OB25136CCPA

OB2513xC High Precision CC/CV Primary-Side PWM Power Switch GENERAL DESCRIPTION FEATURES OB2513xC is a high performance offline PSR power switch for low power AC/DC charger and adapter applications. It operates in primary-side sensing and regulation. Consequently, opto-coupler and TL431 could be eliminated. Proprietary Constant Voltage (CV) and Constant Current (CC) control is 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 cable drop 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. The chip consumes very low operation current, it can achieve less than 75mW standby power. OB2513xC offers comprehensive protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, VDD over voltage protection, short circuit protection, built-in leading edge blanking, VDD under voltage lockout (UVLO), OTP etc. OB2513xC is offered in SOP8 package.  Primary-side sensing and regulation without TL431 and opto-coupler  High precision constant voltage and current regulation at universal AC input  Multi-mode PWM/PFM operation for efficiency improving  Quasi-resonant operation for highest overall efficiency  Programmable CV and CC regulation  Built-in line voltage and primary winding inductance compensation  Programmable cable drop compensation  No need for control loop compensation  Audio noise free operation  Internal BJT switch  Good dynamic response with synchronous rectifier application  Built-in leading edge blanking (LEB)  Comprehensive protection coverage with auto-recovery  VDD over voltage protection  VDD under voltage lockout with hysteresis (UVLO)  Cycle-by-cycle current limiting  Feedback loop open protection  Output short circuit protection  Over temperature protection (OTP) APPLICATIONS Low Power AC/DC offline SMPS for  Cell Phone Charger  Digital Cameras Charger  Small Power Adapter  Auxiliary Power for PC, TV etc.  Linear Regulator/RCC Replacement Figure.1. Typical CC/CV Curve TYPICAL APPLICATION ©On-Bright Electronics Confidential -1- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch GENERAL INFORMATION Pin Configuration FB 1 8 C GND 2 7 C VDD 3 6 C CS 4 5 Absolute Maximum Ratings Parameter CB Voltage VDD Voltage FB Input Voltage CS Input Voltage Min/Max Operating Junction Temperature TJ Operating Ambient Temperature TA Min/Max Storage Temperature Tstg Lead Temperature (Soldering, 10secs) C Ordering Information Part Number Description OB25135CCP SOP8, Pb-free, Tube OB25135CCPA SOP8, Pb-free, T&R OB25136CCP SOP8, Pb-free, Tube OB25136CCPA SOP8, Pb-free, T&R -40 to 150 ℃ -20 to 85 ℃ -55 to 150 ℃ 260 ℃ Note: Stresses beyond 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 under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability. Recommended Output power Table AdapterNote1 Product 90V~264V OB25135C 10W OB25136C 12W Package Dissipation Rating Package RθJA (℃/W) SOP8 95 Recommended Operating Condition Symbol Parameter Range VDD VDD Supply Voltage 5 to 16V ©On-Bright Electronics Value 750V -0.3 to 20V -0.3 to 7V -0.3 to 7V Notes: 1. Maximum practical continuous power in an adapter design with sufficient drain pattern as a heat sink, at 40℃ ambient Confidential -2- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch Marking Information YWWZZZ OB25135CP C YWWZZZ OB25136CP C S Y:Year Code WW:Week Code(01-52) ZZZ:Lot Code C:SOP8 Package P:Pb-free Package C:Character Code S:Internal Code(Optional) S Y:Year Code WW:Week Code(01-52) ZZZ:Lot Code C:SOP8 Package P:Pb-free Package C:Character Code S:Internal Code(Optional) TERMINAL ASSIGNMENTS Pin Num Pin Name I/O 1 FB I 2 GND P Ground 3 4 VDD CS P I Power Supply Current sense input 5、6、7、8 C P HV BJT collector pin. ©On-Bright Electronics Description The voltage feedback from auxiliary winding. Connected to resistor divider from auxiliary winding reflecting output voltage. Confidential -3- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch BLOCK DIAGRAM ©On-Bright Electronics Confidential -4- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch ELECTRICAL CHARACTERISTICS (TA = 25℃, VDD=15V, if not otherwise noted) Symbol Parameter Supply Voltage (VDD) Section I start-up Start up current Test Conditions Min VDD=UVLO_OFF-1V Operation current without switching UVLO(OFF) VDD under voltage lockout exit UVLO(ON) VDD under voltage lockout enter VDD_OVP VDD over voltage protection VDD_max Max. Operating Voltage Current Sense Input Section TLEB LEB time Vth_ocp_min Minimum over current threshold Vth_ocp_max Maximum over current threshold Ton_max Maximum Ton Td_oc OCP propagation delay FB Input Section Reference voltage for feedback Vref_fb threshold Tpause_min Minimum Toff F_min Minimum frequency F_max Maximum frequency Maximum cable compensation Icomp_cable current Output Over Voltage Protection Vovp Output Over voltage threshold On chip Over temperature Section Over temperature protection