The HV9921DB1 from Supertex, Inc. is a LED driver IC designed for step-down (buck) constant current regulators. It is specifically optimized for driving high-brightness LEDs from a wide input voltage range. This device offers a compact and efficient solution for LED lighting applications.

Applications

• LED lighting
• Automotive lighting
• General illumination
• Backlighting
• Street lighting

Features

• Buck (Step-Down) Topology
• Constant Current Regulation
• Wide Input Voltage Range
• High Efficiency
• PWM Dimming Control
• Open LED Protection

Benefits

• Stable LED Current: Provides constant current to the LEDs, ensuring consistent brightness and long lifespan.
• Efficient Power Conversion: High efficiency minimizes power losses and reduces heat generation.
• Wide Input Voltage Range: Allows for operation from a variety of power sources.
• Flexible Dimming Control: PWM dimming enables precise control over LED brightness.
• Robust Protection: Open LED protection prevents damage to the IC and other components in the event of an LED failure.

The HV9921DB1 operates as a buck converter, stepping down the input voltage to a level suitable for driving the LEDs. The device employs a constant current regulation scheme, ensuring that the LEDs receive a consistent current, regardless of variations in input voltage or LED forward voltage. This provides stable brightness and prolongs the lifespan of the LEDs. The HV9921DB1 includes a PWM dimming input, allowing for precise control over the brightness of the LEDs. The device also features built-in protection features, such as open LED protection, which prevents damage to the IC and other components in the event that an LED fails open. The switching frequency of the HV9921DB1 can be adjusted to optimize efficiency and minimize EMI. The HV9921DB1 is typically used in applications where a regulated constant current is required to drive one or more LEDs. The high efficiency of the HV9921DB1 allows for cool operation and reduces the need for external heat sinks. The device is available in a compact package. The PWM dimming control provides a wide dimming range. Its integrated protection features enhance system reliability.