MAX16822A

The MAX16822A step-down constant-current high-brightness LED (HB LED) drivers provide a cost-effective design solution for automotive interior/exterior lighting, architectural and ambient lighting,LED bulbs, and other LED illumination applications.The MAX16822A offer an analog dimming feature that reduces the output current by applying an external DC voltage below the internal 2V threshold voltage from TEMP_I to GND. TEMP_I also sources 25A to a negative temperature coefficient (NTC) thermistor connected between TEMP_I and GND, thus providing an analog thermal-foldback feature that reduces the LED current when the temperature of the LED string exceeds a specified temperature point.

Features of the MAX16822A are:(1)high-efficiency solution; (2)6.5V to 65V input-voltage range; (3)output current up to 500mA; (4)on-board 65V, 0.85 power MOSFET; (5)hysteretic control: up to 2MHz switching frequency; (6)200mV current-sense reference; (7)resistor-programmable constant LED current; (8)integrated high-side current sense; (9)thermal-foldback protection/linear dimming; (10)thermal-shutdown protection; (11)available in an 8-pin SO package.These devices are well suited for applications requiring a wide input-voltage range.The high-side current sensing and an integrated current-setting circuitry minimize the number of external components while delivering an average output current with ±3% accuracy. A hysteretic control method ensures excellent input supply rejection and fast response during load transients and PWM dimming.

The absolute maximum ratings of the MAX16822A can be summarized as:(1)IN, CS, LX, DIM to GND:-0.3V to +70V;(2)storage temperature range:-65 to +150;(3)operating temperature range:-40 to +125;(4)junction temperature:+150;(5)continuous power dissipation:588.2mW.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.For stability and best efficiency, a low forward-voltage drop diode with fast reverse-recovery time and low capacitance is recommended. A Schottky diode is a good choice as long as its breakdown voltage is high enough to withstand the maximum operating voltage.