David Manners
Fairchild has launched an LED dimmer IC which detects the AC input voltage condition and allows it to create an internal reference signal that results in high power factor correction.
The LED lamp driver IC (FL7701) will also work from a DC input voltage condition, automatically sensing AC versus DC input voltage conditions.
The traditional technique of using a transformer in an MR application incurs additional losses with the transformer conversion; this can now be replaced using the dimmer connected directly to a DC or AC off-line input.
The chip’s reliability is claimed to increase the luminary lifespan to more than five years, compared to the three years achievable by current solutions.
Reliability is improved by having no electrolytic capacitors for the input, output, or VDD supply.
Digital power factor (PF) realization (>0.9), lower total harmonic distortion (THD), and 90% electrical efficiency deliver energy savings compliant with EnergyStar.
Suitable for residential applications, it comes in an SOP-8 package.
