STMicroelectronics VIPER20ASP-E

Overview

VIPER20ASP-E from STMicroelectronics is a 700V, 0.5A integrated primary-side SMPS controller combining a current-mode PWM controller and a vertical power MOSFET in a single PENTAWATT HV package. It delivers up to 10W in wide-input offline power supplies, features adjustable 90–110 kHz switching frequency, internal 13V VDD regulation, and burst-mode operation enabling <1W standby consumption per Blue Angel requirements. Used in auxiliary power supplies for TVs, set-top boxes, and smart home adapters.

For engineers reviewing the VIPER20ASP-E datasheet, VIPER20ASP-E pinout, VIPER20ASP-E application, or VIPER20ASP-E equivalent, key selection considerations include its integrated high-voltage start-up current source, 18Ω R_DS(on), 250 ns current-sense blanking time, thermal shutdown at 140–190°C, and compatibility with both primary- and secondary-side regulation topologies.

Technical Context

The VIPER20ASP-E implements current-mode control using an internal transconductance error amplifier (G_m = 1.5 mA/V) and a PWM comparator with 0.5 V current-sense threshold. Its oscillator uses an external R_t-C_t network to set frequency between 90–110 kHz, with built-in synchronization capability via the OSC pin.

Standby operation is managed through automatic burst mode triggered when V_COMP falls below 0.5 V, forcing zero-duty-cycle shutdown until V_DD recovers to ≥11 V. Over-temperature protection activates at 140–190°C with 40°C hysteresis, and undervoltage lockout operates with 7.5–9 V shutdown and 11–12 V restart thresholds.

Key Specifications

Pinout & Package

PENTAWATT HV (022Y) package: 5-pin thermally enhanced SIP with isolated drain tab, optimized for high-voltage isolation and PCB-level heat dissipation in compact offline SMPS designs.

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, the VIPER20ASP-E offers superior integration (HV start-up, burst mode, thermal shutdown), wider power range (up to 10 W), and greater design flexibility via programmable oscillator and dual regulation support-making it optimal for cost-sensitive, space-constrained, and energy-compliant offline converters.

Availability

VIPER20ASP-E is available at Aetrix Electronics and suitable for smart home adapters, industrial IoT power modules, and consumer electronics auxiliary supplies requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant manufacturing.

Supply support for VIPER20ASP-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.

The VIPer™ family targets highly integrated, low-component-count AC-DC conversion for sub-25W applications-designed to replace discrete MOSFET+controller solutions with single-chip reliability and energy-efficiency certification support.

FAQ

What is the minimum recommended VDD bypass capacitor value for reliable startup?

The minimum V_DD capacitor must satisfy C_VDD > (I_DD × t_SS) / V_DDhyst, where I_DD is 13–14 mA (at 100–200 kHz), t_SS is worst-case startup time (typically 50–100 ms), and V_DDhyst is ≥2.4 V. For most designs, a 10 µF/25 V electrolytic capacitor with ≤1 Ω ESR ensures robust startup across temperature and line variations.

Can VIPER20ASP-E operate without an optocoupler in primary-side regulation?

Yes. The device supports direct primary-side regulation using a resistive divider from the auxiliary winding to the VDD pin. When VDD reaches 13 V, internal regulation clamps it, providing stable feedback without optocoupler or secondary-side components-ideal for cost-sensitive, low-isolation applications like non-isolated buck-derived topologies.

How does the 250 ns blanking time affect transformer design?

The 250 ns blanking window suppresses false current-sense triggering caused by transformer leakage inductance ringing or secondary rectifier reverse recovery. This allows use of standard low-cost ferrite cores without snubbers, but requires careful attention to primary winding layout to minimize parasitic inductance-exceeding 300 ns ring duration may cause premature switch-off and instability.

Is the OSC pin compatible with external clock sources above 200 kHz?

No. The OSC pin is designed for synchronization within the device's operational frequency range (90–110 kHz). External clocks above 120 kHz risk violating internal timing margins, causing erratic PWM behavior or latch-up. For higher-frequency systems, use dedicated sync-capable controllers such as the STNRG388A or ICE5QSBG.