OB2710MP

OB2710 Adaptive Multi-Mode PWM Controller GENERAL DESCRIPTION 85KHz minimum clamping frequency in CCM mode @ Heavy Load in low line voltage Valley switching operation @ Green mode Burst Mode @ Light Load & No Load ■ Frequency shuffling for EMI ■ Extended burst mode control for improved efficiency and low standby power design ■ Audio noise free operation ■ Adjust Vth_oc compensation through CS pin, the compensate value can be regulated by the resister series with CS pin. ■ Comprehensive protection coverage o VCC Under Voltage Lockout with hysteresis (UVLO) o VCC Over Voltage Protection (VCC OVP) o Cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range o Over Load Protection (OLP) with autorecovery o Brownout protection with auto-recovery, line OVP with auto-recovery o Output Over Voltage Protection(Output OVP) with auto-recovery, and the OVP triggered voltage can be adjusted by the resistors connected between auxiliary winding and ground o Adjust Over Temperature Protection(OTP) through CS pin with auto-recovery o Output diode short protection with autorecovery o Output SCP Protection with auto-recovery ht co n FEATURES fid en tia lt o 森 树 强 OB2710 is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. At normal load condition, it operates in fixed frequency mode. When the loading goes low, it operates in PFM mode for high power conversion efficiency. 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. VCC low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2710 offers Vth_oc compensation. OB2710 offers comprehensive protection coverage with auto-recovery including Cycle-byCycle current limiting (OCP), over load protection (OLP), AC brownout protection,VCC under voltage lockout (UVLO), external over temperature protection (OTP), over voltage protection (OVP) and short protection(SCP).Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique. The tone energy at below 23KHz is minimized in the design and audio noise is eliminated ng operation. OB2710 is offered in SOT23-6 package. Power on soft start reducing MOSFET Vds stress ■ Multi-Mode Operation 77KHz maximum clamping frequency in QR mode @ Full Load in high line voltage 65KHz minimum clamping frequency in CCM mode @ Heavy Load in high line voltage 100KHz maximum clamping frequency in QR mode @ Full Load in low line voltage APPLICATIONS Offline AC/DC flyback converter for ■ General power supply ■ Power Adapter Br ig ■ O n- TYPICAL APPLICATION AC IN EMI Filter DC Out Vaux OB2710 GND GATE FB DEM ©On-Bright Electronics VCC CS Confidential -1- Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller GENERAL INFORMATION 1 6 Gate FB 2 5 VCC DEM 3 4 CS Ordering Information Part Number Description SOT23-6,Halogen-free OB2710MP T&R Marking Information ht co n Adaptive Multi-Mode PWM Controller Br ig 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. X X fid OB2710 O n- -55 to 150 ℃ 森 in Recommended operating condition Symbol Parameter Range VCC VCC Supply Voltage 12 to 26V ©On-Bright Electronics -40 to 150 ℃ en tia lt o Package Dissipation Rating Package RJA(℃/W) SOT23-6 200 Value 32V -0.3 to 7V -0.3 to 7V -0.3 to 7V 树 GND Absolute Maximum Ratings Parameter VCC DC Supply Voltage FB Input Voltage CS Input Voltage DEM Input Voltage Min/Max Operating Junction Temperature TJ Min/Max Storage Temperature Tstg Lead Temperature (Soldering, 10secs) 强 Pin Configuration Package Green Package M:SOT23-6 P:Green (Halogen-free) 710YWW . ZZZ S Y:Year Code WW:Week Code(01-52) ZZZ: Lot code S: Internal code Confidential -2- Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller TERMINAL ASSIGNMENTS I/O Description VCC P Power Supply CS I Current sense input. Series a resister to Rsense can adjust the Vth_oc to regulate the OCP point. This pin is also connected to an auxiliary winding of the PWM transformer through a NTC resistor and a diode for over temperature protection. Gate O Totem-pole gate driver output for power MOSFET GND P Ground DEM I Multiple functions pin. Connecting two resistors from Vaux to ground can adjust output OVP trigger voltage, SCP trigger voltage, Brown-in/Brown-out, line OVP trigger current and detect transformer core demagnetization. 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. FUNCTIONAL BLOCK DIAGRAM S S fid Valley en tia lt o 森 树 强 Pin Name OVP ht co n OVP Q Logic Control EX OTP AVDD Diode short VDD_FB Vref& Iref OSC Internal blocks Diode short Br ig GND OLP OCP Comparator O nDEM Vocp EX OTP Diode short Slope compensation Vin Icomp LEB CS Vin VDD_FB PWM Comparator Multi Mode Control Temp sense BO/Line OVP GATE R UVLO VCC Soft Driver Timer OLP FB OTP OVP EX OVP/UVP EX OVP/ SCP Valley Detector Line Voltage Detector ©On-Bright Electronics EX OTP Valley Vin Confidential -3- Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller ELECTRICAL CHARACTERISTICS (TA = 25℃, VCC=18V, unless otherwise noted) Symbol Parameter Supply Voltage (VCC) Test Conditions VCC=UVLO(OFF)-1V, measure leakage current into VCC VCC=18V,CS=4V, FB=3.5V,measure I(VCC) CS=0V,FB=0.5V, measure I(VCC) Operation Current I_VCC_Burst Burst Current UVLO(ON) VCC Under Voltage Lockout Enter VCC Under Voltage Lockout Exit (Recovery) Pull-up PMOS active OVP VCC Over Voltage threshold