A6282 and A6285 LED Drivers
Allegro MicroSystems, Inc. Introduces Two 16-Channel LED Driver ICs for Display Applications

The new LED driver ICs from Allegro, the A6282 and A6285, are designed for use in displays, signs, and control panels. Both devices have 16 constant-current output channels and serial data inputs and outputs, which can be cascaded to create large, mega pixel 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 12 V, which allows stacking of three or more LEDs per channel. Logic supply voltage can range from 3.3 V to 5 V, 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 under voltage lockout (UVLO) and thermal shutdown. The devices are available in a selection of surface-mount packages.

The A6282 device is designed for LED display applications. This CMOS device includes an input shift register, accompanying data latches, and 16 MOS constant current sink drivers. The CMOS shift registers and latches allow direct interfacing with microprocessor-based systems. With a 3.3 or 5 V logic supply, typical serial data input rates can reach up to 30 MHz. The LED drive current level can be set by a single external resistor, selected by the application designer. A serial data output permits cascading of multiple devices in applications requiring additional drive lines. The A6282 is available in a variety of 24-terminal packages: QFN (package ES) and TSSOP (LP), which have an exposed thermal pad, and SOIC (LW). All packages are lead (Pb) free with 100% matte tin lead frame plating.
Features  • 16 Constant-Current Outputs, up to 50 mA Each  • LED Output Voltage up to 12 V  • 3.0 to 5.5 V Logic Supply Range  • Schmitt Trigger Inputs for Improved Noise Immunity  • Power-On Reset (POR), All Register Bits = 0	• Low-Power CMOS Logic and Latches  • High Data Input Rate: 30 MHz  • Output Current Accuracy: Between Channels < ±3% and    Between ICs ±7%, over the Full Operating Temperature Range  • Internal UVLO and Thermal Shutdown (TSD) Circuitry
Applications  • Monocolor, Multicolor, or Full-Color LED Display  • Monocolor, Multicolor, or Full-Color LED Signboard	• Display Backlighting  • Multicolor LED Lighting

The A6285 is designed for LED display applications. This BiCMOS device includes an On/Off shift register, a Dot Correction (DC) shift register, accompanying data latches, and 16 MOS constant-current sink drivers with active pull-ups that can be enabled or disabled as required by the application. The CMOS shift registers and latches allow direct interfacing with microprocessor-based systems. With a 3.3 or 5 V logic supply, typical serial data input rates can reach up to 30 MHz. The LED drive current level can be set by a single external resistor, selected by the application designer. A CMOS serial data output permits cascading of multiple devices in applications requiring additional drive lines. Individual LED light intensity can be adjusted to correct for light intensity variations by using the Dot Correction feature. Open LED connections can be detected, and then signaled back to the host microprocessor through the serial data output (SDO pin). The FAULT output flags an LED open circuit (LOD) condition or a thermal shutdown (TSD) condition. A staggering delay on the load outputs during ON/OFF transitions helps to reduce ground bounce. The A6285 is available in a 32-lead QFN (package ET), with an exposed thermal pad. It is lead (Pb) free with 100% matte tin lead frame plating.
Features  • 3.0 to 5.5 V logic supply range  • Schmitt Trigger Inputs for Improved Noise Immunity  • Power-On Reset (POR)  • Up to 80 mA Constant-Current Sinking Outputs  • LED Open Circuit Detection (LOD)  • Dot Correction (DC) for Adjusting LED Light Intensity on each    Channel with 7-Bit Resolution	• Low-Power CMOS logic and Latches  • High Data Input Rate up to 30 MHz  • Active Output Pull-Ups with Enable/Disable  • 20 ns Typical Staggering Delay Between Outputs  • Internal UVLO and Thermal Shutdown (TSD) Circuitry  • Fault Output Flags for an LED Open Circuit (LOD) or a    Thermal Shutdown (TSD) Condition
Applications  • Monocolor, Multicolor, or Full-Color LED Display  • Monocolor or Multicolor LED Signboard	• Display Backlighting  • Multicolor LED Lighting