OB2506PCPA

OB2506x Ni battery charger IC GENERAL DESCRIPTION FEATURES OB2506x is a highly integrated current mode PFM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. 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, multimode operations are utilized to achieve high performance and high efficiency. Device operates in PFM in CC mode at heavy load condition and it operates in PWM with frequency reduction at medium load. When the load is very small, the IC operates in ‘Extended Burst Mode’ to minimize the standby power loss. As a result, high conversion efficiency can be achieved in the whole loading range. OB2506x offers comprehensive protection coverage with auto-recovery feature including Cycle-by-Cycle current limiting, VCC over voltage protection, built-in leading edge blanking, VCC under voltage lockout (UVLO), OTP etc. OB2506x is offered in SOP8 and DIP8 packages. ■ ■ ■ en t ia lt o ■ 源 ■ ■ ■ 科 ■ 汇 ■ Extended burst mode control for improved efficiency and low standby power design High precision constant voltage and current regulation at universal AC input Multi-mode PWM/PFM operation for efficiency improving Integrated 1A/2A MOSFET Programmable CV and CC regulation Built-in primary winding inductance compensation Built-in leading edge blanking (LEB) Ultra low start-up current and low operating current. Comprehensive protection coverage with auto-recovery o On-chip OTP o VCC over voltage protection o VCC under voltage lockout with hysteresis (UVLO) o Cycle-by-Cycle current limiting o Output over voltage protection APPLICATIONS co n fid Offline AC/DC flyback converter for ■ General power supply ■ Power Adapter ht Figure.1. Typical CC/CV Curve O n- Br ig TYPICAL APPLICATION ©On-Bright Electronics Confidential -1- Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC Value -0.3V to Bvdss -0.3 to 28V -0.3 to 7V -0.3 to 7V -0.3 to 7V -40 to 150 ℃ -20 to 85 ℃ 科 Pin Configuration 源 Absolute Maximum Ratings Parameter Drain Voltage (off state) VCC Voltage AUX Input 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) GENERAL INFORMATION -55 to 150 ℃ 260 ℃ 汇 Ordering Information Part Number Description OB2506NCP SOP8, Halogen-free in Tube OB2506NCPA SOP8, Halogen-free in T&R OB2506PCP SOP8, Halogen-free in Tube OB2506PCPA SOP8, Halogen-free in T&R OB2506PAP DIP8, Halogen-free in Tube o 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. ia lt Package Dissipation Rating Package RJA(℃/W) SOP8 95 DIP8 70 Output Power Table Part Number 90Vac~264Vac OB2506NCP 5W OB2506PCP 12W OB2506PAP 12W fid en t Recommended operating condition Symbol Parameter Range VCC VCC Supply Voltage 8 to 25V co n OB2506x Package C:SOP8 A:DIP8 X X Green Package P:Halogen-free Packing Blank:Tube A: Tape/Reel ht Ni battery charger IC X Br ig Marking Information O n- YWWZZZ OB2506NCP S Y:Year Code WW:Week Code(01-52) ZZZ:Lot Code C:SOP8 Package P:Halogen-free Package S:Internal Code(Optional) ©On-Bright Electronics Confidential -2- Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC TERMINAL ASSIGNMENTS I/O Description VCC P Power Supply CS I Current sense input AUX I The voltage feedback from auxiliary winding. Connected to resistor divider from auxiliary winding reflecting output voltage. GND P Ground Drain O Drain of internal power MOSFET FB I Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and the current-sense signal at Pin CS. 