OB2362CMP

OB2362C Adaptive Multi-Mode PWM Controller GENERAL DESCRIPTION FEATURES OB2362C is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. At full loading, the IC operates in fixed frequency (65KHz) mode. When the loading goes low, it operates in Green mode with valley switching 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 OB2362C. OB2362C offers comprehensive protection coverage with auto-recovery including Cycle-byCycle current limiting (OCP), over load protection (OLP), VCC under voltage lockout (UVLO), over temperature protection (OTP), and over voltage protection (OVP). 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 during operation. OB2362C is offered in SOT23-6 package. ■ ■ nf id en tia lt o ■ 狮 ■ 飞 ■ co APPLICATIONS ■ Power on soft start reducing MOSFET Vds stress Multi-Mode Operation 65KHz fixed frequency mode @ Full Load 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 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 o Line Over Voltage Protection(Line OVP) 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 Output diode short protection with autorecovery Br ig ht Offline AC/DC flyback converter for ■ General power supply ■ Power Adapter O n- TYPICAL APPLICATION ©On-Bright Electronics Confidential -1- Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller Absolute Maximum Ratings Parameter Value Pin Configuration 1 6 Gate FB 2 5 VCC DEM 3 4 VOVP-1V FB Input Voltage -0.3 to 7V CS Input Voltage -0.3 to 7V DEM Input Voltage -0.3 to 7V Min/Max Operating Junction Temperature TJ CS Operating Ambient Temperature TA -40 to 85 ℃ Min/Max Storage Temperature Tstg -55 to 150 ℃ o Ordering Information Part Number Description OB2362CMP SOT23-6, Pb-free in T&R -40 to 150 ℃ 飞 GND VCC DC Supply Voltage 狮 GENERAL INFORMATION nf id en tia lt Lead Temperature 260 ℃ (Soldering, 10secs) Note: Stresses beyond those listed under Package Dissipation Rating Package RJA(℃/W) SOT23-6 200 “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 operating condition Symbol Parameter Range VCC VCC Supply Voltage 12 to 26V co OB2362C Br ig ht High Performance Current Mode PWM Controller X Package M:SOT23-6 X Package Pb-free P:Pb-free O n- Marking Information 362YWW . ZZZC S Y:Year Code WW:Week Code(01-52) ZZZ: Lot code C:Character Code S: Internal code ©On-Bright Electronics Confidential -2- Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller TERMINAL ASSIGNMENTS I/O Description VCC P Power Supply CS I Current sense input 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, Brown-in/Brown-out trigger voltage, Line OVP trigger voltage 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. O n- Br ig ht co nf id en tia lt o 飞 狮 Pin Name ©On-Bright Electronics Confidential -3- Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller FUNCTIONAL BLOCK DIAGRAM S S Q Logic Control Soft Driver R OVP AVDD Diode short Vref& Iref OSC Diode short GND Vocp Slope compensation LEB CS OLP AVDD PWM Comparator Multi Mode Control Temp sense Timer OLP FB OTP BO DEM OCP Comparator o Internal blocks Diode short nf id en tia lt VCC 飞 OVP UVLO GATE 狮 Valley OVP Line OVP EX OVP Valley O n- Br ig ht co Valley Detector ©On-Bright Electronics Confidential -4- Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller ELECTRICAL CHARACTERISTICS (TA = 25℃, VCC=18V, unless otherwise noted) Symbol Parameter Supply Voltage (VDD) Operation Current I_VCC_Burst Burst Current UVLO(OFF) mA 0.6 0.7 mA 6.8 7.3 7.8 V 16 17 18 V 10 FB=3V,CS=0V. Slowly VCC Over Voltage Protection OVP ramp VCC, until no 26.5 28 threshold voltage gate switching. Feedback Input Section(FB Pin) VFB_Open VFB Open Loop Voltage 5.1 Avcs PWM input gain ∆VFB/∆VCS 3.5 Maximum duty Max duty cycle @ 77 80 cycle VCC=18V,VFB=3V,VCS=0V The threshold enter green Vref_green 2.1 mode Vref_burst_H The threshold exits burst mode 1.33 The threshold enters burst Vref_burst_L 1.23 mode Short FB pin to GND IFB_Short FB pin short circuit current 0.21 and measure current Open loop protection, FB VTH_OLP 4.4 Threshold Voltage Open loop protection, Td_OLP 60 Debounce Time ZFB_IN Input Impedance 30 Current