V 1.935 1.975 2.015 V protection Min Error Amplifier Section Vref_EA Reference voltage for EA Gain DC gain of EA I_comp_max Max. Cable current compensation INV=2V,COMP=0V 60 dB 37.5 uA 625 ns Current Sense Section TLEB Leading edge Blanking Time Zsense Input impedance TD_OC OCP control delay VTH_OC OCP threshold T_ss Soft start time 50 kΩ 110 0.895 0.91 ns 0.925 17 V ms Oscillator Section Freq_Max IC Maximum frequency 60 Freq_Nom System nominal switch frequency Freq_startup INV=0V,COMP=5V ∆f/Freq Frequency shuffling range 67.5 75 khz 60 khz 14 khz ±6 % MOSFET Section MOSFET Drain-Source breakdown voltage Static Drain to Source on resistance BVdss Ron 600 V 10 Ω Note Note: 1. Freq_Max indicates IC internal maximum clock frequency. In system application, the maximum operation frequency of 67.5 kHz nominal occurs at maximum output power or the transition point from CV to CC. WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 5/10 WS3254 Product Description Typical Operating Characteristics UVLO (OFF ) (V )vs Temperature ( C ) UVLO (ON ) ( V ) vs Temperature ( C ) O O UVLO( OFF )( V ) UVLO ( ON )( V) 1 0 .5 1 0 .0 9 .5 9 .0 8 .5 8 .0 7 .5 -4 0 20 -1 0 50 80 1 6 .5 0 1 5 .5 0 1 5 .0 0 1 4 .5 0 1 4 .0 0 1 3 .5 0 1 3 .0 0 -4 0 11 0 -1 0 20 50 11 0 80 Temperature ( C ) O Temperature ( C ) O Istarup ( uA ) vs Temperature ( C ) O Freq_Max ( kHz )vs Temperature ( C ) 7 0 .0 Istarup ( uA ) Freq_Max ( kHz ) O 6 5 .0 6 0 .0 5 5 .0 3 .0 2 .5 2 .0 1 .5 1 .0 5 0 .0 -4 0 20 -1 0 50 80 -40 11 0 M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 50 80 11 0 Temperature ( C ) O WIN SEM I 20 O Temperature ( C ) www.winsemi.com -10 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 6/10 WS3254 Product Description Function Description output filter capacitor Co. The current in the primary winding WS3254 is a high-integrated offline PWM power switch, ramps up. When MOSFET turns off, the primary current optimized for high performance low power AC/DC charger transfers to the secondary at the amplitude of and adapter application. WS3254 operates in primary-side sensing and regulation. Consequently, opto-coupler and Is = NP *Ip Ns TL431 could be eliminated, thus reduce the cost. High precision CC/CV control can meet most adapter and charger The auxiliary voltage reflects the output voltage, given by N AUX * (Vo + ∆V ) NS application requirements. V AUX = Startup Current and Startup Control Where △V indicates the drop voltage of the output Diode. Startup current of WS3254 is designed to be extremely low at Via a resistor divider connected between the auxiliary 5uA, so that VCC could be charged up above UVLO winding and INV, the auxiliary voltage is sampled at the end threshold level and device starts up quickly. A large value of the demagnetization and it is hold until the next sampling. startup resistor can therefore be used to minimize the power The sampled voltage is compared with Vref (2V) and the loss, predigest the design of startup circuit and provides error is amplified. The error amplifier output COMP reflects reliable startup in application. the load condition and controls the PWM switching frequency to regulate the output voltage, thus the constant Operating Current output current can be achieved. The operating current of WS3254 is low at 2mA. Excellent When sampled voltage is below Vref and error amplifier efficiency is achieved with low operating current together and output COMP reaches its maximum, the switching frequency multi-mode control circuit. is controlled by the sampled voltage thus the output voltage to regulate the output current, thus the constant output CC/CV Operation current can be achieved. WS3254 is designed to produce good CC/CV control characteristic as shown in the fig.1. In charger applications, a Adjustable CC point and Output Power discharged battery charging starts in the CC portion of the In WS3254, the CC point and maximum output power can be curve until it is nearly full charged and smoothly switches to externally adjusted by external current sense resistor Rs at operate in CV portion of the curve. In an AC/DC adapter, the CS pin. The output power is adjusted through CC point normal operation occurs only on the CV portion of the curve. change. The larger Rs, the smaller CC point is, and the The CC portion provides output current limiting. In CV smaller output power becomes, and vice versa. operation, the output voltage is regulated through the primary Vo side control. In CC operation