STMicroelectronics VIPER26HDTR

Overview

VIPER26HDTR from STMicroelectronics is a high-voltage offline PWM controller IC integrating an 800 V avalanche-rugged power MOSFET, current-mode control, and embedded HV startup circuitry. It delivers up to 20 W in open-frame designs at 50 °C ambient, supports flyback/buck/buck-boost topologies, and achieves <30 mW no-load input power at 230 VAC - enabling compliance with stringent energy-saving standards such as EU CoC v5 Tier 2 and DOE Level VI.

For engineers reviewing the VIPER26HDTR datasheet, VIPER26HDTR pinout, VIPER26HDTR application, or VIPER26HDTR equivalent, this device is selected for auxiliary power supplies requiring wide AC input range (85–265 VAC), low standby consumption, jittered switching frequency (115 kHz ±8 kHz) to reduce EMI filter cost, and integrated thermal shutdown with automatic restart on overload/short-circuit.

Technical Context

The VIPER26HDTR implements a fixed-frequency current-mode PWM architecture with internal 800 V power MOSFET, sense-FET, transconductance error amplifier (VREF_FB = 3.3 V), and burst-mode operation below VCOMP = 1.1 V. Its oscillator operates at 115 kHz ±8 kHz with 230 Hz modulation frequency to spread spectral energy and reduce conducted EMI peaks.

Control logic includes cycle-by-cycle overcurrent protection (IDlim = 0.7 A typ.), soft-start (tSS = 8.5 ms), hysteretic thermal shutdown (TSD = 150 °C, THYS = 30 °C), and dual-stage UVLO (VDDon = 12–14 V, VDDoff = 7–9 V). The LIM pin enables adjustable current limiting via external resistor, while FB and COMP pins support both isolated (optocoupler-driven) and non-isolated regulation schemes.

Key Specifications

Pinout & Package

Available in SO16 narrow (SO16N) and DIP-7 packages. Both variants feature exposed DRAIN pins (pins 13–16 in SO16N; pins 1 and 8 in DIP-7) for direct PCB copper thermal pad attachment to minimize junction-to-ambient thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK364PG, VIPER26HDTR provides superior EMI performance via jittered 115 kHz operation, lower standby consumption (<30 mW), and design flexibility through the LIM pin - making it optimal for globally certified, high-reliability auxiliary supplies.

Availability

VIPER26HDTR is available at Aetrix Electronics and suitable for appliance auxiliary supplies, smart metering systems, and LED driver reference designs requiring stable component supply, long-lifecycle availability, and full traceability under industrial temperature grade (-40 to +150 °C).

Supply support for VIPER26HDTR 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.

VIPER26HDTR belongs to the VIPerPlus family of high-voltage offline controllers designed specifically for compact, low-BOM-count AC/DC converters targeting energy-efficient auxiliary power supplies in white goods, smart meters, and consumer electronics.

FAQ

What is the maximum continuous output power achievable with VIPER26HDTR in an open-frame design?

VIPER26HDTR delivers up to 20 W continuous output power in open-frame configurations at 50 °C ambient temperature when mounted on a standard FR4 board with 100 mm² of 35 µm copper for thermal relief. This rating assumes proper heatsinking under the DRAIN pins and operation within the SOA limits defined in Figure 17 of DS6901 Rev 3.

How does the LIM pin adjust the drain current limit, and what resistor value yields 0.5 A IDlim?

The LIM pin sinks current proportional to the external resistor RLIM connected between LIM and GND. Per Figure 12 in DS6901 Rev 3, a 47 kΩ resistor sets IDlim ≈ 0.5 A at 25 °C. RLIM values above 80 kΩ default to the nominal 0.7 A limit; capacitors ≤470 nF may be added for noise immunity without affecting functionality.

Can VIPER26HDTR operate in isolated flyback topology without an auxiliary winding?

Yes - VIPER26HDTR supports primary-side regulation in isolated flyback topologies without an auxiliary winding by using the FB pin tied to a resistive divider from the primary-side VCC node. This method eliminates the need for a third winding while maintaining output voltage accuracy within ±5% across line/load variations, as validated in Figure 21 of DS6901 Rev 3.

What protection features activate during a sustained short-circuit on the secondary side?

Under sustained short-circuit, VIPER26HDTR activates overload protection (OLP) via an internal up-down counter that triggers automatic restart after ~1 second (tRESTART = 1 s typ.). During fault, the device enters burst mode with reduced IDlim_bm (145 mA), limits average power, and maintains thermal safety via hysteretic shutdown (TSD = 150 °C, THYS = 30 °C) - all without external components.