Taillight LED controller ensures even energy distribution

November 16, 2017 // By Christoph Hammerschmidt
Chipmaker Elmos AG presents the product family ICs E522.90/91/92/93 for use as LED controllers for vehicle taillights. A patented power management system ensures constant light intensity of the LEDs even under difficult thermal conditions.

The E522.9x family has an output current of 14mA to 55mA per channel; in parallel operation up to 165mA per IC are possible. The power management system ensures constant light intensity. For this purpose, a variable part of the resulting power dissipation is shifted to external shunts, which enables an even and effective heat distribution without hot spots on the circuit board. The unique dual concept avoids an additional drop over the linear controller stage.

Other features include diagnostic features that ensure reliable operation of the system through LED driver open/short detection, IR config open/short, junction temperature control and overvoltage control.

Both common and channel-specific PWM dimming is provided. A diagnostic interface "RUN" supports the operation of LED clusters with more than three strings, which are then powered by connected ICs.

Full compatibility with the Elmos’ E522.80-83 ICs, which provide 48mA up to 151mA, allows for drop-in replacement and easy adaptation of existing systems.

The ICs have two configurable modes of operation for error processing: On the one hand, a "Failure Feedback Mode" (when an error is detected, the affected channel is deactivated and the individual error signalled), and on the other hand, the "Single Lamp Mode", in which all connected LED strings behave like a single connected light source. In the event of a fault, all channels are deactivated in the event of a fault, and in this case the IC only draws a small quiescent current from the supply - the feeding control unit can thus clearly and unambiguously detect a failure. Input voltage range is specified from 5V to 25V at a maximum value of 40V.

The product family is supplied in a SO16N package with exposed die pad and is qualified according to AEC-Q100.

More information: www.elmos.com