STMicroelectronics' ALED7709 LED driver is a highly efficient solution for driving high-brightness LED strings in automotive applications. The device features a boost/SEPIC controller and four low-side constant-current sinkers, all housed in an AEC-Q100 compliant package.
The switching converter section provides the supply rail for the LED strings, which is optimized for maximum efficiency. The boost/SEPIC controller supports external synchronization and spread spectrum, allowing for flexible operation. The device can work simultaneously or exclusively in standalone mode (SAM) or bus-driven mode (BDM) through an I²C serial interface.
Brightness control of the four LED strings can be achieved in global or local mode, with mixed pulse width modulation (PWM) and analog dimming support improving brightness range capability. The BDM provides full access to advanced features, including programmable PWM dimming frequency and internal oscillator, avoiding the need for an external clock source.
The ALED7709A version is dedicated to BDM, featuring basic protections for overvoltage, overcurrent, thermal shutdown, and open/short LED fault detection with optional channel auto-disconnect. An optional P-channel MOSFET in series to the input protects the system, LED strings, and channels in case of fault or output short-to-ground, while also reducing power consumption when in standby.
AEC-Q100 qualified
Operating temperature range -40°C <TJ <+150°C
Simultaneous or exclusive control by PWMI and I²C interface
Two versions available: ALED7709A and ALED7709B
4.5 V to 42 V operating input voltage range:
Up to 60 V tolerant for load dump at 24 V battery
Supports battery cranking events down to 4 V supply
Switching controller section:
Low shutdown current: ISHDN <15 µA
Fixed frequency peak current-mode control
Cycle-by-cycle power switch OCP
Adjustable (250 kHz to 2.2 MHz) switching frequency with optional spread spectrum
Synchronized boost and SEPIC topology support
Line switch control for standby power saving and inrush current protection
Input overvoltage and output short-circuit protection
LED string control section
Four 40 V rated constant current outputs
Adjustable current up to 200 mA per channel
±2% typ. output current accuracy
Mixed PWM and analog dimming
100 Hz to 12.8 kHz dimming frequency
Dimming ratio 10,000:1 at 100 Hz
LED temperature sensor (NTC) management
Selectable channel phase-shifting and adjustable rise/fall time for reducing EMI
Open channel, LED short-circuit detection qualification ongoing
Tell us what you're after