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OB2273MP

OB2273MP

  • 厂商:

    ob(昂宝)

  • 封装:

    SOT23-6

  • 描述:

    高性能电流型PWM控制器

  • 数据手册
  • 价格&库存
OB2273MP 数据手册
OB2273 High Performance Current Mode PWM Controller GENERAL DESCRIPTION FEATURES OB2273 is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. PWM switching frequency at normal operation is internally fixed and is trimmed to tight range. At no load or light load condition, the IC operates in extended ‘burst mode’ to minimize switching loss. Lower standby power and higher conversion efficiency is thus achieved. VDD low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2273. OB2273 offers complete protection coverage with auto-recovery including Cycle-by-Cycle current limiting (OCP), over load protection (OLP), and VDD under voltage lockout (UVLO). It also provides the protections with latched shut down including over temperature protection (OTP), and over voltage (fixed or adjustable) protection (OVP). Excellent EMI performance is achieved with OnBright proprietary frequency shuffling technique. The tone energy at below 20KHZ is minimized in the design and audio noise is eliminated during operation. ■ 科 nt i al to ■ ■ ■ 乐 ■ ■ Power on Soft Start Reducing MOSFET Vds Stress Frequency shuffling for EMI Extended Burst Mode Control For Improved Efficiency and Minimum Standby Power Design Audio Noise Free Operation Fixed 65KHZ Switching Frequency Comprehensive Protection Coverage o VDD Under Voltage Lockout with Hysteresis (UVLO) o Cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range o Overload Protection (OLP) with autorecovery o Over Temperature Protection (OTP) with latch shut down o VDD Over voltage Protection(OVP) with latch shut down o Adjustable OVP through external Zener id e APPLICATIONS Co nf OB2273 is offered in SOT23-6 and DIP-8 package. Offline AC/DC flyback converter for ■ Battery Charger ■ Power Adapter ■ Set-Top Box Power Supplies ■ Open-frame SMPS On Br i gh t TYPICAL APPLICATION ©On-Bright Electronics Confidential -1- Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller Pin Configuration The OB2273 is offered in SOT23-6 and DIP8 package, shown as below. 乐 Package Dissipation Rating Package RθJA(℃/W) SOT23-6 200 DIP8 90 科 Ordering Information Part Number Description OB2273MP SOT23-6, Pb-free in T&R OB2273AP DIP8, Pb-free in Tube GENERAL INFORMATION id e nt i al to Absolute Maximum Ratings Parameter Value VDD DC Supply Voltage 30 V VDD Zener Clamp VDD_Clamp+0.1V VoltageNote VDD DC Clamp Current 10 mA FB Input Voltage -0.3 to 7V Sense Input Voltage -0.3 to 7V RT Input Voltage -0.3 to 7V Min/Max Operating -40 to 150 ℃ Junction Temperature TJ Min/Max Storage -55 to 160 ℃ Temperature Tstg Lead Temperature 260 ℃ (Soldering, 10secs) Note: VDD_Clamp has a nominal value of 32V. Br i gh t Co nf 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. OB2273 On Current Mode PWM Controller with Frequency shuffling ©On-Bright Electronics X Package M:SOT23-6 A: DIP8 Confidential -2- X Package Pb free Blank:Normal P:lead-free Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller Marking Information 科 73YWW 乐 S nt i al to Y:Year Code WW:Week Code(01-52) S:Internal Code(Optional) TERMINAL ASSIGNMENTS I RT I CS VDD Gate I P O id e FB Description Ground Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and the current-sense signal at Pin 4. Dual function pin. Either connected through a NTC resistor to ground for over temperature shutdown/latch control or connected through Zener to VDD for adjustable over voltage protection Current sense input Power Supply Totem-pole gate driver output for power Mosfet nf I/O P Co Pin Name GND Parameter VDD Supply Voltage Operating Ambient Temperature Min/Max 12 to 25 -40 to 85 Unit V ℃ On Br i Symbol VDD TA gh t RECOMMENDED OPERATING CONDITION ©On-Bright Electronics Confidential -3- Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller On Br i gh t Co nf id e nt i al to 乐 科 BLOCK DIAGRAM ©On-Bright Electronics Confidential -4- Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller ELECTRICAL CHARACTERISTICS VDD Start up Current I_VDD_Operation Operation Current Over voltage voltage OVP(ON) protection Ivdd=10mA CS=0V,FB=3V Ramp up VDD until gate clock is off nf id e Vlatch_release Latch release voltage Feedback Input Section(FB Pin) VFB_Open VFB Open Loop Voltage PWM input gain Δ VFB/ Δ Avcs VCS Maximum duty Max duty cycle @ cycle VDD=18V,VFB=3V,VCS=0V The threshold enter green Vref_green mode Vref_burst_H The threshold exit burst mode The threshold enter burst Vref_burst_L mode FB pin short circuit