汇 科 源 Pin Name ia lt o FUNCTIONAL BLOCK DIAGRAM VDD Drain Gate Driver en t UVLO 5V POR Internal Supply fid OVP AUX co n Output OVP CC Controller Logic core OCP CS Vcs CV Controller GND LEB O n- Br FB ig ht AVDD LEB ©On-Bright Electronics Confidential -3- Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC ELECTRICAL CHARACTERISTICS 18.2 6.5 7.0 26.0 20.5 V 7.5 V 28.5 V 25 V 科 16.0 27.0 o 485 500 ns 515 590 co n ht ig Br mV 5 V 4.8 V/V 1.05 V 0.95 V 15 35 KΩ uA 2.8 3.0 3.2 V 135 150 165 ℃ 105 120 135 ℃ 600 Confidential -4- mV mV 150 Static drain to source on OB2506N resistance OB2506P ©On-Bright Electronics mA 300 O nRdson Unit 源 0.7 fid VCC_OVP Max. Operating Voltage Current Sense Input Section TLEB LEB time Minimum over current Vth_ocp_min threshold Maximum over current Vth_ocp_max threshold Vcs_min CS minimum threshold Feedback Input Section(FB Pin) VFB Open VFB Open Loop Voltage PWM input gain Avcs ∆VFB/∆VCS The threshold exits burst Vref_burst_H mode The threshold enters burst Vref_burst_L mode Rfb FB pin pull high resistor Ifb FB pin pull high current Output Over Voltage Protection Output Over voltage V_OVP threshold On chip Over temperature Section Over temperature protection T_otp trigger point Over temperature protection T_otp_rec recovery point MOSFET Section Mosfet Drain-Source BVdss Breakdown Voltage Max uA ia lt UVLO(ON) VCC under voltage lockout exit VCC under voltage lockout enter VCC over voltage protection Typ. 5 en t UVLO(OFF) Min 汇 (TA = 25℃, VCC=18V, unless otherwise noted) Symbol Parameter Test Conditions Supply Voltage (VCC) Section VCC=UVLO_OFFI start-up Start up current 1V I static Static current V 8 4 Ώ Ώ Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC CHARACTERIZATION PLOTS VCC = 18V, TA = 25℃ condition applies if not otherwise noted. 2 4 6 8 科 源 800 700 600 500 400 300 200 100 0 10 12 14 16 18 20 22 汇 Istatic(uA) VDD vs Istatic o VDD(V) ia lt 7.50 7.30 7.10 6.90 6.70 6.50 -40 -10 20 50 80 en t UVLO(ON)(V) UVLO(ON)(V) vs Temperature 110 140 co n fid Temperature( ℃) 0.480 0.440 0.400 ht 0.600 0.560 0.520 ig Vocp(V) Vocp(V) vs Tem perature -10 20 50 80 110 140 Temperature(℃) O n- Br -40 ©On-Bright Electronics Confidential 5 Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC OPERATION DESCRIPTION OB2506x is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. The ‘extended burst mode’ control greatly reduces the standby power consumption and helps the design easier to meet the international power conservation requirements. Sampling Instance VAUX 科 TDemag Startup Current and Start up Control Startup current of OB2506x is designed to be very low so that VCC could be charged up above UVLO threshold level and device starts up quickly. A large value startup resistor can therefore be used to minimize the power loss yet achieve a reliable startup in application. 源 PWM Off TON 汇 PWM On o Figure.2. Auxiliary voltage waveform Via a resistor divider connected between the auxiliary winding and AUX pin , the auxiliary voltage is sampled at the middle of the demagnetization and it is hold until the next sampling. The sampled voltage is compared with reference voltage V_ovp (typical 3V). When the sampled voltage is higher than V_ovp OB2506x will stop switching and enter output OVP mode. ia lt Operating Current The Operating current of OB2506x is low at 0.7mA (typical). Good efficiency is achieved with OB2506x low operation current together with the ‘extended burst mode’ control features. Adjustable CC Point and Output Power In OB2506x series, the CC point and maximum output power can be externally adjusted by external current sense resistor Rs at CS pin as illustrated in the 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. co n fid en t CC/CV Operation OB2506x 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 secondary side control. O n- Br ig ht Principle of Operation To support OB2506x series proprietary CC/CV control, system needs to be designed in DCM mode for flyback system (Refer to Typical Application Diagram in page1). In the DCM flyback converter, the output voltage can be sensed via the auxiliary winding. During MOSFET turn-on time, the load current is supplied from the output filter capacitor, Co, and the current in the primary winding ramps up. When MOSFET turns off, the energy stored in the primary winding is transferred to the secondary side and the current in the secondary winding is IS  NP  IP NS Figure.3. Adjustable output power by changing Rs Operation Switching Frequency The switching frequency