T_otp trigger point Over temperature protection T_otp_rec recovery point I op 12 3.5 17 Typ. Max Unit 1 3 uA 0.77 1.0 mA 13 3.7 18 14 3.9 19 16 V V V V 0.33 500 555 40 100 485 2.475 450 90 515 2.500 2.525 V 2.0 500 us Hz KHz 550 53 2.85 us mV mV us ns 3.00 uA 3.15 V 165 ℃ 130 ℃ Power BJT Section Parameter Product Vceo(V) Note1 Vcbo(V)Note2 Collector-emitter breakdown voltage Collector-base voltage Min. Typ. Max. Min. Ic (A) Typ. breakdown Max. Collect Peak Current Min. Typ. OB25135 450 750 1.2 OB25136 450 750 1.6 Max. Note1：Test condition：Ic=10mA, Ib=0 Note2：Test condition：Ic=10mA ©On-Bright Electronics Confidential -5- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch CHARACTERIZATION PLOTS ©On-Bright Electronics Confidential -6- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch OPERATION DESCRIPTION OB2513xC is a cost effective PSR power switch optimized for off-line low power AC/DC applications including battery chargers. It operates in primary side sensing and regulation, thus opto-coupler and TL431 are not required. Proprietary built-in CV and CC control can achieve high precision CC/CV control meeting most charger application requirements. Startup Current and Startup Control Startup current of OB2513xC is designed to be very low so that VDD can be charged up quickly. A large value startup resistor can therefore be used to minimize the power loss in application. Figure 2 Auxiliary voltage waveform Via a resistor divider connected between the auxiliary winding and FB, the auxiliary voltage is sampled and hold during the demagnetization cycle. The sampling instance is variable according to the demagnetization width. The output voltage can be monitored when the secondary current is small. Thus ∆V can be ignored. The sampled voltage is compared with reference voltage Vref_EA and the difference is amplified by the error amplifier. The error amplifier output reflects the load condition and controls the switching off time to regulate the output voltage, thus constant output voltage can be achieved. When the sampled voltage is below Vref_EA and the error amplifier output reaches its maximum, the switching frequency is controlled by the sampled voltage to regulate the output current, thus the constant output current can be achieved. Operating Current The operating current of OB2513xC is as low as 550uA (typical). Good efficiency and low standby power is achieved with the low operating current. CC/CV Operation OB2513xC is designed to produce good CC/CV control characteristic as shown in the Figure. 1. In charger applications, a discharged battery charging starts in the CC portion of the curve until it is nearly full charged and smoothly switches to operate in CV portion of the curve. The CC portion provides output current limiting. In CV operation, the output voltage is regulated through the primary side control. In CC operation mode, OB2513xC will regulate the output current constant regardless of the output voltage drop. Adjustable CC Point and Output Power In OB2513xC, the CC point and maximum output power can be externally adjusted by external current sense resistor Rs at CS pin as illustrated in typical application diagram. The larger Rs, the smaller CC point is, and the smaller output power becomes, and vice versa as shown in Figure.3. Principle of Operation To support OB2513xC proprietary CC/CV control, system needs to be designed in DCM mode for flyback system (Refer to Typical Application Diagram on page1). In the DCM flyback converter, the output voltage can be sensed via the auxiliary winding. During BJT turn-on time, the load current is supplied from the output filter capacitor, Co. The current in the primary winding ramps up. When BJT turns off, the energy stored in the primary winding is transferred to the secondary side such that the current in the secondary winding is IS  NP  IP NS (1) Figure 3. Adjustable output power by changing Rs The auxiliary voltage reflects the output voltage as shown in Figure.2 and it is given by V AUX  N AUX  (VO  V ) NS On Time OCP Compensation The variation of max output current in CC mode can be rather large if no compensation is provided. The OCP threshold value is self adjusted higher at higher AC voltage. This OCP threshold slope adjustment helps to compensate the increased output current limit at higher AC voltage. In OB2513xC, a proprietary OCP compensation (2) Where V indicates the drop voltage of the output Diode. ©On-Bright Electronics Confidential -7- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch block is integrated and no external components are needed. The OCP threshold in OB2513xC is a function of the switching ON time. For the ON time less than 4.0us (typical), the OCP threshold changes linearly from 500mV (typical) to 555mV (typical). For the ON time larger than 4.0us (typical), the OCP threshold is clamped to 555mV (typical), as shown in Figure 4. 