The AT9933 is a variable frequency PWM controller IC, designed to control an LED lamp driver using a low-noise boost-buck (Ćuk) topology. The AT9933 uses patent-pending hysteretic current-mode control to regulate both the input and the output currents. This enables superior input surge immunity without the necessity for complex loop compensation. Input current control enables current limiting during startup, input under-voltage and output overload conditions. The AT9933 provides a low-frequency PWM dimming input that can accept an external control signal with a duty cycle of 0 - 100% and a high dimming ratio.The AT9933 based LED driver is ideal for automotive LED lamps. The part is rated for up to 125°C ambient temperatures and is AEC-Q100 compliant.

  Constant current LED Driver

  Steps input voltage up or down

  Low EMI

  Variable frequency operation

  Internal 75V linear regulator

  Input and output current sensing

  Input current limit

  Enable & PWM dimming

  Ambient temperature rating up to 125°C

  Meets AEC-Q100 requirements