Diodes introduces three-channel linear LED drivers for a more streamlined lighting system

     Diodes Corporation expands its portfolio of devices to support automotive exterior lighting with the introduction of the AL5873Q three-channel linear LED driver designed to simplify the design of the taillight set. The automotive standard, AEC-Q100 Level 1 compliant ambient temperature rating of 125C meets the needs of the next generation of automotive designs. It also saves energy and space, which reduces overall system costs.

     Each channel of the device can drive up to 250mA of current and is set via two reference resistors that are connected to the REF1 and REF2 pins of the driver IC. Supporting two different LED current levels enables a more streamlined lighting system because the same LED can be used in taillight sets for both taillight and brake lights, which significantly reduces BO costs.

     The device has analog and main PWM dimming control and supports PWM frequencies up to 1kHz. When the LED is driven at low current levels, the PWM dimming function is essential to improve current accuracy. The current regulation on each channel is within the tolerance range of ±4%, which provides better channel matching for the rear combination lights. To save power, if no PWM signal is detected, the device will go into standby mode.

     The device has built-in protection with bidirectional (input/output) fault pins to flag any faults. It allows the fault pins of up to four devices to be connected together, so any faults identified are usually reported. As part of its protection feature set, the internal junction temperature monitoring circuit reduces the LED current if the threshold temperature it determines is exceeded. In addition to this thermal reentry, it also includes thermal shutdown and LED string open/short circuit protection mechanisms, as well as input undervoltage locking.