MAX16835

The MAX16835 current regulator operates from a 6.5V to 40V input voltage range and delivers up to a total of 350mA to one or more strings of high-brightness LEDs (HB LEDs). The output current of the MAX16835 is adjusted by using an external current-sense resistor in series with the LEDs. An enable input allows widerange "pulsed" dimming. Wave-shaping circuitry reduces EMI. The differential current-sense input increases noise immunity.

Features of the MAX16835 are:(1)+6.5V to +40V operating range; (2)adjustable LED current (35mA to 350mA); (3)integrated pass element with low-dropout voltage (0.55V typ); (4)output short-circuit protection; (5)+5V regulated output with 4mA source capability; (6)thermal shutdown; (7)differential LED current sense; (8)high-voltage enable pin for dimming interface; (9)low shutdown supply current (35A typ); (10)low 200mV current-sense reference reduces power losses; (11)wave-shaped edges reduce radiated EMI during PWM dimming; (12)available in small, thermally enhanced,5mm x 5mm, 16-Pin TQFN package.The MAX16835 is well suited for applications requiring high-voltage input and is able to withstand automotive load-dump events up to 40V.An on-board pass element minimizes external components while providing ±3.5% output current accuracy.Additional features include a 5V regulated output and short-circuit and thermal protection.

The absolute maximum ratings of the MAX16835 can be summarized as:(1)IN to GND:-0.3V to +45V;(2)storage temperature range:-65 to +150;(3)operating temperature range:-40 to +125;(4)junction temperature:+150;(5)continuous power dissipation:2666.7mW.Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied.Exposure to absolute maximum rating conditions for extended periods may affect device reliability.The MAX16835 provides pulsed or chopped current dimming. Generally, HB LEDs are binned to match at their full-rated current; however, LEDs from the same bin exhibit poor matching at currents other than fullrated current. To achieve uniformity, HB LED manufacturers recommend PWM pulsing of the LED current at their full-rated value. There are two methods for producing a PWM output. One method is by pulsing the enable input (EN) while having a constant voltage at IN.