STMicroelectronics VIPER012LSTR

Overview

VIPER012LSTR from STMicroelectronics is a high-voltage off-line PWM controller IC integrating an 800 V avalanche-rugged N-channel power MOSFET, current-mode control, and self-supply capability. It delivers up to 4.5 W in open-frame designs at 50 °C ambient, operates at 60 kHz ±7% jittered switching frequency, supports flyback/buck/buck-boost topologies, and achieves <10 mW no-load input power at 230 VAC - ideal for low-power SMPS in home appliances and lighting.

For engineers reviewing the VIPER012LSTR datasheet, VIPER012LSTR pinout, VIPER012LSTR application, or VIPER012LSTR equivalent, key selection criteria include its integrated 800 V MOSFET, 60 kHz jittered oscillator, 240 mA typical drain current limit (VIPER012 variant), self-supply operation eliminating bias windings, and built-in protections including OCP, OLP, VCC clamp, and thermal shutdown.

Technical Context

The VIPER012LSTR implements a current-mode PWM architecture with an internal transconductance error amplifier (1.2 V reference), jittered oscillator (60 kHz ±7%), and cycle-by-cycle peak current limiting. Its embedded HV startup circuit delivers 8.8 mA typical charging current to VCC during startup and self-supply mode.

Protection logic includes pulse-skip to prevent flux-runaway, automatic restart after overload/short-circuit (tOVL_MAX = 200 ms), thermal shutdown at 155 °C, and DIS pin overvoltage detection with 1.2 V threshold and 1 ms debounce. The device uses a single external CS capacitor for VCC supply and supports primary-side regulation via FB pin.

Key Specifications

Pinout & Package

Package: SSOP-10 (3.9 mm × 4.9 mm, 0.65 mm pitch), thermally enhanced with DRAIN pins (6–10) connected to internal MOSFET metal pad for PCB copper-area heat sinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage off-line PWM controller applications.

Compared with ICE2QS03G and LNK306P, VIPER012LSTR offers superior surge immunity (800 V), lower no-load consumption, jittered EMI reduction, and full primary-side regulation capability - making it optimal for compact, energy-compliant, universal-input flyback designs.

Availability

VIPER012LSTR is available at Aetrix Electronics and suitable for home appliance power supplies, LED lighting drivers, smart building sensor nodes, and industrial control interfaces requiring stable component supply across extended product lifecycles.

Supply support for VIPER012LSTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, and analog/mixed-signal devices for industrial, automotive, and consumer markets.

VIPER012LSTR belongs to the VIPerPlus family of high-voltage converters engineered for ultra-low standby power and minimal external component count in sub-10 W off-line SMPS applications.

FAQ

What is the maximum continuous output power achievable with VIPER012LSTR?

VIPER012LSTR delivers up to 4.5 W in open-frame configurations at 50 °C ambient temperature with adequate PCB copper area (100 mm²), and 4 W in enclosed non-ventilated adapters. This is validated per Table 8 in DS11423 Rev 2, based on thermal resistance R_TH-JA = 95 °C/W with 100 mm² copper pour.

Can VIPER012LSTR operate without an auxiliary winding?

Yes - VIPER012LSTR supports self-supply mode using only the VCC capacitor charged by its internal HV current source (ICH3 = 8.8 mA typ.), eliminating the need for an auxiliary winding or bias resistor network. This is confirmed in Section 4.4 of DS11423 Rev 2.

How does the DIS pin provide overvoltage protection?

The DIS pin triggers auto-restart OVP when voltage exceeds 1.2 V for more than 1 ms. A resistive divider from rectified mains or output rail to DIS enables line- or output-OVP. If unused, DIS must be soldered to GND - this behavior is specified in Table 1 and Section 4.8 of DS11423 Rev 2.

What topologies does VIPER012LSTR support beyond flyback?

VIPER012LSTR supports flyback, buck, and buck-boost topologies, as explicitly stated in the "Description" section of DS11423 Rev 2. Its current-mode control, integrated MOSFET, and flexible feedback architecture enable all three configurations with minimal external components.