High-Voltage Switcher

NCP1028 High−Voltage Switcher for Medium Power Offline SMPS Featuring Low Standby Power The NCP1028 offers a new solution targeting output power levels from a few watts up to 15 W in a universal mains flyback application. Our proprietary high−voltage technology lets us include a power MOSFET together with a startup current source, all directly connected to the bulk capacitor. To prevent lethal runaway in low input voltage conditions, an adjustable brown−out circuitry blocks the activity until sufficient input level is reached. Current−mode operation together with an adjustable ramp compensation offers superior performance in universal mains applications. Furthermore, an Over Power Protection pin brings the ability to precisely compensate all internal delays in high input voltage conditions and optimize the maximum output current capability. Protection wise, a timer detects an overload or a short−circuit and stops all operations, ensuring a safe auto−recovery, low duty cycle burst operation. Finally, a great RDS(on) figure makes the circuit an excellent choice for standby/auxiliary offline power supplies or applications requiring higher output power levels. Features http://onsemi.com MARKING DIAGRAM 8−LEAD PDIP P SUFFIX CASE 626A P1028Pxxx AWL YYWWG xxx A WL YY WW G = 65 or 100 = Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Package • • • • • • • • • • • • • • Built−in 700 V MOSFET with Typical RDS(on) of 5.8 W, TJ = 25°C Current−Mode Fixed Frequency Operation: 65 kHz and 100 kHz Fixed Peak Current of 800 mA Skip−Cycle Operation at Low Peak Currents Internal Current Source for Clean and Lossless Startup Sequence Auto−Recovery Output Short Circuit Protection with Timer−Based Detection Programmable Brown−Out Input for Low Input Voltage Detection Programmable Over Power Protection Input to Permanently Latchoff the Part Internal Frequency Jittering for Improved EMI Signature Extended Duty Cycle Operation to 80% Typical No−Load Input Standby Power of 85 mW @ 265 Vac 500 mW Loaded, Input Power of 715 mW @ 230 Vac These are Pb−Free Devices** www.DataSheet4U.com PIN CONNECTIONS VCC Ramp Comp. Brown−Out FB (Top View) Drain GND OPP ORDERING INFORMATION Device NCP1028P065G NCP1028P100G Package PDIP−8 (Pb−Free) PDIP−8 (Pb−Free) Shipping* 50 Units / Rail 50 Units / Rail Typical Applications • Medium Power AC−DC Adapters for Chargers • Auxiliary/Standby Power Supplies for ATX and TVS Power Supplies Reference NCP1028 − 5.8 W 230 VAC 25 W* 90−265 VAC 15 W* *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. *Typical values, open−frame, 65 kHz version, RqJA < 75°C/W, TA = 50°C. **For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. © Semiconductor Components Industries, LLC, 2007 January, 2007 − Rev. 0 1 Publication Order Number: NCP1028/D NCP1028 Vout + OPP* NCP1028 1 + 85−265 VAC BO + + 2 3 4 8 7 5 GND Ramp Comp.* *Optional component Figure 1. Typical Application PIN FUNCTION DESCRIPTION Pin No. 1 2 Symbol VCC Ramp Comp. Function Powers the Internal Circuitry Ramp Compensation in CCM Brown−Out and Latchoff Input Feedback Signal Input Drain Connection − Over Power Protection The IC Ground Description This pin is connected to an external capacitor of typically 22 mF. To extend the duty cycle operation in Continuous Conduction Mode (CCM), pin 3 offers the ability to inject ramp compensation in the controller. If unused, short this pin to VCC. By monitoring the bulk level via a resistive network, the circuit protects itself from low mains conditions. If an external event brings this pin above 4.0 V, the part fully latches off. By connecting an optocoupler to this pin, the peak current setpoint is adjusted accordingly to the output power demand. The internal drain power switch circuit connection. This unconnected pin ensures adequate creepage distance. Driving this pin reduces the power supply capability in high line conditions. If no Over Power Protection is needed, short this pin to ground. − 3 Brown−Out 4 5 − 7 8 FB Drain − OPP GND http://onsemi.com 2 NCP1028 IC1 VCC Vclamp VCC Mngt Fault UVLOs 4 V rst VDD GND + Vlatch VCC < 4 V Reset + − + − 20 ms RC S R Q Q LEB IBO BO VBO + Timer OPP Jittering V Icomp dd 65 kHz or 100 kHz CLOCK Ip Flag Vcc S R Q Q Ramp Comp. + 25% of lp + − Skip Vdd RFB −+ Soft−Start UVLO Drain FB + − Ip Flag Max Ip Selection Over Power Protection Input Ramp Compensation Figure 2. Internal Block Diagram http://onsemi.com 3 NCP1028 MAXIMUM RATINGS Rating Power Supply Voltage on all Pins, Except Pin 5 (Drain) Drain Voltage Maximum