STMicroelectronics STLUX385A

Overview

STLUX385A from STMicroelectronics is a digital lighting and power conversion controller integrating an STM8 microcontroller core and six autonomous SMED (State Machine Event Driven) PWM generators. It delivers 1.3 ns PWM resolution, hardware DALI 2.0 compliance (IEC 62386), 10-bit ADC with op-amp gain options, four ultrafast comparators (<50 ns propagation), and operates from –40 °C to 105 °C. It targets high-precision LED driver and resonant SMPS control where event-driven timing and noise-immune bus communication are critical.

For engineers reviewing the STLUX385A datasheet, STLUX385A pinout, STLUX385A application, or STLUX385A equivalent, key selection considerations include SMED coupling flexibility, DALI hardware encoder latency, comparator reference configurability, ADC input impedance (1 MΩ), and flash/ECC memory retention specs under thermal stress.

Technical Context

The STLUX385A implements a dual-layer control architecture: six independent SMED units operate autonomously at up to 96 MHz PLL-derived timing, reacting to internal events (comparator outputs, other SMEDs) or external signals (DIGIN pins) with ≤10.4 ns detection latency. Each SMED supports IDLE/S0–S3/HOLD states and configurable time registers per state.

Its integrated STM8 core (16 MHz max CPU, Harvard architecture, 3-stage pipeline) configures SMEDs, manages DALI frame encoding/decoding in hardware, sequences the 8-channel ADC, and handles UART bootloading - all while supporting multiple low-power modes including active halt with AWU wake-up from 153.6 kHz LSI.

Key Specifications

Pinout & Package

TSSOP38 package (38-pin thin shrink small outline package) with exposed thermal pad; pin-compatible with STLUX325A except for additional PWM5 output and DIGIN pin allocation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STLUX325A, the STLUX385A adds a sixth PWM output and dedicated DIGIN pin for enhanced multi-channel control; versus UCC2897A, it replaces analog loop dependency with deterministic hardware state machines and integrated DALI - reducing BOM count and enabling firmware-upgradable lighting protocols.

Availability

STLUX385A is available at Aetrix Electronics and suitable for smart LED driver design, digital HID ballast development, resonant SMPS prototyping, and DALI-2 certified lighting system production requiring stable component supply across extended temperature ranges.

Supply support for STLUX385A 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 devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The STLUX family is engineered specifically for digitally controlled lighting and switched-mode power conversion - combining event-driven PWM, DALI compliance, and robust analog front-ends to replace discrete timing and communication components in high-reliability systems.

FAQ

What is the maximum operating frequency of the SMED subsystem?

The SMED units operate synchronously with the 96 MHz PLL clock, enabling a native PWM resolution of 10.4 ns and, with dithering, up to 1.3 ns effective resolution. This timing precision is maintained across all six SMEDs simultaneously and is independent of CPU load or software execution latency.

Does STLUX385A support DALI-2 commands and configuration?

Yes - the hardware DALI peripheral fully implements IEC 62386-102 (DALI-2), including 24-bit extended frame support, reverse polarity tolerance on Tx/Rx lines, and configurable noise rejection filtering. It handles all physical layer timing and frame encoding/decoding without CPU intervention.

How does the ADC achieve 12-bit equivalent resolution?

The integrated 10-bit SAR ADC achieves 12-bit effective resolution by routing its input through an on-chip programmable operational amplifier with selectable gain settings (x1 or x4). This amplification extends dynamic range for low-amplitude sensor signals while maintaining 1 MΩ input impedance to avoid loading effects.

Can SMEDs be reconfigured dynamically during runtime?

Yes - SMED configuration registers (state transition logic, time registers, event mapping) are fully accessible via the STM8 CPU over the APB bus. The SMED continues running autonomously during reconfiguration, and changes take effect on the next state transition - enabling adaptive control loops without PWM interruption.