VIPER27 Off-line high voltage converters Features 800 V avalanche rugged power section PWM operation with frequency jittering for low EMI SO16 narrow DIP-7 Operating frequency: SO16 60 kHz for L type Description 115 kHz for H type Standby power < 50 mW at 265 Vac The device is an off-line converter with an 800 V rugged power section, a PWM control, two levels Limiting current with adjustable set point of over-current protection, overvoltage and Adjustable and accurate overvoltage overload protections, hysteretic thermal protection protection, soft-start and safe auto-restart after On-board soft-start any fault condition removal. Burst mode operation and device very low consumption help to meet the Safe auto-restart after a fault condition standby energy saving regulations. Hysteretic thermal shutdown Advance frequency jittering reduces EMI filter cost. Brown-out function protects the switch mode Application power supply when the rectified input voltage level is below the normal minimum level specified Auxiliary power supply for consumer and home for the system. The high voltage start-up circuit is equipments embedded in the device. ATX auxiliary power supply Figure 1. Typical topology Low / medium power AC-DC adapters + + SMPS for set-top boxes, DVD players and DC input high voltage wide range DC Output voltage recorders, white goods - - DRAIN DRAIN BR VIPER27 GND VDD CONT FB Table 1. Device summary Order codes Package Packaging VIPER27LN / VIPER27HN DIP-7 Tube VIPER27HD / VIPER27LD SO16 narrow VIPER27HDTR / VIPER27LDTR Tape and reel July 2010 Doc ID 15133 Rev 5 1/31 www.st.com 31 Contents VIPER27 Contents 1 Block diagram 3 2 Typical power . 3 3 Pin settings 4 4 Electrical data 5 4.1 Maximum ratings 5 4.2 Thermal data . 5 4.3 Electrical characteristics . 6 5 Typical electrical characteristics 10 6 Typical circuit . 13 7 Operation descriptions 14 7.1 Power section and gate driver . 14 7.2 High voltage startup generator . 14 7.3 Power-up and soft-start up 15 7.4 Power down operation . 17 7.5 Auto restart operation 17 7.6 Oscillator . 17 7.7 Current mode conversion with adjustable current limit set point . 18 7.8 Overvoltage protection (OVP) . 18 7.9 About CONT pin 20 7.10 Feed-back and overload protection (OLP) 20 7.11 Burst-mode operation at no load or very light load 23 7.12 Brown-out protection 23 7.13 2nd level over current protection and hiccup mode . 25 8 Package mechanical data 26 9 Revision history . 30 2/31 Doc ID 15133 Rev 5