OB2269

OB2269 Description CR MI JS The OB2269 is a highly integrated currentmode PWM controller IC for those high output power of off line flyback convertor. The output power is up to 120W. OB2269 is integrated start-up circuit that realizes low quiescent dissipation and overload compensation. OB2269 has comprehenisve protecit onf eature to ensure reliability of application system. The packaging of OB2269 has SOP8 and DIP8.   Features    Applications    Digital Cameras Charger Power adaptor Battery charger r to uc d on ic   m Se  O  Digit frequency shuffling technology to improve EMI performance. External programmable PWM switching frequency. Leading edge Blanking on current sense input. Internal synchronized slope compensation . Burst mode control to improve efficiency and optimize standby power consumption. Low start-up current and low operating current. Comprehensive protection functions 1 、 Under voltage locked with hysteresis (UVLO) on VDD 2、Over voltage protection (OVP) on VDD. 3、Cycle-by-Cycle current limitation 4、Over load protection (OLP) 5、Over temperature protection (OTP) Current limitation compensation to obtain the same output current in universal AC line input. 800mA Drive Capability www.jsmsemi.com 第１／１１页 OB2269 Application Circuit O CR MI JS Pin Assignment & Marking Information r to uc d on ic m Se 2269CP www.jsmsemi.com 第２／１１页 OB2269 Ordering Information Part number OB2269 OB2269 Package SOP-8 DIP-8 Pin Description 1 2 3 4 Type Description GND P Ground. FB I Feedback input pin. VIN I Start-up and overload compensation current input pin RI I/O Internal oscillator frequency setting pin. RT I/O Temperature sensing input pin,connected through a NTC O 5 Symbol CR MI JS Pin Number resistor to GND. I 7 VDD P 8 GATE O Current sense input pin. Chip DC power supply pin. Totem-pole gate diver. Recommended Out Power Product OB2269 Input:230VAC±15% Adapter 120W www.jsmsemi.com Input:85-264VAC r to uc d on ic SENSE m Se 6 Adapter 90W 第３／１１页 OB2269 Block Diagram O CR MI JS Value Unit 30 V 32 V 10 mA -0.3 to 7 V VDD/VIN Input voltage VDD clamp voltage VDD clamp continuous current FB input voltage r to uc d on ic Parameter m Se Absolute Maximum Rating SENSE input voltage -0.3 to 7 V RT input voltage -0.3 to 7 RI input voltage -0.3 to 7 Operating ambient temperature -20 to 85 ℃ Min/Max operating junction temperature -55 to 150 ℃ V V Thermal resistance,Junction to ambient SOP8 150 ℃/W Thermal resistance,Junction to ambient DIP8 100 ℃/W Note: Stresses above absolute maximum ratings may cause permanents damage to the device. Exposure to absolutely maximum-rated conditions for extended periods may affects device reliability www.jsmsemi.com 第４／１１页 OB2269 Recommended Operating Conditions Symbol VDD TA Parameter Supply Voltage Operating Ambient Temperature Min. 8 -20 Max. 25 85 Unit V ℃ ESD Information Symbol HBM Test Conditions CR MI JS MM Parameter Human body model on all pins Machine model on all pins Min. Typ. Max. Unit JEDEC-STD 3 KV JEDEC-STD 250 V Electrical Characteristics (TA = 25 ℃ without special notation ) Symbol Parameter O Supply Voltage (VDD Pin) Idd_start-up VDD start-up current VDD operating current UVLO (enter) VDD under voltage lockout enter VDD under voltage lockout exit VDD over voltage protection enter VDD clamp voltage VDD_clamp Voltage Feedback (FB Pin) AVCS PWM input gain VFB_open open loop voltage Idd = 10mA ΔVFB / ΔVSENSE Burst mode voltage 6 10 2.3 uA mA 8.5 9 10 V 14.5 15 16 V 25.5 26.5 27.5 V 29 30 31 V 2.8 5.8 V/V V 1.1 V r to uc VFB_burst d on ic OVP(enter) VDD=12.5V, RI=24K VDD=18V, RI=24K , FB=3.6V m Se Idd UVLO(exit) Value Unit Min. Typ. Max Conditions IFB_short FB pin short current Short FB pin to GND and measure current 780 uA VTH_PL Power limiting FB threshold voltage Iout =－10mA 3.7 V TD_PL Power limiting delay time Current Sense(CS Pin) Leading-edge blanking T_blanking time ZSENSE_IN Input impedance Current limitation threshold VTH voltage Oscillator(RI Pin) 80 I(VIN)= 0 uA www.jsmsemi.com mS 250 nS 30 K 0.85 V 第５／１１页 OB2269 Normal oscillation frequency Frequency temperature stability Fosc Δf_temp Δf_VDD Frequency voltage stability RI_range Operating resistor range VRI Voltage of RI to GND Fosc_BM Burst mode base frequency DC_MAX Maximum duty cycle VOH V_Clamp T_f 12 65 Output low level VDD=18V, IO=-20mA Output high level VDD=18V, IO=20mA output clamp voltage level 70 Khz 2 % 2 % 24 60 K 2 V 25 Khz 80 % -5 +5 % 0.3 V 11 V 16 V Output rising time VDD=18V, CL=1nF 110 nS Output falling time VDD=18V, CL=1nF 40 nS O T_r TA -20℃ to 100℃ VDD=16V, RI=24K VDD=12V to 25V RI=24K VDD=18V, FB=3V SENSE=0V CR MI JS VOL 60 RI=24K Frequency modulation range /Base frequency Gate Drive Output(GATE Pin) Δf_OSC RI=24K m Se Over Temperature Protection (RT pin) Output current of RT pin 70 uA V_OTP OTP threshold voltage OTP recovery threshold voltage OTP delay time 0.65 V 0.8 V 100 uS 2 mS V_OTP_off T_OTP Start up and Current limitation compensation (VIN pin) Current limitation G_VIN ΔIVIN/ΔVCS compensation gain www.jsmsemi.com r to uc d on ic I_RT 第６／１１页 OB2269 Application