The CL520 and CL525 from Supertex ( http://www.supertex.com ) are fixed, linear current regulators designed for driving LEDs at 20 or 25mA respectively. With maximum ratings of 90V, they are able to withstand transients without the need for additional transient protection circuitry.
They are ideally suited for applications employing single or multiple LEDs. The minimum dropout voltage of 1.0V accomodates extra LEDs, permits lower supply voltages, and provides more efficient operation.
The 1.0V dropout accommodates extra LEDs, permits a lower supply voltage, and provides more efficient operation. Featuring temperature-compensated current and cnsistent brightness regardless of temperature, they have a 90V rating for transient immunity.