HV9918

HV9918 Hysteretic, Buck, High Brightness LED Driver with High-Side Current Sensing Features ► ► ► ► ► ► ► ► ► ► Hysteretic control with high-side current sensing Integrated 40V 1.0Ω MOSFET >90% Efficiency Wide input voltage range: 4.5 to 40V ±5% LED current accuracy Up to 2.0MHz switching frequency Adjustable constant LED current Analog or PWM control signal for PWM dimming Over-temperature protection -40ºC to +125ºC operating temperature range General Description The HV9918 is a PWM controller IC designed to drive high brightness LEDs using a buck topology. It operates from an input voltage of 4.5 to 40VDC and employs hysteretic control with a high-side current sense resistor to set the constant output current up to 700mA. The device is 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 accurate average output. Dedicated pulse-width modulation (PWM) input enables pulsed LED dimming over a wide range of brightness levels. A hysteretic control method ensures excellent input supply rejection and fast response during load transients and PWM dimming. The HV9918 offers an analog-controlled PWM dimming feature that reduces the output current by applying an external DC voltage below the internal 2.0V threshold voltage from ADIM to GND. ADIM can also accept input from a resistor divider including a negative temperature coefficient (NT...