A1569E Datasheet, PDF (1/21 Pages) Allegro MicroSystems – LED Driver with Integrated Hall-Effect Switch

A1569E
LED Driver with Integrated Hall-Effect Switch
FEATURES AND BENEFITS
• Linear LED drive current ≤150 mA set by an external
reference resistor
• High sensitivity, omnipolar Hall-effect switch for LED
on/off control
• Low component count for small size and ease of design
• Elegant fade-in/fade-out effects with adjustable duration
(optional)
• Low dropout voltage and low supply current
• Chopper-stabilized Hall switch
□□Low switchpoint drift over temperature
□□Insensitivity to physical stress
• Input pin for external LED driver control
• Slew-rate-limited LED output drive for current transient
suppression
• Ruggedness and reliability
□□Integrated voltage regulator for operation from 7 to 24 V
□□Reverse-battery protection
□□Automatic short-circuit and thermal overload
protection and recovery
□□–40ºC to 85ºC ambient temperature range
• Small 8-pin SOIC package with thermal pad
PACKAGE:
8-Pin SOICN with Exposed Thermal Pad (Suffix LJ)
DESCRIPTION
The A1569E is a highly integrated solution that combines a
Hall-effect switch with a linear, programmable current regulator,
providing up to 150 mA to drive one or more LEDs. With the
addition of only two passive components and one or more
LEDs, the A1569E forms a complete, magnetically actuated
lighting solution that is small, flexible, elegant, easy to design,
rugged, and reliable. It is optimized for automotive interior and
auxilliary lighting such as map lights, glove boxes, consoles,
vanity mirrors, hood/truck/bed lights, etc.
The LED drive current is set by an external resistor; the LED is
then activated by the built-in Hall-effect switch and features an
adjustable fade-in/fade-out effect. Omnipolar operation (either
north or south pole) and high magnetic sensitivity make the
A1569E tolerant of large air gaps and mechanical misalignment.
System assembly is easier, as the magnet can be oriented with
either pole facing the device. Chopper stabilization provides
low switchpoint drift over the operating temperature range.
The driver can also be activated via an external input for direct
control of the LED.
In addition to contactless operation and safe, constant-current
LED drive, reliability is further enhanced with reverse-battery
protection, thermal foldback, and automatic shutdown for
thermal overload and shorts to ground.TheA1569E will prevent
damage to the system by removing LED drive current until
the short is removed and/or the chip temperature has reduced
below the thermal threshold. The driver output is slew-rate-
limited to reduce electrical noise during operation.
Not to scale
Continued on the next page…
+V
For standalone operation, ^CBYPASS
SEN_EN is pulled high
(e.g., tied to VIN)
VIN
LA
Optional
Control Signals
From MCU or
Remote Switch
SLEEP
LED_ON
SEN_EN
EXT HALL
R_IREF
IREF
No Connect
or
THTH
Connect to GND
FADE
GND
150 mA
C_FADE
(optional)
A1569E-DS
Typical Application Diagram