Catalyst Semiconductor has added a high efficiency white LED driver to its family of ICs for panel illumination circuitry. The CAT3604 current regulated charge pump delivers uniform, flicker-free white LED illumination for backlighting LCD displays and keypads in today's highly integrated, mobile applications.
Optimised for use with lithium ion battery powered systems, the circuit maximizes power transfer by achieving very high efficiencies of up to 93%. Each output channel is current regulated to provide precise matching of up to four parallel LEDs, guaranteeing even brightness control across the panel. Soft start, combined with a unique fractional charge pump topology ensures stable output voltage over the life of the battery by automatically switching between 1x LDO mode and 1.5x boost mode.
The CAT3604 's digital inputs provide full control of each LED channel for dimming or system shutdown, where the device draws less than 1µA. The 1 MHz fixed frequency control scheme enables the use of small external capacitors, while the inductor-less design minimises EMI interference.
The device comes in a space saving 4 x 4mm x 0.8mm thin QFN package. It is the ideal white LED driver for use in today's mobile phones, smart phones, PDAs, digital still and video cameras, portable MP3 players and hand-held instruments.
Priced at $1.68 in1000 piece quantities, the CAT3604 is available in halogen and lead free environment friendly “green” packages. Samples are available now.
Catalyst Semiconductor Inc , Sunnyvale, CA 94089, USA.