Information The OB2269 is a highly integrated current mode PWM controller IC for those high output power of off line flyback convertor. The output power is up to 120W. Its main features are optimized for OB2269 in driving capability, quiescent dissipation, current limitation compensation and low cost and reliability. Start-up Current and Start-up Control OB2269 has very low start-up current that is less than 10uA. Therefore, the voltage of VDD could be CR MI JS charged up above UVLO(exit ) threshold level quickly. A large value resistor can be used in the start-up circuit to minimize quiescent dissipation. The typical resistance value of resistor is 2M Ohms in start-up circuit of OB2269 The start-up resistor can be connected with the VIN pin or the capacitor of VDD to provide start-up current. O Operating Current m Se The Operating current of OB2269 is less than 2.3mA. Therefore, OB2269 can have good efficiency. Frequency shuffling for EMI improvement Burst Mode Operation d on ic The frequency Shuffling is implemented in OB2269 The oscillation frequency is modulated with a random source so that the harmonic energy is spread out. The spread spectrum minimizes the conduction EMI and therefore reduces system design challenge. r to uc At zero load or light load condition, the main power dissipation in a switching mode power supply is from switching on the MOSFET, the core of transformer and the snubber circuit. The magnitude of power dissipation is proportional to the number of switching frequency within certain period. Less switching frequency can reduce the power dissipation.OB2269 adjusts the switching frequency according to the loading condition. From light load to no load, the FB voltage drops. While the FB voltage is less than 1.1V, the gate pin output is disabled and kept low, while the FB voltage is higher than 1.2V, the gate output recovers to normal working mode. To reduce audio noise, the switching frequency will be kept higher than 20KHz in burst mode. Oscillator Operation The oscillating frequency of OB2269 is set by the externally resistor between the RI pin and the GND pin. It is recommended that the range of oscillation frequency is in between 20KHz and www.jsmsemi.com 第７／１１页 OB2269 100KHz. The relationship between the resistor and the oscillation frequency follows below equation. Fosc  1625 (KHz) RI (K) 1 Current Sensing and Leading-Edge Blanking Cycle-by-Cycle current limitation is offered in OB2269. The switching current is detected by a resistor into the SENSE pin. An internal leading-edge blanking circuit chops off the SENSE voltage spike at initial so that the external RC filtering on SENSE pin is no longer required. The current CR MI JS limiting comparator is disabled and thus cannot turn off the external MOSFET during the blanking period. PWM duty cycle is determined by the voltage in the SENSE pin and the FB pin Internal Synchronized Slope Compensation Built-in slope compensation circuit adds voltage ramp onto the current sense input voltage for O PWM generation. This greatly improves the close loop stability at CCM and prevents the Over Temperature Protection m Se sub-harmonic oscillation and thus reduces the output ripple voltage. d on ic OB2269 is specially optimized for the high output power system. If the temperature from the environment or the component is too high, it results in the system damage.OB2269 provides the function of temperature sensing and the function of over temperature protection. The voltage on the RT pin is determined by resistor between the RT pin and the GND pin. The resistor is usually a r to uc NTC resistor. With the Fixed internal current flowing through the resistor, the voltage on the RT pin varies with the resistance value of NTC resistor. When the voltage on the RT pin is less than 0.65V, OB2269 is shut down and recovers when the voltage on the RT pin is higher than 0.8V. Gate Drive OB2269 Gate pin is used to drive Gate of the external MOSFET. OB2269 has 800mA of sinking and sourcing current that can minimize the switching dissipation of the MOSFET. Therefore, higher efficiency can be obtained. The internally totem pole circuit of the GATE pin can control the MOSFET to be turned on slowly and turned off faster. There is very good compromise between high efficiency and low radiation EMI. www.jsmsemi.com 第８／１１页 OB2269 Protection Controls OB2269 has comprehensive protection functions, including Cycle-by- Cycle current limitation (OCP), Over Load Protection (OLP) and over voltage clamp, Under Voltage Lockout on VDD (UVLO), Over Temperature Protection (OTP). Current limitation compensation O CR MI JS To obtain the same output current capability in the universal AC line voltage range, OB2269 has current limitation compensation. To obtain good current limitation compensation, the start-up resistor must be connected with the VIN pin. r to uc d on ic m Se www.jsmsemi.com 第９／１１页 OB2269 Package Information： SOP-8 O CR MI JS r to uc d on ic m Se www.jsmsemi.com 第１０／１１页 OB2269 DIP-8 O CR MI JS r to uc d on ic m Se www.jsmsemi.com 第１１／１１页