When driving high-brightness LEDs with switching regulators, LED requirements will influence many details of regulator design including the methods used for closing the feedback loop and for LED dimming.
In backlights where two cold-cathode fluorescent lamps
share a common low-voltage connection, the lamps can be
driven by a dual-channel controller chip in combination
with an indirect high-side current-monitoring scheme.
Toys and novelty items sometimes require random light displays to create a desired visual effect. However, creating a battery-powered random light display that consumes minimal power is a significant challenge. The simplest approach is to use LEDs...
Selecting a driver architecture for white LEDs used in LCD backlighting requires consideration of the desired TV features, the available dc system voltages, and the manufacturing tolerances of the LEDs themselves.
The popular Xenon photoflash bulb is typically driven by
a battery-powered high-voltge source. A flyback converter
based on peak current limiting is the best option for this
circuit in portable applications.
Light-emitting diodes (LEDs) are often used with a voltage source from a power-supply output voltage. The output voltage increases until the current through the LEDs reaches the value of the constant-current source from the power supply. Also, a...