STMicroelectronics VIPER28HDTR

Overview

VIPER28HDTR from STMicroelectronics is a high-voltage AC-DC converter IC integrating an 800 V avalanche-rugged power MOSFET, current-mode PWM controller, and embedded HV startup circuit. It delivers up to 12 W continuous output in open-frame designs at 50 °C ambient, supports dual switching frequencies (60 kHz or 115 kHz), and achieves ≤30 mW no-load consumption at 230 Vac - enabling compliance with stringent energy-saving standards like EU CoC Tier 2 and DOE Level VI in auxiliary power supplies.

For engineers reviewing the VIPER28HDTR datasheet, VIPER28HDTR pinout, VIPER28HDTR application, or VIPER28HDTR equivalent, key selection considerations include its adjustable dual-level overcurrent protection (IDlim = 0.8 A typ., IDMAX = 1.2 A), digital noise-filtered output overvoltage protection (VOVP = 3.0 V ±0.3 V), and EPT-enabled sustained overload capability for up to 2 seconds - critical for robust flyback SMPS design in cost-sensitive industrial and metering applications.

Technical Context

The VIPER28HDTR implements a current-mode PWM architecture with integrated gate driver, jittered oscillator (±4 kHz or ±8 kHz modulation depth), and burst-mode operation below 0.6 V FB input to minimize light-load losses. Its power section uses a single-chip 800 V N-channel MOSFET with RDS(on) = 7 Ω @ 25 °C and COSS = 40 pF, enabling high dv/dt immunity and efficient flyback topology implementation without external sense resistors.

Control logic includes soft-start (8.5 ms typ.), leading-edge blanking (300 ns), thermal shutdown at 155 °C (30 °C hysteresis), and auto-restart with low repetition rate after fault clearance. The CONT pin configures either cycle-by-cycle current limit adjustment or digital OVP strobing, while the EPT pin accepts an external capacitor to extend overload tolerance before entering hiccup mode.

Key Specifications

Pinout & Package

VIPER28HDTR is housed in a SO16 narrow (SOIC-16) surface-mount package with exposed DRAIN pads (pins 13–16) for enhanced thermal dissipation. The package complies with JEDEC MS-012AC and features 1.27 mm pitch, 10.3 mm × 7.5 mm body size, and 1.75 mm max height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE3B0565J and VIPER17LN, VIPER28HDTR provides higher voltage margin (800 V vs. 650/700 V), configurable protection thresholds via CONT pin, and EPT-based overload resilience - making it uniquely suited for safety-critical, high-reliability auxiliary supplies in energy infrastructure and industrial automation.

Availability

VIPER28HDTR is available at Aetrix Electronics and suitable for smart energy meters, industrial PLC auxiliary supplies, and home appliance control boards requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for VIPER28HDTR 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, sensors, and analog devices for industrial, automotive, and consumer markets.

VIPER28HDTR belongs to the VIPer Plus family of high-voltage offline controllers, engineered specifically for cost-optimized, low-component-count AC-DC flyback converters targeting energy-efficient auxiliary power in metering, appliances, and IoT edge devices.

FAQ

What is the maximum continuous output power achievable with VIPER28HDTR in a standard FR4 PCB layout?

VIPER28HDTR delivers 12 W continuous output in open-frame configurations at 50 °C ambient when mounted on a standard single-sided FR4 board with 100 mm² copper pour under DRAIN pins. This assumes adequate airflow and no enclosure derating. Peak power reaches 20 W for ≤2 seconds with EPT enabled and proper heatsinking.

How does the EPT function interact with the dual-level OCP during a sustained overload condition?

During overload, VIPER28HDTR first limits current at IDlim (0.8 A). If the condition persists beyond the EPT timeout set by the external capacitor, the IC triggers the second OCP (IDMAX = 1.2 A), enters hiccup mode, and shuts down until VDD drops below 4.5 V. This two-stage response prevents transformer saturation while allowing brief surges like motor startup.

Can VIPER28HDTR operate with primary-side regulation only, without an optocoupler?

No - VIPER28HDTR requires feedback via the FB pin for closed-loop regulation. While it supports primary-side sensing schemes using auxiliary winding voltage, an optocoupler or equivalent isolation barrier is mandatory to maintain safety isolation between primary and secondary sides per IEC 62368-1.

What is the recommended minimum copper area under DRAIN pins for thermal performance in SO16N package?

STMicroelectronics specifies a minimum 100 mm² (0.155 in²) copper pour, 35 µm thick, directly beneath pins 13–16 on the component side. This reduces RthJA from 105 °C/W to 80 °C/W, enabling full 1.5 W power dissipation at 60 °C ambient without thermal throttling.