mode, WS3254 will regulate the Large R s output current constant regardless of the output voltage drop. Small R s Principle of Operation To achieve high precision CC/CV control, system needs to be Io designed in DCM mode for flyback system. In DCM mode, the output voltage can be sensed via the auxiliary winding. During Fig.2 Adjustable output power by changing Rs MOSFET turn-on time, the load current is supplied from the WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 7/10 WS3254 Product Description Operation switching frequency comparator is disabled and thus cannot turn off the internal The switching frequency of WS3254 is adaptively controlled MOSFET during the blanking period. PWM duty cycle is according to the load conditions and the operation modes. determined by the current sense input voltage and the EA The operation switching frequency at maximum output power output voltage. is set to 67.5KHz internally. In DCM mode, the maximum Programmable Cable Drop Compensation output power is given by PoMAX = 1 2 LP FSW I P 2 Cable drop compensation is implemented to achieve good load regulation in WS3254. An offset voltage is generated at Where Lp indicate the inductance of primary winding and Ip is peak current of primary winding. current is inversely proportional to the voltage across pin The change of the primary winding inductance results in the change of the maximum output power and constant output current in CC mode. To compensate the change from variations of primary winding inductance, the switching frequency is locked by an internal loop such that the switching frequency is FSW = INV by an internal current flowing into the resister divider. The COMP, as a result, it is inversely proportional to the output load current, thus the drop due to the cable loss can be compensated. As the load current decreases from full-load to no-load, the offset voltage at INV will increase. It can also be programmed by adjusting the resistance of the divider to compensate the 1 drop for various cable lines used. 2TDemag Since TDemag is inversely proportional to the inductance, as a result, the product Lp and Fsw is constant, thus the maximum output power and constant current in CC mode will not change as primary winding inductance changes. Up to ±10% variation of the primary winding inductance can be Gate Drive The gate drive strength which is too weak leads to over switch loss of MOSFET while too strong gate drive output compromises in the over EMI. A good tradeoff between output strength and dead time control is achieved through the design of the built-in totem pole gate. The low standby dissipation compensation. and good EMI system design is easier to achieve through this dedicated devise. For MOSFET gate protection, an internal Frequency Shuffling Excellent EMI performance is achieved by using frequency 12V clamp is added at higher than expected VCC input. jittering in WS3254. Protection Controls Excellent system stability is achieved by the comprehensive Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in WS3254. The switch current is detected by a sense resistor into the sense pin. An internal leading edge blanking circuit chops off the sense voltage spike at initial MOSFET on state due to snubber diode reverse recovery so that the external RC filtering on sense input is no longer required. The current limit protection of WS3254. Including Cycle-by-Cycle current limiting (OCP), VCC Clamp, Under Voltage Lockout on VCC (UVLO). Device restarts when VCC voltage drops below UVLO limit. It is clamped when VCC is higher than threshold value. The power MOSFET is shut down when VCC drops below UVLO limit and device enters power on start-up sequence thereafter. WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 8/10 WS3254 Product Description Package Information DIP-8 Package Outline Dimensions D2 θ1 C1 C C4 θ2 C2 C3 θ3 D1 A2 A5 A3 A1 D A4 B A Winsemi Dimensions in Millimeters Symbol Dimensions in Inches 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 WIN SEM I 7.62TYP M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I 0.3TYP M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 9/10 WS3254 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: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 WIN SEM I M ICROELECTRON ICS www.winsemi.com WIN SEM I M ICROELECTRON ICS Tel : +86-755-8250 6288 WIN SEM I M ICROELECTRON ICS Fax : +86-755-8250 6299 WIN SEM I M ICROELECTRON ICS WIN SEM I M ICROELECTRON ICS 10/10