of OB2506x is adaptively controlled according to the load conditions and the operation modes. For flyback operating in DCM, the maximum output power is given by (1) The auxiliary voltage reflects the output voltage as shown in Figure.2 and it is given by V AUX N  AUX  (VO  V ) NS Po MAX  (2) (3) Where Lp indicate the inductance of primary winding and Ip is the peak current of primary winding. Where V indicates the voltage drop of the output Diode. ©On-Bright Electronics 1 LP FSW I p2 2 Confidential 6 Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC The maximum CS threshold voltage Vcs_max is given by 1 Naux Ros (5) Vcs _ max  Vth _ ocp    2  Vac  Rup M Np Where Vth_ocp a threshold determined by internal CC comp voltage, M is the FB current mirror ratio(M=32), Naux/Np is the auxiliary winding to primary winding turns ratio, Vac is the effective voltage of input voltage, Ros is the internal line compensation offset resistor(Ros=2.63Kohm) , Rup is the external AUX PIN up side resistor. 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 and the switching frequency is 1 (4) 2TDemag 源 FSW  科 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. 汇 Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in OB2506x. 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 MOSFET on state so that the external RC filtering on sense input is no longer needed. ia lt o CC Line Voltage Compensation The variation of maximum output current in CC mode can be rather large at high input voltage (such as 264Vac) if no compensation is provided. The CC threshold value is self adjusted higher at higher AC voltage due to CC propagation delay. In OB2506x, the AC line voltage information is sampled through detecting AUX sourcing current when gate turns on, and the AC line voltage information is added to the CS pin voltage. So the maximum CS threshold voltage Vcs_max in OB2506x is a function of the CC threshold and AC line voltage information as shown in Figure4. ht co n fid en t Protection Control Good power supply system reliability is achieved with its rich protection features including precise on-chip OTP, cycle-by-cycle current limiting (OCP), output over voltage protection, VCC over voltage protection, under voltage lockout on VCC (UVLO). VCC is supplied by transformer auxiliary winding output. The output of OB2506x is shut down when VCC drops below UVLO (ON) and the power converter enters power on start-up sequence thereafter. O n- Br ig Figure.4. CC line voltage compensation ©On-Bright Electronics Confidential -7- Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC co n fid en t ia lt o 汇 科 源 PACKAGE MECHANICAL DATA O n- Br ig A A1 A2 b c D E E1 e L θ Dimensions In Millimeters Min Max 1.350 1.750 0.050 0.250 1.250 1.650 0.310 0.510 0.100 0.250 4.700 5.150 3.800 4.000 5.800 6.200 1.270 (BSC) 0.400 1.270 0º 8º ht Symbol ©On-Bright Electronics Confidential -8- Dimensions In Inches Min Max 0.053 0.069 0.002 0.010 0.049 0.065 0.012 0.020 0.004 0.010 0.185 0.203 0.150 0.157 0.228 0.244 0.050 (BSC) 0.016 0.050 0º 8º Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC co n fid en t ia lt o 汇 科 源 DIP8 PACKAGE OUTLINE DIMENSIONS O n- Br ig A A1 A2 B B1 C D E E1 e L E2 Dimensions In Millimeters Min Max 3.710 5.334 0.381 2.921 4.953 0.350 0.650 1.524 (BSC) 0.200 0.360 9.000 10.160 6.096 7.112 7.320 8.255 2.540 (BSC) 2.921 3.810 7.620 10.920 ht Symbol ©On-Bright Electronics Confidential -9- Dimensions In Inches Min Max 0.146 0.210 0.015 0.115 0.195 0.014 0.026 0.06 (BSC) 0.008 0.014 0.354 0.400 0.240 0.280 0.288 0.325 0.1 (BSC) 0.115 0.150 0.300 0.430 Preliminary Datasheet OB_DOC_DS_2506x00 OB2506x Ni battery charger IC IMPORTANT NOTICE 源 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. o 汇 科 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. ia lt 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. O n- Br ig ht co n fid en t 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_2506x00