VIPER28LN STMicroelectronics, VIPER28LN Datasheet
VIPER28LN
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VIPER28LN Summary of contents
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... ATX auxiliary power supply ■ Low / medium power AC-DC adapters ■ SMPS for set-top boxes, DVD players and recorders, white goods Table 1. Device summary Order codes VIPER28LN / VIPER28HN VIPER28LE / VIPER28HE VIPER28HD / VIPER28LD VIPER28HDTR / VIPER28LDTR August 2010 Off-line high voltage converters SDIP10 Description AC ...
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Contents Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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VIPER28 1 Block diagram Figure 2. Block diagram LEB LEB EPT Tov l Tov l EPT Tovl Tovl BLOCK BLOCK OLP OLP SOFT SOFT START START OCP OCP BLOCK BLOCK CONT CONT OVP DETECTION OVP DETECTION LOGIC LOGIC PWM PWM ...
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Pin settings 3 Pin settings Figure 3. Connection diagram (top view) Note: The copper area for heat dissipation has to be designed under the DRAIN pins. Table 3. Pin description Pin n. Name SDIP10 DIP-7 SO16N 1 1 1...2 GND ...
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VIPER28 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 (limited by ...
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Electrical data 4.3 Electrical characteristics (T = -25 to 125 ° Table 6. Power section Symbol Parameter V Break-down voltage BVDSS I OFF state drain current OFF Drain-source on state R DS(on) resistance Effective (energy related) C OSS ...
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VIPER28 Table 8. Controller section Symbol Parameter Feed-back pin V Over-load shut down threshold FBolp V Linear dynamics upper limit FBlin V Burst mode threshold FBbm V Burst mode hysteresis FBbmhys I Feed-back sourced current FB R Dynamic resistance FB(DYN) ...
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Electrical data Table 8. Controller section (continued) Symbol Parameter nd Over-current protection (2 OCP) I Second over-current threshold DMAX Over-voltage protection V Over-voltage protection threshold OVP T Over-voltage protection strobe time STROBE Extra power management I Drain current limit with ...
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VIPER28 Figure 4. Minimum turn-on time test circuit 14 V Figure 5. OVP threshold test circuits 14 V Note: Adjust V above V DD GND DRAIN VDD DRAIN 50 Ω CONT FB EPT 3.5 V GND DRAIN VDD DRAIN CONT ...
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Typical electrical characteristics 5 Typical electrical characteristics Figure 6. Current limit vs T Figure 8. Drain start-up voltage vs T Figure 10. Operating supply current (no switching 10/32 Figure 7. J Figure 9. J Figure 11. Operating supply ...
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VIPER28 Figure 12. Current limit vs R Figure 14. Power MOSFET break down voltage Figure 13. Power MOSFET on-resistance vs T LIM Doc ID 15028 Rev 4 Typical electrical characteristics J 11/32 ...
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Typical electrical characteristics Figure 15. Thermal shutdown DDon V DDoff V DD(RESTART) I DRAIN HYST SD Normal operation 12/32 Shut down after over temperature Doc ID 15028 Rev 4 VIPER28 ...
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VIPER28 6 Typical circuit Figure 16. Min-features flyback application Figure 17. Full-feature flyback application EPT EPT Doc ID 15028 Rev 4 Typical circuit 13/32 ...
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Operation descriptions 7 Operation descriptions is a high-performance low-voltage PWM controller chip with an 800 V, avalanche VIPER28 rugged Power section. The controller includes: the oscillator with jittering feature, the start up circuits with soft-start feature, the PWM logic, the ...
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VIPER28 7.3 Power-up and soft-start up If the input voltage rises up till the device start threshold, V begins to grow due to the I high voltage start up circuit. If the V page 6) the power MOSFET starts switching ...
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Operation descriptions Figure 19. Timing diagram: normal power-up and power-down sequences DRAIN_START DDon V DDoff V DD(RESTART) V DRAIN (3mA) DDch Figure 20. Soft-start: timing diagram 16/32 Normal operation Power-on I ...
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VIPER28 7.4 Power down operation At converter power down, the system loses regulation as soon as the input voltage is so low that the peak current limitation is reached. The V the V threshold (see DDoff energy transfers to the ...
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Operation descriptions 7.7 Current mode conversion with adjustable current limit set point The device is a current mode converter: the drain current is sensed and converted in voltage that is applied to the non inverting pin of the PWM comparator. ...
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VIPER28 Where: ● the OVP threshold (see OVP ● the converter output voltage value to activate the OVP set by designer OUT OVP ● the auxiliary winding turns AUX ● the secondary ...
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Operation descriptions 7.9 About CONT pin Referring to the Figure 1. Current limit set point 2. Overvoltage protection on the converter output voltage The Table 9 on page 20 activate one or plus of the CONT pin functions. Figure 23. ...
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VIPER28 When the feedback pin voltage reaches the threshold V starts to charge the feedback capacitor (C threshold, the converter is turned off and the start up phase is activated with reduced V FBolp value 0.6 mA, ...
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Operation descriptions Equation 7 Equation 8 The R is the dynamic resistance seen by the FB pin. FB(DYN) The C capacitor fixes the OLP delay and usually C FB1 The Equation 5 can be still used to calculate the OLP ...
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VIPER28 7.11 Burst-mode operation at no load or very light load When the load decrease the feedback loop reacts lowering the feedback pin voltage falls down the burst mode threshold, V switched on. After the MOSFET stops, as ...
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Operation descriptions 7.12 Extra power management function (EPT) Some applications need an extra power for a limited time window during which the converter regulation has to be guaranteed. The extra power management function allows to design a converter that can ...
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VIPER28 nd 7.13 2 level overcurrent protection and hiccup mode The is protected against short-circuit of the secondary rectifier, short-circuit on the VIPER28 secondary winding or a hard-saturation of fly-back transformer. Such as anomalous condition is invoked when the drain ...
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Package mechanical data 8 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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VIPER28 Figure 28. Package dimensions Doc ID 15028 Rev 4 Package mechanical data 27/32 ...
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Package mechanical data Table 11. SO16 narrow mechanical data Dim ccc 28/32 mm Min. Typ. 0.1 1.25 0.31 0.17 9.8 9.9 5.8 6 3.8 3.9 1.27 0.25 0.4 ...
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VIPER28 Figure 29. SO16 narrow mechanical data Doc ID 15028 Rev 4 Package mechanical data 29/32 ...
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Package mechanical data Table 12. SDIP10 mechanical data Dim Figure 30. SDIP10 mechanical drawing 30/32 mm Min. Typ. 0.38 2.92 0.36 0.51 0.2 9.02 7.62 6.1 7.62 ...
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VIPER28 9 Revision history Table 13. Document revision history Date 30-Sep-2008 22-Jan-2009 21-Oct-2009 31-Aug-2010 Revision 1 Initial release 2 Updated Figure 3 on page 4 3 Added SO16N and SDIP10 packages Updated Figure 3, Figure 4 page 4 Doc ID ...
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