STMicroelectronics VIPER114XSTR

Overview

VIPER114XSTR from STMicroelectronics is a high-voltage offline PWM controller IC integrating an 800 V avalanche-rugged N-channel MOSFET, current-mode control, and embedded HV startup. It delivers 12 W in open-frame designs at 50 °C ambient, supports flyback/buck/buck-boost topologies, and achieves <10 mW no-load input power at 230 VAC - enabling compliance with stringent energy-saving standards for low-power SMPS.

For engineers reviewing the VIPER114XSTR datasheet, VIPER114XSTR pinout, VIPER114XSTR application, or VIPER114XSTR equivalent, key selection criteria include its 480 mA drain current limit, 30 kHz ±7% jittered switching frequency (X-type), 4.5–30 V VCC range, integrated thermal shutdown, and SSOP10 package with five dedicated DRAIN pins for enhanced thermal dissipation.

Technical Context

The VIPER114XSTR implements a current-mode PWM architecture with an internal transconductance error amplifier (1.2 V reference), pulse-skipping protection to prevent flux-runaway during startup, and auto-restart fault recovery for OLP, OVP, and thermal events. Its HV startup circuit delivers up to 8.5 mA charging current to VCC using an 800 V auxiliary MOSFET and programmable RG resistor network.

It features a fixed-frequency oscillator with ±7% spread-spectrum jitter at 260 Hz, enabling reduced EMI filter cost; soft-start ramps current limit over 8 ms; and direct feedback via FB pin enables primary-side regulation without optocoupler in non-isolated topologies.

Key Specifications

Pinout & Package

Package: SSOP10 (3.9 mm × 4.9 mm, 0.65 mm pitch), thermally enhanced with exposed metal pad connected to DRAIN pins 6–10 for PCB copper area heat sinking (R_TH-JA = 95 °C/W with 100 mm² Cu).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK364PG, VIPER114XSTR offers superior input voltage margin (800 V vs ≤725 V), built-in jitter for EMI reduction, and direct feedback capability - making it optimal for compact, low-noise, primary-regulated SMPS where board space and regulatory compliance are critical.

Availability

VIPER114XSTR is available at Aetrix Electronics and suitable for home appliance power supplies, industrial sensor node PSUs, and smart LED lighting systems requiring stable component supply, long-term lifecycle support, and full traceability.

Supply support for VIPER114XSTR 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, designing and manufacturing microcontrollers, power ICs, sensors, and analog devices for industrial, automotive, and consumer markets.

The VIPer™ family targets low-power offline SMPS design, integrating high-voltage switches and controllers to reduce component count, improve efficiency, and accelerate time-to-market for energy-compliant AC/DC converters.

FAQ

What is the maximum continuous output power achievable with VIPER114XSTR in an open-frame design?

The VIPER114XSTR delivers up to 12 W continuous output power in open-frame configurations at 50 °C ambient temperature with adequate heatsinking, as confirmed in ST's DS11873 Rev 5 (Table 8). This rating assumes proper PCB copper area under DRAIN pins and standard FR4 board with 100 mm² of 35 μm-thick copper.

Does VIPER114XSTR support primary-side regulation without an optocoupler?

Yes - VIPER114XSTR supports direct feedback via its FB pin, enabling primary-side regulation in non-isolated topologies (e.g., buck) or VCC-sensing in isolated flyback designs. The internal 1.2 V reference and transconductance error amplifier allow stable regulation without secondary-side feedback components.

How does the jittered oscillator reduce EMI in VIPER114XSTR designs?

The 30 kHz oscillator applies ±7% frequency modulation at 260 Hz, spreading harmonic energy across a wider bandwidth. This lowers peak conducted emissions - particularly under average detection - allowing smaller, lower-cost EMI filters while maintaining EN55032 Class B compliance without Y-capacitors.

Can VIPER114XSTR operate with input voltages below 85 VAC?

No - VIPER114XSTR is designed for universal AC input (85–265 VAC). Its 800 V MOSFET and HV startup circuit are optimized for this range. Operation below 85 VAC falls outside specified electrical characteristics and may result in insufficient VCC charging or unstable regulation due to marginal DRAIN voltage headroom.