High-Voltage, High-Efficiency LED Drivers with Integrated MOSFET Save Space and Cost
The MAX16822A/MAX16822B 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/MAX16822B operate from a +6.5V to +65V input-voltage range and can provide an output current up to 350mA, if operated up to a temperature of +125°C, or up to 500mA, if operated up to a temperature of +105°C. A high-side current-sense resistor adjusts the output current and a dedicated pulse-width modulation (PWM) input enables pulsed LED dimming over a wide range of brightness levels. 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 MAX16822A allows 10% current ripple and the MAX16822B allows 30% current ripple. Both devices operate up to a switching frequency of 2MHz, thus allowing the use of small-sized components. The MAX16822A/MAX16822B 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 25µA 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. An additional feature includes thermal-shutdown protection that turns off the LX driver when the junction temperature exceeds +165°C. The MAX16822A/MAX16822B operate over the -40°C to +125°C automotive temperature range and are available in an 8-pin SO package.
title | Download file |
---|---|
MAX16822A-MAX16822B Data Sheet | MAX16822A-MAX16822B.pdf |
Part Number | Regulation Topology | Max. No. of LEDs | LED Channels | LED Configuration | ILED per Channel (A) | PWM Dimming Freq. (kHz) | Dimming Ratio | Dimming Control | VDROPOUT (mV) | VCURR_SENSE (mV) | POUT (W) | VIN (V) | VIN (V) | ICC (mA) | LED String Volt. (V) | Oper. Freq. (kHz) | Package/Pins | Budgetary Price |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
max | max | max | typ | min | max | max | max | See Notes | ||||||||||
MAX16822A | Inductor Based | 15 | 1 | Series | 0.5 | 20 | 200 | Analog PWM | 600 | 170 | 20 | 6.5 | 65 | 1.5 | 63 | 2000 | SOIC(N)/8 | $1.04 @1k |
MAX16822B | SOIC(N)/8 | |||||||||||||||||
Part Number | Status | Recommended Replacement | Package | Temp | RoHS |
---|---|---|---|---|---|
MAX16822BASA+ | Active | SOIC(N),;8 pin;30.9 mm² | -40°C to +125°C | Lead Free | |
MAX16822BASA+T | Active | SOIC(N),;8 pin;30.9 mm² | -40°C to +125°C | Lead Free |