A6217 Datasheet, PDF (1/19 Pages) Allegro MicroSystems – Automotive-Grade, Constant-Current PWM Dimmable Buck Regulator LED Driver

A6217 and A6217-1
Automotive-Grade, Constant-Current
PWM Dimmable Buck Regulator LED Driver
FEATURES AND BENEFITS
• AEC-Q100 qualified
• 6 to 48 V supply voltage
• True average output current control
• 3 A maximum output over operating temperature range
(1.5 A for A6217-1)
• Cycle-by-cycle current limit
• Integrated MOSFET switch
• Enable / PWM 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
• Enhancements over A6213:
▫ Dithering of switching frequency to reduce EMI
▫ Able to drive single white LED from 18 V supply at 2.2 MHz
▫ Smaller package option
PACKAGES:
10-pin DFN with
wettable flank
(suffix EJ)
Not to scale
8-pin SOICN
(suffix LJ)
DESCRIPTION
The A6217 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 3 mm × 3 mm wettable flank 10-pin
DFN (suffix EJ) or an 8-pin narrow SOIC (suffix LJ), both with
exposed pad for enhanced thermal dissipation. Both packages
are lead (Pb) free, with 100% matte-tin leadframe plating.
APPLICATIONS:
Automotive lighting
• Daytime running lights
• Front and rear fog lights
• Turn/stop lights
• Map light
• Dimmable interior lights
V_IN (6 to 48 V)
TYPICAL APPLICATION CIRCUIT
GND ^C1
EN
1, 2
R1 ₃
VIN
TON
A6217
(EJ)
SW
BOOT
9,10
8 ^C4
4 _EN
5 _CS
PAD ^{GND 7}
VCC ⁶
Enable/PWM Dimming
C5
(100 Hz to 2 kHz)
L1
D1
LED+
LED–
RSENSE
A6217-DS