STMicroelectronics VIPERGAN65TR

Overview

VIPERGAN65TR from STMicroelectronics is a high-voltage quasi-resonant flyback controller integrating a 650 V E-mode GaN HEMT, embedded sense FET, and dynamic valley-synchronization logic. It delivers up to 65 W (85–265 VAC) with ZVS operation, <30 mW standby power, and multi-mode control (QR/valley-skipping/frequency foldback/burst). Used in fast-charger adapters requiring high efficiency, low EMI, and mains-independent OVP.

For engineers reviewing the VIPERGAN65TR datasheet, VIPERGAN65TR pinout, VIPERGAN65TR application, or VIPERGAN65TR equivalent, key selection criteria include its integrated GaN switch rating (650 V), valley-lock timing precision (±10 ns blanking control), adaptive burst-mode threshold (0.7 V FB), and input feed-forward compensation (55 µA/mA gain) - all critical for compact, high-density offline SMPS design.

Technical Context

The VIPERGAN65TR implements a multi-mode QR controller with valley-lock synchronization: it detects transformer demagnetization via ZCD pin (trigger threshold 60 mV, arming 110 mV), enforces dynamic blanking time (3.04–20 µs, adjustable via TB pin), and forces turn-on after TFORCE (2.7 µs) if no valid valley is detected. Its internal HV start-up generator draws 3.55 mA at VDD < VDD-FOLD and clamps HV pin to 27 V post-startup.

Protection architecture includes auto-restart brown-in/out (0.5 V / 0.4 V thresholds), iOVP (5 V threshold), output OVP (2.5 V), OCP_LEB (2.69 A), and thermal shutdown (140 °C). All protections use digitally filtered, strobed sensing with dedicated pins (BR, iOVP, ZCD, FB) and share a common GND return path across pins 1–4 and EP.

Key Specifications

Pinout & Package

Package: PowerSSO-24 (exposed pad, 16-pin, thermally enhanced SOIC variant with integrated GaN die and controller).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quasi-resonant GaN flyback controller applications.

Compared with ICE5QSBGx and MPX2002, VIPERGAN65TR delivers higher power density (65 W in PowerSSO-24), eliminates external sense and driver components, and ensures silent operation via valley-lock-critical for consumer-facing fast chargers and lighting.

Availability

VIPERGAN65TR is available at Aetrix Electronics and suitable for high-efficiency power adapters, fast battery chargers, and industrial auxiliary power supplies requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for VIPERGAN65TR 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 microcontrollers, power ICs, sensors, and automotive-grade components with ISO 9001 and IATF 16949 certification.

VIPERGAN65TR belongs to ST's VIPer™ GaN product line, engineered specifically for high-density, high-efficiency offline SMPS targeting USB PD 3.1, industrial auxiliary rails, and smart home power systems.

FAQ

What is the maximum continuous output power achievable with VIPERGAN65TR?

The VIPERGAN65TR delivers up to 65 W at 85–265 VAC input with 50°C ambient temperature and adequate PCB copper area (4-layer, 2 oz, 5 vias under EP). At 185–265 VAC, typical capability increases to 85 W due to reduced conduction losses and improved thermal margin. Output power is limited by junction temperature (155°C max) and ZVS boundary conditions-not by peak current alone.

How does the TB pin adjust blanking time and valley synchronization?

The TB pin accepts a voltage divider from the transformer auxiliary winding. During GaN on-time, current into TB sets blanking time (3.04–20 µs); during off-time, the same divider sets turn-on delay (197 ns–1.1 µs) to align GaN turn-on precisely with the lowest drain resonance valley. A grounded TB disables both functions, defaulting to fixed 4.16 µs blanking and 2.7 µs forced turn-on.

Does VIPERGAN65TR require an external bootstrap capacitor for the GaN gate drive?

No. VIPERGAN65TR integrates a linear regulator that generates a tightly regulated 6.0 V supply on the DRV pin, powered from VDD. A 1 µF low-ESR ceramic capacitor between DRV and GND is mandatory for transient stability-but no bootstrap diode, capacitor, or charge pump is needed. This simplifies layout and eliminates bootstrap-related startup failures.

Can VIPERGAN65TR operate without the ZCD pin connection?

No. The ZCD pin is mandatory for quasi-resonant operation. It provides the negative-going edge signal used to detect transformer demagnetization and synchronize GaN turn-on to the drain voltage valley. If left unconnected, the device defaults to forced TFORCE turn-on only, resulting in non-ZVS hard switching, excessive losses, and potential GaN failure under load.