Constant-Curr A6217 A6217-1:汽车ent PWM Dimmable Buck Regulator LED Driver

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 pulsewidth-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

• 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