Sense Input(CS Pin) SST_CS Soft start time for CS peak 2.5 T_blanking Leading edge blanking time 300 From Over Current Over Current Detection and Occurs till the Gate Td_OC 90 Control Delay driver output start to turn off Internal Current Limiting VTH_OC 0.43 0.45 Threshold Voltage with zero duty cycle VTH_OC_Clamp OCP CS voltage clamper 0.72 DEM pin Ibrown-in Brown-in threshold current 110 Ibrown-out Brown-out threshold current 95 100 V 29.5 V V V/V 83 V ht V mA V Br ig Confidential -5- % V ms KΩ O n- ©On-Bright Electronics uA 3.1 co Vpull-up VCC Under Voltage Lockout Enter VCC Under Voltage Lockout Exit (Recovery) Pull-up PMOS active 5 2.6 nf id en tia lt UVLO(ON) 2 狮 I_VCC_Operation VCC=UVLO(OFF)-1V, measure leakage current into VCC VDD=18V,CS=4V, FB=3.5V,measure I(VCC) CS=0V,FB=0.5V, measure I(VCC) Max Unit 飞 VCC Start up Current Min Typ. o Istartup Test Conditions ms ns ns 0.47 V V 105 uA uA Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller Voutput_ovp Td_output_ovp In-chip OTP OTP enter 25 29 33 ms 405 440 120 475 uA ms 2.85 3 3.15 V 6 Cycles 狮 I_lineovp Td_lineovp Brown-out protection debounce Time Line OVP threshold current Line OVP debounce time Voltage threshold for adjustable output OVP Output OVP debounce time OTP exit Oscillator VDD=18V,FB=3V, CS=0V 150 ℃ 120 ℃ 飞 Td_BO Normal Oscillation Frequency 60 65 70 KHz ᇞf_OSC Frequency jittering +/-6 % F_shuffling Shuffling frequency 32 Hz ᇞf_Temp Frequency Stability 1 % ᇞf_VCC Frequency Voltage Stability 1 % F_Burst Gate driver Burst Mode Switch Frequency 23 KHz co Output low level @ VDD=18V, Io=5mA Output high level @ VCC=18V, Io=20mA Output clamp voltage Output rising time 1.2V ~ 10.8V @ CL=1000pF Output falling time 10.8V ~ 1.2V @ CL=1000pF Br ig VOH Temperature ht VOL nf id en tia lt o FOSC V_clamping O n- T_r T_f ©On-Bright Electronics Confidential 6 1 6 V V 11 V 100 ns 30 ns Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller CHARACTERIZATION PLOTS VDD = 18V, TA = 25℃ condition applies if not otherwise noted. UVLO(OFF)(V) vs Tem perature 7.20 7.00 -40 -10 20 50 80 狮 7.60 7.40 19.00 18.20 17.40 16.60 15.80 15.00 飞 8.00 7.80 UVLO(OFF)(V) UVLO(ON)(V) UVLO(ON)(V) vs Tem perature -40 110 140 -10 -10 20 50 80 110 140 0.9 0.8 0.7 0.6 0.5 0.4 0 10 20 Temperature(℃) co OVP(V) ht Br ig Vth_ocp(V) O n- -10 20 50 60 70 29.30 28.94 28.58 28.22 27.86 27.50 50 80 110 140 -40 Temperature(℃) ©On-Bright Electronics 40 OVP(V) vs Tem perature 0.400 -40 30 Duty(%) Vth_ocp(V) vs Tem perature 0.500 0.480 0.460 0.440 0.420 110 140 Duty vs Vth_oc Vth_oc(V) Fosc_nom(Khz) -40 80 o nf id en tia lt Fosc_nom (Khz) vs Tem perature 68.00 66.00 64.00 62.00 60.00 50 Temperature(℃) Temperature(℃) 70.00 20 -10 20 50 80 110 140 Temperature(℃) Confidential 7 Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller OPERATION DESCRIPTION 狮 OB2362C 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. o 飞 Startup Current and Start up Control Startup current of OB2362C 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. nf id en tia lt Multi Mode Operation for High Efficiency OB2362C is a multi mode controller. The controller changes the mode of operation according to the FB pin voltage. At the normal operating condition, the IC operates in traditional fix frequency （65KHz）PWM mode. As the output load current is decreased , the IC enter into green mode smoothly from the PWM mode. In this mode , the switching frequency will start to linearly decrease from 65KHz to 23KHz, meanwhile the valley turn on can be realized by monitoring the voltage activity on auxiliary windings through the DEM pin. So the switching loss is minimized and the high conversion efficiency can be achieved. At light load or no load condition, most of the power dissipation in a switching mode power supply is from switching loss of the MOSFET, the core loss of the transformer and the loss of 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 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. ht co Operating Current The Operating current of OB2362C is low at 2.5mA (typical). Good efficiency is achieved with OB2362C low operation current together with the ‘extended burst mode’ control features. O n- Br ig Soft Start OB2362C 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. Frequency shuffling for EMI improvement The frequency shuffling (switching frequency modulation) is implemented in OB2362C. 