Design Win

100 W high efficiency and low THD dimmable LED driver solution for Street Lighting

Solution Description

LED street and zone lighting applications typically require robust and highly efficient power supplies able to generate tightly regulated output currents and voltages with high power factor, low THD and minimal voltage ripple.

In smart lighting outdoor applications sub-1 GHz connectivity is widely adopted. 

The SL-LLL008V1 solution combines extremely high efficiency power supply, thanks to the implemented dual stage architecture, with flexible wireless connectivity.

The front-end AC/DC HPF flyback converter stage, based on STF23N80K5 N-channel power MOSFET is controlled by the HVLED001B offline led driver who guarantees very high PF, low THD and implements CV primary side regulation.

The second stage is an inverse buck converter, based STL4N10F7 power MOSFET, driven by the HVLED002 controller, able to translate external dimming commands into current limitations.

Digital control stage is performed by STM32L071KZ microcontroller, which can receive remote on, off and dimming commands via an embedded SPSGRFC sub-1 GHz transceiver module. The connectivity functionality can be extended to allow wireless control of multiple lighting nodes in a 6LowPAN mesh network.

In addition, The ST 6LowPAN Smart Streetlight mobile application allow the user to control (ON/OFF) and change light intensity of network nodes connected to a Data Concentrator Unit (DCU) via Bluetooth.

  • Key Product Benefits

    HVLED001B High power factor flyback controller

    Enhanced peak current mode controller able to control mainly high power factor (HPF) flyback or buck-boost. The innovative high voltage technology allows direct connection to the input voltage to both start up the device and to monitor the input voltage, without the need for external components. Abnormal conditions like open circuit, output short-circuit, input over-voltage or under-voltage and circuit failures like open loop and overcurrent of the main switch are effectively controlled

    STF23N80K5 High Voltage MOSFET

    Very high voltage N-channel Power MOSFET designed using MDmesh™ K5 technology based on an innovative proprietary vertical structure, featuring a low on-resistance and ultra-low gate charge for applications requiring superior power density and high efficiency.

    HVLED002 LED Controller

    The HVLED002 control IC provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes to implement LED drivers. Internally implemented circuits include a trimmed oscillator for the precise duty cycle control, undervoltage lockout, a precision reference trimmed for accuracy at the error amplifier input, a PWM comparator which also provides current limit control and a totem pole output stage designed to the source or sink high peak current


    STL4N10F7 STripFET™

    This N-channel Power MOSFET utilizes STripFET™ F7 technology with an enhanced trench gate structure that results in very low on-state resistance, while also reducing internal capacitance and gate charge for faster and more efficient switching.

    STM32L071KZ Ultra-low power Microcontroller

    The access line ultra-low-power STM32L071xx microcontrollers incorporate the high-performance Arm Cortex-M0+ 32-bit RISC core operating at a 32 MHz frequency, a memory protection unit (MPU), high-speed embedded memories (up to 192 Kbytes of Flash program memory, 6 Kbytes of data EEPROM and 20 Kbytes of RAM) plus an extensive range of enhanced I/Os and peripherals.

    SPSGRFC Sub-1GHz Transceiver

    Easy-to-use sub-1 GHz transceiver certified module with many programmable features. The module provides a complete RF platform in a tiny form factor.

  • All Features

    • High efficiency,
    • PSR control loop without optocoupler,
    • Option to connect a control board with programmable STM32 microcontroller for dimming and Enable/Disable functionality.
    • Connectivity functionality can be extended to multiple lighting nodes in a 6LowPAN mesh network.