The A6268 is a DC-to-DC converter controller, providing a programmable constant current output for driving high power LEDs in series. Driving the LEDs in series ensures identical currents and uniform brightness. For automotive applications, optimum performance is achieved when driving up to 15 LEDs at currents up to 1 A.
The A6268 provides a cost-effective solution using an external logic-level MOSFET and minimum additional external components. The maximum LED current is set with a single external sense resistor and can be modified using a current reference input. Direct PWM control is possible via the Enable input, which also provides a shutdown mode.
This DC-DC converter can be configured as a ground-referenced boost converter or as a supply-referenced boost converter providing buck-boost capability. The buck-boost topology used ensures that there is no leakage path through the LEDs when in shutdown and no inrush current at power-up.
Integrated diagnostics and two fault outputs give indication of VIN and VREG undervoltage, chip overtemperature, output open circuit, LED short circuit and LED undercurrent, and can be configured to provide short to supply and short to ground protection for the LED connections, LED overcurrent and shorted LED string protection. A unique feature is the ability to detect one or more shorted LEDs.
The device is provided in a 16-pin TSSOP package with exposed thermal pad (suffix LP). It is lead (Pb) free, with 100% matte tin leadframe plating.
- Automotive high power LED lighting systems
- Fog lights, reversing lights, daytime running lights