STMicroelectronics VIPER318HDTR

Overview

VIPER318HDTR from STMicroelectronics is an integrated 800 V avalanche-rugged high-voltage PWM converter IC combining a power MOSFET, current-mode controller, HV startup circuit, and embedded sense FET in SO-16N package. It delivers up to 31 W in open-frame designs at 50°C ambient, supports flyback/buck/buck-boost topologies, and features 850 mA drain current limit, 132 kHz ±7% jittered switching frequency, and <20 mW no-load consumption at 230 VAC - enabling energy-efficient low-power SMPS for lighting and home automation.

For engineers reviewing the VIPER318HDTR datasheet, VIPER318HDTR pinout, VIPER318HDTR application, or VIPER318HDTR equivalent, key selection criteria include its 800 V MOSFET breakdown rating, 132 kHz (H-type) fixed-frequency jittered oscillator, 850 mA OCP threshold, 1.2 V internal E/A reference, and UVP/OVP pins with user-configurable thresholds - all critical for offline AC/DC converter design under IEC 61000-3-2 and Energy Star requirements.

Technical Context

The VIPER318HDTR implements a current-mode PWM control architecture with integrated transconductance error amplifier referenced to 1.2 V, enabling direct feedback in non-isolated topologies via FB pin. Its oscillator operates at 132 kHz ±7% with 200 Hz spread-spectrum modulation to reduce EMI filter size and cost.

Protection logic includes auto-restart thermal shutdown (150–160°C), overload/short-circuit (50 ms delay), and overvoltage (4 V threshold, 500 ms restart), plus non-auto-restart functions like pulse-skipping to prevent flux runaway and UVLO disable with <0.35 mA quiescent current during UVP hold-off.

Key Specifications

Pinout & Package

Package: SO-16N (16-pin small outline, exposed drain pad for thermal dissipation). Pin 13–16 are internally connected to MOSFET drain and serve as high-current output terminals and thermal conduction paths; PCB copper area under these pins reduces R_TH-JA to 85°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE3B0565J and LNK3206P, VIPER318HDTR offers superior input voltage headroom (800 V), lower no-load power (<20 mW), and active EMI reduction via jitter - making it optimal for global-input, energy-certified, and thermally constrained applications.

Availability

VIPER318HDTR is available at Aetrix Electronics and suitable for LED lighting drivers, smart home power supplies, white goods auxiliary PSUs, and industrial sensor node adapters requiring stable component supply, long-lifecycle assurance, and compliance with global energy regulations.

Supply support for VIPER318HDTR 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 analog, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

VIPER31 is part of ST's high-voltage AC/DC converter product line, engineered specifically for compact, low-component-count offline SMPS targeting energy-efficient lighting, home automation, and appliance auxiliary power with minimal external components.

FAQ

What is the purpose of the four DRAIN pins (13–16) on VIPER318HDTR?

These pins are electrically and mechanically connected to the internal MOSFET drain and serve dual roles: conducting high pulsed drain current and dissipating heat through direct copper contact. Using all four pins lowers effective R_DS(on) and reduces junction-to-ambient thermal resistance to 85°C/W with 100 mm² PCB copper, enabling higher continuous power in space-constrained layouts.

Can VIPER318HDTR operate without an auxiliary winding for VCC supply?

Yes - its integrated 800 V HV startup circuit charges the VCC capacitor directly from the DRAIN pin via an external resistor (RG), eliminating the need for an auxiliary winding. At 230 VAC, typical RG = 45 MΩ draws only 2.4 mW, supporting ultra-low no-load designs. An auxiliary winding may be added later for improved efficiency at full load.

How does the UVP pin function beyond undervoltage detection?

UVP serves as a hardware disable input: pulling it below 0.4 V for >30 ms halts switching and reduces quiescent current to 0.25–0.35 mA, enabling ultra-low-power standby modes. Leaving it open disables the function entirely; tying it to a microcontroller GPIO allows remote on/off control without additional level-shifting circuitry.

What topology configurations does VIPER318HDTR support beyond flyback?

It natively supports buck and buck-boost topologies in non-isolated configurations using direct FB feedback. In buck mode, DRAIN connects to input, GND to output, and VOUT derived from the switch node. The 800 V rating and integrated sense FET allow operation up to 265 VAC rectified input, ideal for high-input-voltage DC-DC stages in industrial controls.