Primary-side control is used, together with driver isolation, allowing the LEDs to be affixed directly to a metal heatsink, removing the need – and expense – of an electrically isolating enclosure. Constant-current output tolerance across temperature s ±3% at both low-line and high-line voltages, exceeding the ±5%, to meet requirements such as the Energy Star minimum-lumens-delivered specification, for example. Typical efficiency is up to 90%.
Protecting the LED load from surges in line voltage increases the lifetime of the bulb, even when subjected to frequent peaks. The constant-current and constant-voltage control maintains a voltage on the output of the driver during no-load operation, preventing damage to the output filter or shutting down the driver when being tested or installed with no LED string connected.
Over-temperature, over-current and open feedback-loop protection are provided. Devices are packaged in SO-8 (surface mount), MSOP and eSIP (vertical) package options.