Datasheet

ManualsBrandsST ManualsAC / DC ConvertersAC/DC Off-Line Switching Converter 60kHz 800 V SO-16

September 2010 Doc ID 17736 Rev 2 1/25

VIPER26

Fixed frequency VIPer

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

■ Standby power < 50 mW at 265 V

■

Limiting current with adjustable set point

■ On-board soft-start

■ Safe auto-restart after a fault condition

■ Hysteretic thermal shutdown

Application

■ Auxiliary power supply for appliances

■ Power metering

■ LED drivers

■ SMPS for set-top boxes, DVD players and

recorders

Description

The device is an off-line converter with an 800 V

avalanche ruggedness power section, a PWM

controller, user defined overcurrent limit,

protection against feedback network

disconnection, hysteretic thermal protection, soft

start up and safe auto restart after any fault

condition.

Advance frequency jittering reduces EMI filter

cost. Burst mode operation and the devices very

low consumption both help to meet the standard

set by energy saving regulations.

Figure 1. Typical topology (V

OUT

≤ V

DDCSon

)

DIP-7

SO16 narrow

VIPER26

DRAIN COMP

GND FBLIM

VDD

VIPER26

DRAIN COMP

GND FBLIM

VDD

DC Output Voltage

DC Input Voltage

Table 1. Device summary

Order codes Package Packaging

VIPER26LN

DIP-7 Tube

VIPER26HN

VIPER26HD

SO16 narrow

Tube

VIPER26HDTR Tape and reel

VIPER26LD Tube

VIPER26LDTR Tape and reel

www.st.com

Summary of content (25 pages)

