VIPER16 Fixed frequency VIPerTM plus family Features ■ 800 V avalanche rugged power section ■ PWM operation with frequency jittering for low EMI ■ Operating frequency: – 60 kHz for L type – 115 kHz for H type ■ No need of auxiliary winding for low power application ■ Standby power < 50 mW at 265 VAC ■ Limiting current with adjustable set point ■ On-board soft-start ■ Safe auto-restart after a fault condition ■ Hysteretic thermal shutdown DIP-7 Description Application ■ Replacement of ca
Contents VIPER16 Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Typical power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1 Maximum ratings . . . . .
VIPER16 1 Block diagram Block diagram Figure 2. 2 Block diagram Typical power Table 2. Typical power 230 VAC Part number VIPER16 85-265 VAC Adapter(1) Open frame(2) Adapter(1) Open frame(2) 9W 10 W 5W 6W 1. Typical continuous power in non ventilated enclosed adapter measured at 50 °C ambient. 2. Maximum practical continuous power in an open frame design at 50 °C ambient, with adequate heat sinking.
Pin settings 3 VIPER16 Pin settings Figure 3. Connection diagram (top view) $2!). $2!). $2!). . # $2!). . ! $2!). $2!). !- V Note: The copper area for heat dissipation has to be designed under the DRAIN pins. Table 3. Pin description Pin N. Name Function 1-2 GND Connected to the source of the internal power MOSFET and controller ground reference. - 4 N.A. Not available for user. It can be connected to GND (pins 1-2) or left not connected.
VIPER16 Electrical data 4 Electrical data 4.1 Maximum ratings Table 4. Symbol Value Pin (DIP-7) Parameter Unit Min VDRAIN 7, 8 Drain-to-source (ground) voltage EAV 7, 8 IAR Max 800 V Repetitive avalanche energy (limited by TJ = 150 °C) 2 mJ 7, 8 Repetitive avalanche current (limited by TJ = 150 °C) 1 A IDRAIN 7, 8 Pulse drain current (limited by TJ = 150 °C) 2.5 A VCOMP 5 Input pin voltage -0.3 3.5 V VFB 4 Input pin voltage -0.3 4.8 V VLIM 3 Input pin voltage -0.
Electrical data 4.3 VIPER16 Electrical characteristics (TJ = -25 to 125 °C, VDD = 14 V (a); unless otherwise specified) Table 6. Power section Symbol VBVDSS IOFF RDS(on) COSS Table 7. Symbol Parameter Test condition Break-down voltage IDRAIN = 1 mA, VCOMP = GND, TJ = 25 °C OFF state drain current VDRAIN = max rating, VCOMP = GND Drain-source on state resistance Min Typ Max Unit 800 V 60 μA IDRAIN = 0.2 A, TJ = 25 °C 20 24 Ω IDRAIN = 0.
VIPER16 Table 8. Electrical data Controller section Symbol Parameter Test condition Min Typ Max Unit Error amplifier VREF_FB FB reference voltage 3.2 IFB_PULL UP Current pull up GM Trans conductance 3.3 3.4 V -1 μA 2 mA/V 0.
Typical electrical characteristics VIPER16 5 Typical electrical characteristics Figure 4. IDlim vs TJ Figure 5. FOSC vs TJ ,' O LP ,' O LP# & ) 2 6& ) 2 6& # & !- V !- V VDRAIN_START vs TJ 6 $2! ) . ? 34 ! 2 4 6 $2 ! ). ? 34 !2 4 7- >&@ 7- >&@ Figure 6. Figure 7.
VIPER16 Typical electrical characteristics Figure 10. ICOMP vs TJ )# / - 0 ) # /- 0 Figure 11. Operating supply current (no switching) vs TJ # ,' ' , '' # & 7- >&@ 4* ; #= !- V Figure 12. Operating supply current (switching) vs TJ !- V Figure 13.
Typical electrical characteristics VIPER16 Figure 16.
VIPER16 6 Typical circuit Typical circuit Figure 17. Buck converter 5IE $& ,1 / & 9,3HU & '5$,1 9'' 5IE *1' )% & &21752/ & &203 ' /,0 &IE *1' 5FRPS 5/,0 RSWLRQDO &FRPS /RXW 'RXW 9RXW &RXW !- V Figure 18.
Typical circuit VIPER16 Figure 19. Flyback converter (primary regulation) )86( $& ,1 75$16) / ' %5,'*( $& ,1 & & &FO 5FO ' 9RXW 5DX[ ' 'DX[ &RXW 9,3HU 5IEK '5$,1 9'' )% &21752/ &9'' &203 *1' /,0 5IEO &IE 5F &S 5/,0 RSWLRQDO &F !- V Figure 20.
VIPER16 7 Power section Power section The power section is implemented with an n-channel power MOSFET with a breakdown voltage of 800 V min. and a typical RDS(on) of 20 Ω. It includes a SenseFET structure to allow a virtually lossless current sensing and the thermal sensor. The gate driver of the power MOSFET is designed to supply a controlled gate current during both turn-ON and turn-OFF in order to minimize common mode EMI.
Oscillator 9 VIPER16 Oscillator The switching frequency is internally fixed at 60 kHz (part number VIPER16LN or LD) or 115 kHz (part number VIPER16HN or HD).
VIPER16 FB pin and COMP pin The device can be used both in non-isolated and in isolated topology. In case of nonisolated topology, the feedback signal from the output voltage is applied directly to the FB pin as inverting input of the internal error amplifier having the reference voltage, VREF_FB, see the Table 8 on page 7. The output of the error amplifier sources and sinks the current, ICOMP, respectively to and from the compensation network connected on the COMP pin.
Burst mode VIPER16 Figure 23. COMP pin voltage versus IDRAIN ,'5$,1 , 'OLP ,'OLPBEP 9&203/ 9&203+ 9&203 !- V 13 Burst mode When the voltage VCOMP drops below the threshold, VCOMPL, the power MOSFET is kept in OFF state and the consumption is reduced to IDD0 current, as reported on Table 7 on page 6.
VIPER16 14 Automatic auto restart after overload or short-circuit Automatic auto restart after overload or short-circuit The overload protection is implemented in automatic way using the integrated up-down counter. Every cycle, it is incremented or decremented depending if the current logic detects the limit condition or not. The limit condition is the peak drain current, IDlim , reported on Table 8 on page 7 or the one set by the user through the RLIM resistor, as reported in Figure 13 on page 9.
Open loop failure protection 15 VIPER16 Open loop failure protection In case the power supply is built in fly-back topology and the VIPer16 is supplied by an auxiliary winding, as shown in Figure 27 on page 18 and Figure 28 on page 19, the converter is protected against feedback loop failure or accidental disconnections of the winding.
VIPER16 Open loop failure protection Figure 28.
Package mechanical data 16 VIPER16 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 at: www.st.com. ECOPACK® is an ST trademark. Table 9. DIP-7 mechanical data mm Dim.
VIPER16 Package mechanical data Figure 29.
Package mechanical data Table 10. VIPER16 SO16N mechanical data mm Dim. Min Typ A 1.75 A1 0.1 A2 1.25 b 0.31 0.51 c 0.17 0.25 D 9.8 9.9 10 E 5.8 6 6.2 E1 3.8 3.9 4 e 0.25 1.27 h 0.25 0.5 L 0.4 1.27 k 0 8 ccc 22/25 Max 0.
VIPER16 Package mechanical data Figure 30.
Revision history 17 VIPER16 Revision history s Table 11.
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