STMicroelectronics VIPER012HSTR

Overview

VIPER012HSTR from STMicroelectronics is a high-voltage off-line SMPS controller integrating an 800 V avalanche-rugged N-channel MOSFET, current-mode PWM control, and embedded HV startup. It delivers up to 4 W in open-frame designs at 50 °C ambient, supports 85–265 VAC input, and operates at 120 kHz ±7% switching frequency with jittered spread-spectrum modulation. Used in low-power flyback, buck, and buck-boost converters for home appliances and lighting.

For engineers reviewing the VIPER012HSTR datasheet, VIPER012HSTR pinout, VIPER012HSTR application, or VIPER012HSTR equivalent, key selection criteria include its self-supply capability (eliminating auxiliary winding), <10 mW no-load power consumption at 230 VAC, integrated thermal shutdown, and drain current limit of 240 mA (typ.) with automatic restart protection.

Technical Context

The device implements a current-mode PWM controller with internal transconductance error amplifier (1.2 V reference), soft-start (8 ms), and pulse-frequency modulation (PFM) below 0.8 V on COMP pin. Its HV startup circuit delivers up to 8.8 mA charging current (ICH3) to VCC during OFF-time only, enabling true self-supply operation without external bias winding.

Protection architecture includes line/output OVP via DIS pin (1.2 V threshold), overload/short-circuit detection with 200 ms max delay (for H-type), thermal shutdown at 155 °C, and flux-runaway prevention via pulse-skip logic tied to tON_MIN (360 ns) and FOSC_MIN (15 kHz). The DRAIN pins (6–10) are internally connected to the MOSFET die pad for enhanced thermal conduction.

Key Specifications

Pinout & Package

Package: SSOP10 (3.9 mm × 4.9 mm, 0.65 mm pitch), thermally enhanced with exposed DRAIN pads (pins 6–10) connected to internal MOSFET metal pad for low R_TH-JA (95 °C/W with 100 mm² copper).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage offline SMPS controller applications.

Compared with VIPER012HSTR, ICE2QS03G offers lower integration but simpler layout, while LNK306P provides stronger safety features at the expense of self-supply flexibility and higher no-load loss - VIPER012HSTR uniquely balances ultra-low standby, jittered EMI reduction, and full self-supply in a single SSOP10 package.

Availability

VIPER012HSTR is available at Aetrix Electronics and suitable for home appliance power supplies, LED lighting drivers, and industrial sensor node PSUs requiring stable component supply across extended product lifecycles.

Supply support for VIPER012HSTR 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

VIPER012HSTR belongs to the VIPer™ energy-saving off-line high-voltage converter family, engineered specifically for compact, low-noise, ultra-low-standby AC-DC power supplies in space-constrained and thermally demanding applications.

FAQ

What is the maximum continuous output power achievable with VIPER012HSTR in an open-frame design?

VIPER012HSTR delivers up to 4.5 W continuously in open-frame configurations at 50 °C ambient temperature with adequate heat-sinking, as confirmed in Table 8 of DS11423. This rating assumes use of the SSOP10 package mounted on a standard FR4 board with 100 mm² copper area, leveraging its low R_TH-JA (95 °C/W) and 800 V MOSFET for efficient thermal management under full load.

How does the self-supply mode eliminate the need for an auxiliary winding?

The self-supply mode uses the internal HV current source (ICH3 = 8.8 mA typ.) to recharge the VCC capacitor during MOSFET OFF-time only, maintaining VCC between 4.25 V (VCSon) and 8.0 V (VCCon). This eliminates reliance on transformer auxiliary windings or bias resistors, reducing transformer complexity and enabling single-winding designs - verified in Figure 26 and Section 4.4 of DS11423.

Can VIPER012HSTR support primary-side regulation without an optocoupler?

Yes - VIPER012HSTR supports primary-side regulation using the FB pin directly connected to a voltage divider from the VCC rail, as described in Section 1 (Pin Description) and Figure 25's block diagram. In this configuration, the internal error amplifier compares FB voltage to its 1.2 V reference, enabling regulation without optocoupler or secondary-side feedback components.

What protection mechanisms activate during output short-circuit conditions?

Under output short-circuit, VIPER012HSTR triggers overload protection (OLP) with a 200 ms max delay (tOVL_MAX for H-type), then enters auto-restart mode with full soft-start (8 ms). Concurrently, pulse-skip prevents flux runaway by disabling switching cycles when peak drain current exceeds 240 mA within 360 ns minimum on-time, as specified in Tables 7 and 4.7 of DS11423.