current Co IFB_Short VTH_OC Vocp_clamping Oscillator Normal Oscillation Frequency △f_OSC F_shuffling Frequency jittering Shuffling frequency ©On-Bright Electronics 5 20 uA 1.8 2.5 mA 14.3 15.3 -5- V V V 26 28 30 V 3.9 75 60 5 V 4.2 V 2 V/V 80 85 % 2 V 1.275 V 1.175 V 0.4 mA 3.7 V 88 96 mSec 16 Kohm 4 220 40 ms ns Kohm 120 nSec 0.75 V 0.9 V 65 +/-4 32 Confidential 16.3 34 From Over Current Occurs till the Gatedrive output start to turn off FB=3V, V 13 32 80 VDD=18V, CS=0V 10 30 Internal Current Limiting Threshold Voltage with zero duty cycle CS voltage clamper FOSC Unit 9 gh t Br i On TD_OC Over Current Detection and Control Delay Max 8 Short FB pin to GND and measure current Power Limiting FB Threshold Voltage Power limiting Debounce TD_PL Time ZFB_IN Input Impedance Current Sense Input(CS Pin) SST Soft start time T_blanking Leading edge blanking time ZSENSE_IN Input Impedance VTH_PL Typ to Vpull-up Vdd_clamp VDD Under Voltage Lockout Enter VDD Under Voltage Lockout Exit (Recovery) Pull-up PMOS active al UVLO(OFF) VDD=UVLO(OFF)1V, measure leakage current into VDD VDD=18V,VFB=3V, CS=0V,Cgate=1nF nt i UVLO(ON) Min 科 Istartup Test Conditions 乐 (TA = 25℃, VDD=18V, unless otherwise noted) Symbol Parameter Supply Voltage (VDD) 70 KHZ % Hz Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller △f_VDD F_Burst Gate driver Frequency Temperature Stability Frequency Voltage Stability Burst Mode Switch Frequency Output low level @ VDD=18V, Io=5mA Output high level @ VOH VDD=18V, Io=20mA V_clamping Output clamp voltage Output rising time 1V ~ 12V T_r @ CL=1000pF Output falling time 12V ~ 1V T_f @ CL=1000pF Over temperature protection IRT Output current of RT pin VOTP Threshold voltage for OTP Td_OTP OTP debounce time VRT_FL Float voltage at RT pin External OVP threshold Vth_OVP voltage 1 % 1 22 % KHZ VOL 1 6 V 科 △f_Temp V 乐 12 nS 85 nS to 175 100 1 32 2.3 4 105 1.05 uA V Cycle V V On Br i gh t Co nf id e nt i al 95 0.95 V ©On-Bright Electronics Confidential -6- Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller CHARACTERIZATION PLOTS VDD = 18V, TA = 25℃ condition applies if not otherwise noted. Istartup(uA) vs Temperature(℃ ) Vth_otp(V) vs Temperature(℃ ) 3.5 乐 4.0 1.01 1.00 0.99 0.98 3.0 -40 0 40 80 -40 120 80 120 al UVLO(on)(V) vs Temperature(℃ ) UVLO(off)(V) vs Temperature(℃ ) 15.4 15.2 15 UVLO(off)(V) nt i 9.6 9.4 id e 9.2 9 8.8 0 40 80 14.8 14.6 14.4 120 -40 0 nf -40 Temperature(℃ ) Co 0.95 120 64.0 Fosc(KHz) gh t 0.85 0.80 Br i 80 Fosc(KHz) vs Temperature(℃ ) 0.90 63.8 63.5 63.3 63.0 0.75 14 28 42 Duty(%) 56 -40 70 0 40 80 120 Temperature(℃) On 0 40 Temperature(℃ ) Vth_OC(V)vs duty(%) Vth_OC(V) 40 Temperature(℃) Temperature(℃) UVLO(on)(V) 0 to 4.5 科 1.02 Vth_otp(V) Istartup(uA) 5.0 ©On-Bright Electronics Confidential 7 Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller OPERATION DESCRIPTION OB2273 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 easily to meet the international power conservation requirements. 乐 科 Vref_burst_L (the threshold enter burst mode) and device enters Burst Mode control. The Gate drive output switches when FB input rises back to Vref_burst_H (the threshold exit burst mode). Otherwise the gate drive remains at off state to minimize the switching loss and reduces the standby power consumption to the greatest extend. The switching frequency control also eliminates the audio noise at any loading conditions. • Startup Current and Start up Control Startup current of OB2273 is designed to be very low so that VDD 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. to al Co nf id e • Soft Start OB2273 features an internal 4ms soft start to soften the electrical stress occurring in the power supply during startup. It is activated during the power on sequence. As soon as VDD reaches UVLO(OFF), the CS peak voltage is gradually increased from 0.05V to the maximum level. Every restart up is followed by a soft start. • Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in OB2273 current mode PWM control. 