STMicroelectronics VIPER20ASPTR-E

Overview

VIPER20ASPTR-E from STMicroelectronics is a 700V, 0.5A integrated primary-side SMPS controller combining a current-mode PWM controller and a vertical high-voltage Power MOSFET in a single PENTAWATT HV package. It delivers up to 10W in universal-input offline flyback converters, features adjustable 90–110 kHz switching frequency, internal 13V VDD regulation, and burst-mode operation enabling <1W standby power per Blue Angel requirements.

For engineers reviewing the VIPER20ASPTR-E datasheet, VIPER20ASPTR-E pinout, VIPER20ASPTR-E application, or VIPER20ASPTR-E equivalent, key selection criteria include its integrated 700V/0.5A MOSFET, 18Ω R_DS(on), undervoltage lockout with 3V hysteresis, thermal shutdown at 140–190°C, and COMP-pin-based primary/secondary regulation flexibility.

Technical Context

This IC implements current-mode control using an internal transconductance error amplifier (G_m = 1.5 mA/V) and a peak-current-sensing comparator with 250 ns blanking time and 350 ns minimum on-time. The oscillator supports external RT/CT programming and synchronization via the OSC pin.

It integrates a high-voltage start-up current source tied to the DRAIN pin, automatic UVLO hysteresis (8 V off / 12 V on), over-temperature protection with 40°C hysteresis, and a soft-start function implemented via the COMP pin capacitor network.

Key Specifications

Pinout & Package

Package: PENTAWATT HV (vertical-mount, 5-pin, thermally enhanced through-hole). Pin 1 = DRAIN, Pin 2 = SOURCE, Pin 3 = VDD, Pin 4 = COMP, Pin 5 = OSC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK304P, VIPER20ASPTR-E uniquely combines 700V integration, programmable frequency, COMP-driven secondary regulation, and certified <1W standby-making it optimal for globally compliant, multi-rail, low-to-mid-power offline supplies.

Availability

VIPER20ASPTR-E is available at Aetrix Electronics and suitable for AC-DC wall adapters, smart home power supplies, industrial control sensors, and white goods auxiliary supplies requiring stable component supply and long-term lifecycle support.

Supply support for VIPER20ASPTR-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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

VIPER series ICs are part of ST's AC-DC conversion portfolio, engineered specifically for highly integrated, low-component-count offline SMPS designs targeting energy-efficient, compact, and cost-optimized power supplies.

FAQ

What is the maximum continuous output power achievable with VIPER20ASPTR-E?

The VIPER20ASPTR-E supports up to 10W in universal-input (85–265 V_AC) offline flyback configurations with adequate heatsinking and proper transformer design. In single-range (e.g., 230 V_AC) or doubler configurations, it can deliver up to 20W. Power capability is constrained by thermal limits (R_thJC = 2.0 °C/W) and the 0.5A current limit, not just peak power calculations.

How does the COMP pin enable both regulation and shutdown functionality?

The COMP pin serves as the output of the transconductance error amplifier. When used for regulation, it drives an RC compensation network to stabilize the feedback loop. When its voltage drops below 0.5 V-due to light load or fault-the internal logic forces zero duty cycle, entering burst mode. This dual behavior eliminates need for separate shutdown circuitry while preserving regulation accuracy across load ranges.

Can VIPER20ASPTR-E operate without an external RT/CT network?

No. The OSC pin requires an external resistor (RT) and capacitor (CT) to set the switching frequency; typical values are RT = 8.2 kΩ and CT = 2.4 nF for ~100 kHz. Without this network, the oscillator remains inactive and the device will not switch. The RT/CT configuration also enables external clock synchronization if needed.

Is the DRAIN pin rated for continuous 700V operation during startup and transient events?

Yes. The DRAIN pin is rated for continuous 700V V_DS and supports unclamped inductive switching with repetitive avalanche energy up to I_D(AR) = 0.4 A at T_C = 100°C. Its integrated HV start-up current source operates directly from DRAIN, eliminating external startup resistors and enabling robust operation during line surges and cold-start conditions.