STMicroelectronics STNRG011TR

Overview

STNRG011TR from STMicroelectronics is a digital combo multi-mode PFC + time-shift LLC resonant half-bridge controller in SO20 package, integrating 800 V startup circuitry, line sensing, and X-cap discharge compliant with IEC 62368-1. It delivers fixed-on-time TM/DCM PFC control with input voltage feed-forward, THD optimization, and frequency limitation, plus burst-mode light-load operation with fast transient response and line-adaptive brown-out protection for open-frame SMPS and flat-screen TV power supplies.

For engineers reviewing the STNRG011TR datasheet, STNRG011TR pinout, STNRG011TR application, or STNRG011TR equivalent, key selection criteria include its dual-control architecture (PFC + LLC), integrated 800 V HV startup, UART-based configuration and black-box logging, NVM-programmable protection thresholds, and compliance-ready X-cap discharge functionality.

Technical Context

The STNRG011TR implements two independent State Machine Event Driven (SMED) controllers - one for PFC (driving PFC_GD) and two for LLC (driving HVG/LVG) - triggered by analog comparator outputs (e.g., PFC_ZCD, LLC_CS) and internal timers. Its 8-bit core executes optimized digital algorithms stored in 16 kB ROM, with real-time loop control assisted by a 16×16 MAC unit and 32-bit accumulator.

It integrates a multichannel event-driven ADC (10-bit resolution, 15 MHz clock, 7-cycle sampling), programmable comparator thresholds (e.g., PFC_CS OC1 at 500 mV, LLC_FB burst at 0.75/1/1.25 V), and hardware-accelerated protections including latched/unlatched shutdown, X-cap discharge (4 mA min, 50 ms inactivity detection), and AC line monitoring via internal 20 MΩ divider on VAC.

Key Specifications

Pinout & Package

STNRG011TR is housed in a 20-pin SOIC (SO20) package with creepage-enhancing NC pins (pins 4 and 19) isolating high-voltage sections per safety standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital PFC + LLC controller applications.

Compared with UCC28070 and ICE5QSAG, STNRG011TR uniquely integrates PFC+LLC digital control, HV startup, safety-compliant X-cap discharge, and field-upgradable configuration in a single SO20 package - reducing system BOM, layout area, and certification effort for >150 W resonant SMPS.

Availability

STNRG011TR is available at Aetrix Electronics and suitable for open-frame SMPS, flat-screen TV power supplies, and ATX power supply designs requiring stable component supply, long-term lifecycle support, and compliance with IEC 62368-1 safety standards.

Supply support for STNRG011TR 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 management ICs, and analog/mixed-signal devices for industrial, automotive, and consumer markets.

The STNRG series targets digitally controlled high-efficiency AC-DC conversion, specifically engineered to replace multi-chip analog solutions with single-package, NVM-configurable, safety-certifiable controllers for next-generation power supplies.

FAQ

What is the function of the VAC pin beyond startup?

The VAC pin serves three critical roles beyond HV startup: (1) it feeds an internal 20 MΩ resistor divider to generate Vline_sense for brown-in/out detection (114 V / 108 V thresholds), (2) it enables X-cap discharge activation upon 50 ms AC inactivity, and (3) it provides line synchronization signals to align PFC switching with AC phase - all without external components.

How does STNRG011TR achieve IEC 62368-1 X-cap discharge compliance?

STNRG011TR meets IEC 62368-1 by integrating an internal 800 V DMOS switch on the VAC pin that automatically activates when AC line activity ceases for >50 ms. It sinks ≥4 mA to discharge X-class capacitors safely, eliminating the need for external bleeders and reducing standby power loss while ensuring human-safe residual voltage within mandated time limits.

Can STNRG011TR operate without external NVM programming?

Yes - STNRG011TR ships with factory-programmed default parameters in ROM, enabling immediate operation. The 256-byte NVM is optional and used only for application-specific calibration (e.g., PFC OVP threshold, LLC burst level, X-cap discharge enable). Unprogrammed NVM defaults to ROM values, requiring no mandatory configuration step for basic functionality.

What protection features are hardware-latched versus software-configurable?

Hard-wired protections with <100 ns propagation include PFC_OC2 (900 mV), LLC_CS_OC2 (700 mV), and LLC_FB_SHUTDOWN (145 V) - these trigger immediate latched shutdown. Software-configurable protections include PFC_OC1 (500 mV), LLC_FB_BURST (0.75/1/1.25 V), and brown-out masking time (45 ms), all adjustable via UART or NVM during production calibration.