Automotive-compliant LED driver simplifies rear lighting designs

17-06-2021 | Diodes Inc | Automotive Technologies

Diodes Incorporated expands its portfolio of devices supporting automotive exterior illumination with the launch of the AL5873Q three-channel linear LED driver aimed at simplifying rear lamp cluster designs.


Rated for 125C ambient temperature operation, this automotive-compliant, AEC-Q100 Grade 1 qualified device satisfies the needs of next-generation vehicle design while also offering energy and space savings, hence, low overall system costs. Each of the device's channels can drive up to 250mA and is set through two reference resistors, which are connected to the driver IC’s REF1 and REF2 pins. Support for two different LED current levels allows more streamlined lighting systems, as the same LEDs can be employed in rear lamp clusters for tail and brake lamps. This lowers the BO) cost substantially.


The device has analog and master PWM dimming control functionality, supporting a maximum PWM frequency of 1kHz. The PWM dimming function is crucial in improving current accuracy when LEDs are driven at low current levels. The current on each channel is regulated to within a ±4% tolerance, which provides better channel-channel matching in the rear combination lamps. To conserve power, the device goes into standby mode if no PWM signal is detected.


The device has built-in protection features with a bidirectional (input/output) fault pin, which flags any faults. It enables up to four devices to have their fault pins connected together, so any faults identified are commonly reported. As part of its protection feature set, an internal junction temperature monitoring circuit decreases the LED current if its determined threshold temperature is exceeded. In addition to this thermal foldback, thermal shutdown and LED string-open/-short protection mechanisms are also included, as well as input undervoltage lockout.


The device is supplied in a compact 16-pin TSSOP package, supports PPAP documentation, and is manufactured in IATF 16949 certified facilities.

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