OB2362DMP

OB2362D Multi-Mode PWM Controller GENERAL DESCRIPTION FEATURES OB2362D 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 OB2362D. OB2362D 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. OB2362D is offered in SOT23-6 package. ■ ■ ■ ■ ht c on fid en tia lt o 涵 旺 ■ ■ ig APPLICATIONS Power on soft start reducing MOSFET Vds stress Multi-Mode Operation: 130KHz maximum frequency PWM at peak load; 65KHz fixed frequency PWM at full load; Valley switching operation at light to middle load range; Burst mode at light load and 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) with latch shut down. o Internal integrated two level OCP protection o Internal integrated SCP protection o Over Load Protection (OLP) o External (if NTC resistor is connected at RT pin) or internal (if RT pin floating) Over Temperature Protection (OTP) with auto recovery protection. o Output diode short protection with auto recovery protection o Cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range o Output Over Voltage Protection(Output OVP) with latched shut down, and the OVP triggered voltage can be adjusted by the resistor connected between auxiliary winding and PRT pin O n- Br Offline AC/DC flyback converter for ■ General power supply ■ Power Adapter TYPICAL APPLICATION AC IN EMI Filter DC Out Vaux OB2362D GND FB PRT ©On-Bright Electronics GATE VCC CS Confidential -1- Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller GENERAL INFORMATION Pin Configuration Absolute Maximum Ratings Parameter Value GND 1 6 Gate FB 2 5 VCC PRT 3 4 CS -0.3 to 7V CS Input Voltage -0.3 to 7V PRT Input Voltage -0.3 to 7V Min/Max Operating Junction Temperature TJ -40 to 150 ℃ Operating Ambient Temperature TA -40 to 85 ℃ Min/Max Storage Temperature Tstg -55 to 150 ℃ 涵 en tia lt o “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. on fid Recommended operating condition Symbol Parameter Range VCC VCC Supply Voltage 12 to 26V ht c OB2362D Multi-Mode PWM Controller ig FB Input Voltage Lead Temperature 260 ℃ (Soldering, 10secs) Note: Stresses beyond those listed under Package Dissipation Rating Package RJA(℃/W) SOT23-6 200 X Package M:SOT23-6 X Package Pb-free P:Pb-free n- Br VOVP-1V 旺 Ordering Information Part Number Description SOT23-6, Pb-free in T&R, OB2362DMP VCC DC Supply Voltage O Marking Information ©On-Bright Electronics Confidential -2- Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller TERMINAL ASSIGNMENTS I/O Description GND P Ground 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. PRT I Multiple functions pin. Connecting a NTC resistor to ground for OTP detection. Connecting a resistor from Vaux can adjust OVP trigger voltage and detect transformer core demagnetization. If both OTP and OVP are needed, a diode should be connected between PRT pin and the NTC resistor. CS I Current sense input VCC P Power Supply GATE O Totem-pole gate driver output for power MOSFET O n- Br ig ht c on fid en tia lt o 涵 旺 Pin Name ©On-Bright Electronics Confidential -3- Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller FUNCTIONAL BLOCK DIAGRAM S S Valley Timer OCP Internal blocks Diode short Slope compensation VTH_PK_CS lt o 涵 OLP PK load Comparator LEB 旺 OSC OCP Diode short Vref& Iref OCP Diode short AVDD UVLO Soft Driver R OVP OVP Logic Control Q PWM Comparator Temp sense OTP tia en Timer OLP ig OVP OVP EX OVP Latch Br EX OVP ht c EX OTP on fid Multi Mode Control AVDD Valley O n- Valley Detector ©On-Bright Electronics Confidential -4- Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller ELECTRICAL CHARACTERISTICS (TA = 25℃, VCC=18V, unless otherwise noted) Symbol Parameter Supply Voltage (VDD) Istartup VCC Start up Current I_VCC_Operation Operation Current I_VCC_Burst Burst Current UVLO(OFF) VCC Under Voltage