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 FB will increase. It can also be programmed by adjusting the resistance of the divider to compensate the drop for various cable lines used. The percentage of maximum compensation is 6 V I comp _ cable  R1 // R2 10  100% Vout 2.5 V is load compensation voltage and Vout is output voltage; For example: R1//R2=5.1Kohm, the percentage of maximum compensation is V 53  5100 10 6  100%  10.8% Vout 2.5 Figure.4. On time OCP compensation Operation Switching Frequency The switching frequency of OB2513xC is adaptively controlled according to the load conditions and the operation modes. For flyback operating in DCM, The maximum output power is given by Po MAX  1 LP FSW I p2 2 Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in OB2513xC. The switch current is detected by a sense resistor into the CS pin. An internal leading edge blanking circuit chops off the sensed voltage spike at initial power BJT on state so that the external RC filtering on sense input is no longer needed. (3) Where Lp indicate the inductance of primary winding and Ip is the peak current of primary winding. Refer to the equation 3, the change of the primary winding inductance results in the change of the maximum output power and the 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  1 2TDemag Protection Control Good power supply system reliability is achieved with its rich protection features including Cycle-by-Cycle current limiting (OCP), Output over voltage protection, VDD over voltage protection, short circuit protection, Under Voltage Lockout on VDD (UVLO) and over temperature protection (OTP). VDD is supplied by transformer auxiliary winding output. The output of OB2513xC is shut down when VDD drops below UVLO (ON) and the power converter enters power on start-up sequence thereafter. To prevent the circuit being damaged under abnormal conditions, OB2513xC provides over thermal protection function. When the die temperature rises above over temperature threshold T_otp, the OB2513xC will shut down the base output and then latch the power supply off. The controller will remains latched until the die temperature drops below the recovery threshold T_otp_rec and the OB2513xC will reset at the same time. (4) Since TDemag is inversely proportional to the switching frequency, 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 ± 7% variation of the primary winding inductance can be compensated. Programmable Cable Drop Compensation In OB2513xC, cable drop compensation is implemented to achieve good load regulation. An offset voltage is generated at FB pin by an internal current flowing into the resister divider. The current is proportional to the switching off time, as a result, it is inversely proportional to the output load ©On-Bright Electronics Confidential -8- Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch PACKAGE MECHANICAL DATA Symbol A A1 A2 b c D E E1 e L θ ©On-Bright Electronics Dimensions In Millimeters Min Max 1.350 1.750 0.050 0.250 1.250 1.650 0.310 0.510 0.170 0.250 4.700 5.150 3.800 4.000 5.800 6.200 1.270 (BSC) 0.400 1.270 0º 8º Confidential -9- Dimensions In Inches Min Max 0.053 0.069 0.002 0.010 0.049 0.065 0.012 0.020 0.006 0.010 0.185 0.203 0.150 0.157 0.228 0.244 0.05 (BSC) 0.016 0.050 0º 8º Preliminary datasheet OB_DOC_DS_2513xC04 OB2513xC High Precision CC/CV Primary-Side PWM Power Switch IMPORTANT NOTICE RIGHT TO MAKE CHANGES On-Bright Electronics Corp. reserves the right to make corrections, modifications, enhancements, improvements and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. WARRANTY INFORMATION On-Bright Electronics Corp. warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with its standard warranty. Testing and other quality control techniques are used to the extent it deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. On-Bright Electronics Corp. assumes no liability for application assistance or customer product design. Customers are responsible for their products and applications using On-Bright’s components, data sheet and application notes. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. LIFE SUPPORT On-Bright Electronics Corp.’s products are not designed to be used as components in devices intended to support or sustain human life. On-bright Electronics Corp. will not be held liable for any damages or claims resulting from the use of its products in medical applications. MILITARY On-Bright Electronics Corp.’s products are not designed for use in military applications. On-Bright Electronics Corp. will not be held liable for any damages or claims resulting from the use of its products in military applications. ©On-Bright Electronics Confidential - 10 - Preliminary datasheet OB_DOC_DS_2513xC04