STMicroelectronics STLUX385ATR

Overview

STLUX385ATR from STMicroelectronics is a digital lighting and power conversion controller integrating an STM8® core, six autonomous SMED PWM generators (1.3 ns resolution), DALI 2.0-compliant interface, 4× analog comparators (<50 ns propagation), and 10-bit ADC with op-amp gain (x1/x4). It targets high-precision LED/HID ballast control and resonant SMPS topologies requiring sub-10 ns event response.

For engineers reviewing the STLUX385ATR datasheet, STLUX385ATR pinout, STLUX385ATR application, or STLUX385ATR equivalent, this page delivers verified technical context on SMED coupling modes, DALI noise rejection configuration, comparator reference sourcing, and flash/ECC retention specs under thermal stress - all critical for lighting firmware development and power stage timing validation.

Technical Context

The STLUX385ATR implements six independent SMEDs-hardware state machines triggered by internal timers or external events (DIGIN, comparator outputs, PWM feedback)-with configurable transitions between S0–S3 states plus HOLD, enabling deterministic <10.4 ns reaction time without CPU intervention. Each SMED supports single, synchronous/asynchronous coupled, or two-coupled operational modes via MSC_SMEDCFGxy registers.

Its DALI peripheral provides interrupt-driven hardware encoding compliant with IEC 62386-102 (24-bit frame extension) and IEC 60929, with programmable noise rejection filter and reverse-polarity tolerant Tx/Rx lines operating at 1.2/2.4/4.8 kHz. The integrated 96 MHz PLL feeds SMED timing while the 16 MHz RC oscillator (user-trimmable ±1%) serves as system clock source.

Key Specifications

Pinout & Package

TSSOP38 package: 38-pin thermally enhanced thin shrink small outline package with exposed pad for improved thermal dissipation in lighting driver PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital lighting controller applications.

Compared with STLUX325A, the STLUX385ATR adds a sixth SMED output and dedicated DIGIN pins for higher channel count and deterministic timing; versus NCP1654, it replaces analog-only control with full digital programmability, DALI integration, and embedded firmware extensibility.

Availability

STLUX385ATR is available at Aetrix Electronics and suitable for LED streetlight drivers, HID electronic ballasts, PFC+LLC combo power supplies, and smart fluorescent dimmers requiring stable component supply across extended product lifecycles.

Supply support for STLUX385ATR 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 analog devices for automotive, industrial, and consumer markets.

The STLUX family targets digitally controlled lighting and power conversion systems, emphasizing deterministic real-time PWM generation, DALI interoperability, and long-term reliability in thermally demanding environments.

FAQ

What is the maximum achievable PWM frequency using SMED dithering?

The STLUX385ATR's SMEDs achieve up to 768 MHz effective PWM frequency when using dithering with the 96 MHz PLL base clock, enabling sub-nanosecond edge placement for ultra-precise timing in resonant converters. This is derived from 96 MHz × 8-phase dithering, not a continuous carrier frequency.

How does the DALI peripheral handle bus collisions during multi-master communication?

The STLUX385ATR DALI interface operates exclusively as a slave per IEC 62386-102; it does not implement master arbitration logic. Collision handling is managed externally by the DALI master controller, while the STLUX385ATR ensures strict timing compliance on RX/TX edges and automatic noise filtering during frame reception.

Can the 4 analog comparators operate simultaneously during SMED autonomous execution?

Yes - all four comparators run continuously and independently of CPU or SMED activity, with outputs directly routable to SMED inputs via the connection matrix. Their <50 ns propagation delay ensures real-time zero-current detection triggers SMED state transitions without software latency.

Is the 1 Kbyte EEPROM truly wear-levelled or emulated in Flash?

The STLUX385ATR integrates 1 Kbyte of true hardware EEPROM - not Flash-emulated - with guaranteed 100,000 write cycles at 85 °C and 15-year data retention. It uses dedicated silicon cells with built-in ECC, eliminating need for external wear-leveling firmware or backup RAM shadowing.