STMicroelectronics VIPER06HSTR

Overview

VIPER06HSTR from STMicroelectronics is a high-voltage offline PWM controller with integrated 800 V avalanche-rugged N-channel MOSFET, designed for flyback and buck converters in low-power AC/DC applications. It operates at 115 kHz (typ.), delivers up to 8 W in open-frame designs, supports direct mains-powered startup without auxiliary winding, and achieves <30 mW standby power at 265 VAC.

For engineers reviewing the VIPER06HSTR datasheet, VIPER06HSTR pinout, VIPER06HSTR application, or VIPER06HSTR equivalent, key selection criteria include its fixed 115 kHz switching frequency, adjustable current limit via LIM pin, burst-mode operation for ultra-low standby, hysteretic thermal shutdown at 150–160 °C, and self-biasing capability eliminating auxiliary windings in compact adapters.

Technical Context

The VIPER06HSTR integrates a SenseFET-based current-sensing power stage with 32 Ω typical R_DS(on) at 25 °C and 800 V breakdown voltage. Its oscillator implements ±8 kHz frequency jittering at 230 Hz to reduce EMI peaks, and the controller uses cycle-by-cycle current-mode PWM with internal soft-start (8.5 ms) and safe auto-restart after fault.

Feedback is implemented via an internal transconductance error amplifier (G_M = 2 mA/V, V_{REF_FB} = 3.3 V) with FB and COMP pins supporting both isolated (optocoupler-driven) and non-isolated topologies. Burst mode activates when V_COMP falls below 1.1 V, reducing average switching frequency and limiting peak drain current to 85 mA to suppress audible noise.

Key Specifications

Pinout & Package

Available in SSO10 (10-lead shrink small outline) package with exposed metal pad for thermal dissipation. DRAIN pins (6–10) are internally connected and must be soldered to large copper area for heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK306P, VIPER06HSTR offers higher voltage ruggedness (800 V), higher switching frequency (115 kHz), and finer control over current limit and burst behavior-making it optimal for compact, globally compliant, low-standby AC/DC supplies where design flexibility and thermal resilience are critical.

Availability

VIPER06HSTR is available at Aetrix Electronics and suitable for smart meter power supplies, LED lamp drivers, home appliance auxiliary PSUs, and non-isolated buck converters requiring stable component supply, long-term lifecycle support, and compliance with global energy regulations.

Supply support for VIPER06HSTR 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.

VIPER06 belongs to ST's VIPer™ family of high-voltage offline controllers-designed specifically for cost-effective, compact, and energy-compliant AC/DC conversion in sub-10 W applications.

FAQ

What is the maximum continuous output power achievable with VIPER06HSTR in an open-frame design?

VIPER06HSTR delivers up to 8 W continuous output power in open-frame configurations at 50 °C ambient, assuming adequate PCB copper area under DRAIN pins for thermal dissipation. This rating assumes proper layout per ST's AN4170 guidelines and use of recommended transformer turns ratio and snubber components. Power derates linearly above 50 °C ambient due to thermal shutdown hysteresis and R_DS(on) increase.

Can VIPER06HSTR operate without an auxiliary winding in isolated flyback topologies?

Yes-VIPER06HSTR supports primary-side regulation in isolated flybacks using only the main transformer secondary for feedback via an optocoupler connected to the COMP pin, with FB pin tied to GND. The internal HV current generator powers the IC directly from DRAIN during startup and steady-state, eliminating need for auxiliary winding while maintaining regulation accuracy within ±5% over line/load.

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

The LIM pin sinks current proportional to external resistor R_LIM between LIM and GND. As R_LIM decreases from open-circuit, peak drain current reduces from 0.35 A (default) down to ~0.1 A at R_LIM = 10 kΩ, per Figure 14 in the datasheet. Below 10 kΩ, further reduction is limited by internal clamp; precise values require interpolation from the IDlim vs RLIM curve.

Does VIPER06HSTR support both DIP-7 and SSO10 packages, and which one is used for VIPER06HSTR?

VIPER06HSTR is exclusively offered in the SSO10 (shrink small outline, 10-lead) package with exposed thermal pad, as confirmed by ST's ordering information table (Section 18). The DIP-7 variant exists for other VIPER06 suffixes (e.g., VIPER06XSP), but HSTR denotes SSO10 packaging optimized for surface-mount assembly and improved thermal performance in compact adapters.