12W High Precision CC/CV Primary-Side PWM DriverFEATURES◆ 5% Constant Voltage Regulation, 5%Constant Current Regulation at Universal AC input◆ Primary-side Sensing and Regulation Without TL431 and Opto-coupler ◆ Low Start-up Current: 5μA (Typical) ◆ Low Operating Current: 2mA (Typical) ◆ Programmable CV and CC Regulation ◆ Adjustable Constant Current and Output Power Setting◆ Built-in Secondary Constant CurrentControl with Primary Side Feedback ◆ Peak-Current-Mode Control◆ Compensates for transformer inductance tolerances◆ Compensates for cable voltage drop ◆ Fixed PWM Frequency at 60kHz withFrequency Hopping to Solve EMI Problems ◆ Power on Soft-start◆ Built-in Leading Edge Blanking (LEB) ◆ Cycle-by-Cycle Current Limiting ◆ VDD Under-Voltage lockout (UVLO) ◆ VDD Over-Voltage Protection(OVP)APPLICATIONSbelow 12W AC/DC offline SMPS for ◆ Cell Phone Charger◆ Digital Cameras Charger ◆ Small Power Adapter◆ Auxiliary Power for PC, TV etc.◆ Linear Regulator/RCC ReplacementCL1112 is offered in SOP-8 and DIP-8 package.TYPICAL APPLICATIONSPin ConfigurationThe pin map is shown as below for SOP8/DIP8CL1112CL1112GENERAL DESCRIPTIONCL1112 is a high performance offline PWM driver for low power AC/DC charger and adaptor applications. It operates in primary-side sensing and regulation. Consequently, opto-coupler andTL431 could be eliminated. Proprietary Constant Voltage (CV) and Constant Current(CC) controlis integrated as shown in the figure below.In CC control, the current and output power setting can be adjusted externally by the sense resistor Rs at CS pin. In CV control, multi-mode operations are utilized to achieve high performance and high efficiency. In addition, good load regulation is achieved by the built-in cabledrop compensation. Device operates in PFM in CC mode as well at large load condition and it operates in PWM with frequency reduction at light/medium load. CL1112 offers power on soft start control and protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, VDD OVP, VDD clamp and UVLO. Excellent EMI performance is achieved with frequency jittering technique. High precision constant voltage (CV) and constant current (CC) can be achieved by CL1112.Fig.1. Typical CC/CV CurveCL1112 PACKAGE DISSIPATION RATINGPackage RθJA (℃/W) MarkingCL1112S SOP8 90CL1112D DIP8 40ABSOLUTE MAXIMUM RATINGS (note1)Parameter VALUEDrain Voltage (off state) -0.3V to BvdssVDD Voltage -0.3 to VDD_clamp10 mAVDD Zener ClampContinuous CurrentCOMP Voltage -0.3 to 7VCS Input Voltage -0.3 to 7VFB Input Voltage -0.3 to 7VMin/Max Operating-20 to 150 CJunction Temperature TJ-55 to 150 CMin/Max StorageTemperature Tstg260 o CLead Temperature(Soldering, 10secs)Note: Stresses beyond those listed under “absolute maximum ratings” may cause permanentdamage to the device. These are stress ratings only, functional operation of the device at these orany other conditions beyond those indicated “recommended operating conditions” is not implied.Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.TERMINAL ASSIGNMENTSPin NumPin Name I/O Description1 VDD P Power Supply2COMPILoop Compensation for CV Stability3 FB IThe voltage feedback from auxiliary winding. Connected to resistor divider from auxiliary winding reflecting outputvoltage. PWM duty cycle is determined by EA output and current sense signal at pin 4.4 CS I Current sense input 5/6 DRAIN OHV MOSFET Drain Pin. The Drain pin is connected to the primary lead ofthe transformer 7/8 GND P GroundBLOCK DIAGRAMCompFBCSDRAINGNDCL1112ELECTRICAL CHARACTERISTICS(TA = 25℃, VDD=16V, if not otherwise noted)Symbol Parameter TestConditionsMinTyp.Max.Unit Supply Voltage (VDD) SectionI DD ST StandbyCurrent V DD=13V520uAI DD op OperationCurrent Operation supplycurrent FB=2V, CS=0V,VDD=VDDG=20V- 2.5 3.5 mAUVLO(ON) V DD Under Voltage LockoutEnterV DD falling 7.58.510VUVLO(OFF) V DD Under Voltage LockoutExitV DD rising 13.514.516.0VV DD_clamp Maximum V DD operationvoltageI DD=10mA 30.532.534.5VOVP Over voltage protectionThresholdRamp VDD until gateshut down27.5 29.5 31.5 VCurrent Sense Input SectionTLEB LEBtime 540 ns V th_oc Over current threshold 870 900 930 mVTd_oc OCPPropagationdelay 150 ns Z SENSE_IN InputImpedance 50 KohmT_ss Softstarttime 10 ms Frequency SectionFreq_Max NoteIC Maximum frequency 65 70 75 kHzFreq_Nom System Nominal switchfrequency60KHzFreq_startup FB=0V, Comp=5V 14 KHz f/Freq Frequency shuffling range +/-4 % Error Amplifier sectionVref_EA Reference voltage for EA 1.97 2 2.03 V Gain DC gain of EA 60 dBI_COMP_M AX Max.Cable compensationcurrentFB=2V, Comp=0V 42 uAPower MOSFET SectionBVdss MOSFET Drain-SourceBreakdown Voltage600 VRdson OnResistance Static,Id=0.4A 12 15 ΏNote:1. Freq_Max indicates IC internal maximum clock frequency. In system application, the maximum operation frequency of 70Khz nominal occurs at maximum output power or the transition point fromCV to CC.CL1112Application InformationOperation OverviewThis highly integrated PSR PWM controller contains several features to enhance the performance of low-power flyback converters. The patented topology of the PSR controller allows for simplified of circuit designs, particularly battery charger applications. It operates in primary side sensing and regulation, thus opto-coupler and TL431 are not required. CV and CC control can be accurately achieved without secondary feedback circuitry. A frequency jittering function is built in to improve EMI system performance. As a result, a low-cost, smaller, and lighter charger is produced when compared to a conventional design or a linear transformer.Under Voltage Lockout (UVLO)An UVLO comparator is implemented to detect the voltage of VDD pin. It would assure the supply voltage enough to turn on the CL1112 PWM