PAGE 1
VIPER26 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 SO16 narrow SO-16 DIP-7 Description ■ 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 The device is an off-line converter with an 800 V avalanche ruggedness p
PAGE 2
Contents VIPER26 Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Typical power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1 Maximum ratings . . . . .
PAGE 3
VIPER26 1 Block diagram Block diagram Figure 2. 2 Block diagram Typical power Table 2. Typical power 230 VAC Part number VIPER26 85-265 VAC Adapter(1) Open frame(2) Adapter(1) Open frame(2) 18 W 20 W 10 W 12 W 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.
PAGE 4
Pin settings 3 VIPER26 Pin settings Figure 3. Connection diagram (top view) . # . ! !- V Note: The copper area for heat dissipation has to be designed under the DRAIN pins. Table 3. Pin description Pin n. Name Function DIP-7 SO16 1 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. 2 5 VDD Supply voltage of the control section.
PAGE 5
VIPER26 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) 5 mJ 7, 8 Repetitive avalanche current (limited by TJ = 150 °C) 1.5 A IDRAIN 7, 8 Pulse drain current (limited by TJ = 150 °C) 3 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.
PAGE 6
Electrical data 4.3 VIPER26 Electrical characteristics (TJ = -25 to 125 °C, VDD = 14 V (a); unless otherwise specified) Table 6. Symbol VBVDSS IOFF RDS(on) COSS Table 7. Symbol Power section Parameter Test condition Min Typ Max Unit Break-down voltage IDRAIN = 1 mA, VCOMP = GND, TJ = 25 °C OFF state drain current VDRAIN = max rating, VCOMP = GND 60 µA IDRAIN = 0.2 A, TJ = 25 °C 7 Ω IDRAIN = 0.
PAGE 7
VIPER26 Table 8. Electrical data Controller section Symbol Parameter Test condition Min Typ Max Unit Error amplifier VREF_FB IFB_PULL UP GM FB reference voltage 3.2 3.3 3.4 V Current pull up -1 µA Trans conductance 2 mA/V ILIM = -100 µA 0.
PAGE 8
Typical electrical characteristics VIPER26 5 Typical electrical characteristics Figure 4. IDlim vs TJ Figure 5. ,'/,0 ,'/,0# & )26& )26&# & FOSC vs TJ Figure 6. VDRAIN_START vs TJ Figure 7.
PAGE 9
VIPER26 Typical electrical characteristics Figure 10. ICOMP vs TJ Figure 11. Operating supply current (no switching) vs TJ ,&203 ,&203# & ,'' ,'' # & !- V !- V Figure 12. Operating supply current (switching) vs TJ Figure 13. IDlim vs RLIM ,'' ,'' # & ,'/,0 ,'/,0# .
PAGE 10
Typical circuits VIPER26 Figure 16. Thermal shutdown VDD VDDon VDDCSon VDDoff time IDRAIN time TJ TSD TSD - THYST time Normal operation 6 Normal operation Shut down after over temperature Typical circuits Figure 17. Buck converter (VOUT>VDDCSon) $ 2FB !# ). $ 2 , 6)0%2 $2 !). 6$$ $ &" # # # #FB #/-0 2FB #/. 42 /, ,)- # '.$ 2COMP 2,) OPTIONAL #COMP ,OUT $OUT '2/5.$ 6/54 #OUT '2/5.
PAGE 11
VIPER26 Typical circuits Figure 18. Fly-back converter (isolated) !# ). 2 4 , #C L 2C L $ $ 6OUT $ $ 2 !# ). # 6)0%2 $ 2!). 6$ $ # 2 # &" # 2REF # /. 4 2 /, # /- 0 ,)- '.$ # /04/ 2 2 # 2 2,)- # )# # 2REF '2/5. $ '2/5. $ !- V Figure 19.
PAGE 12
Typical circuits VIPER26 Figure 20. Flyback converter (non isolated, VOUTmVDDCSon) 2IN , !# ). $IN # # 2CL #CL $OUT 6/54 !# ). $ #OUT $AUX 6)0%2 2FB 6$$ &" 2FB #/-0 # $2!). #/.42/, ,)- '.$ 2COMP #COMP #COMP 2,)- OPTIONAL !- V Figure 21.
PAGE 13
VIPER26 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 7 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.
PAGE 14
Oscillator 9 VIPER26 Oscillator The switching frequency is internally fixed at 60 kHz (VIPER26LN or LD) or 115 kHz (VIPER26HN or HD). In both cases the switching frequency is modulated by approximately ±4 kHz (60 kHz version) or ±8 kHz (115 kHz version) at 230 Hz (typical) rate, so that the resulting spreadspectrum action distributes the energy of each harmonic of the switching frequency over a number of sideband harmonics having the same energy on the whole but smaller amplitudes.
PAGE 15
VIPER26 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.
PAGE 16
Burst mode VIPER26 Figure 24. COMP pin voltage versus IDLIM ,'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.
PAGE 17
VIPER26 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.
PAGE 18
Open loop failure protection 15 VIPER26 Open loop failure protection In case the power supply is built in fly-back topology and the VIPer26 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.
PAGE 19
VIPER26 Open loop failure protection Figure 28. FB pin connection for isolated fly-back 2 # !58 $ !58 6!58 6$$ 6 2%&?&" 2 COMP 07- ST OP 6 #/-0, 37 "53 $ISABLE D &" 6/54 FROM2 3%.
PAGE 20
Package mechanical data 16 VIPER26 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. Typ Min A 5.33 A1 0.38 A2 3.30 2.92 4.95 b 0.46 0.36 0.56 b2 1.52 1.14 1.78 c 0.25 0.20 0.36 D 9.
PAGE 21
VIPER26 Package mechanical data Figure 29.
PAGE 22
Package mechanical data Table 10. VIPER26 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.
PAGE 23
VIPER26 Package mechanical data Figure 30.
PAGE 24
Revision history 17 VIPER26 Revision history Table 11. 24/25 Document revision history Date Revision Changes 26-Aug-2010 1 Initial release. 01-Sep-2010 2 Updated Figure 30 on page 23.
PAGE 25
VIPER26 Please Read Carefully: 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.