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 internal power MOSFET on state due to snubber diode reverse recovery and surge gate current of power MOSFET. The current limiting comparator is disabled and cannot turn off the internal power MOSFET during the blanking period. The PWM duty cycle is determined by the current sense input voltage and the FB input voltage. nt i • Operating Current The Operating current of OB2273 is low at 1.8mA. Good efficiency is achieved with OB2273 low operating current together with the ‘Extended burst mode’ control features. • Oscillator Operation The switching frequency is internally fixed at 65KHZ. No external frequency setting components are required for PCB design simplification. • Internal Synchronized Slope Compensation Built-in slope compensation circuit adds voltage ramp onto the current sense input voltage for PWM generation. This greatly improves the close loop stability at CCM and prevents the subharmonic oscillation and thus reduces the output ripple voltage. gh t • Frequency shuffling for EMI improvement The frequency Shuffling (switching frequency modulation) is implemented in OB2273. The oscillation frequency is modulated so that the tone energy is spread out. The spread spectrum minimizes the conduction band EMI and therefore eases the system design. Br i • Drive The power MOSFET is driven by a dedicated gate driver for power switch control. Too weak the gate drive strength results in higher conduction and switch loss of MOSFET while too strong gate drive results the compromise of EMI. A good tradeoff is achieved through the built-in totem pole gate design with right output strength and dead time control. The low idle loss and good EMI system design is easier to achieve with this dedicated control scheme. On • Extended Burst Mode Operation At light load or zero load condition, most of the power dissipation in a switching mode power supply is from switching loss on the MOSFET, the core loss of the transformer and the loss on the snubber circuit. The magnitude of power loss is in proportion to the switching frequency. Lower switching frequency leads to the reduction on the power loss and thus conserves the energy. The switching frequency is internally adjusted at no load or light load condition. The switch frequency reduces at light/no load condition to improve the conversion efficiency. At light load or no load condition, the FB input drops below ©On-Bright Electronics • Confidential 8 Protection Controls Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller Good power supply system reliability is achieved with auto-recovery protection features including Cycle-by-Cycle current limiting (OCP), Over Load Protection (OLP), and Under Voltage Lockout on VDD (UVLO), and latch shutdown features including over temperature protection (OTP), fixed or adjustable VDD over voltage protection (OVP). With On-Bright Proprietary technology, the OCP is line voltage compensated to achieve constant output power limit over the universal input voltage range. On Br i gh t Co nf id e nt i al to 乐 科 At overload condition when FB input voltage exceeds power limit threshold value for more than TD_PL, control circuit reacts to shut down the converter. It restarts when VDD voltage drops below UVLO limit. For protection with latch shut down mode, control circuit shutdowns (latch) the power MOSFET when an Over Temperature condition or Over Voltage condition is detected until VDD drops below 5V (Latch release voltage) , and device enters power on restart-up sequence thereafter. ©On-Bright Electronics Confidential -9- Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller Co nf id e nt i al to 乐 科 PACKAGE MECHANICAL DATA On Br i A A1 A2 b c D E E1 e e1 L θ Dimensions In Millimeters Min Max 1.000 1.300 0.000 0.150 1.000 1.200 0.300 0.500 0.100 0.200 2.800 3.020 1.500 1.700 2.600 3.000 0.950 (BSC) 1.800 2.000 0.300 0.600 0º 8º gh t Symbol ©On-Bright Electronics Confidential - 10 - Dimensions In Inches Min Max 0.039 0.051 0.000 0.006 0.039 0.047 0.012 0.020 0.004 0.008 0.110 0.119 0.059 0.067 0.102 0.118 0.037 (BSC) 0.071 0.079 0.012 0.024 0º 8º Preliminary Datasheet OB_DOC_DS_227305 OB2273 Co nf id e nt i al to 乐 科 High Performance Current Mode PWM Controller 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 gh t Symbol On Br i A A1 A2 B B1 C D E E1 e L E2 ©On-Bright Electronics Confidential - 11 - Dimensions In Inches Min Max 0.146 0.210 0.015 0.115 0.195 0.014 0.026 0.06 (BSC) 0.008 0.354 0.240 0.288 0.014 0.400 0.280 0.325 0.1 (BSC) 0.115 0.300 0.150 0.430 Preliminary Datasheet OB_DOC_DS_227305 OB2273 High Performance Current Mode PWM Controller IMPORTANT NOTICE 科 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. al to 乐 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. nt i 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. On Br i gh t Co nf id e 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 - 12 - Preliminary Datasheet OB_DOC_DS_227305
OB2273MP 价格&库存

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OB2273MP
    •  国内价格
    • 1+1.09760

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    OB2273MP
      •  国内价格
      • 1+1.39668

      库存:40