controllers and further to drive the power MOSFET. A hysterics is built in to prevent the shutdown from the voltage dip during startup. The turn-on and turn-off threshold level are set at 14.8V and 9V, respectively.Soft StartCL1112 incorporates an internal soft-start function with no external components to minimize the component electrical over-stress during power on startup. The soft-start time is set at 17ms. As soon as VDD reaches UVLO (OFF), the control algorithm will ramp peak current voltage threshold gradually from nearly zero to normal setting of 0.90V. Every restart is a soft start.CC/CV OperationCL1112 is designed to produce good CC/CV control characteristic as shown in the Fig. 1.Battery chargers are typically designed for two modes of operation, constant-voltage charging and constant-current charging. When the battery voltage is low, the charger operates on a constant current charging. This is the main method for charging batteries and most of the charging energy is transferred into the batteries. When the battery voltage reaches its end-of-charge voltage, the current begins to taper-off. The charger then enters the constant voltage method of charging. Finally, the charging current continues to taper-off until reaching zero.Output Voltage settingThe CL1112 monitors the auxiliary fly-back signal from FB pin through a resistor divider pair of Ra and Rb. An error signal, which represents the difference between the voltage at FB and the reference voltage, is integrated with the error amplifier to control switching duty cycle.The output voltage is determined by the following relationship. For improving the output voltage accuracy, the transformer leakage inductance should be reduced as much as possible.a sOUT b aR N V 2V(1)()R N =+Where,Ra and Rb are the top and bottom feedback resistor value,Ns and Na are the turn ratios of transformer secondary and auxiliaryThe load regulation and line regulation for primary side feedback control are sensitive to the structure of transformer. For getting good regulation and efficiency, the sandwich structure consisting of two secondary separate parallel layer windings surrounding primary winding isCL1112CL1112recommended.Inductance Correction CircuitryIf the primary magnetizing inductance is either too high or low the converter will automatically compensate for this by adjusting the oscillator frequency. Since this controller is designed to operate in discontinuous-conduction mode the output power is directly proportional to the set primary inductance and its tolerance can be completely compensated with adjustments to the switching frequency.Frequency TremblingThe CL1112 is implemented with an adjustable modulating frequency for trembling function, which enable the power supply designers to achieve optimized EMI performance and excellent systemcost. The trembling frequency is internally fixed between ±3.6KHz to incorporate with the 65KHz switching frequency.Current Sensing and Leading EdgeBlanking Cycle-by-Cycle current limiting is offered in CL1112. The switch current is detected by asense resistor into the CS pin. When the power switch is turned on, a turn-on spike will occur on thesense-resistor. To avoid false-termination of the switching pulse, 625ns leading-edge blanking isbuilt in. During this blanking period, the current sense comparator is disabled and the gate drivercan not be switched off.Programmable Cable drop CompensationIn CV regulation control, the on-time of MOSFET only regulates on-board voltage, not includingoutput cable. Different cable wire gauge or length results in different output voltage. The CL1112has a cable compensation function used to compensate the output voltage drop due to output cableloss. An offset voltage is generated at FB by an internal current flowing into the resister divider. Asthe converter load increases from no-load to the peak power point (transition point between CV andCC) the voltage drop introduced across the output cable is compensated by increasing internal current flowing into the resister divider.Protection ControlGood power supply system reliability is achieved with its rich protection features includingCycle-by-Cycle current limiting (OCP), VDD clamp, Power on Soft Start, and Under Voltage Lockout on VDD (UVLO). VDD is supplied by transformer auxiliary winding output. The output ofCL1112 is shut down when VDD drops below UVLO (ON) limit and the power converter enterspower on start-up sequence thereafter.z The information described herein is subject to change without notice.z is not responsible for any problems caused by circuits or diagrams described hereinwhose related industrial properties, patents, or other rights belong to third parties. The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design.z When the products described herein are regulated products subject to the WassenaarArrangement or other agreements, they may not be exported without authorization from the appropriate governmental authority.z Use of the information described herein for other purposes and/or reproduction or copyingwithout the express permission of is strictly prohibited. z The products described herein cannot be used as part of any device or equipment affecting thehuman body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of z Although exerts the greatest possible effort to ensure high quality and reliability, the failure or malfunction of semiconductor products may occur. The user of these products should therefore give thorough consideration to safety design, including redundancy, fire-prevention measures, and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue.SANY SemiconductorSANY SemiconductorSANY SemiconductorSANY SemiconductorCL1112。