Allegro's Four-Channel Constant-Current LED Driver ICs



A new family of constant-current LED driver ICs designed to address the emerging requirements of internal and external illumination applications in the automotive market is now available from Allegro MicroSystems Europe. The new A6261/62/64 devices have been fully qualified to the highest levels of automotive quality standards and robustness. A single device offers four channels, each providing up to 100 mA LED current, which can be paralleled for higher currents. The driver ICs operate with a low dropout voltage to minimise power dissipation, and do not require any ballast resistors. The user-selected current is provided to four outputs with each output equally sharing the load. The A6261/62/64 family also features short-circuit to ground protection which disables the shorted channel, allowing the others to continue to operate. An open LED situation on any channel is also detected. As with Allegro's established A6260 LED driver, the A6261/2/4 family features a current fold-back circuit which uses the chip junction temperature in order to fold back the LED current and to protect the IC and LEDs in situations where they are mounted close to one another on the same substrate. Key automotive applications include exterior brake, turn, tail, and rear combination lighting as well as interior dome, map and 'puddle' lighting. A commercial grade version of the A6261 (suffix E) is also available for consumer lighting applications. The A6261/62/64 devices are offered in the eMSOP-10 (LY) and eTSSOP-16 (LP) packages.