Multi-LED driver touts tight programmability

Catalyst Semiconductor's LED driver, the CAT3626, is a 1x/1.5x charge pump with precision current-setting capabilities. With an I²C interface for programming, the CAT3626 serves applications from display backlighting (up to six white/color LEDs) to driving RGB "fashion-lighting" and flash functions in cellphones, handheld devices and digital cameras.

The CAT3626's six outputs are configured into three banks; with each bank containing a pair of tightly regulated and matched output channels. LED currents within each dual output channel bank can be set in 0.5mA steps (dimming resolution) from zero to 32mA; total device output current is up to 192mA. The CAT3626 also features a current regulation scheme that minimizes LED flicker during periods of sudden battery fluctuations—a common problem in portable systems experiencing repetitive load bursts, such as RF or audio power amplifiers.

The CAT3626 offers protection against short-circuit and thermal overload fault conditions. A dedicated Enable control pin places the device in a "zero current" shutdown mode to minimize battery drain.

The CAT3626, in a RoHS-compliant, environment friendly "green" 4-by-4mm TQFN 16-lead package, is priced at 96 cents each in 10,000 quantities. Samples and evaluation kits are now available. Projected lead-time for production quantities is currently six to eight weeks ARO.

- Vince Biancomano
eeProductCenter