The MAX16819/MAX16820, step-down constant-current high-brightness LED (HB LED) drivers provide a cost-effective solution for architectural and ambient lighting, LED bulbs such as MR16 and other LED illumination applications. The MAX16819/MAX16820 operate from a 4.5V to 28V input voltage range and feature a 5V/10mA on-board regulator. A high-side current-sense resistor adjusts the output current and a dedicated PWM input (DIM) enables a wide range of pulsed dimming. The MAX16819/MAX16820 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 LED current with ±5% accuracy. A hysteretic control algorithm ensures excellent input-supply rejection and fast response during load transients and PWM dimming. The MAX16819 features a 30% inductor current ripple and the MAX16820 features a 10% current ripple. These devices operate up to 2MHz switching frequency, thus allowing for small component size. The MAX16819/MAX16820 operate over the -40°C to +125°C automotive temperature range and are available in 3mm x 3mm x 0.8mm, 6-pin TDFN packages.