Current into Pin 1 when Activating the 8.7 V Active Clamp Thermal Resistance, Junction−to−Air – PDIP7 Thermal Resistance, Junction−to−Air – PDIP7 with 1.0 cm@ of 35 m Copper Area Maximum Junction Temperature Storage Temperature Range ESD Capability, Human Body Model (HBM) (All Pins Except HV) ESD Capability, Machine Model (MM) Symbol VCC BVdss I_VCC RqJA RqJA TJMAX − − − Value −0.3 to 10 −0.3 to 700 15 100 75 150 −60 to +150 2.0 200 Unit V V mA °C/W °C/W °C °C kV V Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 1. This device series contains ESD protection and exceeds the following tests: Human Body Model 2000 V per Mil−Std−883, Method 3015. Machine Model Method 200 V. 2. This device contains latchup protection and exceeds 100 mA per JEDEC Standard JESD78. VCC = 8.0 V, unless otherwise noted.) ELECTRICAL CHARACTERISTICS (For typical values TJ = 25°C, for min/max values TJ = 0°C to +125°C, Max TJ = 150°C, Characteristic SUPPLY SECTION AND VCC MANAGEMENT Pin Symbol Min Typ Max Unit VCC Increasing Level at which the Switcher Starts to Operate VCC Decreasing Level at which the Switcher Stops Operation Hysteresis between VCCON and VCC(min) Offset Voltage above VCCON at which the Internal Clamp Activates VCC Voltage at which the Internal Latch is Reset Internal IC Consumption, MOSFET Switching at POWER SWITCH CIRCUIT Power Switch Circuit On−State Resistance NCP1028 (Id = 100 mA) TJ = 25°C TJ = 125°C Power Switch Circuit and Startup Breakdown Voltage (ID(off) = 120 mA, TJ = 25°C) Power Switch and Startup Breakdown Voltage Off−State Leakage Current TJ = 25°C (Vds = 700 V) TJ = 125°C (Vds = 700 V) Switching Characteristics (RL = 50 W, Vds Set for Idrain = 0.7 x Ilim) Turn−on Time (90%−10%) Turn−off Time (10%−90%) INTERNAL STARTUP CURRENT SOURCE High−Voltage Current Source, VCC = VCCON – 200 mV High−Voltage Current Source, VCC = 0 VCC Transition Level for IC1 to IC2 Toggling Point 65 kHz or 100 kHz 1 1 − 1 1 1 VCCON VCC(min) VCChyste VCCclamp VCCreset ICC1 7.9 6.7 − 140 − − 8.5 7.2 1.2 200 4.0 1.4 8.9 7.9 − 300 − 1.9 V V V mV V mA 5 RDS(on) − − 5.8 9.8 − 7.0 11 − W 5 BVdss Idss(OFF) 700 V mA 5 5 − − 50 30 − − 5 5 ton toff − − 35 35 − − ns ns 1 1 1 IC1 IC2 VCCTh 3.5 350 − 6.0 650 1.3 8.0 900 − mA mA V http://onsemi.com 4 NCP1028 Max TJ = 150°C, VCC = 8.0 V, unless otherwise noted.) Characteristic CURRENT COMPARATOR Maximum Internal Current Setpoint, Pin 4 Open, TJ = 25°C, FSW = 65 kHz (Note 3) Final Switch Current with a Primary Slope of 200 mA/ms, FSW = 65 kHz (Note 4) Maximum Internal Current Setpoint, Pin 4 Open, TJ = 25°C, FSW = 100 kHz (Note 3) Final Switch Current with a Primary Slope of 200 mA/ms, FSW = 100 kHz (Note 4) Setpoint Decrease for a Pin 7 Injected Current of 40 mA, TJ = 25°C Voltage Level in Pin 7 at which OPP Starts to Operate Soft−Start Duration Propagation Delay from Current Detection to Drain OFF State Leading Edge Blanking Duration INTERNAL OSCILLATOR Oscillation Frequency (Note 5) 65 kHz Version, TJ = 25°C Oscillation Frequency (Note 5) 100 kHz Version, TJ = 25°C Frequency Jittering in Percentage of fOSC Jittering Swing Frequency Maximum Duty Cycle FEEDBACK SECTION Internal Pullup Resistor Ramp Compensation Level on Pin 1 – Rramp = 100 kW SKIP CYCLE GENERATION Internal Skip Mode Level, in Percentage of Maximum Peak Current PROTECTIONS Brown−Out Level Brown−Out Hysteresis Current, TJ = 25°C (Note 3) Brown−Out Hysteresis Current, TJ = 0°C to 125°C Fault Validation further to Error Flag Assertion OFF Phase in Fault Mode Latching Voltage on Brown−Out Pin Latch Input Integrating Filter Time Constant TEMPERATURE MANAGEMENT Temperature Shutdown Hysteresis in Shutdown − − TSD − 160 − − 40 − − °C °C 3 3 3 − − 3 3 VBO IBOhyste IBOhyste TimerON TimerOFF Vlatch TdelBOL 510 10 − 40 − 3.15 − 570 11.5 10 55 440 3.5 20 620 13 − − − 3.85 − mV mA mA ms ms V ms − Iskip − 25 − % 4 2 Rupp Rlevel − − 16 2.75 − − kW V − − − − − fOSC fOSC fJitter fswing Dmax 58.5 90 − − 74 65 100 "6.0 300 80 71.5 110 − − 87 kHz kHz % Hz % − − − − 7 7 − − − Ipeak_27_CS_ 65 k Ipeak_27_SW_ 65 k Ipeak_27_CS_ 100 k Ipeak_27_SW_ 100 k IOPP IOPPtripV TSS Tprop TLEB 720 − 720 − − − − − − 800 820 800 820 23 1.5 1.0 100 200 880 − 880 − − − − − − mA mA mA mA % V ms ns ns ELECTRICAL CHARACTERISTICS (continued) (For typical values TJ = 25°C, for min/max values TJ = 0°C to +125°C, Pin Symbol Min Typ Max Unit 3. See characterization curves for full temperature span evolution. 4. The final switch current is: Ipeak_2X_CS + Tprop x Vin / Lp, with Vin the input voltage and Lp the primary inductor in a flyback. 5.