voltage Protection fid FB pin short circuit current O n- VTH_OC Icomp_90v Icomp_264v Vref_dio TD_dio VTH_OTP TD_OTP DEM pin Ibrown-in Over Current Control Delay Detection and From Over Current Occurs till the Gate driver output start to turn off FB > Vref_burst_H Brown-in threshold current ©On-Bright Electronics 8.0 V 17 18 V 10 V 3.8 4 4.2 V V/V 75 80 85 % 3.0 Internal Current Limiting Threshold Voltage with zero duty cycle Compensation current@90Vac flow out from CS pin Compensation current@264Vac flow out from CS pin CS pin threshold for diode short CS pin external OTP threshold External OTP debounce time 7.5 3.4 Short FB pin to GND and measure current ht co n Br ig Td_OC mA FB=3V,CS=0V. Slowly ramp VCC, until no 28.5 30.0 31.5 V gate switching. Open loop protection, FB Threshold Voltage Open loop protection, Debounce Td_OLP Time ZFB_IN Input Impedance Current Sense Input(CS Pin) SST_CS Soft start time for CS peak T_blanking Leading edge blanking time VTH_OLP 3 uA 0.25 0.50 mA 16 Feedback Input Section(FB Pin) VFB_Open VFB Open Loop Voltage Avcs PWM input gain ΔVFB/ΔVCS Maximum duty Max duty cycle @ cycle VCC=18V,VFB=3V,VCS=0V Vref_green The threshold enter green mode Vref_burst_H The threshold exits burst mode Vref_burst_L The threshold enters burst mode IFB_Short 2 7.0 en tia lt o Vpull-up 5 强 I_VCC_Operation 2 树 VCC Start up Current 森 Istartup UVLO(OFF) Min Typ. Max Unit 2.0 1.15 1.05 V V V 0.12 mA 3.3 3.6 V 60 ms 31.5 KΩ 2.5 250 ms ns 80 ns 0.45 V 140 uA 335 uA 0.8 V 8 Cycles 0.28 0.30 0.32 V 60 ms 100 107 114 uA Confidential -4- Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller Brown-out threshold current Brown-out protection, Debounce Time Line_OVP threshold current Line_OVP threshold current exit Line_OVP, Debounce Time Voltage threshold for adjustable output OVP Toff sampling delay time Output OVP debounce time SCP threshold (Startup blanking 12ms) Output SCP debounce time Tsamp Td_output_ovp VTH_scp TD_SCP In-chip OTP OTP enter OTP exit Oscillator 415 440 465 uA 425 uA 400 ms 2.85 3.0 3.15 V 强 Voutput_ovp ms 2.2 8 uS Cycles 600 mV 8 Cycles 150 120 ℃ 树 Iline_OVP Iline_OVP_exit Td_Lineovp 100 105 uA 30 森 Td_BO 95 en tia lt o Ibrown-out ℃ Average max clamp oscillation frequency in QR mode VCC=15V,FB=3V,Vac165V 77 KHz △f_OSC_max_QR Max clamp oscillation frequency jittering ±6 % Fosc_min_CCM_H Min clamp oscillation frequency in CCM mode VCC=15V,FB=3V,Vac165V 65 KHz △f_OSC_CCM Min clamp oscillation frequency jittering ±6 % Shuffling frequency Burst Mode Switch Frequency 240 25 Hz KHz ht co n Br ig F_shuffling F_Burst Gate driver fid Fosc_max_QR_H Output low level @ VCC=18V, Io=5mA Output high level @ VCC=18V, VOH Io=20mA V_clamping Output clamp voltage Output rising time 1.1V ~ 9.9V @ T_r CL=1000pF Output falling time 9.9V ~ 1.1V @ T_f CL=1000pF Note1: In burst mode output OTP is disable. O n- VOL ©On-Bright Electronics Confidential 5 1 6 V V 11 V 300 ns 50 ns Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller CHARACTERIZATION PLOTS O n- Br ig ht co n fid en tia lt o 森 树 强 VCC = 18V, TA = 25℃ condition applies if not otherwise noted. ©On-Bright Electronics Confidential 6 Preliminary Datasheet OB_DOC_DS_271000 OB2710 Adaptive Multi-Mode PWM Controller OPERATION DESCRIPTION 森 树 Startup Current and Start up Control Startup current of OB2710 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. en tia lt o Operating Current The Operating current of OB2710 is low at 2mA (typical). Good efficiency is achieved with OB2710 low operation current together with the ‘extended burst mode’ control features. VDD UVLO(OFF) UVLO(ON) Operation current fid time ht co n time Br ig Soft Start OB2710 features an internal 2.5ms (typical) 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 VCC 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. Demagnetization Detection The transformer core demagnetization is detected by monitoring the voltage activity on the auxiliary windings through DEM pin. This voltage features a flyback polarity. After the on time (determined by the CS voltage and FB voltage), the switch is off and the flyback stroke starts. After the flyback stroke, the drain voltage shows an oscillation with O n- Multi Mode Operation for High Efficiency OB2710 is a multi-mode QR/PWM controller. The controller changes the mode of operation according to line voltage and load conditions. Frequency QR mode 77KHz (100KHz) a frequency of approximately 1 / 2 Fmax jittering L p Cd , where L p is the primary self inductance of 65KHz (85KHz) primary winding of the transformer and C d is the capacitance on the drain node. The typical detection level is fixed at -50mV at the DEM pin. Demagnetization is recognized by Fix Frequency CCM Mode 25KHz 0 At full load conditions, there are two situations: firstly, if the system input is in low line input range, the IC operates in 85K fixed frequency CCM mode. Thus, small size transformer can be used with high power conversion efficiency. Secondly, if the system input is in high line input range, the IC operates in QR mode. In this way, high power conversion efficiency can be achieved in the universal input range when system is at full loading conditions. At normal operating conditions (Vth2