iWatt improves mains LED driver
iWatt has introduced a mains LED driver for loads up to 25W, claiming it to be flicker-less.
“This new platform expands iWatt’s existing line of LED drivers, offering compatibility with an even wider range of installed dimmers, including residential TRIAC dimmers as well as the more sophisticated digital dimmers,” said the firm.
Called iW3617, power factor is said to be greater than 0.95 from the two stage design with total harmonic distortion (THD) under 15%.
The device is designed for isolated or non-isolated operation in 120V and 230V AC offline LED lighting bulbs and fixtures, with efficiency exceeding 85%.
Dimming frequency is 630-900Hz, and dimming from 1-100% is possible if the dimmer supports it, with +/-5% LED current regulation.
“iW3617 is built on iWatt’s 15W iW3614 LED driver by expanding dimmer compatibility, and improving dimming and EMI performance,” said the firm. “It enables a 10% to 20% savings in BOM cost and a smaller overall solution size compared to the iW3614.”
Savings are achieved by replacing FETs with bipolar transistors, reducing the component count in the protection circuit and EMI filtering, and by using a smaller lower-cost E-capacitor.
Safety features include: LED open/short circuit protection, input over-voltage protection, over-temperature thermal shutdown, and AC line over-voltage/frequency protection. “LED current de-rating at high temperatures also protects LEDs,” said iWatt.
The chip is compatible with Zhaga for hot-plug LED module interchangeability.
There is also a 12W version, the iW3616. Both come in a standard, 14pin SOIC.
According to iWatt, Greatech Industrial has designed in the lower power version.