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Allegro |
A6211
Constant-Current 3-Ampere PWM Dimmable
Buck Regulator LED Driver
Features and Benefits
• Supply voltage 6 to 48 V
• True average output current control
• 3.0 A maximum output over operating temperature range
• Cycle-by-cycle current limit
• Integrated MOSFET switch
• Dimming via direct logic input or power supply voltage
• Internal control loop compensation
• Undervoltage lockout (UVLO) and thermal shutdown
protection
• Low power shutdown (1 μA typical)
• Robust protection against:
▫ Adjacent pin-to-pin short
▫ Pin-to-GND short
▫ Component open/short faults
Package 8-pin SOICN with exposed
thermal pad (suffix LJ):
Not to scale
Description
The A6211 is a single IC switching regulator that provides
constant-current output to drive high-power LEDs. It integrates
a high-side N-channel DMOS switch for DC-to-DC step- down
(buck) conversion. A true average current is output using a
cycle-by-cycle, controlled on-time method.
Output current is user-selectable by an external current sense
resistor. Output voltage is automatically adjusted to drive
various numbers of LEDs in a single string. This ensures the
optimal system efficiency.
LED dimming is accomplished by a direct logic input pulse
width modulation (PWM) signal at the enable pin.
The device is provided in a compact 8-pin narrow SOIC package
(suffix LJ) with exposed pad for enhanced thermal dissipation.
It is lead (Pb) free, with 100% matte tin leadframe plating.
Applications:
• General Illumination
• Scanners and multi-function printers (light bars)
• Architectural lighting
• Industrial Lighting
• Display case lighting / MR16
Typical Application Circuit
VIN (6 to 48 V)
GND C1
EN
R1
Enable/PWM Dimming
(100 Hz to 2 kHz)
1 VIN
2 TON
3 EN
4 CS
A6211 SW
BOOT
8
7
GND 6
VCC 5
C4
C5
L1
D1
LED+
LED–
RSENSE
A6211-DS
A6211
Constant-Current 3-Ampere PWM Dimmable
Buck Regulator LED Driver
Selection Guide
Part Number
A6211GLJTR-T
Operating Ambient
Temperature, TA
–40ºC to 105ºC
Package
8-pin SOICN with exposed thermal pad
Absolute Maximum Ratings
Characteristic
Supply Voltage
Bootstrap Drive Voltage
Switching Voltage
Linear Regulator Terminal
Enable and TON Voltage
Current Sense Voltage
Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
Symbol
VIN
VBOOT
VSW
VCC
VEN , VTON
VCS
TA
TJ(max)
Tstg
Notes
VCC to GND
G temperature range
Packing
3000 pieces per 13-in reel
Rating
–0.3 to 50
–0.3 to VIN + 8
–1.5 to VIN + 0.3
–0.3 to 14
–0.3 to VIN + 0.3
–0.3 to 7
–40 to 105
150
–65 to 125
Unit
V
V
V
V
V
V
ºC
ºC
ºC
Thermal Characteristics may require derating at maximum conditions, see application information
Characteristic
Symbol
Test Conditions*
Package Thermal Resistance,
Junction to Ambient
RθJA 4-layer PCB based on JEDEC standard
Package Thermal Resistance,
Junction to Pad
RθJP
*Additional thermal information available on the Allegro website.
Value
35
2
Unit
ºC/W
ºC/W
Pin-out Diagram
VIN 1
TON 2
EN 3
CS 4
PAD
8 SW
7 BOOT
6 GND
5 VCC
Terminal List Table
Number
Name
Function
1 VIN Supply voltage input terminals
2
TON
Regulator on-time setting resistor terminal
3 EN Logic input for Enable and PWM dimming
4 CS Drive output current sense feedback
5
VCC
Internal linear regulator output
6 GND Ground terminal
7 BOOT DMOS gate driver bootstrap terminal
8 SW Switched output terminals
–
PAD
Exposed pad for enhanced thermal dissipation;
connect to GND
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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