STMicroelectronics VIPER16HD

Overview

VIPER16HD from STMicroelectronics is a fixed-frequency, off-line PWM controller with integrated 800 V avalanche-rugged power MOSFET, designed for low-power AC-DC flyback and buck-boost converters. It operates at 115 kHz (±8 kHz jitter), delivers up to 6 W in open-frame designs at 50 °C ambient, supports self-biasing without auxiliary winding, and achieves <30 mW standby power at 230 VAC - enabling compliance with stringent energy-saving regulations in auxiliary power supplies.

For engineers reviewing the VIPER16HD datasheet, VIPER16HD pinout, VIPER16HD application, or VIPER16HD equivalent, key selection considerations include its 800 V drain rating, adjustable current limit via LIM pin, burst-mode operation below 1.1 V on COMP, hysteretic thermal shutdown at 150–160 °C, and SO16 narrow package suitability for compact, cost-sensitive consumer and industrial SMPS designs.

Technical Context

The VIPER16HD integrates a high-voltage start-up current generator referenced to the DRAIN pin, enabling direct mains-derived biasing without auxiliary windings. Its oscillator implements spread-spectrum frequency jittering (±4–8 kHz at 230 Hz) to reduce EMI filter cost and simplify compliance.

It employs current-mode PWM control with cycle-by-cycle sensing via SenseFET structure, combined with dual protection layers: adjustable overcurrent limit (via external RLIM resistor) and open-loop failure detection that triggers safe auto-restart after overload or short-circuit events within 1 s.

Key Specifications

Pinout & Package

Package: SO16 narrow (300 mil), thermally enhanced with DRAIN pins (13–16) connected to internal metal frame for improved heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK306P, VIPER16HD offers superior 800 V ruggedness, lower standby power, and built-in EMI reduction - making it optimal for compact, globally rated, energy-efficient auxiliary supplies where reliability and regulatory compliance are prioritized over minimal BOM cost.

Availability

VIPER16HD is available at Aetrix Electronics and suitable for smart metering, appliance control boards, LED lighting, and industrial sensor node power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for VIPER16HD 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

VIPER16HD belongs to the VIPer™ plus family of high-voltage offline controllers, engineered specifically for cost-sensitive, low-to-mid power AC-DC conversion in space-constrained applications demanding high integration and regulatory compliance.

FAQ

What is the maximum continuous output power achievable with VIPER16HD in an open-frame design?

VIPER16HD delivers up to 6 W continuous output power in open-frame configurations at 50 °C ambient temperature with adequate heatsinking, as verified in ST's typical power characterization (Table 2). This assumes proper PCB layout with ≥100 mm² copper pour under DRAIN pins and operation within the 103–127 kHz frequency range. Derating is required above 50 °C ambient or in enclosed adapters.

Can VIPER16HD operate without an auxiliary winding, and how is bias supplied?

Yes - VIPER16HD eliminates the need for an auxiliary winding by using its integrated high-voltage current generator, which draws startup and steady-state bias current directly from the DRAIN pin. During startup, it sources −1.8 mA (typical) to charge the VDD capacitor until VDD reaches 12–14 V; in steady state, it delivers −14 mA (typical) during MOSFET off-time to sustain operation.

How does the LIM pin adjust overcurrent protection, and what is the minimum achievable limit?

The LIM pin sinks current proportional to an external resistor (RLIM) connected to GND, reducing the default 0.4 A drain current limit. Per Figure 13 and Table 8, a 10 kΩ RLIM sets IDlim ≈ 0.25 A, while 47 kΩ yields ~0.12 A. Values >80 kΩ revert to the default limit. Capacitors ≤470 nF may be added for noise immunity without affecting functionality.

Does VIPER16HD support both isolated and non-isolated topologies, and how is feedback configured?

Yes - for non-isolated buck/buck-boost, connect output directly to FB pin (single resistor for 3.3 V output); for isolated flyback, short FB to GND to disable internal error amplifier and close the loop via optocoupler to COMP pin. The COMP pin's 1–3 V dynamic range supports both configurations, with burst mode triggered below 1.1 V regardless of topology.