Allegro Introduces Two 16-Channel LED Driver ICs for Display Applications

Allegro Microsystems Inc. announced the release of two new LED driver ICs for use in displays, signs, and control panels. The A6282 and A6285 both have 16 constant-current output channels. They have serial data inputs and outputs, which can be cascaded to create large, megapixel text or video displays. They can also be used in smaller applications such as LCD backlighting or controlling LEDs in an instrument or control panel.

Both the A6282 and A6285 operate with LED supply voltages up to 12V, which allows stacking of three or more LEDs per channel. Logic supply voltage can range from 3.3 to 5V, in many cases allowing the device to be powered from the same supply as the LEDs it is driving. Users can adjust the brightness of LEDs controlled by both devices by pulse�width modulating their output enable inputs. Both devices feature protections such as undervoltage lockout (UVLO) and thermal shutdown. The devices are available in a selection of surface-mount packages.

The A6282 is a basic 16-channel driver. Each output can drive up to 50mA. Its channel-to-channel output current matching of ±3% is said to ensure high-quality displays and to have improved over several alternate sources.

The A6285 has additional features that enable it to be used in video applications. Dot correction allows the user to adjust each channel’s output current to compensate for initial device mismatch and LED agin. Internal pull-ups provide fast turn-off times, eliminating ghosting and improving picture quality for moving images. To minimize radiated EMI and noise on the supply lines, the A6285 outputs have staggered turn-on times. The A6285 features Open LED detection, which allows remote diagnosis of failed LEDs.

The A6282 is available in 24-lead surface-mount packages: QFN, SOIC, and TSSOP. The A6285 comes in a 32-lead QFN.