STEVAL-LLL008V1 [STMicroelectronics]

The STEVAL-LLL008V1 reference design is a dual-stage LED driver with high power factor designed for 100 W LED lighting applications using 6LoWPAN Mesh networking.

The front-end flyback converter provides high power factor and low THD and implements CV primary side regulation (PSR) with input from an auxiliary winding on the transformer through the ZCD pin on the HVLED001B controller, so no isolated optocoupler is required. The flyback converter can deliver 105 W with an average 79 V output voltage and 1.8 V maximum ripple.

The converter output supplies an inverse buck stage that delivers a regulated 1.4 A current to the LED driver load. The secondary transformer is also able to supply (a few milliamps via an auxiliary choke) the voltage needed to power up the HVLED002 controller, which manages the inverse buck circuit to provide current limitation for dimming and On/Off control.

The STEVAL-LLL008V1 integrates an STM32L071KZ microcontroller, which is able to receive remote on, off and dimming commands via an embedded SPSGRFC sub-1 GHz transceiver module. The connectivity functionality can be extended to multiple lighting nodes in a 6LowPAN mesh network.

A data concentrator unit (DCU) and mobile Android application have been developed to help you explore the LED lighting reference design further. The DCU consists of a NUCLEO-F401RE development platform, plus the X-NUCLEO-IDS01A4 for sub 1-GHz communication with the LED driver board and a X-NUCLEO-IDB05A2 board for Bluetooth communication with a mobile device.

The ST 6LoWPAN Smart Streetlight mobile application (available on Google Play store) collects lighting nodes represented by the microcontroller and RF module on the evaluation board in a 6LoWPAN mesh network.