Lockout Enter VCC Under Voltage Lockout Exit (Recovery) Pull-up PMOS active Typ. Max Unit 2 5 uA 2.5 3 mA 0.6 0.7 mA 7 7.5 8 V 16 17 18 V V 涵 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 Max duty cycle @ Maximum duty cycle 77 80 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 Peak load, FB Threshold VTH_PK 4.4 Voltage Td_PK Peak load, Debounce Time 13.5 15 ZFB_IN Input Impedance 30 Current Sense Input(CS Pin) SST_CS Soft start time for CS peak 2 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 Threshold Voltage with zero 0.43 0.45 duty cycle VTH_OC_Clamp OCP CS voltage clamper 0.6 Td_OLP Over load, debounce Time 11.5 13 Internal Current Limiting VTH_PK_CS Threshold Voltage with zero 0.55 duty cycle for PK load 29.5 V tia lt o Vpull-up Min 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) 旺 UVLO(ON) Test Conditions 83 V Br ig V mA n- O ©On-Bright Electronics Confidential -5- % V ht c on fid en V V/V V 18.5 ms KΩ ms ns ns 0.47 V 15.5 V s V Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller VTH_PK_ CS_Clamp PK load CS voltage clamper 0.87 V 100 106 uA PRT pin IRT VOTP Ioutput_ovp Td_output_ovp In-chip OTP OTP enter Output current for external OTP detection Threshold voltage for external OTP Current threshold for adjustable output OVP Output OVP debounce time 94 0.95 1 170 OTP exit Oscillator Fosc_PK Peak load frequency (Duty>47%) ᇞf_OSC Frequency jittering F_shuffling Shuffling frequency Frequency Temperature Stability Frequency Voltage Stability Burst Mode Switch Frequency VDD=18V,FB=3V, CS=0V VDD=18V,FB=4.5V, CS=0V 旺 Normal Oscillation Frequency 60 V 180 190 uA 5 Cycles 150 ℃ 120 ℃ 65 70 KHz 130 KHz +/-6 % 32 Hz 1 % 1 23 % KHz VOH V_clamping T_r T_f tia en on fid ht c 1 ig 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 VOL n- ᇞf_VCC F_Burst Gate driver VDD=18V,FB=3V, CS=0V O ᇞf_Temp lt o 涵 FOSC 1.05 ©On-Bright Electronics Confidential 6 6 V V 11 V 100 ns 30 ns Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller CHARACTERIZATION PLOTS VDD = 18V, TA = 25℃ condition applies if not otherwise noted. UVLO(OFF)(V) vs Tem perature 8.00 7.80 UVLO(OFF)(V) UVLO(ON)(V) UVLO(ON)(V) vs Tem perature 7.60 7.40 7.20 7.00 -40 -10 20 50 80 19.00 18.20 17.40 16.60 15.80 15.00 -40 110 140 -10 110 140 旺 70.00 0.9 0.8 0.7 0.6 0.5 0.4 -40 -10 20 50 80 0 20 30 40 50 60 70 Vth_ocp(V) vs Tem perature ig Vref_OTP(V) vs Tem perature O n- Vth_ocp(V) Br 1.100 1.060 1.020 0.980 0.940 10 Duty(%) ht c Temperature(℃) 110 140 en tia Vth_oc(V) lt o 68.00 66.00 64.00 62.00 60.00 on fid Fosc_nom(Khz) 80 Duty vs Vth_oc 涵 Fosc_nom (Khz) vs Tem perature Vref_OTP(V) 50 Temperature(℃) Temperature(℃) 0.900 0.500 0.480 0.460 0.440 0.420 0.400 -40 -10 20 50 80 110 140 -40 -10 Temperature(℃) 20 50 80 110 140 Temperature(℃) OVP(V) vs Tem perature IRT(uA) vs Tem perature 29.30 28.94 28.58 IRT(uA) OVP(V) 20 28.22 27.86 102.0 101.5 101.0 100.6 100.1 99.6 27.50 -40 -10 20 50 80 -40 110 140 20 50 80 110 140 Temperature(℃) Temperature(℃) ©On-Bright Electronics -10 Confidential 7 Preliminary Datasheet OB_DOC_DS_2362D00 OB2362D Multi-Mode PWM Controller OPERATION DESCRIPTION OB2362D 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. Duty >47% 65KHZ 23KHZ Startup Current and Start up Control Startup current of OB236D 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. VG1 VG2 VOCP VPK 旺 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 PRT 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 c on fid en tia lt o 涵 Operating Current The Operating current of OB2362D is low at 2.5mA (typical). Good efficiency is achieved with OB2362D low operation current together with the ‘extended burst mode’ control features. Soft Start OB2362D features an internal 2ms (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. Duty