STMicroelectronics VIPER50ASP-E

Overview

VIPER50ASP-E from STMicroelectronics is a high-voltage, current-mode PWM controller with integrated 700 V/1.5 A vertical power MOSFET, designed for primary-side regulation in offline SMPS. It delivers up to 50 W in single-range AC input configurations, features adjustable switching frequency up to 100 kHz (typ.), burst-mode standby operation (<1 W total system consumption), and built-in over-temperature protection at 140–170 °C.

For engineers reviewing the VIPER50ASP-E datasheet, VIPER50ASP-E pinout, VIPER50ASP-E application, or VIPER50ASP-E equivalent, key selection criteria include its integrated HV start-up current source, 5.7 Ω R_DS(on) at T_j = 100 °C, 1.5 A peak current limit, PENTAWATT HV package thermal resistance (R_thJC = 1.9 °C/W), and compatibility with both primary- and secondary-side regulation topologies.

Technical Context

The VIPER50ASP-E implements a current-mode control architecture with an internal transconductance error amplifier (G_m = 1.5 mA/V typ.) and a dedicated PWM comparator with 250 ns blanking time and 350 ns minimum on-time. Its oscillator supports external RT–CT programming and synchronization via the OSC pin, maintaining stable frequency (90–110 kHz) across V_DD = 9–15 V.

It integrates a high-voltage start-up current source referenced to the DRAIN pin, UVLO with 3 V hysteresis (V_DDon = 12 V, V_DDoff = 8 V), and automatic burst-mode transition triggered when V_COMP falls below 0.5 V - enabling Blue Angel-compliant <1 W standby power without auxiliary circuitry.

Key Specifications

Pinout & Package

Package: PENTAWATT HV (022Y), 10-pin thermally enhanced SIP, with exposed drain pad for direct PCB heat sinking (R_thJC = 1.9 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SMPS primary-side controller applications.

Compared with ICE2QS03G and VIPER06XS, the VIPER50ASP-E uniquely combines 700 V rating, 2 A peak current capability, and integrated burst-mode control - making it the only option among the three capable of delivering 50 W in single-range configuration while meeting <1 W standby without auxiliary circuitry.

Availability

VIPER50ASP-E is available at Aetrix Electronics and suitable for AC-DC wall adapters, appliance power supplies, LED driver power stages, and industrial sensor power modules requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for VIPER50ASP-E 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.

The VIPer™ family targets highly integrated, cost-optimized AC-DC conversion - specifically engineered to replace discrete MOSFET + controller combinations in offline SMPS up to 50 W, with emphasis on ease of certification, thermal robustness, and ultra-low standby power.

FAQ

What is the maximum continuous output power achievable with VIPER50ASP-E in a universal-input flyback design?

The VIPER50ASP-E supports up to 25 W in universal-input (85–265 V_AC) configurations and up to 50 W in single-range (e.g., 230 V_AC ±15%) or doubler-mode operation. This is enabled by its 700 V V_DS rating, 5.7 Ω R_DS(on), and thermal design optimized for the PENTAWATT HV package's 1.9 °C/W junction-to-case resistance.

How does the burst-mode operation reduce standby power below 1 W?

Burst mode activates automatically when load power drops below ~0.5 W, causing V_COMP to fall below 0.5 V. This forces zero-duty-cycle operation, halting switching until V_DD discharges to 8 V and recharges to 12 V via the integrated HV start-up source - resulting in intermittent energy bursts that limit average input power to <1 W system-wide.

Can VIPER50ASP-E operate with primary-side regulation only, without an optocoupler?

Yes - the device supports primary-side regulation using reflected voltage sensing on the auxiliary winding. The VDD pin serves as both supply and regulation node: internal 13 V reference stabilizes VDD, and deviations indicate output voltage drift. This eliminates optocoupler, TL431, and associated compensation components in cost-sensitive designs.

What is the role of the OSC pin beyond frequency setting?

The OSC pin accepts external clock signals for synchronization, enabling EMI reduction through frequency dithering or alignment with system clocks. When driven by a clean square wave (≤500 ns pulse width), it overrides the internal oscillator while preserving blanking timing and current-sense propagation delays - critical for multi-channel or noise-sensitive applications.