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. ©On-Bright Electronics 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 Confidential 8 Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller and the flyback stroke starts. After the flyback stroke, the drain voltage shows an oscillation with a frequency of approximately 1 / 2 where Multiple Functions of Brown-in/Brown-out, Line OVP in/Line OVP out and Output OVP When the power MOSFET is turn on, the voltage on auxiliary windings is negative which make our Brown-in/Brown-out protection feasible. L pCd , L p is the primary self inductance of primary winding of the transformer and Cd is the nf id en tia lt o 飞 狮 capacitance on the drain node. The typical detection level is fixed at -50mV at the DEM pin. Demagnetization is recognized by detection of a possible “valley” when the voltage at DEM is below -50mV in falling edge. I AUX  R1: The resistor connected from DEM to AUX. R2: The resistor connected from DEM to ground. When system starts up, if IAUX < Ibrown_in, Brown-in auto-recovery protection is triggered after 2 Gate cycles debounce. When the system enters the normal operation mode, if IAUX < Ibrown_out, Brownout auto-recovery protection is triggered after 29ms debounce. When the system enters the normal operation mode, if IAUX > ILine_OVP, Line OVP auto-recovery protection is triggered after 120ms debounce. For output OVP detection, when Gate is off, VDEM is equal to VAUX*R2/(R1+R2). If VDEM is larger than 3V (typical), OVP auto-recovery protection is triggered after 6 Gate cycles debounce. By selecting proper R1 and R2 resistance, output OVP level can be programmed. Br ig ht co Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in OB2362C 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. V AUX  Internal Synchronized Slope Compensation Built-in slope compensation circuit adds voltage ramp into the current sense input voltage for PWM generation. This greatly improves the close loop stability at CCM and prevents the sub-harmonic oscillation and thus reduces the output ripple voltage. 3 * ( R1  R 2) R2 O n- Protection Controls Good power supply system reliability is achieved with auto-recovery protection features including Cycle-by-Cycle current limiting (OCP), Under Voltage Lockout on VDD (UVLO), Over Temperature Protection (OTP), Brownout Protection, VCC and output 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. At overload condition when FB input voltage exceeds power limit threshold value for more than Td_OLP, control circuit reacts to shut down the converter. It restarts when VDD voltage drops below UVLO limit. Driver The power MOSFET is driven by a dedicated gate driver for power switch control. Too weak the gate driver strength results in higher conduction and switch loss of MOSFET while too strong gate driver strength 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-Bright Electronics 0.1 0.1  V AUX  R2 R1 Confidential -9- Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller Br ig ht co nf id en tia lt o 飞 狮 PACKAGE MECHANICAL DATA Symbol O n- A A1 A2 b c D E E1 e e1 L θ Dimensions In Millimeters Min Max 1.000 1.450 0.000 0.150 0.900 1.300 0.300 0.500 0.080 0.220 2.800 3.020 1.500 1.726 2.600 3.000 0.950 (BSC) 1.800 2.000 0.300 0.600 0º 8º ©On-Bright Electronics Confidential - 10 - Dimensions In Inches Min Max 0.039 0.057 0.000 0.006 0.035 0.051 0.012 0.020 0.003 0.009 0.110 0.119 0.059 0.068 0.102 0.118 0.037 (BSC) 0.071 0.079 0.012 0.024 0º 8º Datasheet OB_DOC_DS_2362CA0 OB2362C Adaptive Multi-Mode PWM Controller IMPORTANT NOTICE 狮 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. nf id en tia lt o 飞 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. O n- Br ig ht co 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 - 11 - Datasheet OB_DOC_DS_2362CA0