STMicroelectronics VIPER012LS

Overview

VIPER012LS from STMicroelectronics is a high-voltage off-line SMPS controller integrating an 800 V avalanche-rugged N-channel power MOSFET, current-mode PWM control, and embedded HV startup circuitry. It delivers up to 4.5 W in open-frame designs at 50 °C ambient, supports 85–265 VAC input, operates at 60 kHz ±7% (jittered), and achieves <10 mW no-load power consumption at 230 VAC - enabling energy-compliant low-power adapters for home appliances and lighting.

For engineers reviewing the VIPER012LS datasheet, VIPER012LS pinout, VIPER012LS application, or VIPER012LS equivalent, key selection criteria include its self-supply capability (eliminating auxiliary winding), integrated OCP/OLP/VCC clamp protections with auto-restart, thermal shutdown at 150 °C, and SSOP10 package with five DRAIN pins for enhanced thermal dissipation.

Technical Context

The VIPER012LS implements a fixed-frequency current-mode PWM controller with jittered oscillator (60 kHz ±7% at 260 Hz modulation rate) to reduce EMI filter size. Its embedded 800 V MOSFET features R_DS(on) = 30 Ω (T_J = 25 °C) and avalanche energy rating of 1 mJ, enabling direct mains connection without external snubber scaling.

Control architecture includes a transconductance error amplifier (G_M = 500 µA/V, V_{FB_REF} = 1.2 V), dedicated COMP pin for loop compensation or optocoupler interface, and pulse-skipping logic that enforces F_{OSC_MIN} = 15 kHz to prevent flux runaway during light-load or startup conditions.

Key Specifications

Pinout & Package

SSOP10 package with exposed thermal pad (DRAIN pins 6–10 internally bonded to MOSFET drain metal). Five DRAIN pins share current path and provide low-thermal-resistance conduction to PCB copper pour.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage offline SMPS controller applications.

Compared with VIPER012LS, VIPER013LS offers higher power capability and lower R_DS(on) but increases system cost and complexity for sub-5 W applications; ICE2QS03G lacks integration and self-supply, demanding more external components and careful layout to meet same efficiency and EMI targets.

Availability

VIPER012LS is available at Aetrix Electronics and suitable for low-power SMPS in home appliances, lighting drivers, and industrial sensor nodes requiring stable component supply across extended product lifecycles.

Supply support for VIPER012LS 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

VIPER012LS belongs to the VIPer™ energy-saving off-line high-voltage converter family, designed specifically for compact, low-BOM-count AC-DC power supplies targeting EU CoC Tier 2 and DOE Level VI compliance.

FAQ

What is the maximum continuous output power achievable with VIPER012LS?

VIPER012LS delivers up to 4.5 W in open-frame configurations at 50 °C ambient temperature with adequate PCB copper heatsinking (100 mm²). In enclosed non-ventilated adapters, typical continuous output is limited to 4 W due to thermal constraints. Power capability scales with thermal design - doubling copper area reduces R_TH-JA from 95 °C/W to ~75 °C/W, enabling modest derating relief.

Can VIPER012LS operate without an auxiliary winding?

Yes - VIPER012LS supports self-supply mode using only the VCC capacitor charged by its internal HV current source. During steady-state operation, the IC reactivates the HV source when VCC drops to 4.25 V (V_CSON), delivering I_CH3 = 8.8 mA (typ.) to recharge VCC to 8 V. This eliminates the need for auxiliary windings, transformer taps, or bias resistors in most low-power applications.

How does the DIS pin implement overvoltage protection?

The DIS pin triggers auto-restart OVP when voltage exceeds 1.2 V for >1 ms. In isolated flyback designs, a voltage divider from the secondary-side optocoupler output pulls DIS high upon output overvoltage. In non-isolated buck topologies, a divider from the regulated output connects directly to DIS. If unused, DIS must be soldered to GND to disable the function and prevent floating-node instability.

What is the purpose of the five DRAIN pins in the SSOP10 package?

The five DRAIN pins (6–10) are electrically and thermally bonded to the internal MOSFET's drain metal pad. They collectively carry the high-voltage switching current and conduct heat directly into the PCB copper pour. Using all five pins with ≥100 mm² of 35 µm-thick copper reduces R_TH-JA from 155 °C/W to 95 °C/W, enabling reliable 4.5 W operation without external heatsinks in space-constrained designs.