STMicroelectronics L99LD01 hocheffizienter Konstantstrom-LED-Treiber

Der STMicroelectronics L99LD01 hocheffiziente Konstantstrom-LED-Treiber ist ein kompletter Konstantstrom-DC-DC-Wandler-LED-Treiber für Anwendungen in der Automobilindustrie. Er wird mit der BCD5S 70V-Technologie gefertigt und in einem LQFP32-Gehäuse montiert. L99LD01 wird in Aufwärts-, Abwärts-Aufwärts- und Flyback-Wandler-Topologien verwendet. Ein interner, zufälliger Ditheroszillator arbeitet in einer niederfrequenten Modulation und ermöglicht, dass sich das HF-Spektrum der Schaltfrequenz ausbreiten und damit EMV-Abstrahlungen verringern kann.

The device includes an internal low drop voltage regulator, that can be used to supply a microcontroller, and a reset pin, that is useful for resetting the microcontroller at the start up and every time that the regulated output voltage falls down below an established voltage threshold.

Merkmale

Automotive qualified
Constant current operation
Current LED settable by external sensing resistor and adjustable via SPI
Converter switching frequency adjustable by external resistor (RSF)
EMC reduction by internal spread spectrum dither oscillator
Low frequency PWM dimming operation
Maximum input current limiter
Maximum switching duty cycle limiter
Slope compensation adjustable by external resistor (R9)
Battery overvoltage shutdown protection (ext. R3, R4 resistors required)
LED chain OV detection (ext. R5, R6)

Multiplexed output for monitoring and control of LED temperature (external NTC resistor required), voltage of LED chain, and low frequency PWM
SPI communication serial interface transceiver (SDI, SDO, SCK, CSN)
Regulated output for micro supply 5V ±2% -20mA
Parameter programming and settings of internal memory registers by the dedicated SPI interface:
LED current reference adjusting (±66.7%)
Maximum input current limiter reference adjusting (±55.5%)
Random dither frequency sweeping, modulation frequency and deviation percentage
Power on reset pin output
ESD protection