English
Language : 

A6274 Datasheet, PDF (1/24 Pages) Allegro MicroSystems – Linear Current Regulator and Controller for Automotive LED Arrays
A6274, A6274-1
A6284, A6284-1
Linear Current Regulator and Controller
for Automotive LED Arrays
FEATURES AND BENEFITS
• Six LED current sinks rated up to 60 mA (A6274) or
120 mA (A6284)
• Total LED drive current—up to 360 mA or 720 mA
• Wide input voltage range of 5 to 42 V for start/stop, cold-
crank, and load-dump requirements
• Low-dropout voltage—drives two series WLEDs from
7 V input
• Gate driver for external ballast P-MOSFET
• LEDs combined in two groups with separate ENx and
ISETx
• LED current level set by external reference resistors
• Internal or external PWM dimming
• Controlled output drivers slew during PWM for lower
EMI
• Fault detection features: LED string open, LED pin
short-to-ground, single LED short, VOUT short-to-
ground, VIN overvoltage, and thermal protection
• Input supply and temperature-based derating
• Automotive K-temperature range (–40°C to 150°C)
PACKAGES:
20-Pin eTSSOP (LP) with Exposed Thermal Pad
AEC-Q100 qualified
DESCRIPTION
The A6274 and A6284 are programmable linear current
regulator ICs for driving automotive LED arrays. The LED
current is programmed by external resistors. These devices
sink up to 60 mA (A6274) or 120 mA (A6284), from each of
six LED pins, to drive strings of high-brightness LEDs. LED
pins can be paralleled to drive even higher current LED strings.
Current settings are typically accurate to 2%, while typical
matching between LED strings is 0.8%.
LED light output can be adjusted by PWM dimming. The ICs
provide an internal PWM dimming circuit that is programmed
by external resistors for PWM frequency and duty cycle. It
can also accept an external PWM signal. Multiple ICs can be
configured in parallel for larger lighting systems. An internal
FULL (VDR > 3.6 V) option is provided to override the PWM-
dimming ratio for full LED current.
LED current derating with temperature and programmable
VIN levels allows operation over a wide range of operating
conditions.
Continued on next page...
APPLICATIONS
• Automotive rear combination light
• DRL/position
• General automotive lighting
Not to scale
Q1
C2
C3
C4
DIM
D1
FULL
D2
D3
C1
R1
C5
EN1
EN2
R2
R3
R4
FFn
R5
R6
R7
R8
R9
GATE COMP OUT
VIN
LED1
LED2
EN1
LED3
EN2
LED4
BIAS A6274-84 LED5
VTH
LED6
FFn
GND
DR
PWMIN
ISET1
ISET2
A6274-84-DS, Rev. 1
Figure 1: Typical Application Diagram for “-1” Latching Version