Features
• 800 V avalanche-rugged power MOSFET to cover ultra-wide VAC input range
• Embedded HV startup and sense FET
• Current mode PWM controller
• Drain current limit protection (OCP):
– 710 mA (VIPER317)
– 850 mA (VIPER318)
– 990 mA (VIPER319)
• Wide supply voltage range: 4.5 V to 30 V
– < 20 mW @ 230 VAC in no-load;
– < 430 mW @ 230 VAC, 25 0mW output load
• Jittered switching frequency reduces the EMI filter cost:
– 30 kHz ± 7% (type X)
– 60 kHz ± 7% (type L)
– 132 kHz ±7% (type H)
• Embedded E/A with 1.2 V reference
• Built-in soft-start for improved system reliability
• Protections with automatic restart:
– overload/short-circuit (OLP)
– thermal shutdown
– overvoltage
• Protections without automatic restart:
– pulse-skip protection to avoid flux runaway
– undervoltage/disable
– max. duty cycle

Application
• Low power SMPS for home appliances, home automation, industrial,
consumers, lighting
• Low power adapters

Description
The VIPER31 device is a high-voltage converter that smartly integrates an 800 V
avalanche rugged power MOSFET with PWM current-mode control. The 800 V
breakdown allows extended input voltage range to be applied, as well as to reduce
the size of the DRAIN snubber circuit. The IC can meet the most stringent energysaving
standards as it has very low consumption and operates in pulse frequency
modulation at light load. Overvoltage and undervoltage protections with separate and
settable intervention thresholds are available at OVP and UVP pins respectively. UVP
can also be used as a disabling input for the entire SMPS, with ultra-low residual
input power consumption. Integrated HV startup, sense FET, error amplifier and
oscillator with frequency jitter allow a complete application to be designed with a
minimum component count. Flyback, buck and buck boost topologies are supported.