STMicroelectronics,
makers of semiconductor technologies mastering the semiconductor supply chain
with state-of-the-art manufacturing facilities, has revealed a highly
integrated and flexible automotive LED driver.
The
STMicroelectronics ALED6000 single-chip automotive LED driver with integrated
DC/DC converter is a low-BoM (Bill of Materials) solution that allows design
flexibility and keeps the lighting intensity consistent as electrical
conditions within the vehicle fluctuate.
Suitable
for exterior lighting such as daytime running lights, headlights, rear lights,
stop lights, and turn signals, as well as interior lighting, the ALED6000
drives a single string of LEDs at up to 3A and has a wide input-voltage range
of 4.5V to 61V.
The
ALED6000 implements digital dimming and has a dedicated pin to apply the PWM
control signal. There is also an Enable pin and a Sync pin that ensures low
noise in multi-device applications. The output current is accurate within 3.2%
and is monitored efficiently with a sense resistor that has a typical voltage
drop of 250mV. The quiescent current is extremely low, at just 2.4mA in
operation and 11µA in shutdown. Also featuring a VBIAS auxiliary-input pin and
pulse-skipping operation at light load, the ALED6000 ensures high efficiency
across the load range.
The
on-chip converter allows buck, buck/boost, and floating-boost topologies,
giving flexibility to power LED strings that require a voltage above or below
the input voltage while also handling supply fluctuations. In addition, the
converter can operate in low-dropout mode with close-to 100% duty cycle if the
input voltage falls near or below the programmed output.
In
the event of over-current, the ALED6000 invokes pulse-by-pulse protection to
limit the output current at the preset maximum. There is also programmable
soft-start circuitry to limit inrush current, and thermal protection with
auto-recovery. Both the output-current limit and converter switching frequency
can be selected using external components, allowing the inductor to be
optimized for high energy efficiency, fast dynamic response, small size, and
low output ripple in conjunction with a low-ESR capacitor.