High efficiency constant current LED driver for automotive
Datasheet - production data
Operation supply battery voltage
Oscillator frequency range
5.6 - 24 V
100 - 500 kHz
• 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
• Low frequency PWM dimming operation.
• Maximum input current limiter
• Maximum switching duty cycle limiter
• Slope compensation adjustable by external
• Battery overvoltage shut down 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
• SPI communication serial interface transceiver
(SDI, SDO, SCK, CSN)
• Regulated output for micro supply 5 V ± 2 %
• Parameter programming and settings of
internal memory registers by the dedicated SPI
– LED current reference adjusting (± 66.7 %)
– Maximum input current limiter reference
adjusting (± 55.5 %)
– Random dither frequency sweeping,
modulation frequency and deviation
• Power on reset pin output
• ESD protection
Automotive day time running light, LED
L99LD01 is a precise constant current DC–DC
converter LED driver for automotive applications,
dedicated to the control of high-brightness LED
headlights and housed in a LQFP32™ package.
The device is designed to be used in Boost, Buck-
Boost and Fly back converter topologies. An
internal random dither oscillator works in low
frequency modulation, allowing the RF spectrum
of the switching frequency to spread so to reduce
EMC emissions. The slope compensation
ensures good converter loop stability whatever is
the duty cycle needed by the application.
The converter is able to work either in full power
mode or in low frequency dimming mode.
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.
This is information on a product in full production.
DocID025319 Rev 3