VIPER37LE STMicroelectronics, VIPER37LE Datasheet
VIPER37LE
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VIPER37LE Summary of contents
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... Auxiliary power supply for consumer and home equipment ■ ATX auxiliary power supply ■ Low / medium power AC-DC adapters Table 1. Device summary Order codes VIPER37LE VIPER37HE February 2012 SDIP10 Description This device is an offline converter with an 800 V rugged power section, a PWM control, two levels of overcurrent protection, overvoltage and nd ...
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Contents Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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VIPER37 9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Block diagram 1 Block diagram Figure 2. Block diagram BRth 15uA SOFT START CONT . OVP LOGIC 6uA OVP FB 2 Typical power Table 2. Typical power Part number Adapter VIPER37 1. Typical continuous power in ...
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VIPER37 3 Pin settings Figure 3. Connection diagram (top view) Note: The copper area for heat dissipation must be designed under the DRAIN pins. Table 3. Pin description Pin n. Name 1 GND 2 VDD 3 CONT ...
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Electrical data 4 Electrical data 4.1 Maximum ratings Table 4. Absolute maximum ratings Symbol V Drain-to-source (ground) voltage DRAIN Repetitive avalanche energy E AV (limited by T Repetitive avalanche current I AR (limited Pulse drain current DRAIN ...
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VIPER37 4.3 Electrical characteristics (T = -25 to 125 ° Table 6. Power section Symbol V Breakdown voltage BVDSS I OFF state drain current OFF Drain-source on state R DS(on) resistance Effective (energy related) C OSS output capacitance ...
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Electrical data Table 7. Supply section Symbol Voltage Drain-source start voltage V DRAIN _START I Startup charging current DDch V Operating voltage range DDclamp DDon DDoff shutdown threshold V DD ...
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VIPER37 Table 8. Controller section Symbol Feedback pin Overload shutdown V FBolp threshold V Linear dynamics upper limit FBlin V Burst mode threshold FBbm V Burst mode hysteresis FBbmhys I Feedback sourced current FB R Dynamic resistance FB(DYN) ∆V H ...
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Electrical data Table 8. Controller section (continued) Symbol Overcurrent protection (2 Second overcurrent I DMAX threshold Overvoltage protection Overvoltage protection V OVP threshold Overvoltage protection T STROBE strobe time Brownout protection V Brownout threshold BRth Voltage hysteresis above V BRhyst ...
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VIPER37 Figure 4. Minimum turn-on time test circuit 14 V Figure 5. Brownout threshold test circuits Figure 6. OVP threshold test circuits 14 V Note: Adjust V above V DD GND DRAIN VDD DRAIN CONT DRAIN ...
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Typical electrical characteristics 5 Typical electrical characteristics Figure 7. Current limit vs. T Figure 9. Drain start voltage vs. T 12/35 Figure 8. J Figure 10. HFB vs Doc ID 022218 Rev 1 VIPER37 Switching frequency vs. T ...
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VIPER37 Figure 11. Brownout threshold vs. T Figure 13. Brownout hysteresis current vs. T Typical electrical characteristics Figure 12. Brownout hysteresis vs Figure 14. Operating supply current J (not switching) vs. T Doc ID 022218 Rev 1 J ...
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Typical electrical characteristics Figure 15. Operating supply current (switching) vs. T Figure 17. Power MOSFET ON resistance vs 14/35 Figure 16. Current limit vs Figure 18. Power MOSFET breakdown voltage Doc ID 022218 Rev 1 VIPER37 ...
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VIPER37 Figure 19. Thermal shutdown Typical electrical characteristics Doc ID 022218 Rev 1 15/35 ...
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Typical circuit 6 Typical circuit Figure 20. Min-features flyback application Figure 21. Full-features flyback application 16/ Vcc V DRAIN DD BR CONTROL ...
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VIPER37 7 Efficiency performances for a typical flyback converter The efficiency of the converter has been measured in different load and line voltage conditions. In accordance with the ENERGY STAR method, the efficiency measurements have been performed at 25%, 50% ...
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Efficiency performances for a typical flyback converter Figure 23. Power supply consumption at no output load, V 18/ brownout 55 With brownout 100 150 Input voltage [Vac] ...
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VIPER37 8 Operation description The device is a high-performance low-voltage PWM controller chip with an 800 V avalanche rugged power section. The controller includes: the oscillator with jittering feature, the startup circuits with soft-start feature, the PWM logic, the current ...
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Operation description 8.3 Power-up and soft-start If the input voltage rises up to the device start threshold V begins to grow due to the I startup circuit. If the V MOSFET starts switching and the HV current generator is turned ...
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VIPER37 Figure 24. I current during startup and burst mode DD Figure 25. Timing diagram: normal power-up and power-down sequences Doc ID 022218 Rev 1 Operation description 21/35 ...
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Operation description Figure 26. Timing diagram: soft-start I DRAIN I Dlim FBolp V FBlin 8.4 Power down operation At converter power down, the system loses regulation as soon as the input voltage is so low that the ...
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VIPER37 Figure 27. Timing diagram: behavior after short-circuit 8.6 Oscillator The switching frequency is internally fixed to 60 kHz or 115 kHz. In both cases the switching frequency is modulated by approximately ±4 kHz (60 kHz version) or ±8 kHz ...
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Operation description 8.8 Overvoltage protection (OVP) The device can monitor the converter output voltage. This operation is done by the CONT pin during Power MOSFET OFF-time, when the voltage generated by the auxiliary winding tracks the converter's output voltage, through ...
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VIPER37 The resistor values are such that the current sourced and sunk by the CONT pin are within the rated capability of the internal clamp. Figure 28. OVP timing diagram VAUX 0 0 CONT (pin 4) ...
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Operation description Table 11. CONT pin configurations Function / component I Dlim I reduction + OVP Dlim 1. R must be fixed before R LIM 8.10 Feedback and overload protection (OLP) The device is a current mode converter: the feedback ...
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VIPER37 After the startup time, t capacitor may not be at its nominal value and the controller interprets this situation as an overload condition. In this case, the OLP delay helps to avoid an incorrect device shutdown during the startup ...
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Operation description Figure 30. FB pin configuration 1 Figure 31. FB pin configuration 2 8.11 Burst mode operation at no load or very light load When the load decreases, the feedback loop reacts by lowering the feedback pin voltage. If ...
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VIPER37 Figure 32. Burst mode timing diagram, light load management 8.12 Brownout protection Brownout protection is a not-latched shutdown function activated when a condition of mains undervoltage is detected. The brownout comparator is internally referenced to V the voltage applied ...
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Operation description Figure 33. Brownout protection: BR external setting and timing diagram When the V and the V INon relationships can be established for the calculation of the resistors R Equation 9 Equation 10 For a proper operation of this ...
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VIPER37 In order to enable the brownout function, the BR pin voltage must be higher than the maximum V threshold (150 mV), see DIS nd 8.13 2 level overcurrent protection and hiccup mode The device is protected against short-circuit of ...
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Package mechanical data 9 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available ...
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VIPER37 Figure 35. SDIP10 mechanical drawing Doc ID 022218 Rev 1 Package mechanical data 33/35 ...
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Revision history 10 Revision history Table 13. Document revision history Date 17-Feb-2012 34/35 Revision 1 Initial release Doc ID 022218 Rev 1 VIPER37 Changes ...
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... VIPER37 Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...