STMicroelectronics VIPER100ASPTR-E

Overview

VIPER100ASPTR-E from STMicroelectronics is a high-voltage, current-mode PWM controller with integrated 700 V vertical power MOSFET (R_DS(on) = 2.8 Ω), designed for primary-side regulation in offline SMPS up to 50 W wide-range or 100 W single-range/doubler configurations. It features adjustable switching frequency up to 100 kHz, internal 13 V VDD regulation, undervoltage lockout (8 V turn-off / 12 V reset), and burst-mode standby operation compliant with Blue Angel <1 W requirement.

For engineers reviewing the VIPER100ASPTR-E datasheet, VIPER100ASPTR-E pinout, VIPER100ASPTR-E application, or VIPER100ASPTR-E equivalent, key selection criteria include its integrated HV start-up current source, transconductance error amplifier (G_m = 1.5 mA/V), programmable peak current limit (3–5.3 A), thermal shutdown (140–170 °C), and PENTAWATT HV package compatibility with snubberless operation.

Technical Context

The device implements current-mode control using a SenseFET-based primary current sensing path with 250 ns blanking time and 1.7 µs disable setup delay. Its transconductance error amplifier accepts feedback via COMP pin-supporting both primary regulation (using internal 13 V reference) and secondary regulation (via optocoupler-connected constant-current sink).

Burst-mode stand-by is triggered when V_COMP falls below 0.5 V, forcing zero-duty-cycle shutdown until V_DD recovers to 12 V; oscillator frequency is set externally via R_T-C_T network (e.g., 8.2 kΩ + 2.4 nF yields 100 kHz ±10%) and remains stable across V_DD = 9–15 V.

Key Specifications

Pinout & Package

Delivered in PENTAWATT HV (PowerSO-10™) package with exposed thermal pad for enhanced heat dissipation. Pin layout optimized for high-voltage isolation and minimal parasitic coupling in offline SMPS layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2QS03G and LNK306P, VIPER100ASPTR-E uniquely combines adjustable frequency, integrated HV start-up, and programmable burst-mode-making it optimal for universal-input, low-noise, and regulatory-compliant offline SMPS where design flexibility and component reduction are critical.

Availability

VIPER100ASPTR-E is available at Aetrix Electronics and suitable for USB wall adapters, smart home power supplies, industrial control PSUs, and LED driver auxiliary supplies requiring stable component supply, long-term lifecycle support, and compliance with Blue Angel and CoC Tier 2 standards.

Supply support for VIPER100ASPTR-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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

VIPER™ is ST's dedicated family of high-voltage AC-DC converters targeting compact, low-BOM, and energy-efficient offline power supplies-from sub-watt standby to 100 W continuous output.

FAQ

What is the maximum recommended continuous output power for VIPER100ASPTR-E in wide-range operation?

The VIPER100ASPTR-E is rated for up to 50 W continuous output in universal AC input (85–265 V_AC) flyback configurations with adequate heatsinking and proper transformer design. This rating assumes operation at 100 kHz, 2.8 Ω R_DS(on), and junction temperature maintained ≤125 °C per thermal data (R_thJC = 1.4 °C/W). Derating is required above 60 °C ambient or with insufficient PCB copper area.

How does the burst-mode stand-by function activate and maintain regulation?

Burst-mode activates when load power drops below ~0.5 W, causing V_COMP to fall below 0.5 V. This forces zero-duty-cycle shutdown until V_DD decays to 8 V, then recharges to 12 V via the HV start-up current source. Each burst cycle delivers just enough energy to sustain output voltage ripple within ±5%, with effective frequency dropping to 1–5 Hz-enabling <1 W total system consumption while preserving regulation.

Can VIPER100ASPTR-E operate with secondary-side regulation using an optocoupler?

Yes-the COMP pin functions as a constant-current sink when V_DD is held between 8.5 V and 12.5 V (e.g., by auxiliary winding design), allowing direct connection to an optocoupler's phototransistor collector. The transconductance amplifier's 1.5 mA/V gain and 0.5 V shutdown threshold ensure stable closed-loop response with standard TL431-based feedback networks.

What is the minimum external capacitor value required on the VDD pin for reliable start-up?

The minimum VDD capacitor is calculated as C_VDD > (I_DD1 × t_SS) / V_DDhyst, where I_DD1 = 19 mA (max operating current at 200 kHz), t_SS ≈ 100 ms (worst-case start-up time at full load), and V_DDhyst = 2.4 V (min UVLO hysteresis). This yields C_VDD > 792 µF; a 1000 µF/25 V electrolytic capacitor is recommended for robustness across temperature and line variations.