AN4291 datasheet(7/53 Pages) STMICROELECTRONICS

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AN4291

Demonstration board features

To guarantee the maximum reliability of the demonstration board against the most common

LED failures, the STLUX385A implements the following software and hardware protections:

•

For each LED string:

–

overcurrent

–

short-circuit

–

LED voltage drop falls below the 2.9 V limit

–

LED voltage drop higher than the 4.2 V limit

–

disconnected string (open circuit)

•

Power voltage outside configured lower / upper limits

The STLUX385A device drives the 4 LED channels (CH0, CH1, CH2, CH3) seen on the

right side of the board.

The board uses a DC-DC converter to supply the MOS drivers (U3, U2) with 10 V, while the

STLUX385A (3.3 V or 5 V) is powered by a linear regulator.

There are three buttons to manually change the dimming period. The DALI and UART TTL

interfaces are supported.

Two LEDs indicate the board status: the green one shows that the system is “ready” while

the red one indicates a system fault or the intervention of a protection mechanism.

AN4291 Datasheet(PDF) 7 Page - STMicroelectronics