STMicroelectronics’ STLUX385A is a versatile, programmable controller with a range of features which make it easy to implement sophisticated LED-driver designs.
The STLUX385A features an innovative State Machine, Event Driven (SMED) type of digital controller, and also includes an embedded 8-bit processor core. It can be configured with application-specific algorithms to optimise system efficiency, enabling developers to realise lighting-equipment designs that offer both high performance and low system cost. A SMED is a hardware state machine in which the state progression is automatically triggered by internal or external events. SMED is designed to replace or extend the functions of a traditional analogue architecture. In a power supply, for example, SMED can close the regulation loop and automatically switch off the circuit when it detects an over-current or a short circuit. In LED lighting, the STLUX385A’s six SMEDs, operating as PWM generators, can be used to control the current to six LED channels, or to control the switching of any converter topology for driving strings of LEDs.
Since a SMED is implemented in hardware, it guarantees a reaction time to events shorter than that provided by any normal interrupt-driven microprocessor.
The STLUX385A also integrates a Digital Addressable Lighting Interface (DALI) controller for remote management and monitoring of large-scale lighting systems.
The STLUX385A includes four analogue comparators with internally-generated and external references, an ADC with an eight-channel sequencer, six digital inputs, and serial and I²C communication channels.
The device is provided with software drivers and application examples, to help developers save design time. The development tools include a graphical SMED configurator which generates C code.
- Buck converters for LED driving
- Primary-side regulators with zero-voltage switching
- Boost conversion for PFC
- Half-bridge resonant converters for LED street lighting and TV power supplies
- Full-bridge control in lamp ballasts and wireless power chargers
- 10ns event reaction time
- 1.3ns PWM resolution
- Compliant with IEC 60929 and IEC 62386
- Configurable noise-rejection filter
- 32kbytes of Flash memory