A6285 Datasheet, PDF (1/13 Pages) Allegro MicroSystems – 16-Channel Constant-Current Latched LED Driver with Open LED Detection and Dot Correction

A6285
16-Channel Constant-Current Latched LED Driver
with Open LED Detection and Dot Correction
Features and Benefits
▪ 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
Package: 32 Contact QFN (suffix ET)
5 mm × 5 mm
0.90 mm nominal overall height
Not to scale
Description
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.Astaggering
delay on the load outputs during ON/OFF transitions helps to
reduce ground bounce.
Continued on the next page…
Typical Application
V_DD
V_LED
V_LED
Controller
SDI
FAULT
CLK
LE
MODE
OE
100 KΩ
SDI
FAULT
CLK
LE
MODE
OE
PE OUT0
A6285
10 μF
OUT15
SDO
V_DD
100 nF
REXT
SDO
6285-DS